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Biological
the
by
Education, 1
publisher
(Taylor
&
Chris
June
J.
R.
2003,
Francis
Taylor
Ltd,
www.
Contents
1.
2.
3.
4.
5.
6.
7
.
vi
Foundtions of nvironnt systs nd socitis
1.1
Environmental
1.2
Systems
1.3
Energy
1.4
Sustainability
41
1.5
Humans
48
and
and
value
systems
1
models
17
equilibria
and
27
pollution
ecosysts nd cooy
2.1
Species
and
2.2
Communities
2.3
Flows
2.4
Biomes,
2.5
Investigating
of
populations
and
energy
ecosystems
and
zonation
56
64
matter
and
79
succession
ecosystems
–
99
Practical
work
125
Biodivrsity nd consr vtion
3.1
An
introduction
3.2
Origins
3.3
Threats
3.4
Conservation
of
to
to
biodiversity
144
biodiversity
150
biodiversity
of
163
biodiversity
180
Wtr, food roduction systs nd socity
4.1
Introduction
4.2
Access
4.3
Aquatic
4.4
Water
to
to
water
systems
198
freshwater
food
207
production
systems
214
pollution
227
Soi systs nd socity
5.1
Introduction
5.2
Terrestrial
5.3
Soil
to
soil
food
systems
production
degradation
and
236
systems
and
food
conservation
choices
245
265
atoshric systs nd socity
6.1
Introduction
to
6.2
Stratospheric
6.3
Photochemical
6.4
Acid
the
atmosphere
274
ozone
278
smog
286
deposition
292
Cit chn nd nry roduction
7.1
Energy
choices
and
security
7.2
Climate
change
–
causes
7.3
Climate
change
–
mitigation
and
302
impacts
and
adaptation
318
340
8.
Hun systs nd rsourc us
8.1
Human
population
8.2
Resource
8.3
Solid
8.4
Human
use
in
domestic
dynamics
350
society
371
waste
systems
and
381
resource
use
392
9.
Intrn ssssnt
402
10.
ex trn ssssnt – xs
410
11.
ex tndd ssys in eSS
416
12.
Dirctory/fur thr rdin/rsourcs
426
Indx
429
About the authors
Jill
Rutherford
board
currently
to
IB
teachers.
Director
degrees
writing
of
the
about
Gillian
leadership
Gillian
and
is
In
In
her
Oxford.
from
2011
part
Experiential
School
and
Deputy
began
and
Her
Head,
the
in
lies
on
Head
on
of
She
in
the
of
and
has
two
and
taught
international
has
Year
held
and
IB
workshop
Director
IB
course.
is
Global
is
founding
holds
the
a
the
teaching
Societies
Gillian
She
IB
Education
Zengcheng
and
TOK
advising
of
England.
She
workshops
Examiner,
University
career
review.
vice-chair
passion
and
schools.
offering
Chief
School,
Systems
international
she
administrative
national
included
Reading
Geography
curriculum
UK
Systems
Oakham
of
including
face-to-face)
International
at
teaching,
and
International,
have
Environmental
Societies
currently
of
Ibicus
positions
Systems,
position
and
of
graduated
1993.
Department.
Systems
(online
IB
years
Environmental
Diploma
Williams
since
IB
University
the
Environmental
circuit
IB
the
30
international
director
Previous
Board,
from
some
within
academic
Examining
of
has
experience
various
Head
Environmental
leader
Mentoring
at
Team.
Utahloy
China.
vii
IntroductIon
This
book
Diploma
is
a
Course
Programme
Systems
and
Companion
course
Societies.
–
to
the
to
IB
Environmental
Although
this
the
wet
and
and
gaining
had
a
history
of
some
decades
in
the
one
that
you
are
studying
now
culmination
of
the
ideas
and
errors
or
some
the
big
IB
the
heart
their
that
we
mission
IB
of
students.
environmental
world
The
in
and
work
of
this
introduces
issues
prole
facing
you
Course
humans
course.
As
to
studies
and
which
you
is
read
also
and
consider
questions
expressed
is
at
refer
1.
and
we
point
the
learner
as
a
with
learner
prole.
The
Acquire
and
earth
to
environmental
enquire
and
up
our
into
knowledge
problems.
taking
and
actions
reference
the
across
it
decisions
on
We
about
so
to
many
must
the
that
disciplines
Governments,
mind
the
and
actions.
balance
We
in
groups
risks
not
be
Apply
the
by
planet
which
our
unless
we
actions
globally,
after
act
we
live,
care
and
due
locally’
and
4.
analyse
variety
to
solve
issues
with
it,
the
IB
Diploma
Value
the
you
are
of
Programme
carrying
out
could
also
CAS
involve
Be
of
have
some
environment,
ideas
for
this
CAS
and
we
hope
this
been
this
Diploma
varying
these
Course
possible
Programme
ways
busy
biomes,
and
a
team
or
that
for
6.
‘Think
many
authors
living
ecosystems
and
in
are
understanding
variety
of
of
scales.
methodologies
and
skills
systems
and
issues
at
dynamic
interconnectedness
systems
and
societies
of
and
taking
personal,
in
making
responsible
local
informed
actions
on
issues.
aware
that
these
that
and
exploited,
could
resources
be
are
inequitably
nite,
distributed
is
and
the
that
key
to
management
of
these
sustainability.
Develop
awareness
environmental
of
value
the
diversity
of
systems.
and
Develop
critical
awareness
caused
and
that
environmental
solved
by
decisions
of
you
may
by
individuals
and
societies
that
different
not
We
9.
IB
grateful
countries
environments.
of
are
based
knowledge.
Engage
with
of
the
controversies
environmental
that
surround
a
issues.
have
Many
contributed
most
areas
gain
8.
different
are
repairing
would
have
a
requirement.
approach.
teachers
the
people,
edition.
of
book.
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Topic
Big Questions
A
B
C
D
E
✗
✗
✗
F
Foundations of environmental systems and societies
✗
Ecosystems and ecology
✗
✗
Biodiversity and conservation
✗
✗
✗
✗
✗
✗
✗
✗
✗
✗
✗
Water, food production systems and society
✗
✗
✗
✗
Soil systems, terrestrial food production systems and society
✗
Atmospheric systems and society
✗
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✗
✗
✗
✗
✗
✗
✗
✗
✗
✗
✗
✗
Human systems and resource use
▲
x
Figure I.3 Big Questions relevant to ESS topics
Topic
Concepts
Systems
E VS
Sustainability
Management
approach
Global viewpoint
strategies
Foundations of environmental
1.2, 1.3
1.1
1.4
1.5
1.1, 1.5
2.5
2.4
systems and societies
Ecosystems and ecology
Biodiversity and
2.1, 2.2, 2.3, 2.4
conservation
3.1
3.4
3.2, 3.3
4.1, 4.3
4.2
4.3, 4.4
4.4
4.1, 4.2, 4.3, 4.4
5.1, 5.2
5.3
5.2
5.3
5.2, 5.3
6.1
6.1
6.2, 6.3, 6.4
6.1, 6.2
7.2
7.3
7.3
7.3
7.1, 7.2, 7.3
8.1
8.3
8.4
8.3
8.1, 8.2, 8.3, 8.4
Water, food production systems
and society
Soil systems , terrestrial food
production systems and society
Atmospheric systems and society
Climate change and energy
production
Human systems and resource use
▲
Figure I.4 ESS sub-topics par ticularly relevant to concepts
content
contex t
knowledge and understanding,
case studies and examples
skills and applications
Big Questions
concepts
systems approach, EVS,
sustainability, management
strategies, global viewpoints
▲
The
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Figure I.5 Integration of Big Questions, content, context and concepts in ESS
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Foundations
oF
en vi ron men tal
1
systems
and
societ i e s
1.1 Evoeta vae sstes
sg :
app  k:
➔
Historical events, among other inuences,
➔
Dscss the view that the environment can
aect the development of environmental
have its own intrinsic value.
values systems and environmental
➔
Evaate the implications of two contrasting
movements.
environmental value systems in the context of
➔
There is a wide spectrum of environmental
given environmental issues.
value systems each with their own premises
➔
Jstf the implications using evidence and
and implications.
examples to make the justication clear.
Kwg  g:
➔
Signicant historical inuences on the
of education and encourages self-restraint in
development of the environmental movement
human behaviour.
have come from literature, the media, major
➔
environmental disasters, international
has st sstaab aage the goba
agreements and technological developments.
➔
sste. This might be through the use of taxes,
A evoeta vae sste (E VS) s a
environmental regulation and legislation.
wod vew o paadg that shapes the wa a
Debate would be encouraged to reach a
d vda, o gop of peope, pece ves ad
consensual, pragmatic approach to solving
evaates evoeta sses, inuenced by
environmental problems.
cultural, religious, economic and socio-political
➔
contexts.
➔
➔
A techocetc vewpot ages that
techoogca deveopets ca povde
An EVS might be considered as a ‘system’ in the
sotos to evoeta pobes. This is
sense that it may be inuenced by education,
a consequence of a largely optimistic view of
experience, culture and media (inputs) and
the role humans can play in improving the lot
involves a set of inter-related premises, values
of humanity. Scientic research is encouraged
and arguments that can generate consistent
in order to form policies and understand how
decisions and evaluations (outputs).
systems can be controlled, manipulated or
exchanged to solve resource depletion. A
There is a spectrum of EVSs from ecocentric
pro-growth agenda is deemed necessary for
through anthropocentric to technocentric
society’s improvement.
value systems.
➔
A athopocetc vewpot ages that
A ecocetc vewpot integrates social,
➔
(eg deep ecologists – ecocentric – to cornucopian –
spiritual and environmental dimensions into
technocentric), but in practice EVSs vary greatly with
a holistic ideal. It pts ecoog  ad ate as
culture and time and rarely t simply or perfectly
ceta to hat and emphasizes a less
into any classication.
materialistic approach to life with greater self-
suciency of societies. An ecocentric viewpoint
prioritizes biorights, emphasizes the impor tance
There are extremes at either end of this spectrum
➔
Dierent EVSs ascribe dierent intrinsic values
to components of the biosphere.
1
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
s ys t e m s
TOK
Ke te
1.
a n d
s o c i e t i e s
Using a global
An evoeta vae sste (E VS) is a worldview or paradigm that shapes
environmental issue of
the way an individual or group of people perceive and evaluate environmental
your choice evaluate
issues. This will be inuenced by cultural, religious, economic and socio-political
how one of the ways of
context.
knowing inuences our
EVS approach.
2.
To thk abot
Using a local
environmental issue of
Our environmental value systems will inuence the way we see environmental
your choice evaluate
issues.
how one of the ways of
knowing inuences our
1.
List other value systems that inuence how we view the world.
2.
Outline one named global and one local environmental issue.
EVS approach.
3.
Evaluate how your
Describe your opinion on these issues and explain how your value systems
emotion has aected your
inuence it.
response to this issue.
‘ Whatever befalls the Earth –
dp f h  
befalls the sons of the Earth.
The
Humankind has not woven
environmental
BUT
humans
environment
have
for
movement
been
much
as
we
concerned
know
about
it
originated
the
effect
we
in
the
have
1960s
on
the
longer.
the web of life. We are but one
thread within it. Whatever
●
Romans
●
Between
reported
on
problems
such
as
air
and
water
pollution.
we do to the web, we do to
ourselves. All things are
disease
bound together. All things
connect.’
the
produced
●
Soil
in
Such
years
To
did
events
caused
concern
●
elicited
the
Powerful
also
●
been
those
to
a
to
who
see
those
for
▲
Fge 1.1.1 The only known
photo of Chief Seattle taken in
the 1860s
2
ie
its
do
it
the
goods
who
we
save
in
mid
with
China,
16th
the
century,
spread
India
and
a
these
to
of
waste
epidemic
Peru
as
early
widespread
public
we
activism
must
look
until
back
at
of
reason
in
for
services
managers)
that
for
media,
people’s
we
(deep
our
or
impacts
groups
pressure
and
individuals,
‘grass
groups
they
have
roots’
philosophy
conserving
to
of
governments
impacts.
independent
divide
value
it
rise
environmentalism
individuals,
to
use
and
believe
spiritual
of
and
their
(environmental
●
the
environmental
Nations
make
give
modern
over
continuing
supply
practised
really
responses
United
though
movement
and
associated
which:
individuals
inuential
was
not
●
the
century
was
ago.
understand
historical
and
14th
Europe.
concerns
recently.
the
late
humans
conservation
as2,000
Attributed to Chief Seattle, 1855
by
are
now
catalysed
movement.
very
the
There
has
between:
nature
humankind
in
a
as
being
to
sustainable
continue
way
and
should
and
sake
or
conserve
nature
self-reliance
for
its
sake?
unconditionally,
ecologists);
1 . 1
E n V i r O n m E n T A l
V A l u E
S y S T E m S
Who is involved in the environmental movement?
To eseach
It
is
probably
spend
much
brought
of
a
to
fair
to
time
their
number
of
say
that
focusing
attention
groups
the
on
or
have
majority
of
people
environmental
affect
them
in
issues
directly.
the
world
unless
they
However,
the
do
not
Look up Chief Seattle on the
are
activities
web. His famous speech
was in the Lushootseed
inuenced
language, translated into
●
norms
of
behaviour
(eg
purchasing
recycling)
and
choices
such
as
dolphin-friendly
Chinook Indian trade
tuna
and
language, and then into
●
political
choices
(eg
the
successes
of
the
‘Green
Party’).
English. While he may not
have said these exact words,
Inuential
individuals
often
use
media
publications
(eg
Aldo
does it matter?
Leopold’s
An
A
Sand
Inconvenient
Independent
County
Truth)
Almanac,
to
pressure
raise
Rachel
issues
groups
use
and
Carson’s
start
the
awareness
Silent
Spring,
Al
Gore’s
debate.
campaigns
to
effect
a
‘ We abuse land because we
change
(eg
Greenpeace
on
Arctic
exploration,
World
Wildlife
Fund
on
saving
regard it as a commodity
tigers).
They
inuence
the
public
who
then
inuence
government
and
belonging to us. When we see
corporate
business
organizations
organizations.
(NGOs).
‘Friends
of
These
the
groups
Earth’
is
are
called
another
non-governmental
land as a community to which
example.
we belong, we may begin to
Corporate
and
businesses
transnational
(especially
corporations
–
multinational
TNCs)
are
corporations
involved
since
–
they
MNCs
–
use it with love and respect.’
are
Aldo Leopold,
supplying
consumer
demand
and
in
doing
so
using
resources
and
creating
A Sand County Almanac
environmental
impact
(eg
mining
for
minerals
or
burning
of
fossil
fuels).
(reprinted by permission of
Governments
planning
the
permission
country
other
(eg
for
to
Environment
different
stages
Legislating
enough
of
about
food
environmental
issues
facing
bring
together
use),
controls
consider
the
Earth
in
is
and
and
world
all
must
as
NGOs
be
the
and
development
as
so
are
is
(laws)
also
of
(eg
involved
in
all
corporations
to
manage
are
with
at
there
may
put
aware
nding
Earth
Oxford University Press, USA)
individuals.
are
Nations
holding
to
(eg
United
sure
countries
priority,
ones
meet
countries
different
making
United
by
They
agreements
different
levels
times
legislation
Different
but
While
such
recent
environmental
factories).
important
that
governments,
apply
UNEP).
different
bodies
more
and
over
awareness,
population.
at
including
international
Programme,
awareness
inuential
environmental
land
emissions
for
the
decisions
environmental
Intergovernmental
highly
policy
emissions
governments
Nations
is
make
of
the
solutions.
have
become
Summits
consider
to
global
issues.
TOK
In 2013, 30 Greenpeace activists on board the Greenpeace ship Arctic Sunrise
peacefully protested in Arctic international waters against the Russian Gazprom
oil platform drilling for oil in the Arctic. They were arrested by armed Russian
commandos and kept in prison for 100 days before being freed.
Read about this at www.greenpeace.org and news websites.
Do you agree with what the activists were doing or do you agree with the
Russian authorities in stopping them?
Debate the issues in this with three teams: one represents Greenpeace views,
one the Russian state and the other the Gazprom interests.
To what extent can we rely on reason to evaluate the Greenpeace approach to
this issue?
3
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
s ys t e m s
a n d
s o c i e t i e s
The gowth of the ode evoeta oveet  ote
Evet
ipact
neothc
●
Humans settled to become farmers instead of nomadic hunter-gatherers
●
Human population began to rise
●
Local resources (food, water, fuel) were managed sustainably from around the settlement
●
Population growth and resource usage escalated
●
Large scale production of goods and services for all
●
Burning of large amounts of fuel in the form of trees and coal
●
Mining of minerals from the ear th to produce metals to make machines
●
Limestone quarried for cement production
●
Land was cleared, natural waterways polluted, cities became crowded and smoky
●
Our urban consumer society arose
●
Mechanized agriculture and boosted food production massively
●
Required the building of machinery and burning of enormous amounts of fossil fuels such as oil
●
Technology was applied to agriculture
●
New crop varieties were developed and fer tilizer and pesticide use rose sharply
●
The world population grew to about 3 billion
●
Our resource use and waste production rocketed
●
The impacts became more global: collapsing sh stocks, endangered species, pesticide
Agcta
revoto (10,0 0 0
eas ago)
idsta
revoto (ea
180 0s)
Gee revoto of
the 1940s to 19 60s
mode
evoeta
poisoning, deforestation, nuclear waste, ozone layer depletion, global warming, acid
oveet
precipitation, etc.
●
(19 60s owads)
A new breed of evoetasts surfaced who had scientic backgrounds and
spearheaded the modern environmental movement
Evoetas
●
Greenpeace founded 1971
●
Inuential individuals wrote books (eg Rachel Carson’s Silent Spring)
●
NGOs campaigned and the media repor ted
●
Governments formed nature reserves and put environmental issues on their agenda
●
Some businesses marketed themselves as environmentally friendly
●
UNEP organized Ear th Summits on the environment
●
The movement became public and gained momentum
●
More research on loss of biodiversity and climate change leading to more action to protect
toda
the environment and encourage sustainability from governments, corporations and
individuals
●
Small number of climate sceptics voice doubts over climate change
●
Discovery of fracking process to release shale gas and oil shale reserves increases tensions
between technocentrists and ecocentrists
‘And this is why I
c  – h   h
sojourn here,
 
Alone and palely loitering ,
There
is
general
agreement
that
the
modern
environmental
movement
Though the sedge is wither ’d
was
catalysed
The
title
by
Rachel
Carson’s
book,
Silent
Spring,
published
in
1962.
from the lake,
And no birds sing.’
the
was
comes
effects
being
of
from
the
pesticides
passed
along
John
on
Keats
insects,
the
food
poem
both
chain
(right).
pests
to
kill
and
Carson
others,
others,
warned
and
how
including
of
this
birds
From La Belle Dame Sans Merci
(hence
by John Keats
4
a
silent
spring).
What
really
gained
people’s
attention
was
her
1 . 1
belief
that
pesticides
persistent,
such
synthetic
accumulating
in
as
DDT
insecticide)
fatty
tissues,
E n V i r O n m E n T A l
( dichlorodiphenyltrichloroethane,
were
nding
causing
higher
their
risks
way
of
into
people
cancer.
V A l u E
a
and
S y S T E m S
‘For the rst time in the
history of the world,
Chemical
every human being is now
industries
tried
to
ban
the
book
but
many
scientists
shared
her
concerns
subjected to contact with
and
when
an
investigation,
ordered
by
US
president
John
F
.
Kennedy,
dangerous chemicals, from
conrmed
her
fears,
DDT
was
banned.
the moment of conception
In
the
decades
since
as
scaremongering
of
DDT
the
publication
of
Silent
Spring,
it
has
been
criticized
until death.’
without
enough
scientic
evidence.
The
banning
Rachel Carson, Silent Spring, 1962
the
may
mosquitoes
causing
Al
to
caused
that
millions
Gore,
book
his
have
of
former
carry
malaria
than
to
vice-president,
involved
documentary
harm
good
survive
(see
and
so
2.2)
by
spread
allowing
the
disease
deaths.
US
become
more
on
in
was
heavily
environmental
climate
change
An
inuenced
issues,
by
the
particularly
Inconvenient
Truth,
‘Now I truly believe that
with
2006.
we in this generation must
This
come to terms with nature,
raised
awareness
of
climate
change
–
then
called
global
warming
–
and
and I think we’re challenged,
clearly
stated
that
global
climate
change
was
a
result
of
greenhouse
as mankind has never
gases
released
moral
issue.
president
focus
on
of
by
human
George
the
activities
Bush’s
USA
was
technologies
response
‘Doubt
that
and
it’
enable
that
to
the
and
us
to
he
we
had
to
act
documentary
later
live
said
better
as
when
that
lives
this
we
and
is
he
a
was
should
protect
the
been challenged before, to
prove our maturity and our
mastery, not of nature but of
environment.
ourselves.’
Mercury
nervous
is
a
heavy
system
coordination
Mercury
makers
of
‘mad
illnesses
a
Chisso
and
was
the
the
gas,
at
The
In
of
event
and
a
and
poisoning
industry
is
the
Alice
It
affects
speech
causes
into
the
illnesses
basis
in
the
But
bodies
morning
in
of
and
the
lack
insanity
20th
name
and
or
Rachel Carson, Silent Spring, 1962
of
death.
century.
although
Wonderland
the
the
of
the
Hat
source
the
‘Mad
phrase
a
of
factory
in
Minamata,
by-product
humans,
was
Japan
methylmercury
causing
mercury
total
of
the
40
be
December
of
of
people
This
the
1984,
Madhya
tonnes
3,000
deaths.
to
3
state
has
world’s
methyl
and
in
the
Pradesh,
called
worst
centre
Union
isocyanate
ultimately
been
a
(MIC)
causing
the
Bhopal
industrial
disaster.
shock.
miles
air
in
nearly
considered
the
north
an
in
reactor
which
over
Fission
worst
of
the
and
number
material
caused
and
much
nuclear
Kiev,
explosion
meltdown
drifted
Scotland.
chemicals
released
radioactive
to
a
years.
India,
plant
highest)
uranium
this
in
killing
where
uncontrollable
and
animals.
hearing
mental
This
Carroll’s
for
Chernobyl,
few
USSR)
(the
is
was
at
moderator
from
Severe
suffer
built
the
15,000–22,000
was
the
of
Bhopal,
pesticide
1986,
the
hours
of
world
This
legs.
to
2.2).
immediately
least
vision,
unknown.
successful
(see
early
city
Disaster
poisonous
hat-making
Lewis
bioaccumulated
Carbide
of
often
Corporation
very
poisioning
of
to
is
hatter’.
The
In
loss
the
was
in
and
and
in
known
character
as
which
arms
used
were
such
Hatter’
causing
in
was
metal
of
products
it
a
split
to
Russia
from
then
4.
so
of
ever
resulted
reactor
re.
The
highly
occurred.
Ukraine
exposing
and
the
of
re
The
catch
cloud
disaster
capital
(then
in
a
vessel
the
went
radioactive
Europe
as
7
containing
graphite
reactor
radioactive
part
level
far
west
cloud,
into
material
eg
as
Wales
isotopes
5
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
of
s ys t e m s
caesium,
a n d
strontium
and
s o c i e t i e s
iodine,
have
a
long
half-life
and
were
TOK
accumulated
in
selling
from
sheep
food
chains.
some
In
2009,
there
Welsh
farms
due
were
to
still
their
restrictions
levels
of
on
radiation.
Chernobyl has become
There
is
much
debate
about
how
many
people
have
been
affected
by
synonymous with the
the
radiation
as
long-term
effects,
such
as
cancers
and
deformities
at
dangers of nuclear power
birth,
are
difcult
to
link
to
one
event.
31
workers
died
of
radiation
and the green political lobby
sickness
as
they
were
exposed
to
high
levels
in
trying
to
shut
down
argued that all nuclear power
the
reactor
and
some
had
a
lethal
dose
of
radiation
within
one
minute
generation should stop. But
of
exposure.
Estimates
of
later
deaths
vary
but
some
state
about
1,000
nuclear reactor accidents are
extra
cases
of
thyroid
cancer
and
4,000
other
cancers
caused
by
the
very rare and safety levels
fallout
cloud.
Other
estimates
state
that
1
million
people
will
have
died
ever higher as new plants
as
a
result
of
the
disaster.
are developed.
The
authorities
of
the
day
did
not
announce
the
disaster
but
it
was
More people are killed
picked
up
in
Sweden
when
fallout
was
found
on
the
clothing
of
workers
in car accidents or when
at
one
of
their
nuclear
plants.
shopping than by nuclear
power accidents. Views
about the rights and wrongs
of using nuclear power are
not based on evidence
Even
shell
arch
today,
but
is
the
the
being
estimates
of
reactor
other
built
the
is
still
reactors
as
the
date
of
dangerous.
continued
concrete
to
shell
completion
It
was
run
only
have
encased
until
has
been
in
2000.
a
lifetime
put
back
a
concrete
Now,
to
of
a
30
metal
years
but
2016.
but on emotions. The
In
2011,
there
was
another
nuclear
accident
at
the
Fukushima
Daiichi
rare accidents in nuclear
nuclear
plant
in
Japan.
An
earthquake
set
off
a
tsunami
which
caused
power plants (Three Mile
damage
resulting
in
meltdown
of
3
reactors
in
the
plant.
The
water
Island (Pennsylvania, USA
ooding
these
became
radioactive
and
will
take
many
years
to
remove.
in 1979), Chernobyl and
Although
the
radiation
leak
was
only
about
30%
that
of
Chernobyl
Fukushima being the big
and
radiation
levels
in
the
air
low,
one
third
of
a
million
people
were
ones) have resulted in some
evacuated
as
the
plant
was
sited
in
a
densely
populated
area.
Later
countries banning nuclear
reports
showed
the
accident
was
caused
by
human
error
–
it
was
not
power generation. But our
built
to
withstand
a
tsunami
even
though
it
was
close
to
the
sea
in
an
need for more and more
earthquake
zone.
The
plant
is
still
not
secured.
energy may mean it has to
be used.
After
the
countries
disaster,
and
there
Germany
were
anti-nuclear
announced
it
was
demonstrations
closing
older
in
other
reactors
and
To what extent do you think
phasing
out
nuclear
power
generation.
France,
Belgium,
Switzerland
the arguments about nuclear
all
had
public
votes
to
reduce
or
stop
nuclear
power
plants.
In
other
power are based on emotion
countries,
plans
for
nuclear
plants
were
abandoned
or
reduced.
rather than reason?
▲
6
Fge 1.1.2 The Chernobyl nuclear reactor plant after the explosion in 1986
1 . 1
E n V i r O n m E n T A l
V A l u E
S y S T E m S
To eseach
1.
Ear th Day
Research these environmental disasters and write a
shor t paragraph on each:
Green Revolution
Deepwater Horizon oil spill
Kyoto Protocol
London smog
3.
Research
and
Love Canal
one
society.
2.
one
local
local
environmenta l
environm enta l
Create
an
action
dis as te r
pres su re
plan
for
ea ch
group
to
or
provid e
Research these environmental movements and write
innovative
solutions
to
the
d isa ster
a nd
a
5-year
a shor t paragraph on each:
plan
for
the
environm enta l
press ure
grou p
or
Chipko movement
society.
Rio Ear th Summit and Rio +20
A evew of ajo adaks  evoetas
yeas
10,0 0 0 s BP
Evets
neothc agcta evoto
Sgcace
Settlements, population increase, local resource management
began.
Ea 180 0s
late 180 0s
idsta evoto  Eope
Increased urbanization, resource usage and pollution.
ieta dvdas sch as
First conservation groups form and nature reserves
Thoea ad m wte books o
established. NGOs form (RSPB, NT).
cose vato
1914
1930s ad
Oce the ost poc bd, the
Conservation movement grows. Concern for tigers,
passege pgeo becoes ex tct
rhinoceros, etc.
Dstbow  no th Aeca
Recognition that agricultural practices may aect soils and
1940s
1940s
1949
climate.
Gee revoto – tesve
Resource use (especially fossil fuel use) and pollution
techoogca agcte
increased. Human population rises sharply.
leopod wtes ‘A Sand County
Concept of
‘stewardship’ is applied to nature.
Almanac’
1951
uK ’s te natoa Paks ae
Recognition of need to conserve natural areas.
estabshed
1956 to 19 68
maata Ba Dsaste
Emphasizes the ability of food chains to accumulate toxins
into higher trophic levels, including into humans.
19 62
19 60s ad
rache Caso pbshes ‘Silent
General acceptance of dangers of chemical toxins aecting
Spring ’
humans. The pesticide DDT is banned.
nGOs ga geate foowg
Public awareness grows.
ea 1970s
1972
WWFN, Greenpeace, Friends of the Ear th all formed.
Fst Ea th St – un
Declaration of UN conference.
Cofeece o the Ha
Action Plan for the Human Environment.
Evoet
Environment Fund established.
Formation of UN Environment Programme (UNEP).
Ear th Summits planned at ten-year intervals.
1975
C.i.T.E.S. foed b iuCn
Endangered species protected from international trade.
7
1
F o u n d at i o n s
md 1970s
1979
o F
e n v i r o n m e n ta l
s ys t e m s
a n d
s o c i e t i e s
Evoeta phosoph
Recognition that nature has its own intrinsic value.
estabshed
Stewardship ethic grows.
Jaes loveock pbshes ‘Gaia
Systems approach to studying the environment begins.
– A new look at life on Earth’ ad
Nature seen as self regulating.
pesets the ‘Gaa hpothess’
1982
1983
naob Ea th St
Ineective.
un Wod Cosso o
Sustainability established as the way forward.
Evoet ad Deveopet
pbshes the Bdtad repo t
1984
Bhopa Dsaste
World’s worst industrial disaster.
1986
Cheob Dsaste
Nuclear fallout aects millions.
Btsh Atactc S ve Tea
Public awareness of ozone depletion and risks of skin cancer.
md 1980s
detects ce sheets thg ad
ozoe hoe
1987
1980s
motea Potoco
Nations agree to reduce CFC use.
Gee potca pa tes fo aod
Political pressure placed on governments.
the wod
1988
iPCC foed b unEP
Advises governments on the risks of climate change.
1992
ro Ea th St ad Koto
Agreement to reduce carbon (CO
) emissions to counter
2
Potoco
enhanced greenhouse eect and global warming.
Agenda 21.
1990s
Gee awaeess stegthes
Environmentally friendly products, recycling and ecotourism
become popular.
20 02
Johaesbg Ea th St
Plans to globally improve:
Water and sanitation
Energy supply issues
Health
Agricultural abuse
Biodiversity reduction.
20 05
Koto potoco becoes a ega
174 countries signed and are expected to reduce carbon
eqeet
emissions to some 15% below expected emissions in 2008. It
expires in 2012.
20 0 6
20 07
F ‘An Inconvenient Truth’
Documentary by Al Gore, former US vice-president, describing
eeased
global warming.
nobe Peace Pze
Awarded in 2007 jointly to Al Gore and the IPCC for their work
on climate change.
iPCC eease 4th assesset
Repor t states that ‘Warming of the climate system is
epo t  nov 07
unequivocal’ and ‘Most of the observed increase in globally
averaged temperatures since the mid-20th century is
very likely due to the observed increase in anthropogenic
greenhouse gas concentrations.’
un Ba eetg Dec 07
187 countries meet and agree to open negotiations on an
international climate change deal.
2012
8
ro +20
Paper ‘ The Future We Want’ published.
1 . 1
E n V i r O n m E n T A l
V A l u E
S y S T E m S
To do
To eseach
Evoeta heades
Look up these people who were
involved in environmentalism and
9 March 2014 Lucy Hornby, Beijing in Financial Times
write three sentences on each.
‘Only three Chinese cities meet air quality standards’
Mahatma Mohandas Gandhi
11 March 2014 Suzanne Goldenberg, The Guardian
Henry David Thoreau
‘California drought: authorities struggle to impose water conservation measures’
Aldo Leopold
A.
Look at newspaper headlines for one week .
John Muir
Copy out the headlines that refer to environmental issues.
E O Wilson
Put these in a table or on a notice board.
To do
Good ews
Bad ews
Find a local environmental issue
where a pressure group is ghting
for a cause.
Describe the issue and state the
argument of the pressure group.
What are the opposing arguments
to their case? These may be
economic, aesthetic, socio-
B.
Discuss with your fellow students what the environmental headlines may
political or cultural. State your
be in 2020 and 2050.
own position on this issue and
defend your argument.
‘Nothing in this world is so
To do
powerful as an idea whose
time has come.’
Ea th Das
Victor Hugo 1802–1885
Ths s jst oe of a ages
pootg Ea th Da – what ese ca
appy
H
o d?
In the late 1960s, after Silent Spring,
environmentalism turned into action,
par ticularly in Nor th America. Founded
then were ‘Ear th Days’ to encourage us all
to be aware of the wonder of life and the
E
a
a
r t
hd
y
need to protect it. There are two dierent
ones. The UN Ear th Day each year is on
the Spring equinox (so in March in the
Nor thern hemisphere and September in the Southern when the Sun is directly
above the equator). John McConnell, an activist for peace, drove
this concept.
The other Ear th Day is always on 22 April each year, and was founded by
US politician Gaylord Nelson as an educational tool on the environment. Up to
500 million people now take par t in its activities worldwide each year.
Some are critical of Ear th Days as marginalized activities that do not change
the actions of politicians. Do you think they have an eect?
9
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
s ys t e m s
a n d
s o c i e t i e s
th p f   
●
Different
societies
comparing
●
The
EVS
we
economic
●
The
For
are
to
much
And
of
humans
of
have
subdue
in
improves
half full
the glass is
not
to
the
the
been
to
to
the
us
It
all.
Earth
to
But
is
with
now
not
that
true.
only
the
no
A
and
choices.
religious,
we
were
the
is
of
or
in
driven
limitless.
that
Humans
is
a
resources
them
smaller
beast’,
running
human
The
words
‘conquering
recent
and
even
for
to
humans)
that
may
the
Mars.
conquer
economic
be
on
ideology
Earth’s
that
about
Prometheus’
explore,
This
the
times
think
‘unbound
growth.
clearer
of
many.
very
the
worldview
value
value
environment:
habitable
arrival
Earth’s
fear
among
‘man
intrinsic
this
environment.
much
environment
it
own
our
the
been
industrial
it
on
seen
its
measure
with
nature’,
make
of
we
species
have
the
when
world
been
our
heralded
will
different
cultural,
have
been
them
has
control
the
philosophies
make
by
place
one
we
against
development
of
just
conditions
planet
has
has
how
‘battle
industrial
as
that
can
How
we
exploit
elements’.
Revolution
lot
value
can
has
able
inuenced
viewpoint
we
societies
contexts.
organism
the
describe
(altering
the
limitless
past
been
the
be
environmental
why
humans.
history
survival’,
‘beating
will
any
our
of
use
technological
reigned
the glass is
the
we
Industrial
and
or
value
that
much
terraforming
The
and
in
for
Everest’,
its
history,
for
phrases
‘ghting
of
understanding
population
and
hold
different
explain
socio-political
environment
unlimited
out.
hold
helps
each
and
regardless
key
these
has
growth
resources
rst
are
species
to
half empty
change
the
conditions
on
Earth
and
so
make
it
unt
for
human
life.
What is your environmental worldview?
You
of
▲
have
life
–
a
view
your
Fge 1.1.3 Is this half full or half
you
live.
empty?
pessimistic
This
in
of
the
world
background,
is
your
that
culture,
paradigm
outlook
–
see
the
or
is
formed
through
education
and
worldview.
glass
as
half
the
You
full
or
your
experiences
society
may
half
be
in
which
optimistic
or
empty.
To do
Evoeta atttdes qestoae
7.
Humans have every right to use all resources on
the planet Ear th.
Consider these statements and decide if you agree strongly,
agree, don’t know, disagree or disagree strongly with each.
1.
Humans are par t of nature.
8.
9.
Technology will solve our energy crisis.
We have passed the tipping point on climate
change and the Ear th is warming up and we cannot
2.
Humans are to blame for all the world’s
stop it.
environmental problems.
10.
3.
Animals and plants have as much right to live on
We depend on the environment for our resources
Ear th as humans.
(food, water, fuel).
11.
4.
Looking at a beautiful view is not as impor tant as
Nomadic and indigenous peoples live in balance
economic progress.
with their environment.
12.
5.
Species have always become extinct on Earth and so it
Traditional farming methods do not damage the
does not matter that humans are causing extinctions.
environment .
Discuss your responses with your colleagues. Do they
6.
Nature will make good any damage that humans
have dierent ones? Why do you think this is?
do to the Ear th.
10
1 . 1
E n V i r O n m E n T A l
V A l u E
S y S T E m S
TOK
TOK
Consider these words:
O eatoshp wth the
Ea th
●
Environment
●
Natural
●
Nature.
Can you think of other phrases
that describe our relationship
with nature and the Earth?
Think about what they mean to you. Write down your responses.
The words we use are often
Now discuss what you wrote with two of your classmates. Do you agree?
evaluative and not purely
descriptive.
What have you written that is similar or dierent?
How do you think our
Why do you think your responses may be dierent?
language has inuenced
How dierent do you think the responses of someone from a dierent century or
human perspectives on the
culture may be? Discuss some examples.
environment?
How does the language we
use inuence your viewpoint?
A classication of dierent environmental philosophies
categories of
EVS
ecocentrists
▲
●
no
like
to
to
environmental
mangers
greater
respects
nature
the
so
The
has
use
of
is
to
there
The
a
are
manage
in
in
centred)
the
or
of
of
ecology
less
the
life
EVSs
and
nature
materialistic
Is
is
as
approach
life-centred
dependence
which
philosophies
are:
of
–
central
to
life
which
humans
earth-centred.
on
Extreme
ecologists
worldview
the
global
humans
are
–
believes
system .
regulation
not
humans
This
and
dependent
might
must
be
through
legislation.
on
nature
Is
human-
but
nature
humankind.
technocentric
can
worldview
provide
Environmental
technocentrists
environmental
societies.
environmental
which
benet
problems.
a
and
view
and
categories
puts
of
nature
deep
developments
Many
of
holistic
taxes,
–
–
emphasizes
anthropocentric
centred
major
self-sufciency
sustainably
the
categorize,
The
worldview
and
rights
ecocentrists
and
this.
ecocentric
humanity
with
●
self-reliant
soft ecologists
classify
exception
The
to
●
technocentrists
Fge 1.1.4 EVS categories
Humans
are
anthropocentrists
are
industrial
–
believes
solutions
managers
that
technological
to
environmental
are
technocentrists.
Extreme
cornucopians
world
technocentric
have
an
(planetary
anthropocentric
management)
(human-
worldview.
In
this
11
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
humans
the
s ys t e m s
seen
as
the
environment
to
suit
they
are
are
useful
●
We
●
There
●
We
will
●
We
can
●
Economic
are
the
will
In
to
always
solve
growth
–
all
and
and
or
nothing
see
–
as
problems
and
We
and
degradation
believe
The
that
moment
of
us
to
living
the
value
hunting
cause
us
harm
not
rights
which
We
we
12
are
just
do
manage
have
value
if
charge.
successful.
always
keep
the
sake,
or
nd
thinkers
just
for
any
this
live.
An
to
If
we
holistic
beings
no
and
who
nature
more
can
the
To
stops
all
the
it
is
lot
sees
of
a
control
planet.
crew.
If
we
for
other
of
our
above
alive
that
and
so
so
a
we
an
animals
shing.
this
it
is
at
the
arrogant
can
shall
continue
of
either
inherent
are
We
is
is
we
fall
and
is
–
for
not
does
should
animal
(earth-
habitats
integrity
this
it
value
just
ecocentric
and
further,
others.
environment,
it
what
obligation
the
not
should
that
which
ecological
than
too
Earth
whether
broaden
ethical
managers
us.
having
the
economies.
standard
ecosystems
To
are
environment
are
on
we
high
themselves
of
thrive.
our
as
species,
call
the
and
there
us.
interact
of
that
–
environmental
species,
view
a
are
So
protect
view
tending
Environmental
think
as
to
needs
sustainable
beneath
important
alter
the
and
that
protect
views
has
life
lakes
of
to
after
they
preserve
will
the
from
looks
protection
can
life
and
captain
duty
make
possible
also
through
them,
paradigm
garden
species
extreme
the
its
intervene.
it
alive
any
For
government
hold
humans.
individual
then
species,
of
to
all.
see
for
logging,
Others
out
it
a
suffer
how
not
This
ethical
that
it
that
improve
markets
are
legislate
what
person
or
neither.
of
to
know
just
this.
as
an
and
planet,
extinction
systems,
sentient
duty
manage
is
of
having
environmental
standards.
to
as
think
it.
who
believes
not
trees
the
a
world
any
wealth
managers
to
the
minimal
Earth
have
it.
solve
we
steer
those
every
growth
species
one
We
not
can
believe.
emphasize
are
can
see
manage
and
the
know
afuent
harm
broaden
of
see
the
even
we
of
own
good
the
can
cause.
solve
living
and
way
to
can
has
after
until
eating,
the
complexity
some
not
most
activists
centred)
in
or
in
be
Cornucopians
with
governments
state
premature
cause
way
we
worldview
do
the
can
can
our
spaceship
(life-centred)
and
the
are
and
we
we
who
we
overexploitation
look
that
its
in
Environmental
the
treadmill
for
best
a
we
people
capitalism
compensate
growth
the
as
certainly
think
as
we
then
exploit.
that
and
answers
stand
–
need
we
We
Biocentric
a
and
if
and
economic
off
to
do,
improve
the
worldview.
from
ecocentric
simplistic.
we
resources
humanity.
managers
we
need
we
those
machine,
Earth.
resources
may
thing
inventiveness,
the
Earth
the
the
these
to
and
only
as:
species,
problem
good
benet
should
stewardship
nurture
a
provide
Environmental
the
to
economy
the
understand
is
Earth
species
summarized
resources
pollution
continually
interference
Some
more
on
Other
important
whatever
our
will
free-market
be
manage
include
and
that
and
growth
resources
problem
can
most
species
needs.
growing.
Cornucopians
technology
our
be
any
s o c i e t i e s
dominant
This
Earth’s
summary
innite
us.
control
economy
●
a n d
to
the
Earth.
Because
our
duty
to
1 . 1
restore
degraded
environmental
To
summarize
ecosystems,
the
ecocentric
The
●
Resources
●
We
should
●
We
must
work
●
We
need
the
Ecocentrists
action
and
is
here
are
for
and
deal
with
global
forms
occur.
S y S T E m S
species.
growth
with
Earth
believe
in
our
the
of
so
that
Earth,
more
the
actions
and
all
view:
limited.
manage
the
materialism
pollution
V A l u E
problems.
●
Earth
remove
E n V i r O n m E n T A l
than
not
it
importance
for
more
benecial
against
needs
individuals
need
only
of
us.
small-scale,
making
as
it.
a
wrong
local
difference.
and
do
not
community
They
like
view
centralized
decision-making.
At
the
value
end
on
rights
of
where
humans
policies
think
all
have
to
includes
ecology
the
nature
be
a
continuum
than
species
no
right
altered
decrease
is
not
about
an
our
Another
way
consider
them
to
in
and
to
reduce
the
looking
but
have
this.
impact
with
set
the
of
in
an
on
the
and
and
(technocentric/anthropocentric).
These
and
are
more
value
ecologists
and
would
consuming
and
our
to
obligations
value
extremes
Deep
help
us
towards
systems
or
like
which
less.
values
intervening
two
put
universal
environment,
environmental
(ecocentric)
–
inherent
guidelines
Earth
who
biorights
Deep
population
a
these
nurturing
ecologists
believe
with
our
human
at
deep
ecosystems
ecoreligion
as
the
They
interfere
relationship
of
are
humanity.
is
it.
to
‘A thing is right when it
manipulative
of
tends to preser ve the
the
integrity, stability and
spectrum
on
environmental
values
but
most
of
us
also
think
in
both
beauty of the biotic
ecocentric
and
technocentric
ways
about
issues
and
we
may
change
community. It is wrong when
our
minds
simplistic
depending
to
say
that
on
we
various
t
into
factors
one
or
and
the
as
we
other
get
older.
group
all
It
the
is
too
it tends otherwise.’
time.
Aldo Leopold
As
we
can
only
experience
the
world
through
our
human
perceptions,
our
(reprinted by permission of
views
of
rights
but
the
environment
are
biased
by
this
viewpoint.
We
talk
of
animal
Oxford University Press, USA)
Most
of
green’)
can
us
–
demands
resource
classied
will
faith
and
use
as
an
the
or
of
in
banks,
environmental
our
our
who
survival
of
view
communities
recycling
with
problems
of
and
to
the
to
work
aluminium
in
to
faith
in
appliance
very
few
in
green
human
are
rights
–
Some
deep
of
to
and
of
the
reduce
so
us
be
are
science
ecologists
and
(‘light-
environmental
together
cans)
1.1.6.
the
viewpoint.
environment
adapt
gure
believe
the
anthropocentric
institutions
managers
(‘bright-green’)
the
using
accommodating
and
bottle
‘dark-green’)
above
these
ability
changes
environmental
green’
Earth
discuss
take
in
(eg
cornucopians
solve
only
to
(‘deep-
survival
of
the
species.
To thk abot
Cost-beet aass ad the evoet
Environmental economists working in industry may be
at a high cost nancially and, in doing so, the company
asked how much pollution should be removed from a
may not be able to aord cleaning up the outow of
smokestack of a chimney before the waste is released to
heavy metals into a nearby ditch. The oppor tunity cost of
the atmosphere. All the pollutant could be removed but
the action is high. There are limited funds and unlimited
13
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
s ys t e m s
a n d
s o c i e t i e s
demands on those funds. Usually costs are passed on
an undisturbed ecosystem or a wild animal or human
to the consumer. So decisions may have to be made that
health? Cost-benet analysis is still used in decision-
mean some pollution escapes but both demands are met
making for industry as it is transparent but it may not
to some extent. Often a cost-benet analysis is carried out
be the best way. Later in this book , we talk more about
to trade o the costs and benets.
how to value the environment, but do be aware that an
environmentalist may not always promote the total cleanBut valuing the environmental cost is very dicult
up or eliminate solution if the oppor tunity cost is too high.
and it can be argued that cost-benet analysis cannot
When you add in questions of ethical practice and what is
apply to these nonmarket eects. How do you value
fair to do, you can see how complex this can become.
To do
Practical
For
a
Work
named
local
1.
environmental
Draw a table with two columns labelled ‘Ecocentric’ and ‘Anthropocentric/
issue,
Technocentric’.
investigate
the
relationship
2.
b etween
position
in
Put each of the words or phrases below in one of these columns. Don’t think
society
for too long about each one. Go with your instinct now you have read about
and
EVS.
environmental value systems.
Investigate
b etween
the
age
b etween
the
environmental
national
this
lead
(eg
one
to
often
Ecology
Manipulative
Authoritarian
Economy
Nur turing
Belief in technology
Feminist
Par ticipatory
Capitalism
Global co-existence
Preservation
Centralist
Holistic
Reductionist
Competitive
Human-centred
Seeking progress
Consumerism
Individual
Seeking stability
of
Cooperative
Intervening
Utilitarian
cross
and
conict
clash
of
systems
about
resources.
named
ocean
Animal rights
attitudes.
the
value
exploitation
Managerial
and
may
from
dierent
For
relationship
boundaries
may
arising
Ear th-centred
attitudes.
gender
Ecosystems
Aesthetic
and
environmental
Investigate
relationship
Then put a tick next to the words that best describe your environmental viewpoint.
example
shing,
whaling,
Draw a line with ecocentric on the left hand side and technocentric/anthropocentric
tropical
rainforest
exploitation,
on the right.
Antarctica),
research
the
issue
Put a cross which you think gives your position and get all your classmates to
and
consider
the
actions
taken
mark their own as well.
by
dierent
exploitation
countries
of
the
in
the
resources.
Review this at the end of the course and see if you have moved along the line – to
left or right – or moved relative to your classmates.
To do
Copy and complete this table to show the main points of the dierent
environmental philosophies.
Evoeta vae sste
Environmental management
strategies
Environmental philosophies
Labels and characteristics
Social movements
Politics
14
Ecocetc
Athopocetc
Techocetc
1 . 1
E n V i r O n m E n T A l
V A l u E
S y S T E m S
‘ The earth shall rise on new
v  ww
foundations: We have been
Communism and capitalism in Germany
nought, we shall be all!’
After
the
Iron
Cur ta i n
a nd
Be r li n
Wa ll
f el l
in
G e rm a ny
in
1 989 ,
Taken from the Internationale, the
western
journalis ts
r us he d
to
s ee
Ea st
G e rm an y
and
r ep or t
u po n
anthem of international socialists
it.
Communism
was
seen
as
the
a nt i do te
to
c a pi t al is t
gr e ed
and
and communists
communists
than
capitalism
curing
social
journalists
the
its
Buna
and
ills
one
chemical
did
in
a
with
a
clean
some
the
of
as
the
it
a
d ay
the
smo ky
it
was
not
spri ng
a
w he n
in
wa s
suc h
ma de
B ut
c a rs
e m it t i n g
w e st e r n
c a pi t a li sm
ha d
a nd
car
wou l d
i t se lf.
pr ot e c t e d
 s h er m en
s m e l t er s
int o
G er m an
n on -p ol lu t e r
st a t e
wit h
m er c u r y
We st
a
that
a
fa r m e r s
we re
pr oce ss
Tr a ban t
as
we a lt h
Ge r m a n y
mor e
m o no xi de
tha t
cr op s
E as t
two -s t r oke
comm un i st
la w
t he
com pa ra ble
n ot
li ke
in
mo re
d eg r ad a t ion .
t i m es
me s s ag e
wa s
p r o duce r s
The r e
a
ca r bon
T he
but
te n
tha n
pr od uc e
eve n ly,
c ou n t r y
d umpi ng
p a te r na l is ti c
environment.
co u ld
mo re
pol l ute d
co nv e r te r.
–
s ys t em
e nvi ro nme nt a l
much
indus tr y
in
in
And
primar y
pollute
a
w o r ks
river
yea r.
ways
interests
on
times
catalytic
up
thei r
d i s tr ib ute
reporte d
hundred
tha t
incl ud ing
neighbouring
plant
In
claime d
s hu t
t he
an d
do wn
so
t he
an d
so
gr owin g .
Native American environmental worldview
While
there
their
views
have
a
and
is
use
that
by
down
(descent
extended
as
follows
to
hold
in
a
the
and
natural
for
democratic
side)
objects
broad
as
they
come
opposed
gods)
have
a
and
In
to
The
money,
consensus
laws
a
are
matrilineal
patriarchal,
terms
hold
use
to
have
of
that
of
(communal),
than
process.
density.
generalization
common
rather
communities
population
many
a
in
goods
Politically,
Most
female
low
views,
property
barter
tradition.
(worshipping
as
American
technologies.
oral
families
well
tend
economy,
participation
by
polytheistic
plants
native
they
low-impact
handed
are
many
subsistence
agreements
line
are
with
religion,
animals
they
and
spirituality.
Worldviews of Christianity and Islam
The
two
and
Islam,
in
separation
a
religions
‘dominion’
citizenship
Christian
or
book
of
own
The
and
Are
of
in
humans
humans
for
and
or
their
Judeo-Christian
the
matter
over
the
the
most
some
3.6
or
Earth.
Judaic
love
commands
dominion
to
just
that
be
the
after
Earth
sustenance.
model
in
a
But
are
the
soul
the
to
the
and
stewards
the
which
the
the
and
biblical
earth,
what
Do
of
the
perhaps
the
Earth?
of
view
have
In
But
belief
notion
Greek
West.
1:28).
of
a
covenant
‘replenish
(Genesis
Christianity
share
ancient
of
of
are
They
examples
views
it’
or
and
notion
humans
over
masters
look
adherents
billion.
body
anthropocentric
God
states
with
unconditional
the
have
something
Quran
spirit
democracy,
Genesis,
it;
Earth
numbering
mastery
view
distorted
mean?
of
and
been
subdue
on
together
and
does
this
stewards
it?
(and
The
its
bounty)
Quran
number
of
does
areas
has
been
given
differentiate
from
to
the
however.
15
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
●
s ys t e m s
Humans
are
not
a n d
given
s o c i e t i e s
mastery
or
dominion
over
the
Earth
but
rather
To do
have
been
difference
granted
as
it
it
as
implies
a
gift
or
inheritance.
caretaker
status
of
This
God’s
is
a
signicant
work
not
rulers
over
it.
Shades of gee: Whee ae we ow?
●
The
Quran
also
recognises
that
the
animal
world
is
a
community
In any political movement, there will
equal
to
There
is
the
human
one.
be changes and developments. It is
now dicult to avoid marketing that
●
more
emphasis
on
the
trustee
status
of
human
beings
and
1
is based on environmental well-being,
thus
the
imperative
towards
charity
(the
3rd
pillar
of
Islam).
often related to human well-being.
Another
layer
comes
from
ecofeminism
as
an
environmental
movement
Organic, biotic, low emissions, energyin
which
ecofeminists
argue
that
it
is
the
rise
of
male-dominated
saving, sustainable, free-range, green
societies
since
the
advent
of
agriculture
that
has
led
to
our
view
of
credentials are all terms used in green
nature
as
a
foe
to
be
conquered
rather
than
a
nurturing
Earth
mother.
marketing of products although exactly
what they mean and how we perceive
them is questionable. ‘Greenwash’ and
Buddhism’s environmental worldview – a religious
‘Green sheen’ are terms that describe
ecology
activities that are not as good for the
Buddhism
has
evolved
over
2,500
years
to
see
the
world
as
conjoined
environment as the producer would like
in
four
ways
–
morally,
existentially,
cosmologically
and
ontologically.
us to believe.
Buddhists
believe
that
all
sentient
beings
share
the
conditions
of
birth,
A way of classifying environmentalists
old
age,
suffering
and
death
and
that
every
living
thing
in
the
world
is
co-
today is as dark greens, light greens
dependent.
Buddhist
belief
teaches
that
as
we
are
all
dependent
on
each
and bright greens.
other,
whether
be
plant
Dark greens are dissenters seeking
cannot
more
political change in a radical way as they
loving-kindness
or
animal,
important
and
than
we
are
other
compassion
not
not
autonomous
living
just
to
things
life
believe that economic development
and industrial growth are not the
answer. They see a change in the status
quo and a reduction in the size of the
human population as the way to go.
Light greens are individuals who do
not want to work politically for change
but change their own lifestyles to use
fewer resources. For them, it is an
individual choice. Bright greens want to
use technological developments and
social manipulation to make us live
sustainably and believe that this can be
done by innovation. For bright greens,
economic growth may be benecial if it
means more of us live in ecient cities,
use more renewable energy and reduce
the size of our ecological footprints
while increasing our standard of living.
For them, we can have it all. The viridian
design movement is a spin-o from
the bright greens and is about global
citizenship and improved design of
green products.
What shade of green are you?
1
Personal communication from Kosta Lekanides to the authors.
16
but
and
to
and
must
the
humans
extend
Earth
itself.
1 . 2
S y S T E m S
A n D
m O D E l S
1.2 S stes ad odes
sg :
app  k:
➔
A systems approach can help in the study of
➔
Costct a system diagram or a model from a
complex environmental issues.
given set of information.
➔
The use of models of systems simplies
➔
Evaate the use of models as a tool in a given
interactions but may provide a more holistic
situation, eg for climate change predictions.
view than reducing issues to single processes.
Kwg  g:
➔
➔
A sstes appoach is a way of visualizing
matter across its boundary while a cosed
ecological or societal.
sste only exchanges energy across its
boundary.
These interactions produce the emergent
proper ties of the system.
➔
An ope sste exchanges both energy and
➔
a complex set of interactions which may be
An soated sste is a hypothetical concept in
➔
which neither energy nor matter is exchanged
The concept of a system can be applied to a
across the boundary.
range of scales.
Ecosstes ae ope sstes. Closed systems
➔
➔
A system is comprised of stoages ad ows.
➔
The ows provide inputs and outputs of energy
only exist experimentally although the global
geochemical cycles approximate to closed
and matter.
systems.
➔
The ows are processes and may be
A ode is a simplied version of reality and can
➔
either tasfes (a change in location) or
be used to understand how a system works and
tasfoatos (a change in the chemical
predict how it will respond to change.
nature, a change in state or a change in energy).
A model inevitably involves some approximation
➔
➔
In sste dagas, storages are usually
and loss of accuracy.
represented as rectangular boxes, and ows as
arrows with the arrow indicating the direction of
the ow. The size of the box and the arrow may
represent the size/magnitude of the storage
or ow.
‘Nature does nothing
Wh ?
uselessly.’
A
system
can
be
living
or
non-living.
Aristotle (384–322 BC)
●
Systems
you,
and
●
a
a
Open,
can
be
bicycle,
on
a
any
car,
scale
your
–
small
home,
a
or
large.
pond,
an
A
cell
ocean,
is
a
system
asmart
as
are
phone
farm.
closed
systems
are
and
open
isolated
systems
exist
in
theory
though
most
living
systems.
17
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
●
s ys t e m s
Material
owing
●
and
course
is
There
is
a
called
Science
together
case
in
together
study
are
a
in
a
drop
an
if
We
also
as
set
to
can
be
transformations
useful
A
In
as
in
helping
an
an
in
us
book
biome
of
integrated
and
can
clear
a
be
You
to
seen
a
as
boundaries.
(as
be
an
is
of
plants,
sometimes
You
on
We
scales
coral
whole
they
emphasis
many
a
but
also
which
ecosystem,
The
the
approach.
on
forest,
this
geography),
this
systems
can
to
or
and
not
components
study
system
view,
they
why
environments.
the
the
tree
of
separately
geology
and
approach,
sets
units.
complex
elements
ocean,
considered
systems
not
distinguishes
Societies
systems:
biology,
of
and
you
the
integrated
parts
other
has
Have
complex
such
this
to
Systems
atmosphere
takes
in
water
of
form
the
linkages
ecosystem
ecosystem
but
emphasis.
and
or
course
continent.
an
a
sciences
and
pond
island
helps
and
next.
Studies.
in
component
ecosystems
of
or
as
relation
The
relationships
consider
rocks
the
them
part.
seen
other
as
transfers
the
Environmental
difference
soils,
to
limitations
that
the
Ke te
their
is
function
undergo
storage
environment
animals,
s o c i e t i e s
systems.
Environmental
is?
one
have
understand
This
energy
from
Models
a n d
reef
from
to
though
biosphere
it
is
an
well.
consider
other
systems
such
as
the
social
and
economic
systems
A sste is a set of inter-related
that
make
our
human
world
work.
Decisions
about
the
environment
parts working together to make
are
rarely
simply
decisions
based
on
ecology
or
science.
We
may
want
to
a complex whole.
save
the
tigers
systems
which
A
system
is
a
way
may
of
The
opinions
on
system
all
be
may
occur
–
their
parts,
make
an
with
decisions
abstract
at
within
or
energy
–
inuence
remain
systems
ones
constrained
the
concept
world.
for
their
and
for
matter
in
environment.
example
a
a
own
ecosystems,
and
their
stable
by
we
as
economics,
we
system
how
long
as
that
you
time
they
living
computer
is
draw
you
or
may
and
political
are
more
all
tangible.
system
consists
may
information
than
the
It
a
of
your
than
quickly.
be
exchange
more
as
it.
change
which
usually
a
hold
evaluate
systems,
Systems
something
can
environment
and
society
make.
well
Usually,
value
environment
of
outputs
be
environmental
the
Systems
other
will
looking
diagram.
A
but
made
inputs
in
up
and
non-living
the
sum
materials
of
used
to
it.
The human place in the biosphere
The
biosphere
(atmosphere),
which
layer
life
yet
about
a
fragile
rocks
occurs.
we
the
is
little
the
on
the
(lithosphere)
Humans
know
effects
skin
and
about
human
all
planet
and
water
other
how
it
species
is
is
Earth.
It
includes
(hydrosphere)
organisms
regulated
having
live
or
upon
the
within
within
this
self-regulates,
it.
tp f 
▲
18
Fge 1.2.1 The Ear th and its
Systems
Moon viewed from space
isolated.
can
be
thought
of
as
one
of
three
types:
air
open,
closed
and
thin
or
1 . 2
An
open
(see
system
gure
exchanges
matter
and
energy
with
its
S y S T E m S
A n D
m O D E l S
surroundings
1.2.3).
biosphere = atmosphere + lithosphere
Represented by:
All systems have:
+ hydrosphere + ecosphere
atmosphere
hydrosphere
STORAGES or stores of matter or energy
a box
FLOWS into, through and out of the system
arrows
INPUTS
arrows in
OUTPUTS
arrows out
lithosphere
BOUNDARIES
lines
PROCESSES which transfer or transform
Eg respiration,
energy or matter from storage to storage
precipitation, diusion
biosphere
▲
Fge 1.2.2 Relationships
▲
Fge 1.2.3 Systems terminology
within the biosphere
light
P
consumption
death
noitaripser
taeh
storage
death and waste
C
detritus
nutrient
1
pool
consumption
death and
waste
ni thguorb doof
removed by
wind and
▲
decomposers
C
water
2
Fge 1.2.4 Energy and matter
and
exchange in an immature forest
detritivores
recycling
ecosystem
Transfers and transformations
Both
●
matter
(or
transfers:
the
■
form
the
material)
water
of
■
the
movement
the
being
of
from
of
of
a
other
a
to
or
ow
the
sea,
herbivore
through
through
to
living
ecosystems
chemical
a
energy
carnivore
as:
in
or:
organisms
animals)
material
by
move
river
from
material
carried
movement
energy
moving
eating
movement
(water
■
moving
sugars
(carnivores
and
a
energy
in
a
non-living
process
stream)
(ocean
currents
transferring
heat).
19
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
●
s ys t e m s
transformations:
a n d
liquid
s o c i e t i e s
to
gas,
light
to
chemical
energy:
Ke tes
■
matter
Tasfes occur when energy
in
to
matter
(soluble
glucose
converted
to
insoluble
starch
plants)
or matter ows and changes
■
energy
■
matter
■
energy
to
energy
(light
converted
to
heat
by
radiating
surfaces)
location but does not change
its state.
to
to
energy
(burning
matter
fossil
fuels)
(photosynthesis).
Tasfoatos occur when
energy or matter ows and
changes its state – a change
Both
types
energy
of
and
ow
are
require
therefore
energy;
more
transfers,
efcient
being
than
simpler,
require
transformations.
in the chemical nature, a
change in state or a change
Flows and storages
in energy.
Both
energy
ecosystems
within
Practical
Create
a
the
and
but,
matter
at
ow
times,
(as
they
inputs
are
also
and
outputs)
stored
(as
through
storages
or
stock)
ecosystem.
Work
model
general scheme of
ecosystem
biogeochemical cycles
in
a
plastic
soda
bottle
atmosphere
(sub-topic5.4).
Construct
home,
with
Evaluate
a
model
of
storages
climate
your
and
ows.
respiration
weathering
change
elements
rock cycle
models
(7.2).
combined in
elements
animal
locked in
feeding
tissue
sinks
▲
elements
Fge 1.2.5 The Biogeochemical
combined in
plant tissue
Cycle illustrating the general
volatile gases
ows in an ecosystem. Energy
absorbed
sedimentation
ows from one compartment to
and fossilisation
another, eg in a food chain. But
when one organism eats another
nutrient
organism, the energy that moves
elements in
between them is in the form
soil and
of stored chemical energy: the
water
body of the prey organism
More on systems
To do
labe the pts, otpts, stoages ad ows.
Exapes of sstes
An ecosystem is a good example of a ‘system’.
Using the model below, draw your own systems diagram
inputs
ows
for:
20
a)
A candle
d)
You
b)
A mobile phone
e)
Your school
c)
A green plant
f)
A lake
▲
Fge 1.2.6
storages
ows
outputs
less
1 . 2
Most
systems
exchanging
In
forest
are
Plants
●
Nitrogen
●
Herbivores
x
as
Forest
●
Mineral
energy
from
a
●
●
Water
●
Heat
res
air
live
is
xed
within
but
by
the
when
are
open
m O D E l S
systems
environment.
forest
are
leached
lost
to
streams
through
exchanged
of
the
models
matter
oceans
and
even
systems
out
during
photosynthesis.
bacteria.
may
graze
may
of
they
be
the
in
adjacent
enrich
the
removed
soil
and
by
ecosystems
soil
with
wind
feces.
and
transported
rain.
in
rivers.
and
transpiration
surrounding
from
environment
plants.
across
the
forest.
can
are
even
be
applied
exchanged
energy
extremely
carbon,
with
to
the
the
remotest
atmosphere,
oceanic
island
–
surrounding
birds.
exchanges
are
hydrological,
the
migratory
system
which
and
system
return
evaporation
with
the
soil
they
nutrients
and
the
ecosystems
their
entering
topsoil
system
closed
light
the
energy
Closed
All
with
expose
is
is
the
that
boundaries
A
systems.
energy
from
grassland,
groundwater
Open
and
A n D
ecosystems:
●
such
open
matter
S y S T E m S
rare
and
but
in
not
matter
nature.
nitrogen
with
However,
cycles
are
its
on
closed
–
environment.
a
global
they
scale,
exchange
light energy
only
energy
and
no
matter.
The
planet
itself
can
be
thought
of
as
an
from the Sun
‘almost’
Light
closed
energy
eventually
small
is
in
not
truly
the
large
returned
amount
enter
system.
a
of
space
matter
closed
Earth’s
amounts
to
is
enters
as
the
exchanged
system.
What
atmosphere
Earth’s
long-wave
and
between
types
what
of
system
radiation
the
matter
types
that
and
(heat).
Earth
can
and
you
leave
some
is
(Because
space,
think
of
a
it
that
it?)
long-wave energy
(heat) returned
Most
examples
of
closed
systems
are
articial,
and
are
constructed
for
to space
experimental
purposes.
An
aquarium
or
terrarium
may
be
sealed
so
▲
that
only
energy
in
the
form
of
light
and
heat
but
not
matter
can
Fge 1.2.7 A closed system –
be
the Ear th
exchanged.
usually
do
example
carbon
went
that
Examples
not
not
is
survive
enough
dioxide,
wrong
in
is
include
and
for
food
bottle
long
for
equilibrium
is
2
at
the
the
organisms
Biosphere
as
p
or
system
animals,
die.
(see
gardens
An
22).
becomes
or
not
example
An
sealed
terraria
a
example
oxygen
closed
of
they
unbalanced,
enough
of
but
a
or
system
closed
for
that
system
http://www.dailymail.co.uk/sciencetech/
article-2267504/The-sealed-bottle-garden-thriving-40-years-fresh-air-
water.html
An
isolated
system
environment.
to
think
Sste
of
exchanges
Isolated
the
entire
systems
universe
neither
do
as
not
an
matter
exist
isolated
Eeg
matte
exchaged
exchaged
Open
Yes
Yes
Closed
Yes
No
Isolated
No
No
nor
energy
naturally
with
though
it
its
is
possible
system.
21
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
s ys t e m s
a n d
s o c i e t i e s
To thk abot
Bosphee 2
Biosphere 2, a prototype space city, was a human attempt to create a
habitable closed system on Ear th. Built in Arizona at the end of the 1980s,
Biosphere 2 was a three-hectare greenhouse intended to explore the use of
closed biospheres in space colonization. Two major ‘missions’ were conducted
but both ran into problems. The Biosphere never managed to produce enough
food to adequately sustain the par ticipants and at times oxygen levels
became dangerously low and needed augmenting – they opened the windows
so making it an open system.
To do
There is a TED talk about
this http://www.ted.com/
talks/jane_poynter_life_in_
▲
Fge 1.2.8 Biosphere 2
biosphere_2. Watch it.
Inside were various ecosystems: a rainforest, coral reef, mangroves, savanna,
Qestos
deser t, an agricultural area and living quar ters. Electricity was generated from
1.
Why do you think this
natural gas and the whole building was sealed o from the outside world.
was called Biosphere 2?
For two years, eight people lived in Biosphere 2 in a rst trial. But oxygen levels
2.
Biosphere 2 has been
dropped from 21% to 14% and of the 25 small animal species put in, 19 became
described as a ‘closed
extinct, while ants, cockroaches and katydids thrived. Bananas grew well but
system’. What does this
there was not enough food to keep the eight people from being hungry. Oxygen
mean?
levels gradually fell and it is thought that soil microbes respired much of this.
3.
Biosphere 2 was
Carbon dioxide levels uctuated widely. A second trial star ted in 1994 but
designed to include
closed after a month when two of the team vandalized the project, opening up
some of the major
doors to the outside. Cooling the massive greenhouses was an issue, using
ecosystems of the Ear th.
three units of energy from air conditioners to cool the air for the input of every
one unit of solar energy. So there were social, biological and technological
4.
List the ecosystems
problems with the project as the team split into factions and questions were
and divide them into
asked as to whether this was a scientic, business or ar tistic venture.
terrestrial (land based)
22
and marine (sea-water
The result was to show how dicult it is to make a sustainable closed system
based).
when the complexities of the component ecosystems are not fully understood.
1 . 2
S y S T E m S
A n D
m O D E l S
To thk abot
Atos
Fo B Bso’s ‘A Sho t Hsto of nea Evethg ’
All matter is made up of atoms. You are taught this in some
‘Why atoms take this trouble is a bit of a puzzle. Being
of your rst science lessons. Living things are made up
you is not a gratifying experience at the atomic level. For
of atoms, grouped into molecules and macromolecules,
all their devoted attention, your atoms do not actually
organelles, cells, tissues, organs and systems.
care about you—indeed, they do not even know that
you are there. They don’t even know that they are there.
Read these two excerpts and think about what makes
They are mindless par ticles, after all, and not even
you you.
themselves alive. (It is a slightly arresting notion that if
you were to pick yourself apar t with tweezers, one atom
Fo ‘Qat theo ad eatvt expaed’
at a time, you would produce a mound of ne atomic
(Da Teegaph 20th novebe 20 07)
dust, none of which had ever been alive but all of which
‘Quantum theory has made the modern world possible,
had once been you.) Yet somehow for the period of
giving us lasers and computers and iPod nanos, not to
your existence they will answer to a single overarching
mention explaining how the sun shines and why the
impulse: to keep you you.
ground is solid.
The
bad
news
is
that
atoms
are
fickle,
and
their
time
Take the fact that you are constantly inhaling fragments
of
d ev o t i o n
is
f leeting
indeed.
Ev e n
a
long
human
of Marilyn Monroe. It is stretching it a bit to say that this
life
adds
up
to
only
about
650,000
hours,
and
when
is a direct consequence of quantum theory.
that
modest
milestone
Nevertheless, it is connected to the properties of atoms, the
unknown,
Lego bricks from which we are all assembled, and quantum
disassemble,
theory is essentially a description of this microscopic world.
it
for
you.
Generally
your
atoms
and
S till,
go
you
speaking
f lashes
will
off
may
in
shut
to
be
you
that
universe,
for
reasons
down,
other
rejoice
the
past ,
silently
things.
it
it
And
happens
that's
at
doesn't ...so
all.
far
The impor tant thing to realize is that atoms are small. It
as
we
ca n
tell.’
would take about 10 million of them laid end to end to
span the full stop at the end of this sentence. It means
Bill Bryson continues to say that ‘life is simple in terms
that every time you breathe out, uncountable trillions of
of chemicals – oxygen, hydrogen, carbon, nitrogen make
the little blighters spread out into the air.
up most of all living things and a few other elements too –
sulfur, calcium and some others. But in combination
Eventually the wind will spread them evenly throughout
and for a shor t time, they can make you and that is the
the Ear th’s atmosphere. When this happens, every
miracle of life.’
lungful of the atmosphere will contain one or two atoms
you breathed out.
So, each time someone inhales, they will breathe in
an atom breathed out by you – or Marilyn Monroe, or
Alexander the Great, or the last Tyrannosaurus rex that
stalked the Ear th.’
m f 
A
us
model
is
something
we
just
many
●
a
do
simplied
a
how
changes.
not
forms.
of
version
system
Systems
know
could
be:
model,
for
the
software
a
always
It
physical
model
●
a
understand
solar
model,
(Lovelock’s
the
work
what
example
system,
for
of
works
an
real
and
in
rules
wind
of
or
climate
use
what
ways,
are.
tunnel
aquarium
example
We
predict
predictable
these
a
thing.
to
A
or
models
to
happens
following
model
river,
a
can
help
if
rules,
take
globe
or
terrarium
change
or
evolution
Daisyworld)
23
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
s ys t e m s
●
mathematical
●
data
Models
some
or
for
ow
have
of
the
to
s o c i e t i e s
equations
diagrams.
their
limitations
complexities
simplicity),
change
a n d
an
they
input
to
of
allow
the
as
the
us
well
real
to
as
strengths.
system
look
While
(through
ahead
and
they
lack
predict
of
may
omit
knowledge
the
effects
of
system.
To do
Copae these t wo odes
social-environmental
environmental-economic
environmental
environmental justice
energy eciency
natural resource use
natural resources stewardship
subsidies/incentives for
environmental management
locally & globally
use of natural resources
pollution prevention
(air, water, land, waste)
sustainable
economic
social
prot cost savings
standard of living
economic growth
education
research &
community
development
economic-social
business ethics
fair trade
worker ’s rights
▲
Fge 1.2.9 The spheres of a sustainable model. Only when all three overlap is there sustainability
Why are any of these circles in the Venn diagram outside
the environment?
Is culture relevant to these models of sustainability?
economy
Where would you draw it in?
Does the model change how we treat our environment?
Evaluate these models. (Consider their strengths and
society
weaknesses.)
environment
▲
Fge 1.2.10 An alternative model of sustainability
representing all other systems within the
environmental system
24
a
1 . 2
The
strengths
of
models
S y S T E m S
A n D
m O D E l S
are:
To do
●
Easier
●
Can
be
used
●
Can
be
applied
to
work
with
than
complex
reality.
http://gingerbooth.com/
to
predict
the
effect
of
a
change
of
input.
ash/daisyball/ links to the
●
Help
●
Can
us
be
things
The
see
used
weaknesses
Accuracy
●
If
●
Predictions
our
is
other
similar
situations.
Daisyworld game. Have a go.
patterns.
to
(solar
●
to
visualize
really
small
things
(atoms)
and
really
large
system).
of
models
lost
are:
because
assumptions
may
be
are
the
model
wrong,
the
is
simplied.
model
will
be
wrong.
inaccurate.
Sstaabe deveopet odeg
See
1.4
for
more
on
sustainable
development
and
sustainability.
To thk abot
Gaa – a ode of the Ea th
3.
The oceans’ salinity is constant at about 3.4% but
rivers washing salts into the seas should increase this.
The ‘Great Aerial Ocean’ was Alfred Russel Wallace’s
description of the atmosphere.
He
was
Lynn
much
criticized
Margulis
who
over
worked
this
with
hypothesis
him
also
but
suppor ted
‘ You can cut the atmosphere with a knife’ is a common
his
views
the
Ear th
though
uses
less
emotive
language
about
saying. If we could see the atmosphere, perhaps we
as
an
organism.
Lovelock
has
defended
would consider it and look after it more. As we cannot,
his
hypothesis
for
30
years
and
many
people
are
perhaps we take it for granted.
now
accepting
some
of
his
views.
He
developed
a
In 1979, James Lovelock published The Gaia Hypothesis.
Daisyworld
as
a
mathematical
simulation
to
show
that
In it he argued that the Ear th is a planet-sized organism
feedback
mechanisms
can
evolve
from
the
activities
and the atmosphere is its organ that regulates it and
of
self-interested
in
this
organisms
–
black
and
white
daisies
connects all its par ts. (Gaia is an Ancient Greek Ear th
case.
goddess.) Lovelock argued that the biosphere keeps
In Lovelock’s 2007 book , The Revenge of Gaia, he makes
the composition of the atmosphere within cer tain
a strong case for the Ear th being an ‘older lady’ now,
boundaries by negative feedback mechanisms.
more than half way through her existence as a planet
He based his argument on these facts:
and so not being able to bounce back from changes as
1.
The temperature at the Ear th’s surface is constant
well as she used to. He suggests that we may be entering
even though the Sun is giving out 30% more energy
a phase of positive feedback when the previously stable
than when the Ear th was formed.
equilibrium will become unstable and we will shift to
a new, hotter equilibrium state. Controversially, he
2.
The composition of the atmosphere is constant with
suggests that the human population will survive but with
79% nitrogen, 21% oxygen and 0.03% carbon dioxide.
a 90% reduction in numbers.
Oxygen is a reactive gas and should be reacting but it
does not.
25
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
s ys t e m s
a n d
s o c i e t i e s
To do
1.
Dene a system
2.
Fill in the gaps
Ear th, although the biosphere (or Gaia) itself can be
considered a ________ system.)
●
The terms ‘open’, ‘closed’ and ‘isolated’ are used to
(No such systems exist, with the possible exception
describe par ticular kinds of systems. Match the above
of the entire cosmos.)
names to the following denitions:
●
A __________ system exchanges neither matter nor energy.
A ___________ system exchanges matter and energy with its
surroundings (eg an ecosystem).
All ecosystems are ________ systems, because of the input
of _______ energy and the exchange of ________ with other
ecosystems.
●
A __________ system exchanges energy but not matter
(The ‘Biosphere 2’ experiment was an attempt to
model this. These systems do not occur naturally on
Bg cade
Inputs
Outputs
Energy and material transfers
Energy and material
transformations
26
3.
Systems circus
Look at the following simple systems and complete the table:
Bog kette
A pat
Aa popato
1 . 3
E n E r G y
A n D
E Q u i l i B r i A
1.3 Eeg  ad eqba
sg :
app  k:
➔
The laws of thermodynamics govern the ow of
➔
Expa the implications of the laws of
energy in a system and the ability to do work .
thermodynamics to ecological systems.
➔
Systems can exist in alternative stable states
➔
Dscss resilience in a variety of systems.
➔
Evaate the possible consequences of tipping
or as equilibria between which there are tipping
points.
points.
➔
Destabilizing positive feedback mechanisms
will drive systems toward these tipping
points, whereas stabilizing negative feedback
mechanisms will resist such changes.
Kwg  g:
➔
➔
➔
The st aw of theodacs is the pcpe
➔
when the output of a process inhibits or reverses
energy in an isolated system can be transformed
the operation of the same process in such a way
but cannot be created or destroyed.
to reduce change – it counteracts deviation.
The principle of conser vation of energy can be
➔
tend to amplify changes and drive the system
food chains and energy production systems.
toward a tipping point where a new equilibrium is
adopted.
The secod aw of theodacs states that
➔
The esece of a system, ecological or social,
Etop is a measure of the amount of disorder
refers to its tendency to avoid such tipping
in a system. An increase in entropy arising from
points and maintain stability.
energy tasfoatos reduces the energy
➔
available to do work .
speed of response to change (time lags).
➔
a food chain and energy generation systems.
As an open system, an ecosystem, will
normally exist in a stabe eqb, either a
stead-state or one developing over time (eg
Diversity and the size of storages within systems
can contribute to their resilience and aect the
The second law of thermodynamics explains the
ineciency and decrease in available energy along
➔
Post ve feedback oops (destabilizing) will
modelled by the energy transformations along
the entropy of a system increases over time.
➔
negat ve feedback oops (stabilizing) occur
of cose vato of eeg , which states that
Humans can aect the resilience of systems
through reducing these storages and diversity.
➔
The delays involved in feedback loops make it
dicult to predict tppg pots and add to the
complexity of modelling systems.
succession), and maintained by stabilizing
negative feedback loops.
27
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
s ys t e m s
a n d
s o c i e t i e s
eg  
Ke tes
Energy
in
all
systems
is
subject
to
the
laws
of
thermodynamics.
The st aw of
According
to
the
rst
law
of
thermodynamics ,
energy
is
neither
theodacs is the
created
nor
destroyed.
What
this
really
means
is
that
the
total
energy
in
pcpe of cose vato
any
isolated
system,
such
as
the
entire
universe,
is
constant.
All
that
can
of eeg, which states
happen
is
that
the
form
the
energy
takes
changes.
This
rst
law
is
often
that energy in an isolated
called
the
principle
of
conservation
of
energy.
system can be transformed
but cannot be created or
chanch
destroyed.
chemical energy is metabolized
and lost from the food chain as heat
1
2
3
4
parasitic wasps
move
reected
solar energy
water
heat
photosynthesis
stored chemical energy is
passed along as food
caterpillar of
no new energy is created it is
sycamore moth
some is lost from the food
chain as heat
energy enters the
system as light energy
sycamore tree
Photosynthesis conver ts
light energy to stored
▲
chemical energy (glucose).
Fge 1.3.2 The fate of the
Sun’s energy hitting the
▲
Fge 1.3.1 A simple food chain
Ear th. About 30% is reected
back into space (1), around
50% is conver ted to heat (2),
In
a
power
moving
station,
water)
is
one
form
converted
of
or
energy
(from
transformed
eg
into
coal,
oil,
nuclear
power,
electricity.
and most of the rest powers
In
your
body,
food
provides
chemical
energy
which
you
convert
into
the hydrological cycle: rain,
heat
or
kinetic
energy.
evaporation, wind, etc (3).
Less than 1% of incoming light
If
we
is used for photosynthesis (4).
photosynthesis.
The
look
at
second
isolated
the
sunlight
law
system
of
not
falling
on
Earth,
thermodynamics
in
equilibrium
will
not
states
tend
all
of
that
to
it
is
the
used
for
entropy
increase
over
of
an
time.
Ke tes
●
theodacs refers
Entropy
is
spreading
The secod aw of
●
More
●
Over
a
measure
out
entropy
or
=
of
disorder
dispersal
less
of
of
a
system
and
it
refers
to
the
energy.
order.
to the fact that energy
time,
all
differences
in
energy
in
the
universe
will
be
evened
is transformed through
out
until
nothing
can
change.
energy transfers. Etop
is a measure of the amount
●
Energy
●
When
conversions
are
never
100%
efcient.
of disorder in a system.
energy
is
used
to
do
work,
some
energy
is
always
dissipated
An increase in entropy
(lost
to
the
environment)
as
waste
heat.
arising from energy
28
tasfoatos reduces the
This
energy available to do work .
input
process
and
can
be
outputs.
summarized
by
a
simple
diagram
showing
the
energy
1 . 3
energy
work
=
heat
+
(and
other
wasted
E n E r G y
A n D
E Q u i l i B r i A
energy)
heat
heat generated
heat generated
heat generated
during work
during work
during work
eg respiration
eg respiration
eg respiration
input energy
useful energy: work
conversion
process
▲
Fge 1.3.4 Loss of energy to the environment in a food chain
▲
Fge 1.3.3 The second law
of thermodynamics
In
the
example
energy
level
●
gure
consumed
by
1.3.4,
one
the
trophic
energy
level
is
spreads
less
out
than
the
so
the
total
useful
energy
at
the
below.
Depending
energy
●
in
to
on
Herbivores
about
on
10%
metabolic
the
the
stored
of
type
average
the
chemical
is
plant,
energy
escaping
energy
efciency
in
its
at
converting
solar
1–2%.
assimilate
plant
and
the
around
only
total
processes
stored
of
sugars
(turn
they
from
cells
into
animal
consume.
the
into
The
carnivore.
useful
matter)
rest
This
work
is
lost
in
changes
(running).
Ke te
But
during
converted
its
to
attempted
heat
and
escape
lost
from
some
the
of
the
food
stored
energy
is
chain.
Etop is a measure of
the amount of disorder in a
●
A
carnivore’s
efciency
is
also
only
around
10%
(see
2.3).
As
with
system.
the
herbivore
trying
●
So
as
to
catch
energy
reduction
●
That
0.1
●
This
in
means
=
is
a
means
battle
of
energy,
of
paddling
life
is
the
stored
chemical
energy,
in
this
case
herbivore.
dispersed
the
amount
to
the
of
energy
carnivore’s
the
environment,
total
passed
on
efciency
in
there
to
will
the
the
always
next
chain
be
trophic
is
0.02
×
a
level.
0.1
×
carnivore
against
cannot
by
example
loses
most
of
its
energy
as
heat
into
the
environment.
entropy
exist.
upstream.
downstream
Simple
the
metabolize
0.0002%.
surrounding
Life
they
the
of
Stop
and,
without
Consider
for
current
of
a
this
moment
the
constant
pictorial
and
replenishment
view(gure
you
are
swept
1.3.5)
back
entropy.
entropy:
Living processes
Entropy
▲
Fge 1.3.5 A representation of life against entropy
29
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
The
s ys t e m s
situation
depicted
thermodynamics,
untidy,
a
a n d
in
since
situation
of
s o c i e t i e s
gure
the
high
tidy
1.3.6
obeys
room
entropy.
In
of
the
low
the
second
entropy
process,
law
of
becomes
entropy
increasesspontaneously.
Solar
energy
respiration,
appliances.
electricity.
power
Tidy
room
has
order:
low
the
this
input
happen
of
of
photosynthesis.
all
activities
potential
These
are
all
us
via
of
energy
They
are
photons
macromolecules
in
Chemical
life.
of
a
high-quality
processes.
reaches
bonds
all
waterfall
forms
like
of
ordered
solar
energy,
Electrical
rays;
sugars;
turns
a
energy,
forms
runs
all
turbine
energy.
energy
potential
home
to
because
of
chemical
the
through
energy
produce
they
Solar
is
energy
stored
of
in
falling
entropy
water
Does
The
useful
energy
the
powers
powers
naturally
without
falls.
is
due
These
to
the
specic
ordered
forms
position
have
low
of
water,
disorder,
namely
so
low
that
it
is
high
and
entropy.
energy?
On
the
form
contrary,
of
energy.
warming
is
it
up.
disordered.
high
heat
Heat
Heat
In
may
is
not
simply
dissipates
other
words,
power
any
dispersed
to
the
heat
is
process;
in
space,
environment
a
form
of
it
is
a
being
low-quality
capable
without
energy
any
only
of
order;
characterized
it
by
entropy.
To thk abot
ipcatos of the secod aw fo evoeta sstes
We experience the second law in our everyday lives. All living creatures die and
Untidy
▲
room
has
disorder:
high
entropy
in doing so:
●
entropy or disorder tends to increase
●
the creatures move from order to disorder
●
but organisms manage to ‘survive’ against the odds, that is against the
Fge 1.3.6 Which is your room?
second law of thermodynamics
●
living creatures manage to maintain their order and defy entropy to stay
alive by continuous input of energy by continuously getting chemical
energy from organic compounds via respiration
●
energy is even required at rest – if they do not respire they die.
This is the same as the example of the room; the only way to keep the room
tidy is to continuously clean it, that is to expend energy.
In any process, some of the useful energy turns into heat:
●
Low-entropy (high-quality) energy degrades into high-entropy (low-quality)
heat.
●
So the entropy of the living system stays low, whilst the entropy of the
environment is increasing.
●
Photosynthesis and respiration are good examples.
■
Low-entropy solar energy turns into higher-entropy chemical energy.
■
Chemical energy turns into even higher-entropy mechanical energy and
is ‘lost’ as heat (low-quality, high-entropy).
30
●
This increases the entropy of the environment, in which heat dissipates.
●
As a consequence, no process can be 100% ecient.
1 . 3
E n E r G y
A n D
E Q u i l i B r i A
TOK
Ke te
A last philosophical implication is that, according to physics, the fate of all the
Ecec is dened as the
energy that exists today in the universe is to degrade into high-entropy heat.
useful energy, the work or
When all energy has turned into heat, the whole universe will have a balanced
output produced by a process
temperature, and no process will be possible any longer, since heat may not
divided by the amount of
turn into something of higher entropy. This is referred to as the thermal death
energy consumed being the
of the universe.
input to the process:
What may happen after that?
eciency = work or
energy produced / energy
consumed
eciency = useful output/
cpx  b
input
Most
ecosystems
ows
for
a
than
and
storages.
more
a
down
stable
simple
removed.
others
one
has
will
a
stability.
may
●
likely
can,
a
not
road
system
can
nd
of
as
ecosystems
Monocultures
fairly
(farming
one
and
more
the
simple
lemming
systems
is
route
is
for
hand
which
wiped
by
to
percentage.
is
a
by
eat
are
broken-
If
and
in
a
disease,
prey
simple
populations
to express eciency as a
better
roads.
out
Multiply by 100%, if you want
makes
one
other
them
thus
if
blocked
on
links,
change
over
systems
population
in
and
take
one
and
complexity
road
prey
other
of
feedback
stress
can
alternative
is
on
many
level
pathway
predators
If
eg
high
are
withstand
where
an
there
are
widely,
There
a
can
another
increase.
uctuate
that
which
as
increase
may
Tundra
is
complex.
number
will
●
It
vehicles
numbers
lack
very
system
Imagine
truck;
community
the
are
they
them
numbers.
there
is
only
one
major
Ke te
crop)
of
a
are
pest
also
or
simple
disease
and
thus
through
a
vulnerable
large
area
to
the
with
sudden
spread
devastating
effect.
negatve feedback
The
spread
of
potato
blight
through
Ireland
in
1845–8
provides
an
oops are stabilizing and
example;
potato
was
the
major
crop
grown
over
large
areas
of
the
occur when the output
island,
and
the
biological,
economic
and
political
consequences
of a process inhibits or
were
severe.
reverses the operation of
the same process in such a
way to reduce change – it
eqb
counteracts deviation.
Equilibrium
following
can
these
of
think
equilibria
as
here.
dynamic
the
tendency
disturbance;
components
We
is
that
of
at
Note
the
system
equilibrium,
a
to
return
state
of
to
an
balance
original
exists
state
among
the
system.
systems
well
of
as
in
that
as
the
equilibrium
being
stable
in
or
term
this
in
dynamic
unstable
(steady-state)
equilibria.
steady-state
We
equilibrium
or
static
Ke te
discuss
each
is
instead
used
of
of
A stead-state eqb
is a characteristic of open
book.
systems where there are
Open
systems
tend
to
exist
in
a
state
of
balance
or
stable
equilibrium.
continuous inputs and
Equilibrium
avoids
sudden
changes
in
a
system,
though
this
does
not
outputs of energy and matter,
mean
that
all
systems
are
non-changing.
If
change
exists
it
tends
to
exist
but the system as a whole
between
limits.
remains in a more-or-less
A
steady-state
are
continuous
whole
remains
equilibrium
inputs
in
a
and
is
a
characteristic
outputs
more-or-less
of
energy
constant
of
and
state
open
systems
matter,
(eg
a
but
climax
where
the
there
system
as
a
constant state (eg a climax
ecosystem).
ecosystem).
31
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
Negative
down,
it
s ys t e m s
feedback
neutralize
stabilizes
results
In
a
in
be
small
changes,
Some
or
results
system
removal
may
develop
Successions
of
a
2.4)
are
equilibria.
deviation
steady-state
are
no
short
return
the
time
in
the
will
of
any
there
in
undergo
over
(see
steady-state
from
It
an
tends
to
damp
equilibrium,
(dynamic)
and
equilibrium.
It
system.
equilibrium
the
the
systems
they
stabilizes
uctuations
and
following
as
systems
s o c i e t i e s
counteract
self-regulation
steady-state
may
or
a n d
long-term
term,
to
its
eg
in
changes
response
previous
but
to
there
weather
equilibrium
condition
disturbance.
long-term
while
good
changes
retaining
examples
to
their
integrity
of
to
equilibrium
the
system.
this.
Examples of a steady-state equilibrium
1.
A
water
change
2.
In
In
out
but
death
A
of
a
rates
same
rain
the
6.
The
is
stable
ants
there
are
growing,
are
no
is
It
it
is
but
away
the
any
born
empties,
in
a
there
steady
there
are
no
net
like
a
time,
in
as
gases,
soil.
die.
change
forest,
is
is
no
net
state.
ows
being
out
of
heat
of
all
in
capital
in
It
usually
the
same
and
size.
–
looks
and
younger
light
in
the
much
other
ones.
inputs
respiration;
lost
years,
trees
by
through
over
the
birth
steady-state
system
salts
stay
these
population
replaced
the
lost
outputs
However,
in
in
may
If
changes.
although
and
and
organism
and
long-term
of
outputs
and
or
are
dying
ows
energy
example
body
our
no
food.
steady
We
core
of
a
steady-state
weight,
maintenance
example.
body
that
out.
leaching
inputs
matter
and
and
balance.
from
there
of
periods
rainwater
constant
get
rate
and
be
ecosystem,
there
there
washing
Another
a
are
same
in
organisms
equal,
long
sun,
in
outputs
5.
as
the
may
population
for
However,
inputs
market
climax
organisms
at
ows
market.
are
equilibrium
from
lls
individual
mature,
the
it
water
a
the
ecology,
size
4.
If
the
economics,
and
3.
tank.
but
In
thus
cases
of
equilibrium
‘burning’
all
increasing
the
or
is
people
calories
decreasing
maintaining
(energy)
body
we
weight
state.
of
sweat
a
constant
to
cool
temperature
is
body
ourselves
about
37
temperature
and
shiver
is
to
another
warm
up
but
our
°C.
body temperature
etats metsys
average state
goes up – we sweat
body temperature
goes down – we shiver
time
▲
Fge 1.3.7 Steady-state equilibrium
Maintenance
feedback
32
of
a
steady-state
mechanisms,
as
we
equilibrium
shall
see
is
later.
achieved
through
negative
1 . 3
E n E r G y
A n D
E Q u i l i B r i A
Another
there
is
unless
new
kind
no
of
equilibrium
change
toppled
over
over.
equilibrium
as
When
a
is
time,
a
result
called
eg
a
static
of
the
a
pile
static
of
equilibrium,
books
equilibrium
disturbance.
which
is
does
disturbed
A
pile
of
in
which
not
it
move
will
scree
etats metsys
Static equilibrium
adopt
material
a
(a
time
mass
of
weathered
rock
fragments)
piled
up
against
a
cliff
could
be
said
▲ Fge 1.3.8 Static equilibrium
to
exist
and
in
the
remain
of
or
equilibrium .
components
unchanged
(the
in
The
rock
their
forces
within
fragments,
relationship
the
to
the
cliff
one
system
and
the
another
are
in
balance,
valley
for
long
oor)
periods
time.
Most
of
static
non-living
static
state,
bricks
This
and
systems
equilibrium.
ie
they
stay
in
cannot
matter
look
the
the
same
occur
with
in
the
like
This
a
pile
means
same
of
that
for
rocks
they
long
or
do
a
building
not
periods
of
are
change
time
in
their
and
a
state
position
the
rocks
or
place.
living
systems
as
life
involves
exchange
of
energy
environment.
(a)
(b)
Unstable and stable equilibria
Systems
In
a
can
stable
also
be
stable
equilibrium
equilibrium
after
a
the
or
unstable
system
tends
to
return
to
the
same
disturbance.
▲
In
an
after
unstable
the
system
returns
to
a
new
and (b) unstable equilibrium
equilibrium
disturbance.
Possibly
this
is
happening
to
our
climate
and
the
new
state
will
etats metsys
be
equilibrium
hotter.
Fbk p
Systems
the
are
system.
continually
Simple
affected
examples
of
by
information
this
from
outside
and
If
you
the
start
heating
time
inside
If
you
this
is
feel
feel
up.
the
The
hungry,
systems
you
sense
can
of
either
cold
is
put
the
on
more
clothes
information,
or
putting
act
you
eat
in
have
food,
a
or
exactly
choice
do
the
not
of
reactions
eat
same
and
feel
as
a
result
more
of
on
processing
hungry.
Fge 1.3.10 Stable equilibrium
turn
reaction.
‘information’:
Natural
cold
etats metsys
clothes
2.
to
disturbance
are:
▲
1.
Fge 1.3.9 Diagrams of (a) stable
disturbance
way.
time
Feedback
loop
mechanisms
can
either
be:
▲
●
Fge 1.3.11 Unstable equilibrium
Positive:
■
Change
■
Destabilizing
a
system
to
a
new
state.
Ke te
as
they
increase
change.
A feedback oop is when
●
Negative
information that starts a
■
Return
■
Stabilizing
it
to
its
original
state.
reaction in turn may input
more information which may
as
they
reduce
change.
start another reaction.
33
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
s ys t e m s
a n d
s o c i e t i e s
Examples of negative feedback
1.
Your
body
walking
sensors
you
2.
A
in
start
your
temperature
in
the
your
to
skin
plant
3.
the
be
by
to
and
maintained
the
gure
clouds
so
1.3.14
and
global
because
a
it
°C.
when
or
is
are
The
rising
capillaries
device
a
of
that
the
it
so
under
can
sense
the
temperature
rises
piece
to
of
another
industrial
temperature.
melt.
solar
temperatures
interprets
you
45
heat.
when
to
more
the
lose
limits
caps
is
temperature
on
off
narrow
ice
°C
in
building,
clouds,
which
is
system
a
causing
more
to
system
level,
room,
within
rises
means
a
ow
attempts
heating
37
temperature
surface
blood
heating
predetermined
above
air
your
as
body
a
So
rise
the
that
red
Your
central
temperature
with
go
switches
atmosphere
reected
this
a
a
detect
temperature.
can
Global
to
in
It
starts
sun
and
increases.
thermostat
warmer
skin
sweat
temperature.
decreases
tropical
More
water
radiation
fall.
But
in
is
compare
differently.
rising global
temperatures
melting ice
caps
falling global
temperatures
more solar
more water
radiation
available for
reected by
evaporation
clouds
more clouds
▲
4.
Fge 1.3.12 Negative feedback dampening change
Predator–prey
interactions.
The
Lotka–Volterra
model
(proposed
prey
in
predators
1925
noitalupop
shows
the
When
prey
the
If
there
are
in
prey
of
is
also
(eg
owl)
The
so
which
fewer
The
(eg
mice)
eat
more
there
in
as
the
numbers
they
eat
prey,
change
numbers.
known
changing
populations
predators
decrease.
time
1926)
effect
predator
more
▲
and
is
prey
increase,
less
predator
of
more
prey
snowshoe
predator–prey
food
prey
and
numbers
hare
and
is
breed
the
the
lags
model
predator
there
and
so
on
more
more,
food
predator
behind
for
resulting
numbers
Canadian
and
numbers.
numbers
the
lynx
in
decrease.
change
is
a
well-
Fge 1.3.13 Cycles of
documented
example
of
this
(see
box,
p36).
predator and prey in the
Lotka–Volterra model
5.
Some
organisms
changes
are
high,
feedback
34
have
occurring
internal
that
promoting
breeding
loops
as
such
feedback
prevent
these
systems,
breeding
when
that
they
when
are
maintain
low.
‘the
physiological
population
It
is
densities
negative
balance
of
nature’.
1 . 3
Positive
output
feedback
that
pushed
taking
to
a
new
the
state
of
ever-increasing
Alternatively,
or
results
enhances
factor.
the
a
further
in
may
feedback
of
be
increase
the
equilibrium.
amounts
process
Positive
in
change
The
input
in
a
It
the
decrease
is
process
until
stopped
results
or
system.
in
may
speed
by
A n D
E Q u i l i B r i A
the
destabilized
system
abruptly
‘vicious
E n E r G y
and
up,
collapses.
an
external
force
circle’.
Examples of positive feedback
1.
You
are
that
it
help
lost
is
to
raise
insufcient
processes
do
on
not
a
cooling
your
to
to
so
snowy
37
body
restore
start
work
high
below
core
various
at
When
body
down,
again.
the
As
if
a
senses
as
shivering
these
your
enzymes
temperatures.
body
such
But
temperature,
because
lower
your
mechanisms
temperature
normal
slow
well
mountain.
°C,
are
metabolic
that
result
control
you
them
become
Ke te
lethargic
and
body
to
body
will
cool
sleepy
even
and
move
further.
around
Unless
you
less
are
and
less,
rescued
allowing
at
this
your
point,
your
Postve feedback oops
reach
a
new
equilibrium:
you
will
die
of
hypothermia.
(destabilizing) will tend to
2.
In
some
to
poor
family
standards
planning
growth
circle
3.
developing
and
of
Global
of
illness,
and
adding
In
the
causes
absence
hygiene,
further
to
illness
this
the
of
and
knowledge
contributes
causes
contributes
of
to
of
population
poverty:
‘a
vicious
amplify changes and drive
the system toward a tipping
point where a new equilibrium
is adopted.
poverty’.
so
(reecting
Compare
change
poverty
education.
methods
temperature
exposed
that
countries
more
ability
this
can
of
with
result
predicting
rises
solar
a
causing
radiation
surface)
gure
in
climate
of
1.3.12
positive
ice
is
or
change
caps
Earth
and
so
you
negative
is
to
melt.
absorbed.
so
This
global
can
Dark
soil
reduces
is
the
temperature
see
that
feedback.
the
This
is
albedo
rises.
same
one
reason
difcult.
rising global
temperatures
melting ice
drop in albedo
caps
▲
Whether
may
(see
be
2.4)
system
its
a
a
system
matter
is
in
long-term
natural
shows
a
way.
dark soil
is absorbed
exposed
Fge 1.3.14 Positive feedback in global warming
is
of
viewed
the
state
undergoes
more solar radiation
of
stability
ux
–
long-term
integrity,
A
as
better
and
since
way
all
being
timescale.
to
it
in
An
changes
changes.
it
is
in
or
this
nature
steady-state
undergoing
constantly.
However,
functioning
describe
systems
static
ecosystem
In
the
show
succession,
system
properly,
situation
is
equilibrium
succession
in
a
that
stability
the
retains
balanced,
the
by
system
default.
35
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
Both
natural
Generally,
so
s ys t e m s
and
we
negative
human
wish
to
feedback
However
and
feedback
positive
so
attend
they
move
to
a
systems
usually
there
is
Systems
classes
are
the
regulated
helpful
are
and
and
situations
Societies
and
eg
of
feedback
in
positive
where
if
its
they
feedback
better
is
state,
is
usually
needed
enjoy
want
assignments.
being
mechanisms.
present
change
students
lessons,
complete
equilibrium
by
environment
advantageous,
regularly
new
s o c i e t i e s
preserve
is
undesirable.
Environmental
a n d
their
to
learn
more,
Consequently
educated
about
the
environment.
We
shall
come
particularly
in
back
to
climate
feedback
change
loops
and
in
various
sustainable
sections
of
this
book,
development.
To do
Pedato–pe teactos ad egatve feedback
Figure 1.3.16 (adapted from Odum, Fundamentals of
Ecology, Saunders, 1953) shows a plot of that data.
We have to assume that the numbers of animals trapped
were small compared to the total populations and that
the numbers trapped were roughly propor tional to total
population numbers. Also assumed is the prey always
has enough food so does not starve. Given that, the
cycles are remarkably constant with the lynx populations
always smaller than and lagging behind the hare ones.
1.
On average, what was the cycle length of the lynx
population?
2.
On average, what was the cycle length of the hare
population?
▲
Fge 1.3.15 Canadian lynx chasing snowshoe hare
3.
Why do lynx numbers lag behind hare numbers?
4.
Why are lynx numbers smaller than hare numbers?
The Hudson Bay Trading Company in Nor thern Canada
kept very careful records of pelts (skins) brought in and
sold by hunters over almost a century. This is a classic
Things are never as straightforward in ecology as we
set of data and shows this relationship because the hare
expect though. In regions where lynx died out, hare
is the only prey of the lynx and the lynx its only predator.
populations still continued to uctuate. Why do you think
Usually things are more complicated.
this was?
snowshoe hare
lynx
140
)sdnasuoht( slamina fo rebmun
120
100
80
60
40
20
1845
▲
36
1855
1865
1875
1885
1895
1905
1915
1925
Fge 1.3.16 Snowshoe hare and Canadian lynx population numbers from 1845 to 1940
1935
1 . 3
E n E r G y
A n D
E Q u i l i B r i A
To do
4.
Here are a number of examples of how both positive
As Ear th warms, increased evaporation produces
more clouds.
and negative feedback mechanisms might operate in
the physical environment. No one can be sure which
Clouds increase albedo, reecting more light away
of these eects is likely to be most inuential, and
from Ear th.
consequently we cannot know whether or not the Ear th
Temperature falls.
will manage to regulate its temperature, despite human
Rates of evaporation fall.
interference with many natural processes.
5.
Label each example as either positive or negative feedback.
As Ear th warms, organic matter in soil is decomposed
faster:
Draw diagrams of one example of positive feedback and
More carbon dioxide is released.
one example of negative feedback using the examples
given, to show how feedback aects a system. Include
Enhanced greenhouse eect occurs.
feedback loops on your diagrams.
Ear th warms fur ther.
1.
As carbon dioxide levels in the atmosphere rise the
Rates of decomposition increase.
temperature of the Ear th rises.
6.
As Ear th warms, evaporation increases:
As the Ear th warms the rate of photosynthesis in
Snowfall at high latitudes increases.
plants increases, more carbon dioxide is therefore
removed from the atmosphere by plants, reducing
Icecaps enlarge.
the greenhouse eect and reducing global
More
energy
is
ref lected
by
increas ed
a lbe do
of
temperatures.
ice
2.
cover.
As the Ear th warms:
Ear th cools.
Ice cover melts, exposing soil or water.
Rates of evaporation fall.
Albedo decreases (albedo is the fraction of light that
7.
As Ear th warms, polar icecaps melt releasing large
is reected by a body or surface).
numbers of icebergs into oceans.
More energy is absorbed by Ear th’s surface.
Warm ocean currents such as Gulf Stream are
Global temperature rises.
disrupted by additional freshwater input into ocean.
More ice melts.
Reduced transfer of energy to poles reduces
3.
As Ear th warms, upper layers of permafrost melt,
temperature at high latitudes.
producing waterlogged soil above frozen ground.
Ice sheets reform and icebergs retreat.
Methane gas is released in an anoxic environment.
Warm currents are re-established.
The greenhouse eect is enhanced.
Ear th warms, melting more permafrost.
r f 
The
resilience
more
resilient
is
the
ability
it
has
low
is
or
eucalypt
and
the
a
system
system,
a
generally
forests
regenerate
of
more
return
enter
as
it
produce
to
a
a
after
a
of
re
new
a
re
survive
lot
its
it
responds
is
state
see
thing,
as
a
also
they
can
state
–
res.
which
because
it
stability
seen
forest
litter
initial
good
maintains
Australia,
to
how
disturbance
considered
evolved
quickly
to
will
ecosystem
have
trees
it
measures
the
system
resilience,
individual
eucalypts
a
of
Resilience
In
of
to
after
the
major
If
in
a
society,
system.
is
But
highly
easily.
buds
The
Resilience
disturbance.
hazard.
oil
burns
with.
1.3.17.
whether
of
disturbance.
a
gure
Their
have
a
deal
But
within
ammable
the
their
trees
trunks
37
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
and
plants
s ys t e m s
that
would
a n d
s o c i e t i e s
have
competed
with
them
are
destroyed.
The
tipping point
ecneiliser
eucalypts
current
state
tree
In
are
species
that
managed
predict
this
that
does
resilient.
cannot
systems,
the
not
But
when
withstand
such
amount
happen,
the
as
of
re,
it
can
agriculture,
food
there
indigenous
we
can
be
be
we
grow
is
eucalypts
replaced
by
devastating.
want
about
disastrous
are
stability
the
so
same
we
each
consequences,
for
can
year.
If
example
additional state
the
Irish
potato
famine
or
the
Sahel
drought
and
famine.
initial state
But
▲
resilience
is
not
always
good,
eg
a
pathogenic
bacterium
causing
a
Fge 1.3.17 Resilience can be
fatal
disease
could
be
very
resilient
to
antibiotics
which
means
it
will
kill
modelled as a ball in a bowl. If the
many
people
so,
in
this
case,
its
resilience
is
not
so
good
for
us.
ball is pushed upwards, it returns to
the bottom of the bowl – its initial
state. But if it is pushed enough,
Factors aecting ecosystem resilience
it will leave the bowl and settle
●
The
more
diverse
and
complex
an
ecosystem,
the
more
resilient
it
elsewhere – in an additional state.
tends
to
be
as
there
are
more
interactions
between
different
species.
The higher the walls of the bowl, the
●
The
greater
the
species
biodiversity
of
the
ecosystem,
the
greater
the
more resilience the system has as
likelihood
that
there
is
a
species
that
can
replace
another
if
it
dies
out
the more energy you need to push
and
so
maintain
The
greater
the
equilibrium.
it out of the bowl
●
resilience.
if
diverse
gene
Species
●
The
larger
each
The
is
can
growth.
The
is
faster
faster.
as
In
So
●
Humans
a
shift
their
easily
the
the
and
have
or
a
species,
rice
can
resistance
water
at
remove
are
is
in
be
the
greater
wiped
which
a
(2.4)
the
is
out
more
the
by
a
likely
in
a
as
more
animals
resilient.
can
nd
edge-effect.
Arctic,
slow
species
with
mitigate
are
regeneration
down
growth
of
plants
photosynthesis
rates
are
fast
as
and
light,
limiting.
than
invasive
ranges
resilience
less
forests,
not
better
or
an
–
rain
which
system
more
there
temperatures
tropical
reduce
the
resilience
r-strategists
can
within
wheat
geographical
and
low
rate
the
pollutant,
of
plants
ecosystem,
the
recolonize
the
affects
slow
temperature
●
of
more
climate
diversity
pool.
the
other
very
so
none
that
genetic
monoculture
disease
●
●
the
A
a
can
fast
reproducing
threat
species)
means
reproductive
slowly
the
reproduce
to
and
the
this
system
will
rate
recovery
can
K-strategists.
(eg
result
remove
in
faster
recovery.
Tipping points
ping
Tip
t
poin
Small
changes
But
when
as
tipping
a
Then
An
a
ecological
to
a
and
Fge 1.3.18 Illustrating a
tipping point
●
They
state
the
of
involve
perpetuating;
increases
38
systems
re
may
is
which
services
positive
it
not
the
there
make
over
transform
are
when
to
a
a
into
system
reached
a
a
an
huge
difference.
threshold,
very
new
steady
ecosystem
signicant
known
different
changes
experiences
to
its
points:
feedback
which
which
reduces
causes
forest
makes
the
regional
dieback.
change
rainfall,
one.
state.
provides.
deforestation
risk,
may
equilibrium
drive
point
in
and
the
loops
tipping
eg
tip
system
tipping
Characteristics
▲
the
feedback
new
biodiversity
in
changes
point,
positive
shift
occur
these
self-
which
1 . 3
●
There
is
a
threshold
beyond
which
a
fast
shift
of
E n E r G y
ecological
A n D
E Q u i l i B r i A
states
occurs.
●
The
threshold
●
The
changes
are
long-lasting.
●
The
changes
are
hard
●
There
is
change
a
point
cannot
signicant
and
ecological
the
to
be
precisely
predicted.
reverse.
time
lag
appearance
between
of
the
impacts,
pressures
creating
driving
great
the
difculties
in
management.
Examples of tipping points
1.
Lake
may
eutrophication
not
lake
to
change
a
new
much
state
–
–
if
nutrients
until
then
enough
plants
are
added
nutrients
grow
to
a
are
lake
added
excessively,
light
ecosystem,
to
is
shift
it
the
blocked
Practical
Create
decomposing
plant
material,
oxygen
levels
fall
and
animals
die.
Work
by
a
model
of
a
feedback
a
model
of
a
food
The
loop.
lake
becomes
eutrophic
and
it
takes
a
great
effort
to
restore
it
to
the
Create
previous
2.
state
Extinction
ecosystem
3.
Coral
dies
Tipping
is
people
the
today.
in
say
But
others,
complex
other
If
climate
new,
in
fast
best
don’t
a
(eg
new
acidity
is
elephants)
state
which
levels
local
we
and
or
reaching
caused
warmer
that
some
in
are
change
ecosystems
to
change
point,
The
we
much
evidence
were
respond
the
ocean
well-known
whether
wetter
and
if
species
to
rise
from
cannot
enough,
a
savanna
be
reversed.
the
reef
coral
regenerate.
be
see
regional
a
by
state
–
global
in
ecosystems
tipping
human
as
warming
drier
respond
global
decision-makers.
would
we
a
–
it
activities
much
in
others.
differently,
as
one
The
8
°C
region
global
often
but
point.
will
there
Some
force
warmer
and
than
cooling
system
is
so
independently
of
ecosystems.
there
for
are
that
to
keystone
death
about
Earth
a
transform
cannot
points
debate
of
can
reef
and
web.
(4.4).
in
enough.
there
is
what
case.
Some
once
That
nothing
approach
know
do
while,
tipping
we
will
Such
can
may
it
is
lead
can
have
happen
risk
think
to
do
may
there
that
reached,
could
we
points,
management
below
all
lost
point
the
but
is
is
inaction
now’
be
exactly
are
this
as
or
of
implications
point,
society
despair
take
not
much
could
–
the
not
‘what’s
view.
precautionary
can
the
major
steps
responsible
one
to
where
modify
route
to
we
what
take.
39
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
s ys t e m s
a n d
s o c i e t i e s
To do
1.
Negative and positive feedback control. Look at this example of feedback
control.
a)
How is the growth of the animal population regulated in the diagram?
b)
Explain why it is an example of negative feedback control.
good supply of food
the number of grazers increases
in an area through migration
grassland becomes overgrazed and eroded
a decreased food supply limits the number
of grazers, so they migrate or die
negative feedback
▲
2.
Fge 1.3.19 Negative feedback amongst grazing animals
Explain with a named example how positive feedback may contribute to
global warming.
3.
Complete the diagram of a generalized ecosystem showing inputs, outputs
and stores. Remember to add in human activities.
inputs
40
stores
outputs
1 . 4
S u S T A i n A B i l i T y
1.4 Sstaabt
sg :
app  k:
➔
All systems can be viewed through the lens of
➔
Expa the relationship between natural
sustainability.
capital, natural income and sustainability.
➔
Sustainable development meets the needs of
➔
Dscss the value of ecosystem ser vices to a
the present without compromising the ability of
society.
future generations to meet their own needs.
➔
➔
Dscss how environmental indicators can
Environmental indicators and ecological
be used to evaluate the progress of a project
footprints can be used to assess sustainability.
to increase sustainability, eg Millennium
➔
Environmental Impact Assessments (EIAs) play
Ecosystem Assessment.
an impor tant role in sustainable development .
➔
Evaate the use of EIAs.
➔
Expa the relationship between ecological
footprint (EF) and sustainability.
Kwg  g:
➔
➔
Sstaabt is the use and management of
➔
Evoeta ipact A ssessets (EIAs)
resources that allows full natural replacement of
incorporate baseline studies before a
the resources exploited and full recovery of the
development project is under taken. They assess
ecosystems aected by their extraction and use.
the environmental, social and economic impacts
of the project, predicting and evaluating possible
nata capta is a term used for natural
impacts and suggesting mitigation strategies
resources that can produce a sustainable natural
for the project. They are usually followed by an
income of goods or ser vices.
audit and continued monitoring. Each country or
➔
nata coe is the yield obtained from
region has dierent guidance on the use of EIAs.
natural resources
➔
➔
EIAs provide decision makers with information in
Ecosystems may provide life-suppor ting services
order to consider the environmental impact of a
such as water replenishment, ood and erosion
project. There is not necessarily a requirement to
protection, and goods such as timber, sheries
implement an EIA’s proposals and many socioand agricultural crops.
economic factors may inuence the decisions made.
➔
Factors such as biodiversity, pollution,
➔
Criticisms of EIAs include the lack of a standard
population or climate may be used quantitatively
practice or training for practitioners, the lack of
as environmental indicators of sustainability.
a clear denition of system boundaries and the
These factors can be applied on a range of scales
lack of inclusion of indirect impacts.
from local to global. The me Ecosste
Assesset gave a scientic appraisal
of the condition and trends in the world’s
ecosystems and the ser vices they provide
using environmental indicators, as well as the
scientic basis for action to conser ve and use
them sustainably.
➔
An ecoogca footpt (EF) is the area of land
and water required to sustainably provide all
resources at the rate at which they are being
consumed by a given population. Where the EF is
greater than the area available to the population,
this is an indication of unsustainability.
41
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
‘The ultimate test of a moral
s ys t e m s
a n d
s o c i e t i e s
sb
society is the kind of world
Sustainability
that it leaves to its children.’
Dietrich Bonhoeer,
German theologian
‘interest’
But
means
about
an
is
Economists
what
living
sustainable
sustainability
people.
as
or
a
word
have
sustainable
adjective
in
within
natural
front
a
that
means
means
different
means.
of
the
income
The
words
nature,
different
view
word
such
of
generated
as
from
by
on
the
natural
things
to
capital.
different
environmentalists
sustainable
resource,
is
often
used
development
and
‘He who slaughters his cows
population.
today shall thirst for milk
tomorrow.’
Any
society
natural
that
capital
is
supports
itself
in
unsustainable.
part
There
by
is
depleting
a
nite
essential
amount
of
forms
of
materials
on
Muslim proverb
Earth
as
Ke tes
and
well
make
as
we
the
are
using
interest.
progress
much
Our
outside
of
of
it
unsustainably
societies
and
–
living
economies
environmental
limits
on
cannot
(gure
the
capital
grow
or
1.4.1).
Sstaabt is the use and
Ecological overshoot
management of resources that
According
to
UN
data
(gure
1.4.1)
humanity
has
overshot
its
allows full natural replacement of the
sustainable
level
of
resource
exploitation.
resources exploited and full recovery
of the ecosystems aected by their
160
extraction and use.
140
has been dened as ‘development that
meets the needs of the present without
compromising the ability of future
generations to meet their own needs.’
)%( toohsrevo ht raE
The term ‘sstaabe deveopet’
Maximum level of sustainable resource
120
exploitation. This shows we need 18 months
100
to replenish resources used in 12 months.
80
This demand is due to the
60
40
•
level of overall consumption
•
per capita consumption.
(From Our Common Future, the report of
20
the World Commission on Environment
0
and Development, 1987).
196
1
2001
2014
year
▲
It
Fge 1.4.1 Ecological overshoot
is
more
in
some
parts
of
the
world
and
cannot
continue
indenitely.
Sustainability indicators
How
we
be
we
can
measure
use
anything
poverty
to
or
gender
to
global.
need
a
sustainability
together,
from
US$
GDP
parity.
The
global
air
We
both
quality,
(Gross
can
smaller
crucial
and
to
get
per
many
capita,
sustainability
more
the
are
vulnerability
Product)
measure
the
there
socio-economic.
environmental
scale,
measurement
and
Domestic
also
the
is
ecological
accurate
whole
it
on
and
life
scales
can
indices
These
be
could
water
expectancy
from
but
we
local
also
picture.
To thk abot
42
The me Ecosste Assesset (mE A), funded
last decades and predicts changes that will happen. In
by the UN and star ted in 2001, is a research programme
2005, it released the results of its rst four-year study of
that focuses on how ecosystems have changed over the
the Ear th’s natural resources. It was not happy reading.
1 . 4
●
The repor t said that natural resources (food, freshwater,
sheries, timber, air) are being used in ways that degrade
S u S T A i n A B i l i T y
Nutrient pollution has led to eutrophication of waters
and dead coastal zones.
them so make them unsustainable in the longer term.
●
Key facts repor ted are:
●
Species extinction rates are now 100–1,000 times
above the background rate.
60% of world ecosystems have been degraded.
●
●
About 25% of the Ear th’s land surface is now cultivated.
●
We use 40–50% of all available surface freshwater
and water withdrawals from underground sources
We have had more eect on the ecosystems of Ear th
in the last 50 years than ever before.
Some recommendations were to:
●
have doubled over the past 40 years
Remove subsidies to agriculture, sheries and energy
sources that harm the environment.
●
Over 25% of all sh stocks are overharvested.
●
Since 1980, about 35 % of mangroves have been
●
Encourage landowners to manage proper ty in ways
that enhance the supply of ecosystem services, such
as carbon storage and the generation of fresh water.
destroyed.
●
●
Protect more areas from development, especially in
About 20% of corals have been lost in 20 years and
the oceans.
another 20% degraded.
To thk abot
Using the gure below think about the following questions. Are you optimistic
or pessimistic about the results of the impact of humans on the Ear th?
What evidence are you using for your decision?
If you had the power, what actions would you force governments to take now
to safeguard the environment but also protect humans from suering? Give
your reasons.
3.0
19 60–20 08
ecological footprint
2.5
20 08–2050, scenarios
sht raE tenalp fo rebmun
moderate business-as-usual
rapid reduction
2.0
1.5
1.0
0.5
0.0
1960
1970
1980
1990
2000
2010
2020
2030
2040
2050
years
▲
Fge 1.4.2
43
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
But
how
You
can
may
perhaps
s ys t e m s
we
●
Inertia:
●
The
to
result
destroy
of
the
anyone.
benets
to
do
its
may
you
the
economic
of
their
be
but
will
think
what
the
if
your
the
do
the
of
all
know
that
hunt
it
to
be
so.
It
is
real
gross
world
trillion
per
year,
yet
soil,
water
biodiversity
(see
Topic
and
so
short
starving
eat
of
clean
so
it
is
but
none
each
for
individual
they
continue
may
the
capital
(total
only
air
but
is
species
and
many
resource
there
term
natural
are
when
a
result
only
in
source
it.
product
we
(4.3),
harvest
happen,
the
to
worth
the
will
difcult.
endangered
are
it
to
resource
in
an
family
too
commons ’
this
resource
to
seems
that
of
value
we
self-interest
hunting
probably
that
we
of
own
obvious
taking
if
including:
future
example,
value
US$65
continues
‘tragedy
in
long-term
For
people
as
about
loss
the
from
so.
food,
Some
same
It
this
factors
changing
act
extinction
of
why
many
when
individuals
s o c i e t i e s
change?
wonder
due
a n d
just
and
to
is
global
about
the
output)
beginning
measure
to
the
–
give
cost
of
8).
Natural capital and natural income
Ke tes
Capital
nata capta is a term used
tools,
is
what
economists
machines
–
and
is
term
used
to
the
means
create
of
goods
production
which
–
factories,
provide
income.
for natural resources that can
Natural
capital
is
the
goods
and
services
that
the
environment
provides
produce a sustainable ata
humans
with
in
(natural
capital)
order
to
provide
natural
income.
For
example,
a
forest
coe of goods or services.
an
agricultural
services,
waste.
for
See
provides
crop
provides
example
in
more
timber
erosion
detail
in
(natural
food
for
control,
Topic
us.
income);
Natural
water
a
shoal
capital
of
also
management,
sh
or
provides
recycling
8.
To thk abot
The Millennium Development Goals
Goal 3: Promote gender equality and empower women
http://www.undp.org/mdg/
Goal 4: Reduce child mor tality
The Millennium Development Goals (MDGs) are eight
Goal 5: Improve maternal health
goals to be achieved by 2015 that respond to the world’s
Goal 6: Combat HIV/AIDS, malaria and other diseases
main development challenges. The MDGs are drawn from
Goal 7: Ensure environmental sustainability
the actions and targets contained in the me
Goal 8: Develop a Global Par tnership for Development
Decaato that was adopted by 189 nations and signed
Are we on target to reach these goals? Research what
by 147 heads of state and governments during the un
actions have been taken since 2000. (Try searching
me St in September 2000.
the web for Millenium Development Goals BBC and you
Goal 1: Eradicate extreme pover ty and hunger
should nd some BBC webpages with an update.)
Goal 2: Achieve universal primary education
Do you think these were attainable goals or too ambitious?
e p 
An
environmental
before
to
plant
the
44
a
a
impact
development
forest
relative
or
assessment
project
convert
advantages
or
to
elds
or
change
to
a
EIA
the
golf
disadvantages
is
a
use
report
of
course.
of
the
prepared
land,
An
EIA
for
example
weighs
development.
It
up
is
1 . 4
therefore
necessary
community
would
EIA
will
to
and
amenity
try
look
happen
are
if
at
often
natural
the
EIAs
on
is
to
from
the
as
have
This
human
how
to
occurs.
deal
or
is
also
of
like
options
a
to
now
the
where
and
a
forecast
and
about
scenic
what
the
effect
effects
for
may
impacts
development.
development
effect
These
positive
likely
biotic
An
study.
proposed
the
economic
and
ahead.
biodiversity,
baseline
questions
an
went
development.
negative
consider
true
have
environment
scheme
proposed
Both
with
can
especially
health
abiotic
microclimate,
the
production
other
they
the
development
environment
well
environment
populations.
effect
as
a
changes
development
considered
While
if
resulting
represent
what
the
establish
quantify
value
measurements
EIAs
to
change
S u S T A i n A B i l i T y
a
on
on
might
the
human
have
an
community.
What are EIAs used for?
EIAs
are
often,
though
governments
set
They
a
that
provide
can
be
EIA
but
process
as
The
when
●
major
types
●
airport
●
building
power
●
building
dams
●
quarrying
●
large-scale
parts
road
and
way
in
of
part
large
of
the
developments
most
new
always,
law
evidence
certain
in
not
in
documented
used
development.
country,
out
of
the
examining
that
need
the
world.
EIAs
to
be
that
considered.
process
differ
tend
These
process
are
environmental
decision-making
developments
of
planning
developments
from
impacts
of
any
new
country
included
in
to
the
include:
networks
port
developments
stations
and
reservoirs
housing
projects.
Where did EIAs come from?
In
1969,
Act
the
(NEPA).
natural
US
part
are
the
becoming
of
made
environment
environment
NEPA
Government
NEPA
their
carried
statement)
same
law
to
needs
a
any
the
be
land
as
US,
policy.
determine
to
passed
the
priority
status
in
planning
out
in
it
In
if
for
use
National
federal
planning.
economic
many
the
an
EIA
undertaken
This
priorities.
other
US,
Environmental
agencies
gave
countries
(called
led
EIS
–
with
the
also
Policy
consider
Within
environmental
and
to
20
years
included
federal
of
EIAs
assessments
environmental
the
the
natural
as
(EA)
impact
agencies.
What does an EIA need in it?
There
is
no
minimum
possible
to
set
way
of
conducting
expectations
break
●
Identifying
●
Predicting
●
Limiting
an
the
what
assessment
impacts
the
of
scale
effect
an
EIA,
should
down
be
but
various
included
into
three
in
main
countries
an
EIA.
It
have
is
tasks:
(scoping).
of
of
potential
impacts
to
impacts.
acceptable
limits
(mitigation).
45
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
There
is
s ys t e m s
always
understand
the
a
a n d
s o c i e t i e s
non-technical
summary
so
that
the
general
public
can
issues.
Weaknesses of EIAs
Different
hard
of
to
the
how
countries
compare
have
them.
investigation
much
indirect
does
impacts
should
the
of
different
Also,
EIA
a
it
be.
cost?
is
standards
hard
How
It
is
development
to
large
also
so
for
EIAs
determine
an
very
some
area,
how
difcult
may
which
where
be
to
makes
the
many
it
boundary
variables,
consider
all
missed.
To thk abot
EIAs are models of the system under study and allow us to predict the eects
of the proposed change. A model is only as good as its parameters and asking
the right questions is crucial. A change of land use will always have an eect
but whether this is a net positive or negative one depends on the criteria used
to measure it. Simplistically, if a factory blocks your view of the mountains
that may be a loss to you but it may bring employment to the area, produce
goods that would otherwise be impor ted and reduce the country’s ecological
footprint.
Cost-benet analysis measures impacts of a development or change of land use
translated into monetary values. In theory, this puts all costs into the same units
of measure – money – so they can be assessed. Of course, how the assessment
is made is critical to the values assigned and there are several ways to do this. For
example, it may be based on the cost of restoring the environment to its previous
state (eg after an open cast mine operation) or ask people which of several options
Practical
Work
they would select or be prepared to pay for.
Investigate
what
Ecological
Strategic environmental assessment tries to measure the social and
Footprint
modelling
can
tell
environmental costs of a development but this can be subjective or a not very
us
about
resource
use.
accurate prediction. Does it also depend on the environmental worldview of
Consider
whether
sustainable
those planning the assessment?
development
is
a
term
that
Imagine a development or change of land use in an area near to your school
contradicts
itself.
or home. Decide amongst your class what this will be (it may be an actual one
Can
sustainability
only
be
agreements
that is about to happen or has happened) and discuss:
international?
What
●
is
the
point
of
a
nation
What criteria you would use to select the factors you think will change
b eing
(eg number of jobs provided, net prot, land degradation, habitat loss,
sustainable
if
the
rest
of
the
pollution).
world
is
not?
●
How you value these (is there another way of measuring them apar t from
nancial?)
●
Ke te
How you weigh up the evidence to make a decision on whether the project
should proceed or proceed in a modied state.
An ecoogca footpt (EF)
is the area of land and water
required to sustainably
Ecological footprints
provide all resources at
EF
is
a
model
used
to
estimate
the
demands
that
human
populations
the rate at which they are
place
on
the
environment.
The
measure
takes
into
account
the
area
being consumed by a given
required
to
provide
all
the
resources
needed
by
the
population,
and
population.
the
46
assimilation
of
all
wastes.
Where
the
EF
is
greater
than
the
area
1 . 4
available
to
population
EFs
and
may
the
vary
include
production
population,
exceeds
the
signicantly
aspects
such
systems,
this
is
carrying
land
from
as
an
country
lifestyle
use
indication
capacity
and
(8.4)
to
of
of
unsustainability
the
country
choices
(EVS),
as
S u S T A i n A B i l i T y
the
area.
and
person
productivity
to
of
person
food
industry.
carbon
represents the amount of forest land that
could sequester CO
emissions from the
2
burning of fossil fuels, excluding the
fraction absorbed by the oceans which
leads to acidication.
cropland
grazing land
represents the amount
represents the
of cropland used to grow
amount of grazing
crops for food and bre
land used to raise
for human consumption
livestock for meat,
as well as for animal feed,
dairy, hide and
oil crops and rubber.
wool products.
forest
built-up land
shing grounds
represents the amount
represents the amount
calculated from the
of forest required to
of land covered by
estimated primary
supply timber products,
human infrastructure,
production required
pulp and fuel wood.
including transpor tation,
to suppor t the sh
housing, industrial
and seafood caught,
structures and reser voirs
based on catch data
for hydropower.
for marine and
freshwater species.
▲
Fge 1.4.3 Ecological footprint (EF) (© WWF)
47
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
s ys t e m s
a n d
s o c i e t i e s
1.5 Has ad poto
sg :
app  k:
➔
Pollution is a highly diverse phenomenon of
Costct systems diagrams to show the
➔
human disturbance in ecosystems.
impact of pollutants.
➔
Management strategies can be applied at
Evaate the eectiveness of each of the three
➔
dierent levels.
dierent levels of inter vention, with reference
to gure 1.5.6.
Evaate the use of DDT.
➔
Kwg  g:
➔
Pollution is the addition of a substance or an agent to
➔
source, persistent or biodegradable, acute
than that at which it can be rendered harmless by
or chronic.
the environment, and which has an appreciable
➔
eect on the organisms in the environment.
➔
Pollution may be non-point or point
an environment by human activity, at a rate greater
Pollutants may be primary (active on
emission) or secondary (arising from primary
Pollutants may be in the form of organic/
pollutants undergoing physical or chemical
inorganic substances, light, sound or heat
change).
energy, or biological agents/invasive species,
➔
and derive from a wide range of human activities
Dichlorodiphenyltrichloroethane (DDT)
exemplies a conict between the utility of a
including the combustion of fossil fuels.
‘pollutant’ and its eect on the environment.
Ke te
Poto is the addition of
a substance or an agent to
Help!
an environment by human
I can’t
activity, at a rate greater
breathe!
than that at which it can be
rendered harmless by the
environment, and which has
an appreciable eect on the
▲
Fge 1.5.1 Does the ear th need a gas mask?
organisms within it.
P  p
Pollutants
●
48
matter
are
released
(gases,
by
liquids
atoms)
or
●
energy
(sound,
●
living
human
or
activities
solids)
which
and
is
may
organic
be:
(contains
inorganic
light,
organisms
heat)
(invasive
species
or
biological
agents).
carbon
1 . 5
There
H u m A n S
A n D
P O l l u T i O n
are:
To thk abot
●
primary
pollutants
which
are
active
on
emission
eg
carbon
It is sometimes said that a
monoxide
from
the
incomplete
combustion
of
fossil
fuels,
which
pollutant is a substance in
causes
headaches
and
fatigue
and
can
kill
the wrong place, in the wrong
●
secondary
pollutants
which
are
formed
by
primary
pollutants
amount or at the wrong time.
undergoing
physical
or
chemical
changes
eg
sulphuric
acid
forms
Could this be true of carbon
when
sulphur
trioxide
reacts
with
water.
dioxide, ozone or nitrate?
Photochemical
(see
sub-topic
Since
and
extent.
burning
years.
with
these
effect
of
higher
has
mixture
been
and
of
then
primary
improved
we
are
coal
levels
and
than
secondary
we
that
would
has
monitor
polluted
caused
lower,
pollution
we
pollution
as
have
products
has
were
development
living
Revolution
Earth,
waste
However,
economic
of
on
and
pollutants.
the
also
a
population
standard
Industrial
it
have
Sewage
wood
When
is
pollutants
6.3).
humans
lesser
smog
of
air
the
may
has
pollution
be
an
given
increased
a
greater
but
for
1,000
could
inevitable
most
had.
we
a
far
Since
deal
legislate
cope
side-
humans
have
how
and
or
communities
environment
otherwise
industries
to
human
the
with
against
▲
excessive
Fge 1.5.2 Poster from
pollution.
the USSR before 1950
encouraging production
mj  f p
Figure
1.5.3
considering
lists
some
some
of
major
these
sources
later
of
by saying that the smoke
pollutants.
We
shall
be
from chimneys is the
breath of Soviet Russia
on.
majo soce
Potat
Eect
Cobsto
Carbon dioxide
Greenhouse gas – climate change
Sulphur dioxide
Acid deposition – tree and sh death, respiratory disease in humans
of foss fes
Nitrogen oxides
Respiratory infections, eye irritation, smog
Photochemical smog including
Secondary pollutants (formed from others in the atmosphere) –
tropospheric ozone, PANs, VOCs
damage to plants, eye irritation, respiratory problems in humans
(volatile organic compounds)
Carbon monoxide
Binds with haemoglobin in red blood cells instead of oxygen – can
lead to death by suocation
Doestc
waste
Organic waste (food and sewage)
Eutrophication, waterborne diseases
Waste paper
Volume lls up landll sites, forests cut to produce it
Plastics – containers, packaging
Volume lls up landll sites, derived from oil
Glass
Energy required to manufacture it (as with all products), can be
recycled but most goes into landll sites
idsta
waste
Agcta
waste
▲
Tins/cans
Can be recycled but also goes into landll
Heavy metals
Poisoning, eg mercury, lead, cadmium
Fluorides
Poisoning
Heat
Reduces solubility of gases in water, so less oxygen so organisms may die
Lead
Disabilities in children
Acids
Corrosive
Nitrates
Eutrophication
Organic waste
Eutrophication, disease spread
Pesticides
Accumulate up food chains
Fge 1.5.3 Major sources of pollutants and their eects
49
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
s ys t e m s
a n d
s o c i e t i e s
P   -p  p
Non-point
●
Is
the
for
source
release
example
spread
●
May
on
●
fertilizer
many
travel
it
Air
So
and
Point
source
●
the
Is
a
Is
easier
●
Is
usually
be
to
a
the
It
may
and
be
dispersed
vehicles,
virtually
phosphates
ground
or
before
of
as
origins,
chemicals
impossible
not
be
which
runoff
draining
nitrates
would
blown
hundreds
chimneys
set
limits
monitor
to
detect
and
on
into
a
are
the
lake
or
phosphates
possible
to
say
spread
surface.
river
so
as
It
and
much
which
that
farmer
mix
for
all
what
of
with
kilometres
those
farmers
they
from
and
actually
all
and
chemicals
others.
industries
to
reduce
do.
pollution:
of
pollutants
factory
into
●
of
fertilizer.
to
then
release
works
occurs.
open
is
it
nitrates
kilometres
can
(PS)
example
widely
systems
from.
concentration
from
solution
emissions
numerous,
exhaust
and
coming
collect
excess
pollution
one
is
many
the
the
released
from
the
inltrates
eutrophication
●
from
sources
it
can
as
increasing
spread
pollutants
gases
where
Rainwater
may
of
pollution:
elds.
have
exactly
(NPS)
from
chimney
or
a
single,
the
waste
clearly
identiable
disposal
pipe
of
a
site,
for
sewage
river.
see
who
easier
to
is
polluting
manage
as
–
it
a
factory
can
be
or
house.
found
more
easily.
P g p (PoP) 
bgb p
POPs
to
were
often
breaking
Because
of
down
this,
biomagnify
Examples
Other
▲
in
of
POPs
(PCBs)
and
●
high
●
not
●
highly
manufactured
and
they
food
these
are
remain
chains
are
active
(see
DDT
2.2)
(see
They
in
the
in
in
can
and
cause
dieldrin,
(PVC),
have
the
past.
environment
animal
and
2.2),
chloride
solvents.
molecular
pesticides
bioaccumulate
polyvinyl
some
as
They
for
human
signicant
chlordane
resistant
long
tissues
time.
and
harm.
and
polychlorinated
similar
a
are
aldrin.
biphenyls
properties:
weight
Fge 1.5.4
Practical
Create
wiki
a
on
cell
Work
poster/website/
the
b enets
●
of
a
using
systems
show
pollution
of
in
water
fats
and
lipids
–
which
means
they
can
pass
through
molecules,
often
with
chlorine.
were
widely
used
in
electrical
apparatus
and
as
coolants
since
the
DDT.
but
banned
by
2001.
They
cause
cancers
and
disrupt
hormone
diagram
functions
to
soluble
in
membranes
halogenated
1930s
Construct
soluble
and
PCBs
disadvantages
very
a
and
have
a
similar
structure
and
action
in
animals
to
dioxin
local
which
is
one
of
the
most
deadly
chemicals
that
humans
have
made.
ecosystem.
Because
well
50
as
they
in
are
animal
so
persistent,
tissues,
even
PCBs
in
the
are
found
Arctic
everywhere
Circle.
in
water
as
1 . 5
Biodegradable
down
or
quickly.
physical
sewage,
is
by
may
processes,
degradable
glyphosate
down
pollutants
They
soil
eg
be
light
plastic
which
do
not
broken
or
bags
farmers
persist
down
heat.
made
use
to
in
by
the
kill
environment
decomposer
Examples
of
starch.
weeds.
are
soap,
One
It
H u m A n S
is
and
A n D
P O l l u T i O n
break
organisms
domestic
common
degraded
herbicide
and
broken
organisms.
a  h p
Acute
lot
of
was
pollution
harm.
accidently
Cornwall
them.
small
in
tipped
UK
●
it
is
●
it
often
it
It
goes
usually
example
example
is
is
the
1988
was
was
in
from
a
in
are
chemical
a
people
Bhopal
the
pollutant
the
place
many
the
of
when
wrong
and
undetected
more
amounts
this
serious
water
drank
Disaster
long-term
released,
treatment
water
of
of
a
in
a
sulphate
works
which
1984
release
causing
aluminium
in
poisoned
India
(1.1).
pollutant
but
in
because:
for
difcult
a
to
long
clean
time
it
up
widely.
often
asthma,
of
of
results
spreads
pollution
large
into
in
example
amounts.
often
an
when
pollution
●
for
is
example
the
Another
Chronic
Air
An
chronic
causing
bronchitis,
chronic
air
non-specic
emphysema.
respiratory
Beijing’s
poor
diseases,
air
quality
is
▲
Fge 1.5.5 Chronic air
pollution in Beijing 2014
pollution.
To thk abot
The Psoe ’s Dea
The best economic scenario for a polluter is to keep
polluting as long as he/she is not found out. Not to confess.
A big question about us is whether we are, by nature,
The cost of the pollution is then shared between everyone
loving or aggressive, noble or selsh, nice or nasty. Do
and the polluter does not have to spend money reducing
we not steal or cheat because we may be found out or
their own personal or business pollution. If the polluter
because we know it is wrong. Is it our default position
confesses, they may be punished by a ne, imprisonment
to be kind and helpful to each other or to be top even
or having to spend money in reducing the pollution.
if, or par ticularly if, it hur ts someone else? Scientists,
sociologists, philosophers, politicians and all thinking
people want to know about our innate nature and why
we react as we do.
But, just as in the Prisoner ’s Dilemma, while keeping
silent and polluting is ne in the shor t term, in the longer
term, the best scenario is ‘tit for tat’ – if I cooperate with
you – stop polluting, you will cooperate with me – stop
There is a type of game that you can play as an example
polluting too and the world will be a cleaner place –
of Game Theory and it is called the Prisoner ’s Dilemma.
we both gain. If we keep betraying each other, we will
Here is a version of it.
both be losers at the end. And that is where we are
Two people A and B are suspected of a crime and
with pollution. If we pollute with NPS pollutants, we are
arrested. There is not enough evidence to convict them
unlikely to be found out and everyone pays for the clean
unless they confess. The police separate them and oer
up. An individual, company or country can gain from noneach one the same deal. If one admits that they both did
compliance in the shor t term if the others comply.
the crime and betrays the other, that one goes free and
But what will happen in the long term?
the other goes to prison for 10 years. If both stay silent,
they both go to prison for a year. If both confess, they
both go to prison for 5 years. What should they do? The
best scenario for one is to confess and the other stays
silent. But they don’t know what the other will do. What
has this to do with pollution? Quite a lot.
Think of two par ticular types of pollution (one in the
atmosphere and one in water) that could be examples of
NPS pollution.
What does this mean for international agreements on
pollution?
51
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
s ys t e m s
a n d
s o c i e t i e s
d  g f p
Pollution
Direct
air
or
can
be
measured
measurements
record
measurements
●
the
●
amount
acidity
of
of
nitrogen
a
of
indirectly.
amount
of
a
pollutant
in
water,
the
gas,
oxides
for
in
of
particles
●
amount
of
lead
in
nitrates
●
amount
●
heavy
Indirect
which
and
of
carbon
dioxide,
carbon
monoxide,
by
a
diesel
engine
atmosphere.
water
matter
or
soil
pollution
include
testing
for:
or
bacteria
concentrations.
measurements
pollution
result
of
record
the
changes
pollutants.
in
an
abiotic
Indirect
or
biotic
factor
measurements
of
include:
measuring
oxygen
only
maggot
abiotic
content
recording
are
of
organic
the
measuring:
phosphates
metal
are
include
atmosphere
emitted
the
measurements
●
pollution
example
the
amount
Direct
air
rainwater
●
●
the
or
soil.
Direct
●
directly
the
if
water)
that
change
as
a
result
of
the
pollutant
(eg
water)
presence
found
in
factors
of
the
or
or
absence
of
indicator
conditions
are
either
unpolluted
(eg
leafy
species
polluted
lichens
–
(eg
on
species
that
rat-tailed
trees).
P g g
Pollution
can
managed
●
by
changing
●
by
regulating
●
by
working
The
pollution
available
in
throughout
Pocess of poto
be
the
or
to
in
human
clean
up
the
category
book
or
the
ways:
which
release
restore
model
of
when
main
activity
preventing
management
each
three
in
of
the
damaged
Figure
management
specic
produces
pollutant
pollutants
or
ecosystems.
1.5.6
and
it
lists
will
are
be
the
actions
referred
to
considered.
leve of poto aageet
Ateg ha actvt
The most fundamental level of pollution management is to change the human activity that
HumAn ACTiViTy
PrODuCinG
leads to the production of the pollutant in the rst place, by promoting alternative technologies,
lifestyles and values through:
POlluTAnT
52
●
campaigns
●
education
●
community groups
●
governmental legislation
●
economic incentives/disincentives.
1 . 5
rElE A SE OF
H u m A n S
A n D
P O l l u T i O n
Cotog eease of potat
POlluTAnT inTO
Where the activity/production is not completely stopped, strategies can be applied at the level
EnVirOnmEnT
of regulating or preventing the release of pollutants by:
●
legislating and regulating standards of emission
●
developing/applying technologies for extracting pollutant from emissions.
Cea-p ad estoato of daaged sstes
Where both the above levels of management have failed, strategies may be introduced to
imPACT OF POlluTAnT
recover damaged ecosystems by:
On ECOSySTEmS
extracting and removing pollutant from ecosystem
●
replanting/restocking lost or depleted populations and communities
Fge 1.5.6 Pollution management targeted at three dierent levels
e s a c
▲
●
ddt   q
Agency.
banned
most
public
health
malaria
from
in
a
is
proposed
walls
adult
in
is
most
DDT
of
that
used
Also,
become
resistant
its
may
and
develop
a
Malaria
incidence
of
ban
the
on
so
carry
could
ones
is
its
be
where
involves
as
to
kill
spraying
and
malarial
used,
the
means
for
exempted
that
survive,
repel
parasite.
DDT
job.
is
Outside
persistence
that
been
banned
organophosphate
the
at
since
not
world
recently
good
of
has
it
control
persistence
(the
but
furniture,
because
toxicity.
DDT
areas
was
chemicals
persistent
not
of
malarial
backs
other
and
use
MEDCs,
worldwide
for
mosquitoes
cheap
▲
DDT
and
Although
DDT
use
endemic.
chemicals.
the
The
other
y d u t s
Protection
and
mosquitoes
breed
and
Fge 1.5.7 Malarial mosquito sucking blood from
population
of
resistant
mosquitoes).
a human
In
1970,
the
WHO
(World
Health
resistance,
banned
the
use
of
DDT,
a
persistent
It
is
still
used
in
some
countries
in
but
in
small
quantities
for
spraying
to
kill
the
malarial
mosquito,
is
the
vector
for
malarial
question
is
whether
than
banning
DDT
did
a
is
year,
to
and
people
to
areas
where
malaria
is
In
treating
with
the
other
cause,
DDT
chemicals,
use
is
mosquito
just
one
nets
of
stagnant
water
where
mosquitoes
and
breed.
is
hyperbole,
debate
on
DDT
bias
but
and
misinformation
malaria
probably
in
does
not
good.
believed
infects
due
use
more
receive
It
partly
land
parasites.
the
harm
in
Anopheles,
There
The
of
along
removal
which
increasing,
changes
inside
tool
houses
to
the
endemic.
tropics
partly
organochlorine
migration
insecticide.
is
Organization)
that
mostly
malaria
children
300–500
kills
under
million
a
2.7
the
year.
It
million
age
is
of
also
people
ve,
a
enough
disease
of
the
funding
for
research
as
it
is
mostly
poor.
and
thought
that
To do
DDT
So
prevented
why
the
millions
ban?
In
her
of
deaths
book,
due
Silent
to
malaria.
Spring,
Rachel
Do your own research on DDT. What evidence can you
Carson
discusses
prey
thinning
the
effect
of
DDT
on
birds
of
nd for both sides of the argument?
in
their
eggshells
and
reducing
their
Be careful in looking at sources. Are they biased? Can
population
numbers.
But
some
say
that
evidence
they substantiate their claims?
was
slight
effective
for
bird
egg
insecticide
shell
against
thinning
the
and
malarial
DDT
is
an
mosquito.
Do you now think that DDT should have been banned
or should still be used?
The
US
manufacture
in
1972,
on
and
the
use
advice
of
of
DDT
the
was
US
banned
in
the
Environmental
53
1
F o u n d at i o n s
o F
e n v i r o n m e n ta l
s ys t e m s
a n d
s o c i e t i e s
W E I VE R
State the environmental value
Explain how your own
system that you identify in
environmental value system
your choice of lifestyle and how
compares with others.
sustainable it is.
BiG Questions
F f
 
 
Examine in what ways might
the solutions explored in the
Discuss what are the strengths
pollution management model
and weaknesses of using
alter your predictions for our
models to assess sustainability.
future.
r q
➔
Environmental
environment.
the
➔
a
are
The
EIAs
of
ways
subjects,
➔
On
do
such
pursuit
what
➔
What
➔
Human
➔
the
way
systems
To
of
basis
we
shape
perceive
the
way
the
we
view
know
of
which
reality.
aspects
In
of
the
the
construction
world
to
ignore?
laws
are
examples
differ
to
the
of
scientic
laws
of
laws.
human
In
science
economics?
baseline
studies
extent
before
should
a
development
environmental
project
concerns
is
limit
knowledge?
might
they
impact
models
to
what
we
decide
between
the
judgements
of
the
disagree?
your
EVS?
crosses
international
Can
construction
we
scientic
as
inuences
issues?
54
if
can
which
incorporate
experts
on
shape
value
thermodynamics
undertaken.
our
simplied
how
and
laws
what
➔
a
model,
include,
➔
systems
other
world?
Models
of
value
What
national
environmental
facilitate
boundaries.
issues
international
be
How
can
agreement
reached?
collaboration
on
environmental
7.
Qk w
The
carrying
given
Each
1.
question
A
system
A.
a
is
worth
may
set
of
1
best
capacity
of
an
environment
for
W E I VE R
R E V I E W
a
species
mark
be
dened
components
that
A.
can
B.
is
never
be
exceeded.
as
greater
for
a
population
with
a
slow
function
reproductive
rate.
predictably.
C.
B.
an
assemblage
of
parts
and
is
achieved
when
birth
rates
equal
death
their
rates.
relationships
forming
a
whole.
D.
C.
a
set
of
components
that
can
only
use
of
be
exceeded
with
unsustainable
function
resources.
unpredictably.
8.
D.
an
assemblage
of
functioning
parts
Which
of
the
following
unsustainable
inputs
2.
Inputs
A.
to
or
a
matter
closed
system
only
energy
harvesting
may
What
do
consist
C.
matter
and
only
D.
outputs
Energy
B.
Matter
C.
Energy
D.
Neither
I.
Harvesting
II.
Regularly
heat
lake
of
a
lead
to
forest?
from
an
trees
before
they
are
fully
mature.
the
open
harvesting
the
full
natural
income
forest.
only
system
mineral
content
of
soil
through
harvesting.
A.
I
B.
III
III
only
C.
I
and
II
only
only
D.
I,
II
and
III
only.
and
Sustainable
a
nor
stream
only
system
by
which
matter.
owing
annual
death
into
evaporation,
is
it,
but
an
with
II.
example
isolated
B.
stable
can
at
growth
and
(total
be
dened
as
biomass
time
and
recruitment
–
annual
emigration.
at
time
t
+
1)
–
(total
biomass
t).
is
III. the
A.
yield
matter.
energy
with
lost
and
only.
I.
water
a
of?
A.
A
would
from
energy
9.
4.
timber
be
III. Reducing
3.
of
outputs.
from
B.
conditions
without
C.
unstable
and
closed
be
highest
rate
exploited
at
which
without
natural
reducing
capital
its
can
original
stock.
5.
Which
the
A.
of
and
the
closed
following
ecosphere
The
D.
input
being
of
open
factors
classied
solar
would
as
a
A.
I
and
II
closed
system?
B.
I
and
III
energy.
10.
Which
likely
B.
The
re-radiation
C.
The
arrival
of
to
rocks
space
as
of
heat
only
C.
II
and
D.
I,
II
III
only
prevent
of
to
only
the
be
following
and
populations
III
are
most
sustainable?
energy.
meteorites
Popato
mea dvda
Hgh
dest
cospto
depedece o
high
low
from
space.
A.
D.
The
unstable
state
of
its
renewable
equilibrium.
resources
6.
Which
statement
is
correct?
B.
A.
A
lake
B.
An
The
are
D.
A
an
open
matter
C.
is
system
with
most
closed
its
of
an
exchanges
isolated
energy
but
not
system
its
high
systems
found
exchanges
renewable
resources
C.
high
high
non-renewable
resources
on
Earth
systems.
with
high
system.
surroundings.
common
closed
matter
example
D.
low
low
non-renewable
resources
energy
but
not
surroundings.
55
2
E c o s y s t E m s
a n d
E c o l o g y
2.1 Secies  ltis
sii ie:
appii  ki:
➔
A species interacts with its abiotic and biotic
➔
Iterret graphical representations or models
environment, and its niche is described by
of factors that aect an organism’s niche.
these interactions.
Examples include predator–prey relationships,
➔
Populations change and respond to interactions
competition, and organism abundance over time.
with the environment.
➔
➔
All systems have a carrying capacity for a
Exli population growth cur ves in terms of
numbers and rates.
given species.
Kwee  ueri:
➔
➔
A secies is a group of organisms sharing
➔
predation, herbivory, parasitism, mutualism,
produce fer tile ospring.
disease, competition are termed bitic fctrs
A hbitt is the environment in which a species
➔
normally lives.
➔
population dynamics of others, and upon the
A iche describes the par ticular set of abiotic
organism or population responds.
carrying capacity of the others’ environment .
➔
and which are capable of interbreeding.
of conditions and resources in which a species
➔
➔
S and J lti cr es describe a generalized
describes the actual conditions and resources in
response of populations to a par ticular set of
which a species exists due to biotic interactions.
conditions (abiotic and biotic factors).
The nonliving, physical factors that inuence
the organisms and ecosystem, eg temperature,
sunlight, pH, salinity, precipitation are termed
bitic fctrs
56
A lti is a group of organisms of the same
species living in the same area at the same time,
The fetl iche describes the full range
could sur vive and reproduce. The relize iche
Interactions should be understood in terms
of the inuences each species has on the
and biotic conditions and resources to which an
➔
The iterctis between the organisms, eg
common characteristics that interbreed and
➔
Liitig fctrs will slow population growth as it
approaches the carrying capacity of the system.
2 . 1
This
topic
covers
the
ecology
of
the
ESS
S p E C I E S
a n d
course.
p o p u L a T I o n S
‘And this, our life, exempt
from public haunt, nds
Tis
tongues in trees, books in
the running brooks, sermons
When you study this:
in stones, and good in
●
Use named exles to illustrate concepts or your arguments.
●
Always give the full name of the animal or plant you are mentioning, for
everything.’
William Shakespeare
example not ‘sh’ but ‘Atlantic salmon’, not ‘tree’ but ‘common oak tree’.
●
When you use a habitat or local ecosystem as an example, give as much
detail as possible about it, for example not ‘beach’ but ‘rocky shore, nor th
facing, at Robin Hood’s Bay, Nor th Yorkshire, UK’.
Wh i wh i e
Ecosystems
are
interactions
Examples
given
the
a
of
species
scientic
species
and
made
the
up
between
are
name
name.
genus
of
the
the
living
humans,
is
giraffes
of
names
given
rst
and
non-living
composed
Scientic
name
organisms
and
two
are
with
physical
and
pine
parts:
always
a
environment
components
the
trees.
within
Each
genus
underlined
capital
C e
Scietic r biil e
Human
Homo sapiens
Girae
Giraa camelopardalis
Scots pine
Pinus sylvestris
Aardvark
Orycteropus afer
species
name
or
and
in
the
them.
and
is
then
italics
letter:
Ke ter
A secies is a group
of organisms (living
things) sharing common
Snails
of
another
two
one
species
pond
are
populations
may
cause
a
in
from
density
pond
different
speciation
Population
a
is
each
(see
the
form
a
population
population.
other
and
A
stop
example
gazelles
km
them
or
the
river
snails
may
characteristics that
in
separate
interbreeding.
And
this
interbreed and produce
fer tile ospring.
3.2).
average
number
2
for
road
but
,
of
individuals
in
a
stated
area,
3
or
bacteria
cm
Ke ter
Three
factors
affect
population
size:
A lti is a group
●
natality(birth
●
mortality
●
migration:
rate),
of organisms of the same
(death
rate),
species living in the same
and
area at the same time,
and which are capable of
■
■
This
immigration
emigration
natural
populations
A
niche
is
(moving
(moving
environment
of
different
how
an
into
out
of
includes
species
organism
(a
the
the
the
area)
area).
physical
community)
makes
interbreeding.
a
living.
(abiotic)
environment.
may
share
the
This
includes:
same
Many
habitat.
Ke ter
A hbitt is the environment
Biotic
factors:
in which a species
normally lives.
●
every
●
where
relationship
it
that
organism
may
have
lives
57
2
E c o s ys t E m s
a n d
E c o l o g y
●
how
it
responds
●
how
it
alters
to
resources
available,
to
predators,
to
competitors
Ke ters
these
biotic
factors.
abitic fctrs are the non
Abiotic
factors:
living, physical factors that
●
how
●
availability
inuence the organisms and
much
space
there
is
ecosystem, eg temperature,
of
light,
water
etc.
sunlight, pH, salinity,
No
two
species
can
inhabit
the
same
ecological
niche
in
the
same
place
pollutants.
at
the
same
time:
if
many
species
live
together
they
must
have
slightly
Bitic fctrs are the
different
needs
and
responses
so
are
not
in
the
same
niche.
living components of an
ecosystem – organisms,
their interactions or their
waste – that directly or
indirectly aect another
organism.
For
example,
African
down
savanna
bigger
cheetahs
gazelle
lions
but
cheetahs
they
herbivores
will
and
and
focus
on
hunt
such
the
both
live
different
as
zebra
smaller
in
the
prey.
and
Lions
Cape
antelopes
same
area
typically
Buffalo
such
of
as
the
take
whereas
the
Thompson’s
impalas.
A iche describes the
par ticular set of abiotic
and biotic conditions and
resources to which an
organism or population
responds.
●
Fetl iche
describes the full range of
conditions and resources
in which a species could
survive and reproduce.
▲
●
Figre 2.1.1 Lion preying on a zebra
Relize iche describes
the actual conditions
Limiting
factors
prevent
a
community,
population
or
organism
growing
and resources in which
larger.
There
are
many
limiting
factors
which
restrict
the
growth
of
a species exists due to
populations
in
nature.
Examples
of
this
are
phosphate
being
in
limited
biotic interactions.
supply
tundra
(limiting)
which
Limiting
carrying
in
most
freezes
factors
will
capacity
of
the
slow
the
aquatic
soil
and
systems,
limits
population
and
water
growth
low
temperature
availability
as
it
to
in
the
plants.
approaches
the
system.
T thik bt
Itertil-ieess
Ke ters
The btter  eect is a term from chaos theory and refers to small changes
Liitig fctrs are factors
that happen in a complex system that lead to seemingly unrelated results that
which slow down growth of a
are impossible to predict. It was rst used in meteorology by Edward Lorenz
population as it reaches its
in 1972 in a talk entitled ‘Does the ap of a buttery’s wings in Brazil set o a
carrying capacity.
tornado in Texas?’ Since then, it has been applied to systems other than the
weather eg asteroid travel paths, human behaviour.
Crrig ccit is the
58
maximum number of a
One risk in applying the buttery eect to complex environmental issues is
species or ‘load’ that can be
that we might then think there is nothing to be done to improve things. But
sustainably suppor ted by a
there is order in systems however complex and there is no evidence as yet to
given area.
show that even many butteries apping their wings aect weather patterns.
2 . 1
S p E C I E S
a n d
atmosphere
biotic factors
wind speed
producers
humidity
p o p u L a T I o n S
consumers
light intensity
detritivores
precipitation
decomposers
temperature
interactions
competitors
water
parasites
ph and salinity
pathogens
dissolved nutrients
symbionts
dissolved oxygen
predators
herbivores
soil
available nutrients
moisture pH
structure
temperature
▲
Figre 2.1.2 Biotic and abiotic factors and interactions within an ecosystem
Ppui ieri
No
organism
change
too.
ground,
a
can
Animals
water
habitat
ows
greatly.
path
including
with
many
livestock
of
human
Each
rare
of
Interactions
mutualism,
result
in
others
between
the
the
a
1
risk
damage.
an
Fire,
that
are
shade
may
plague
The
only
hit
natural
in
their
study of the factors that cause
changes to population sizes.
crop,
spraying
disasters
between
ecosystems
others
plti ics is the
the
Madagascar
rice
aerial
habitats
change
vegetation
Interactions
of
All
and
too.
the
carrying
species.
eg
predation,
termed
effect
capacity
all
change
sizes
and
locusts.
and
ecosystems.
dies.
migration
locust
billion
at
and
grow
devastate
communities
for
ages
plants
severe
population
having
eats,
Animal
can
organisms,
carrying
it,
it.
were
competition
species
on
of
and
the
of
over
change
environment
disease,
leave
2013,
with
the
Ke ter
grows,
locusts
In
some
all
it
out
animals
inuences
one
and
stopped
the
of
each
wild
and
and
crops.
populations
species
capacity
our
same:
enter
into
activities
individuals,
the
Plagues
swarms,
and
insecticide
and
stay
on
of
the
the
biotic
herbivory,
factors.
population
others’
All
parasitism,
interactions
dynamics
of
the
environment.
Competition
All
the
organisms
organism
only
in
a
in
that
limited
competition
When
the
any
supply.
takes
Intraspecic
in
ecosystem
ecosystem.
Also
When
have
any
these
some
resource
two
effect
in
on
any
conditions
every
other
ecosystem
apply
exists
jointly,
place.
competition
numbers
of
a
is
between
population
are
members
small,
of
there
the
is
same
little
species.
real
59
2
E c o s ys t E m s
a n d
E c o l o g y
competition
Practical
Work
are
not
will
Investigate
light
of
the
intensity
impact
on
photosynthesis
the
in
be
too
between
small
for
individuals
individuals
for
to
resources.
nd
mates,
Provided
the
population
numbers
growth
high.
of
rate
Take,
for
example,
a
seagull
colony
on
an
oceanic
outcrop
(gure
2.1.3).
aquatic
plants.
number of eggs
Investigate
insect
herbivory
that successfully
on
hatch decreases
pressure for
a
plant.
bir th rate
good nesting
decreases
sites increases
population
population
grows
falls
competition for
bir th rate
good nesting
increases
sites decreases
number of eggs
that successfully
hatch increases
▲
Figre 2.1.3 Competition within a seagull colony
As
the
for
is
population
the
resources
reached.
In
larger
share
Some
species
deer.
that
and
at
An
are
deal
hence
have
does
with
competition
the
often
carrying
the
or
intraspecic
pair
holds
successful
access
between
capacity
stronger
of
individuals
individuals
the
ecosystem
claim
the
to
an
competition
area
and
reproductively
more
resources,
by
fends
will
and
being
off
hold
will
rivals.
the
be
territorial,
Individuals
biggest
more
eg
territory
successful
breeding.
competition
something
S-shaped
(see
tends
called
population
a
competition :
the
a
balance,
outcome
the
is
number
plants
a
of
can
of
that
especially
not
only
owering in a temperate
trees
woodland in spring
woodland
in
totally
may
a
of
very
oor.
get
small
out
by
closely
population
logistic
section,
of
share
totally
different
garden
the
that
An
has
together,
curve
species
competition
resource.
out-compete
exclusion .
numbers.
growth
It
which
is
p62).
Interspecic
species
coexist
example
become
The
the
of
often
the
is
limiting
be
result
other
other:
both
overrun
but
could
may
this
of
by
is
these
weeds.
original
A
domestic
excluded.
deciduous
cannot
shaded
have
seen
species
been
true
both
species
or
Individuals
resource.
competitive
be
temperate
Figre 2.1.4 Snowdrops
one
weed
have
species
which
that
principle
outcomes
in
same
stabilize
changes
competing
for
to
sigmoid
Interspecic
In
the
resources.
produces
in
60
the
most
so
eventually
situation,
individual
the
Intraspecic
▲
this
of
grows,
until
woodland
enough
light
owering
trees
but
light
will
plants
by
overlapping
a
die
on
shrubs
leaves,
out
the
and
in
a
resource.
woodland
bushes
resulting
Plant
woodland.
in
as
an
oor
well.
This
that
is
are
Beech
almost
bare
2 . 1
But
even
in
woods
snowdrops,
European
these
and
of
deciduous
species
tree
species
is
species,
as
grow,
into
that
reduces
in
leaf.
when
the
an
the
spring.
and
for
by
energy
capacity
is
grow.
key
of
to
p o p u L a T I o n S
of
Northern
the
success
the
directly
completing
and
a n d
Carpets
all
before
competing
light
most
same
The
to
part
reproduce
competition
the
manage
integral
avoid
them
carrying
use
are
They
require
the
species
owers
ower
out-compete
cycle
both
trees,
bluebells
woodlands
photosynthesis
Competition
by
and
they
burst
would
yearly
greatest
that
species
that
their
shaded
primroses
S p E C I E S
of
shrub
with
the
therefore
stages
the
less.
for
each
of
the
competing
resource(s).
Predation
Predation
prey.
moose.
eat
is
when
Examples
The
other
one
are
predator
animals,
and
other
and
the
small
kills
some
hare
the
like
the
prey.
Look
in
predator,
lions
plants
animals.
snowshoe
feedback
animal,
plenty,
eating
Be
eats
aware
that
(insectivorous
at
the
sub-topic
as
and
not
plants)
example
1.3
another
zebras
of
an
the
animal,
wolves
only
animals
consume
insects
Canadian
example
of
the
eating
lynx
negative
control.
Sometimes,
however,
a
wider
denition
of
predation
is
used:
predation
▲
is
the
consumption
of
one
organism
by
another.
This
broad
Figre 2.1.5 Poplar sawy
denition
larva (Trichiocampus
includes
not
only
predation
in
the
narrower
sense
of
the
word
but
also
viminalis) eating an aspen
herbivory
and
parasitism.
leaf (Populus tremula) in Glen
Aric, Scotland, UK
Herbivory
Herbivory
Some
or
dened
plants
spines
(eg
between
have
(some
chemicals
small
is
larvae
an
animal
defence
cacti),
(poison
(eg
as
a
ivy).
of
leaf
(herbivore)
mechanisms
stinging
miner
against
mechanism
Herbivores
may
insects
eating
be
that
this,
(eg
the
green
for
(stinging
large
eat
a
plant.
example
nettles),
elephants,
inside
of
thorns
or
toxic
cattle)
leaves)
or
or
in
rabbits).
Parasitism
Parasitism
(the
Normally
high
of
is
a
parasite)
relationship
lives
in
parasites
parasite
parasites
or
do
not
population
are
vampire
between
on
another
kill
the
host,
densities
bats
and
two
(the
can
species
host),
unlike
lead
intestinal
to
in
which
gaining
in
the
one
its
predation.
host’s
species
food
from
it.
However,
death.
Examples
worms.
▲
Figre 2.1.6 A lichen
Mutualism
Mutualism
and
none
types
one
of
is
a
relation
suffer.
symbiosis
partner
epiphyte
is
such
as
people
close
association
alga
on
to
the
a
are
an
think
benets
benets
is
helped
Most
fungus
It
by
from
a
of
the
or
lichens
fungus
obtaining
minerals
two
or
more
symbiosis
parasitism
and
orchid
of
of
between
form
(above)
other
fern
as
is
examples
from
water
in
of
a
green
up
a
A
alga
fungus
eg
top.
alga.
absorbs
an
trunk).
lichen
on
benet
other
(when
tree
photosynthetic
the
all
harmed,
mutualism.
the
that
The
commensalism
half-way
and
which
together).
signicantly
growing
sugars
and
and
not
underneath
species
(living
is
a
The
The
and
passes
alga.
61
2
E c o s ys t E m s
a n d
E c o l o g y
Another
clover,
live
example
vetch,
inside
the
soil
root
and
The
photosynthesis.
very
earliest
often
poor
to
Mycorrhizal
a
▲
Figre 2.1.7 Nitrogenxing
root nodules on a legume root
sheath
with
with
better
Sea
they
anemones
food
for
stinging
the
the
and
sea
during
they
it
protect
are
poor
of
also
soil.
from
sugar
from
legumes
plants
soil.
are
They
The
to
is
The
photosynthesis.
the
also
soil.
fungi
provide
tree
live
among
Clover
example.
form
the
provides
Both
tree
the
grow
one.
mutualistic.
form
with
bacteria
ammonium
agricultural
trees.
the
from
other
the
the
many
from
produces
in
leguminous
of
(beans,
The
nitrogen
form
enables
on
plants
Rhizobium.
absorb
the
another
of
–
bacteria
content
are
up
the
in
the
succession
take
clownsh
They
relationship
roots
leguminous
bacteria
plant
supply
roots
without
anemone
tentacles
the
nutrient
tree
that
do
turn
feeding
that
glucose
than
legumes.
to
consequence,
the
and
the
in
a
increase
fungi
the
mutualistic
As
between
nitrogen-xing
in
plants
species
around
relationship
available
This
phosphates
fungi
it
soils.
pioneer
used
the
and
nodules
make
compounds.
on
is
peas)
of
clownsh
their
from
The
feces.
clownsh
The
predators,
provide
anemone’s
but
do
not
affect
clownsh.
T 
Sr f iterctis bet ee secies
1.
Copy and ll in the last column.
Te f
Secies a
Secies B
-
-
+
-
+
-
+
+
Exle
Itercti
▲
Figre 2.1.8 Clownsh and
Neither species benets,
Competition
sea anemone
both species suer
One species kills the
Predation
other species for food
The parasite benets
Parasitism
at the cost of the host
Mutualism
2.
Both species benet
What four things do all organisms need to survive? (Clue: think back to your
rst biology lesson.)
3.
What is the dierence between interspecic and intraspecic competition?
4.
What eect does intraspecic competition have on the individuals of a species?
5.
What is the link between competition and species diversity?
6.
Why is species diversity believed to be benecial for a community?
Ppui he
Over
time
collect
and
we
62
a
the
few
then,
would
numbers
bacterial
under
nd
a
within
cells,
microscope,
that
there
a
population
place
them
count
would
be
in
the
many
a
change.
suitable
number
more
of
If
we
were
supply
cells
bacteria
of
every
at
to
nutrients
the
hour,
end
of
2 . 1
a
24-hour
by
period
splitting
there
will
in
be
than
two
at
the
(binary
start.
ssion)
2,4,8,16,32,64
etc.
if
Bacteria
so,
if
there
can
you
are
reproduce
start
no
with
S p E C I E S
p o p u L a T I o n S
asexually
one
limiting
a n d
‘It is well to remember that
bacterium,
factors
the entire universe, with
slowing
one triing exception, is
growth.
This
is
called
exponential
or
geometric
growth
(gure
2.1.9).
composed of others.’
S-cur ves
S-curves
growth
John Andrew Holmes Junior
start
at
with
rst.
exponential
However,
growth.
above
a
No
certain
limiting
factors
population
size,
affect
the
the
growth
rate
Ke ters
slows
The
down
graph
constant
grows
but
as
phase).
can
cells
and
of
as
the
it
there
the
the
is
maximum
ecosystem.
of
colony
the
that
The
an
area
food
to
is
between
colony
the
as
around.
which
can
the
few
starts
only
is
the
constant
grown
days
to
set
Any
or
response of populations to a
of
par ticular set of conditions
(abiotic and biotic factors).
yeast
yeast
stabilize
at
number
the
or
support.
carrying
exponential
describe a generalized
colony
(exponential
more
maximum
S and J lti cr es
a
very
number
numbers
size.
in
the
grow
supply
a
phase).
The
carry
the
it
of
yeast
nutrient
(stationary
go
of
rst
then
stabilizes
called
environmental
a
plentiful
environment
size
for
population
phase)
environment
population
called
size
resources
enough
of
a
a
During
(lag
has
population
in
this
nutrient.
multiply
limited
not
capacity
is
to
multiplying
resulting
illustrates
supply
starts
individuals
S-curve
nally
2.1.10
limited
exploit
carrying
the
gure
Eventually
cells
The
in
slowly
rapidly
load
gradually,
capacity
growth
(K)
curve
of
and
the
resistance
J-cur ves
70
number of bacteria
J-curves
(see
gure
2.1.11)
show
a
‘boom
and
bust’
pattern.
The
60
population
carrying
occurs
capacity
capacity
human
The
exponentially
are
called
on
a
(overshoot).
carrying
the
grows
collapses
race
J-curve
is
does
long-term
It
can
is
be
rst
or
important
exceeded
overshooting
not
at
diebacks.
show
the
then,
the
to
note
the
basis
short
term.
capacity
slowdown
of
It
at
collapses.
exceeds
before
‘long-term
carrying
gradual
suddenly,
population
continuing
in
its
and
Often
the
basis’
seems
the
as
airetcab fo rebmun
These
the
collapse
the
likely
that
moment.
population
50
40
30
20
growth
10
with
increasing
population
size.
0
A
J-shaped
sh
and
population
small
growth
curve
is
typical
of
microbes,
invertebrates,
0
mammals.
and
J-curves
are
20
30
40
time, (minutes)
▲
S-
10
idealized
curves.
In
practice,
many
limiting
Figre 2.1.9 Exponential
factors
growth in a bacterial
act
on
the
same
population
and
the
resulting
population
growth
curve
population over time
normally
looks
like
a
combination
of
an
S-
and
a
J-curve.
overshoot
dieback
environmental resistance
slaudividni fo rebmun
carrying capacity
Figre 2.1.10 Sshaped growth
curve of a population
ezis noitalupop
ezis noitalupop
time
▲
carrying capacity
time
▲
Figre 2.1.11 Jshaped growth
curve of a population
time
▲
Figre 2.1.12 Fluctuation of population
size around the carrying capacity
63
2
E c o s ys t E m s
a n d
E c o l o g y
2.2 C ities  ec sstes
sii ie:
appii  ki:
➔
The interactions of species with their
➔
Cstrct models of feeding relationships,
environment result in energy and nutrient ow.
eg food chains, food webs and ecological
➔
Photosynthesis and respiration play a
pyramids, from given data.
signicant role in the ow of energy in
➔
Exli the transfer and transformation of
communities.
energy as it ows through an ecosystem.
➔
The feeding relationships in a system can be
➔
alse the eciency of energy transfers
modelled using food chains, food webs and
through a system.
ecological pyramids.
➔
Cstrct system diagrams representing
photosynthesis and respiration.
➔
Exli the relevance of the laws of
thermodynamics to the ow of energy through
ecosystems.
➔
Exli the impact of a persistent/non
biodegradable pollutant in an ecosystem.
Kwee  ueri:
➔
A cit is a group of populations living and
➔
interacting with each other in a common habitat.
➔
An ecsste is a community and the physical
producing biomass.
➔
environment it interacts with.
➔
in a community that occupy the same position in
food chains.
described as processes with inputs, outputs and
➔
➔
prcers (autotrophs) are typically plants
or algae and produce their own food using
Resirti is the conversion of organic matter
photosynthesis and form the rst trophic level in
into carbon dioxide and water in all living
a food chain. Exceptions include chesthetic
organisms, releasing energy. Aerobic respiration
organisms which produce food without sunlight.
can simply be described as
glucose + oxygen → carbon dioxide + water
The trophic level is the position that an organism
occupies in a food chain, or a group of organisms
Respiration and photosynthesis can be
transformations of energy and matter.
phtsthesis produces the raw material for
➔
Feeding relationships involve rcers,
csers and ecsers. These can be
➔
During respiration large amounts of energy are
modelled using f chis, f ebs and
dissipated as heat, increasing the entropy in
using eclgicl ris
the ecosystem while enabling the organisms to
maintain relatively low entropy/high organization.
➔
Eclgicl ris include pyramids of
numbers, biomass and productivity and are
➔
Primary producers in the majority of ecosystems
quantitative models and are usually measured
conver t light energy into chemical energy in the
for a given area and time.
process of photosynthesis.
➔
➔
In accordance with the second law of
The photosynthesis reaction is:
thermodynamics, there is a tendency for
carbon dioxide + water → glucose + oxygen
64
2 . 2
C o m m u n I T I E S
numbers and quantities of biomass and energy
a n d
E C o S y S T E m S
A ri f biss represents the standing
➔
to decrease along food chains; therefore the
stock/storage of each trophic level measured
pyramids become narrower towards the apex.
in units such as grams of biomass per square
2
metre (g m
Bicclti is the buildup of persistent/
➔
organism or trophic level because they cannot
Pyramids of biomass can show greater
➔
be broken down.
quantities at higher trophic levels because they
represent the biomass present at a given time,
Bigicti is the increase in
but there may be marked seasonal variations.
concentration of persistent or nonbiodegradable
pollutants along a food chain.
pris f rcti it refer to the 
➔
of energy through a trophic level, indicating
Toxins such as ddT and mercury accumulate
➔
the rte at which that stock/storage is being
along food chains due to the decrease of
generated.
biomass and energy.
Pyramids of productivity for entire ecosystems
➔
pris f bers can sometimes display
➔
)
(units of biomass or energy).
nonbiodegradable pollutants within an
➔
2
) or Joules per square metre (J m
over a year always show a decrease along the
dierent patterns, for example, when individuals
food chain.
at lower trophic levels are relatively large
(inver ted pyramids).
A
community
tropical
fungi.
contains
rainforest
An
is
aquarium
a
all
the
biotic
community
is
a
(living)
of
community
plants
as
components
and
of
animals,
a
habitat.
bacteria
A
and
‘In all things of nature,
there is something of the
well.
mar vellous.’
The
term
was
rst
used
in
1930
and
modied
by
Arthur
Tansley,
Aristotle
a
British
ecologist,
organisms
sizes
from
and
a
to
their
drop
of
describe
abiotic
rain
the
complex
environment.
water
to
a
relationships
Ecosystems
forest.
Human
between
may
be
of
ecosystems
varying
include
Ke ter
a
household
or
independently
parts
of
the
considered
a
school
but
Earth
as
or
a
interact
have
examples
nation
to
been
of
make
state.
up
impacted
Ecosystems
the
by
biosphere.
humans,
human-affected
do
all
As
not
exist
virtually
ecosystems
all
may
A cit is a group
be
ecosystems.
of populations living and
interacting with each other
in a common habitat (the
same place).
Repiri  phhei
There
of
are
how
and
else
three
key
everything
productivity.
makes
more
ecological
else
If
works.
you
concepts
These
have
a
that
are:
grasp
are
vital
to
your
photosynthesis,
of
the
basics
of
understanding
respiration
these,
everything
Ke ter
sense.
An ecsste is a community
and the physical environment
Respiration
it interacts with.
All
living
this,
they
glucose,
are:
things
die.
to
MRS
and
GREN.
respire
Respiration
release
Movement,
Nutrition
must
energy
energy
to
breaking
which
used
people
Respiration
get
involves
Respiration,
some
to
is
Sensitivity,
remember
can
in
use
alive.
down
living
Growth,
these
oxygen
stay
by
food,
If
they
often
processes.
do
in
(aerobic)
rst
or
not
the
These
Reproduction,
their
letters
not
do
form
of
processes
Excretion,
which
spell
(anaerobic).
65
2
E c o s ys t E m s
a n d
E c o l o g y
In
aerobic
respiration,
energy
is
released
and
used
and
the
waste
Ke ter
products
bacteria
are
or
carbon
fungi,
dioxide
all
living
and
water.
things
Whether
respire
all
the
plants
time,
or
in
animals,
the
light
Resirti is the
and
dark,
when
asleep
or
awake.
Aerobic
respiration
can
be
conversion of organic matter
summarized
as:
into carbon dioxide and
water in all living organisms,
Glucose
+
oxygen
Energy
+
water
+
carbon
C
+
6
Energy
+
12
+
6
dioxide
releasing energy.
H
6
O
12
Much
of
(see
level
of
of
energy
the
O
CO
2
produced
(dissipated)
1.3)
H
2
the
released
O
6
into
system
organization
the
respiration
environment.
while
(low
in
the
organism
is
2
heat
This
energy
increases
maintains
a
and
the
is
entropy
relatively
high
entropy).
Photosynthesis
Ke ter
phtsthesis is the
Green
plants
This
a
is
convert
light
transformation
energy
of
into
energy
chemical
from
one
energy
state
to
in
photosynthesis.
another.
process by which green
The
leaves
of
plants
contain
chloroplasts
with
the
green
pigment
plants make their own food
chlorophyll.
In
the
chloroplasts
the
energy
of
sunlight
is
used
to
split
from water and carbon dioxide
water
and
combine
it
with
carbon
dioxide
to
make
food
in
the
form
of
using energy from sunlight.
the
glucose.
make
in
every
cells,
Glucose
other
add
●
rearrange
nitrogen
make
molecule
Animals
are
Although
essential
acids
used
that
oxygen
can
amino
is
sulphur
as
it
used
Photosynthesis
starting
needs.
acids
in
of
make
and
the
raw
In
amino
point
complex
most
from
of
which
the
the
acids
oxygen
material
on
for
the
plant
chemical
to
pathways
and
for
we
then
add
make
proteins,
phosphorus
up
cell
producing
chemicals
ones
and
biomass.
produced
need,
we
to
membranes.
by
can
plants.
only
obtain
plants.
photosynthesis
is
oxygen.
This
is
really
useful
as
respiration.
can
be
summarized
light
carbon
Both respiration and
the
lipoproteins
dependent
make
product
to
hydrogen
and
produces
totally
we
waste
and
carbon,
fatty
Photosynthesis
T 
then
plants:
●
The
is
dioxide
+
as:
energy
water
glucose
+
oxygen
C
+
6O
chlorophyll
photosynthesis are
light
energy
systems – biochemical
6CO
+
12H
2
O
2
systems diagrams for them
with inputs, output, storages
H
6
O
12
6
2
chlorophyll
ones – and we can draw
Green
light.
plants
Water
respire
reaches
in
the
the
dark
leaves
and
from
photosynthesize
the
roots
by
and
respire
in
the
transpiration.
and ows which will be
When
all
carbon
dioxide
that
plants
produce
in
respiration
is
used
up
transformations or transfers
in
photosynthesis,
the
rates
of
the
two
processes
are
equal
and
there
is
of energy and matter.
no
net
release
of
either
oxygen
or
carbon
dioxide.
This
usually
occurs
Draw a systems diagram
at
dawn
and
dusk
when
light
intensity
is
not
too
high.
This
point
is
for each of respiration and
called
the
compensation
point
of
a
plant
and
it
is
neither
adding
photosynthesis.
biomass
Where can you link the two?
itself.
nor
This
succession
66
is
using
it
up
important
and
biomes.
to
to
stay
alive
remember
at
this
when
point.
we
It
is
come
just
to
maintaining
think
about
2 . 2
C o m m u n I T I E S
a n d
E C o S y S T E m S
F hi  rphi eve
All
is
energy
the
ocean
get
start
of
vents
their
But
on
Earth
every
give
energy
most
of
us
comes
food
out
get
chain.
heat
from
from
this
ours
from
the
(Well,
the
through
from
Sun
the
so
very
Earth's
a
energy
nearly
all,
mantle
process
Sun’s
Ke ter
solar
as
and
known
as
(solar
some
some
radiation)
A trhic leel is the position
deep
that an organism occupies
organisms
in a food chain, or a group of
chemosynthesis.
organisms in a community
energy.)
that occupy the same
A
food
A
food
chain
is
the
ow
of
energy
from
one
organism
to
the
next.
position in food chains.
chain
ecosystem.
species
end
It
is
1.
a
are
grouped
to
levels
the
species,
other:
into
so
in
trophic
usually
at
classify
Autotrophs
carbon
b.
the
the
start
top
way
simple
methane,
deep
between
usually
the
species
pointing
direction
of
in
an
towards
transfer
of
(Greek
for
the
of
(or
feeding)
with
the
a
chain
organisms
levels
primary
–
a
obtain
producer
top
food
(plant)
is
and
carnivore.
energy
into
two
categories.
and
other
not
which
using
organisms
compounds
require
(also
called
heterotrophs
omnivores,
within
do
plants)
water
eg
make
energy
which
make
ammonia,
sunlight
their
from
and
own
their
hydrogen
are
food
from
sunlight.
often
own
food
sulphide
bacteria
from
or
found
in
oceans.
Consumers
or
(green
dioxide
Chemosynthetic
other
But
the
relationships
Producers
a.
2.
connect
carnivore
possible
feeding
energy).
Trophic
with
the
consumes
(and
Organisms
trophe).
Arrows
that
biomass
shows
the
to
detritivores
consumers
ne f gr
Primary
heterotrophs)
obtain
and
energy
which
feed
(herbivores,
on
autotrophs
carnivores,
decomposers).
there
is
a
hierarchy
Trhic
ntriti: srce f
leel
eerg
1st
Autotrophs:
of
feeding.
Fcti
●
Provide the energy
requirements of all
producers (PP)
Make their own food from
the other trophic
Gree lts
solar energy, CO
2
and H
O
2
levels
●
Habitat for other
organisms
●
Supply nutrients to
the soil
●
Bind the soil/stop
soil erosion
Primary
2nd
Heterotrophs:
consumers (PC)
These consumers
keep each other in
Consume PP
check through negative
Herbires
feedback loops (see
1.3). They also:
●
Disperse seeds
▲
Figre 2.2.1
67
2
E c o s ys t E m s
a n d
E c o l o g y
ne f gr
Secondary
Trhic
ntriti: srce f
leel
eerg
Fcti
3rd
Heterotrophs:
●
Pollinate owers
Consume herbivores
●
Remove old and
consumers (SC)
Crires 
and other carnivores,
diseased animals
ires
sometimes PP
from the population
Ter tiary
4th
Heterotrophs:
consumers (TC)
Consume herbivores
Crires 
and other carnivores,
ires
sometimes PP
decsers
Obtain their energy from
This group of
dead organisms by
organisms provide a
secreting enzymes that
crucial service for the
break down the organic
ecosystem:
Bacteria and
fungi
matter
●
detritires
Derive their energy from
Snails, slugs,
detritus or decomposing
blow y
organic material – dead
maggots,
organisms or feces or
vultures
par ts of an organism, eg
Break down dead
organisms
●
Release the
nutrients back into
the cycle
●
Control the spread of
shed skin from a snake, a
disease
crab carapace
Food webs
It
would
chain.
several
It
is
The
are
other
to
food
to
to
nd
more
construct
a
chains
on
unusual
many
an
ecosystem
organisms
with
involved
only
and
a
one
simple
may
food
eat
species.
create
based
some
▲
very
possible
starts
are
be
There
below
real
pioneer
food
chains
for
an
entire
ecosystem,
but
this
problem.
food
are
from
chains
ecologists
at
a
European
Wytham
worked
in
the
oak
Wood
woodland.
in
Oxford,
In
UK
fact
they
where
1920s.
herbs
insects
spiders
parasites
herbs
insects
voles
owls
hazel
winter
moth
voles
owls
hazel
winter
moth
titmice
weasels
Figre 2.2.2 Decomposer fungi
in a woodland
In
of
the
four
them
species
would
Food
in
So
68
a
of
single
than
and
many
only
and
food
more
wood
for
chains
diet
in
the
run
organism
The
different
are
chains,
one
their
illustrate
almost
all
ten
chain.
interactions
species
If
we
in
are
listed
continued
every
food
and
to
some
list
chain,
all
the
the
list
pages.
another
species
only
food
in
a
a
direct
single
consumers
can
appear
in
feeding
relationship
hierarchy.
is
not
more
The
limited
than
reality
to
one
a
between
is
single
food
very
food
chain.
one
different.
species.
2 . 2
A
further
chains
are
is
limitation
when
a
omnivores
Humans
eat
carnivores.
contained
rather
The
reality
the
is
create
as
or
feeds
well
then
in
there
food
as
at
a
is
and
have
but
to
than
list
one
trophic
they
animals
all
the
them
food
complex
relationships
insects,
the
move
shorter
a
feeding
more
eating
animals
humans
third
that
a
representing
and
would
voles
than
which
and
plants
We
of
species
C o m m u n I T I E S
to
also
may
food
the
by
Voles
plants.
herbivores
chains
second
E C o S y S T E m S
food
level.
eat
be
a n d
again
and
that
trophic
level
chain.
network
of
interrelated
food
chains
web.
lion
hunting dog
leopard
cheetah
baboon
locust
wildebeest
impala
acacias
▲
The
zebra
grasses
Figre 2.2.3 Food web on the African savannah
earliest
food
Island,
Norway)
Elton’s
food
webs
and
web
is
were
Hardy
in
published
(on
gure
in
plankton
the
and
1920s
by
herring
Elton
in
the
(on
Bear
North
Sea).
2.2.4.
kittiwake
nitrogen
ToK
skua
protozoa
guillemots
glaucous gull
fulmar petrel
Feeding relationships can
little auk
be represented by different
pun
models. How can we decide
nor thern eider
when one model is better
long-tailed duck
mineral salts
red-throated diver
than another?
collembola
dead plants
spider
diptera
mites
marine
hymenoptera
arctic fox
animals
ptarmigan
worms
dung
seals
snow bunting
geese
polar
purple sandpiper
diptera
bear
algae
protozoa
decaying
lepidurus
diptera
T 
matter
entomostraca
entomostraca
rotifera
protozoa
rotifera
Tabulate the dierences
tardigrada
between a food chain and a
moss
oligochaeta
freshwater plankton
algae
nematoda
food web.
freshwater benthic and littoral
▲
Figre 2.2.4 One of the rst food webs observed by Elton on Bear Island, Norway
69
2
E c o s ys t E m s
a n d
E c o l o g y
T 
Crires i the tr ecsste
families
(packs)
herbivores
Some
wolves
winter.
feed
that
Ot ters
on
fish.
and
are
prey
too
change
live
to
near
Shrews
on
slow
a
stay
bright
rivers
are
caribou
to
the
and
with
white
and
colour
lakes
smallest
other
their
so
large
groups.
in
they
the
can
carnivores
of
the
small predators
tundra.
Even
summer.
bats
They
are
feed
found
on
the
in
the
tundra
swarms
of
during
insects
the
that
fill
arctic fox
the
air.
primary consumers
The
primary
animal
musk oxen
insects
The
lemmings
on
tiny owering plants
primary producers
life
large
the
production
if
only
small
herbivores
productivity
is
and
of
not
areas
sufficient
of
tundra
carnivores
vast
areas
of
are
to
suppor t
are
considered.
dependent
tundra
and
have
4 inches
grasses
lichens
adopted
a
migratory
way
of
life.
Small
herbivores
or less
sedges
willows
feed
in height
and
roots,
water-saturated ground – small shallow lakes
nematodes
live
in
the
rhizomes
herbivores
like
vegetation
and
bulbs.
lemmings
mat ,
The
show
eating
the
populations
interesting
of
small
f luctuations
bacteria
that
permafrost
also
affect
the
carnivores
dependent
on
them,
life forms (if any)
such
ground is permanently frozen
as
the
arctic
fox
and
snowy
owl.
probably dormant
The blue squares represent the appearance and
▲
Figre 2.2.5 A food web in the tundra; source Dave
frequency of snowy owls after almost exponential
Harrison, used with permission
population increases of lemmings. There is then a lag
period of about two years before lemming numbers
There
are
bears
live
several
species
of
bear
in
the
tundra.
Polar
increase again.
tundra
bear
searching
in
Brown
fur ther
the
nor th,
for
Alaskan
but
food.
The
tundra.
bears
are
not
them
out
to
as
are
It
fierce
also
found
Kodiak
is
is
usually
as
their
in
the
a
the
1.
largest
brown
reputation
2.
makes
be.
They
seldom
Draw a food web for the tundra with l the animals
mentioned.
colour.
eat
meat .
Why do you think the snowy owls only appear when
Wolves
lemming numbers have fallen? (Hint: climate and
are
the
top
predators
of
the
tundra.
They
travel
in
small
decomposers.)
40
sgnimmel
eratceh rep
27
13
0
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
year
▲
70
Figre 2.2.6 Snowy owl and lemming numbers in the tundra from 1929 to 1943
1940
1941
1942
1943
2 . 2
C o m m u n I T I E S
a n d
E C o S y S T E m S
T 
foxes
kestrels
toads and lizards
shor t-eared owls
carnivorous
stoats
insects
herbivorous insects
voles
rabbits
woodlice
worms
detritus
vegetation, fruits and seeds
▲
1.
Figre 2.2.7 A simplied food web from the acid heathland at Studland, Dorset, UK
What is the longest food chain in this food web?
4.
If there is a great increase in the rabbit population,
what happens to (a) rabbit predators and (b) the
2.
Name two species that are found at two trophic
vegetation?
levels.
5.
3.
If a pesticide is added to kill spiders, what may
If all kestrels die, what may happen to (a) voles
happen to the foxes?
and (b) shor teared owls?
Ei pri
Pyramids
amounts
are
of
graphical
living
Ke ter
models
material
of
stored
the
at
quantitative
each
trophic
differences
level
of
a
between
food
chain.
Eclgicl ris include
pyramids of numbers,
●
They
allow
●
They
give
easy
examination
of
energy
transfers
and
losses.
biomass and productivity
at
the
an
idea
different
of
what
trophic
feeds
on
what
and
what
organisms
exist
levels.
and are quantitative models
and are usually measured
for a given area and time.
●
They
in
All
also
help
to
demonstrate
that
ecosystems
are
systems
that
are
balance.
pyramids
may
be
represented
as
in
gure
2.2.8.
C3
secondary
C2
C3
carnivore
primary
C2
C1
carnivore
P
in a grassland
▲
in a pond
Figre 2.2.8
71
2
E c o s ys t E m s
a n d
E c o l o g y
A
pyramid
trophic
are
of
level
number
numbers
in
a
per
food
unit
the
one
number
time
–
of
the
organisms
standing
at
parasites
caterpillars
aphids
tree
length
pyramids
units
rose bush
of
are
producer
(P)
producer
so
each
bar
broad
level.
the
at
gives
their
But
base
a
some
is
measure
base
one
and
may
of
the
have
have
individual
a
1
C2
90 000
C1
200 000
relative
many
large
which
C3
C3
numbers.
individuals
single
plant,
supports
Most
the
tree,
as
the
consumers.
90 blue tits
2000 caterpillars
1 oak tree
P
Figre 2.2.10 Pyramid of numbers for a grazing ecosystem
a
many
C1
1 500 000
in
1 sparrowhawk
C2
▲
The
Figre 2.2.9 Pyramids of numbers
The
P
each
crop.
blue tits
grass
▲
at
area.
foxes
rabbits
shows
chain
▲
Figre 2.2.11 Pyramid of numbers for an oak wood
Advantage
●
This
is
a
simple,
comparing
easy
changes
method
in
of
giving
population
an
overview
numbers
with
and
time
is
or
good
at
season.
Disadvantages
●
All
organisms
pyramid
bottom
based
and
●
Does
●
Numbers
A
not
pyramid
number
(dry)
level
The
of
an
units
on
get
allow
can
of
included
an
oak
larger
for
be
as
regardless
tree
it
too
great
biomass
material
or
to
in
each
an
up
of
their
be
the
inverted
immature
the
a
(have
a
a
small
levels).
accurately.
level.
organism,
therefore
forms.
biomass
trophic
size,
trophic
represent
contains
at
would
goes
juveniles
individuals)
organic
or
are
(mass
of
Biomass
population,
a
each
is
the
individual
quantity
particular
trophic
ecosystem.
of
a
pyramid
of
biomass
are
in
units
of
mass
per
unit
area,
often
2
grams
A
per
square
pyramid
some
of
exceptions,
present
biomass
less
at
than
one
P
m
in
more
small
time
of
the
3
)
particularly
C2
C1
is
(g
(unicellular
only
that
metre
biomass
phytoplankton
are
or
likely
in
eg
in
to
be
oceanic
green
at
any
winter,
zooplankton
a
water
pyramid
volume
one
time.
the
where
the
producers
As
a
primary
2
1.0
470.0
4.0
Figre 2.2.12 Pyramids of biomass (units gm
reproduce
pyramid
bar
are
but
represents
may
zooplankton
).
are
fast
be
consumers.
phytoplankton
)
km
there
0.1
0.6
kg
but
phytoplankton
are
(eg,
shape
Phytoplankton
the
which
per
ecosystems
algae).
amounts
only,
kilograms
2
▲
72
×
of
far
2 . 2
C o m m u n I T I E S
a n d
E C o S y S T E m S
decomposers
C3
1.5
C2
11
5
C1
37
P
807
▲
Figre 2.2.13 Pyramid of biomass for a lake
Advantage
●
Overcomes
some
of
the
problems
of
pyramids
of
numbers.
Disadvantages
●
Only
uses
biomass
samples
●
Organisms
●
The
time
case
of
of
have
trophic
with
populations,
the
year
of
so
not
a
a
few
pyramid
lake
days
these
biomass
would
same
in
it
is
impossible
to
measure
do
not
mass.
measured
by
large
would
have
at
to
dry
the
affects
depend
equivalent
accumulate
the
amounts
on
accumulated
the
same
In
the
The
biomass
level
the
year
season.
their
trophic
the
result.
during
over
may
biomass.
This
differences.
accumulated
usually
mass
is
changes
California
show
total
measure
biomass
the
of
algae
needed
of
that
to
biomass
trees
yet
level
killed
shape
will
Pyramids
be
their
the
years
pyramid
●
the
redwood
many
only
must
algae,
therefore
giant
from
exactly.
be
per
pyramidal
have
to
have
year
in
by
organisms
shape.
the
same
But
two
energy
at
a
organisms
content.
A
1
dormouse
chemical
stores
energy
a
large
yet
a
amount
carnivore
of
of
fat,
around
equivalent
37
kJ
mass
g
of
would
potential
contain
1
larger
amounts
potential
energy.
digestible
Pyramids
of
Depending
web
In
in
the
more
the
A
be
period
of
and
at
time.
They
must
follow
units
of
will
living
on
the
each
So,
unlike
time,
always
the
or
shows
level.
to
square
ow,
metre
whereas
per
mass
year
biomass
the
It
the
of
pyramids
of
per
(J
unit
m
values
can
at
vary
one
for
kJ
g
time
of
and
same
season
in
of
non-
crustaceans.
the
with
Pyramids
17
proportion
marine
growing,
rate
shows
next
of
ow
the
place.
food
and
autumn,
numbers
numbers
show
in
the
area
are
energy
level
and
or
year.
perhaps
may
of
during
period
of
They
time,
a
being
xed
which
energy
ecosystems
(1.3).
or
biomass
biomass,
ow
healthy
per
of
energy
trophic
thermodynamics
2
per
snapshots
producers
pyramids
law
high
of
investigated,
pyramid-shaped
second
energy
are
was
producers.
food
these
a
around
2.2.9).
trophic
as
contain
pyramid
more
the
proteins,
exoskeletons
biomass
productivity
one
are
the
pyramid
be
and
organisms
in
(gure
available
time.
snapshots
and
the
inverted
of
as
ecosystem,
there
through
generated
Some
such
when
same
pyramid
carbohydrates
numbers
on
consumers
biomass
in
parts
spring,
sometimes
of
as
are
are
over
they
measured
often
Joules
1
yr
).
Productivity
stores
existing
at
values
one
are
rates
particular
of
time.
73
2
E c o s ys t E m s
a n d
E c o l o g y
Supermarket analogy
The
at
turnover
the
goods
stocked
shelves
sold
the
considerably
biomass
of
The
on
of
rate
simply
bars
trophic
to
can
are
be
a
the
As
in
the
as
in
only
the
at
standing
on
rate
which
shops
the
the
at
a
may
city
same
shelves,
that
by
stock
just
goods
have
centre
way,
are
well
being
stocked
shop
may
pyramids
whereas
is
looking
being
be
of
pyramids
removed
by
assistants.
to
of
the
the
total
term
energy
energy
productivity,
the
stock
compared
from
In
which
10%
of
the
goods
proportion
about
be
Both
shop.
shop
pyramids
is
of
stock
rate
Sometimes
it
shelves;
village
by
cannot
known.
removal
restocked
one.
here
of
the
to
represent
drawn
either
it
on
than
show
next,
lower
be
avoid
and
level.
the
the
supermarkets
needs
more
productivity
customers
two
displayed
and
but
of
in
each
pyramid
bar
of
(biomass)
or
the
energy
utilized
one
level
will
be
energy
is
productivity.
at
is
each
passed
about
used
We
10%
which
shall
confusing.
Advantages
pri
uits
●
Most
accurate
shows
actual
transferred
and
N m
allows
for
rate
of
production.
2
Biomass (standing crop)
g m
2
Productivity (ow of
g m
biomass/energy)
●
Allows
●
Pyramids
●
Energy
comparison
of
ecosystems
based
on
relative
energy
ows.
1
yr
2
J m
▲
system,
2
Numbers (standing crop)
are
not
inverted.
1
yr
from
solar
radiation
can
be
added.
Figre 2.2.14 Pyramid units.
Disadvantages
Note the notation: N = numbers,
●
It
is
very
difcult
and
complex
to
collect
energy
data
as
the
rate
of
g = grams, J = joules, the negative
2
biomass
production
There
still
over
time
is
required.
indices replace / , eg N/m
●
is
species
to
a
the
problem
particular
(as
in
trophic
the
level
other
when
pyramids)
they
may
of
be
assigning
a
omnivorous.
T 
On graph paper, draw and label pyramids from the data in the table. Comment on these.
nber ri
Primary producers
Primary consumers
Secondary consumers
Top consumers
2
Biss ri / kJ 
2
prctiit ri / 0 0 0 kJ 
100,000
2,500
500
10,000
200
50
2,000
15
5
500
1
–
1
r
T thik bt
Cseqeces f ris  ecsste
Bicclti  bigicti
fcti
If a chemical in the environment (eg a pesticide or a
heavy metal) breaks down slowly or does not break
1.
The concentration of toxic substances in food chains.
2.
The limited length of food chains.
3.
The vulnerability of top carnivores.
down at all, plants may take it up and animals may take
it in as they eat or breathe. If they do not excrete or
74
2 . 2
C o m m u n I T I E S
a n d
E C o S y S T E m S
egest it, it accumulates in their bodies over time. If the
A serious problem with pesticides is how long they
chemical stays in the ecosystem for a prolonged period
last in the environment once they are sprayed. Some
of time the concentration builds up. Eventually, the
decompose into harmless chemicals as soon as they
concentration may be high enough to cause disease or
touch the soil. Glyphosate (rst sold by Monsanto as
death. This is bicclti.
Roundup) is one of these: once it touches the soil, it is
inactivated. Others are persistent and do not break down
If a herbivore eats a plant that has the chemical in its
in this way. They enter the food web and move through
tissues, the amount of the chemical that is taken in by
it from trophic level to trophic level as they do not break
the herbivore is greater than that in the plant that is
down even inside the bodies of organisms. They are
eaten – because the herbivore grazes many plants over
nonbiodegradable (POPs, see subtopic 1.5). Many
time. If a carnivore eats the herbivores, it too will take
early insecticides such as DDT, dieldrin and aldrin fall
in more of the chemical than each herbivore contained
into this group and they are stored in the fat of animals.
as it eats several herbivores over time. In this way the
Seals and penguins in Antarctica and polar bears in the
chemical’s concentration is magnied from trophic level
Arctic have been found with pesticides in their tissues.
to trophic level. While the concentration of the chemical
The nearest land where the pesticides have been used is
may not aect organisms lower in the food chain, the top
thousands of kilometres away. How may the pesticides
trophic levels may take in so much of the chemical that it
have reached them?
causes disease or their death. This is bigicti.
T 
In this food web, the smaller sh (minnows) eat plankton
1.
How many trophic levels are in this food web?
(microscopic plants and animals) in the water. The
2.
How many times more concentrated is the DDT in the
minnow is eaten by the larger sh called pickerel. These
body of the cormorant than the water? Explain how
are eaten by herons, ospreys and cormorants and
this happens.
herons eat the minnows as well. The numbers give the
3.
In which species does bioaccumulation occur?
4.
In which species does biomagnication occur?
percentage concentration of DDT.
Cormorant eats
medium to large
sh 26.4
osprey eats medium
to large sh 13.8
heron eats
small sh
3.57
pickerel eats minnows and
other small sh
1.33
minnow eats plankton
0.23
plankton – small organisms
suspended in water: their
very high ratio of surface area
to volume means they easily
absorb pesticide from water,
concentrating it 800 times
0.04
water
▲
0.00005
Figre 2.2.15 Food web in a freshwater ecosystem
75
2
E c o s ys t E m s
a n d
E c o l o g y
T 
1.
An ecosystem consists of one oak tree on which
3.
Assuming an ecological eciency of 10%, 5% and
10,000 herbivores are feeding. These herbivores are
20% respectively (see gure 2.2.16), what will be
prey to 500 spiders and carnivorous insects. Three
the energy available at the ter tiary consumer level
birds are feasting on these spiders and carnivorous
(4th trophic level), given a net primary productivity
insects. The oak tree has a mass of 4,000 kg, the
of 90,000 kJ m
herbivores have an average mass of 0.05 g, the
gure of the original energy value at the primary
spiders and carnivorous insects have an average
producer level?
2
1
yr
? What percentage is this
mass of 0.2 g and the three birds have an average
20%
mass of 10 g.
a.
Construct a pyramid of numbers.
b.
Construct a pyramid of biomass.
c.
Explain the dierences between these two
5%
10%
pyramids.
2
1
90,000 kJ m
2.
yr
Explain whether the energy ‘loss’ between two
subsequent trophic levels is in contradiction with the
▲
Figre 2.2.16
rst law of thermodynamics (see 1.3).
y d U t s
Story of Minamata Bay
Minamata
is
dominated
Chisso
from
a
by
make
small
one
fertilizer
E s a c
released
to
Bay.
an
1950s,
started
to
plastics.
from
in
estimated
into
several
suffer
1932
24
Minamata
thousand
from
of
released
1968
Bay.
into
Beginning
living
in
the
eat
food
over
in
30
illnesses
locally
the
poisoning.
had
elemental
process
some
to
happened?
mercury
was
released
bacteria
the
can
modied
Methylmercury
small
are
sh.
76
organisms
eaten
The
by
the
elemental
called
easily
as
There
this
the
Also,
shrimp.
does
into
the
When
not
sh.
sh
and
were
years
and
to
of
happens
a
long
shrimp,
The
when
Minamata
recognize
by
the
is
ate
people
a
mercury.
cause
still
although
of
in
lot
It
of
took
their
being
the
the
same
bioaccumulated
compensation
in
for
more
increases.
poisoned
Corporation
bodies
and
Mercury
People
stopped
of
bodies
the
shrimp
enters
break
of
the
down
is
food
small
mercury
methylmercury
methylmercury
from
Bay.
methylmercury.
absorbed
the
more
concentration
chain.
Chisso
in
eat
given
by
mercury
1968.
containing
Minamata
change
such
sh,
water
methylmercury
into
form
is
Waste
and
stay
sh
methylmercury
then
release
What
of
shellsh
and
can
the
increase
the
Chisso
mercury
people
mercury
containing
was
and
As
amount
substances
and
tonnes
time.
factory.
water
process
easily
Japan,
Chisso
Waste
this
Between
methylmercury
the
town
the
petrochemical-based
methylmercury
Minamata
factory
factory,
a
slow
chain:
amounts
bacteria
lots
of
sh
the
sh
top
and
very
of
of
lots
and
the
absorb
many
mercury
building
eat
concentration
at
orders-of-magnitude
up
of
the
−
nally
a
again
small
chain
levels
many
build-up
absorb
shrimp
mercury
shrimp
food
high
bacteria
eat
a
lot
concentration
building
number
eventually
of
along
very
up
of
eat
a
−
the
humans
lot
methylmercury.
of
2 . 2
C o m m u n I T I E S
a n d
E C o S y S T E m S
Why top carnivores are in trouble
Practical
It
is
often
the
highest
trophic
level
in
a
food
chain
(the
top
Construct
that
is
the
most
susceptible
to
alterations
in
the
environment.
In
the
population
of
the
peregrine
falcon
(a
bird
of
prey)
crashed
in
a
pyramid
of
UK,
numb ers
the
Work
carnivore)
the
of
for
a
local
late
ecosystem.
1950s
and
probably
then
thinning
and
recover
The
a
of
the
down
change
in
numbers
low
species
food
breeding
1960s,
food
the
their
the
the
persecution
their
are
therefore
than
mid
agricultural
in
reduced
the
despite
top
further
to
magnifying
and
from
due
chain
chain.
food
because
ability
lower
in
to
the
has
of
a
the
food
such
vulnerable
often
in
chain
to
efciency
with
a
to
banned
Build
local
up
a
food
chain
for
ecosystem.
slowly
effects
of
limited
Their
along
changes
diet
so
population
a
inuences
larger
were
egg-shell
collectors.
the
have
accumulating
cause
began
egg
effect.
negative
to
chemicals
from
knock-on
DDT
appeared
These
threat
fall
as
population
carnivores
withstand
the
This
success.
always
Top
prey
chain.
peregrine
and
is
chemicals
food
is
chain,
more
limited
populations.
T thik bt
plr bers  the e ddT
lifetime of the product, but in fact it lasts much longer.
When sofas, carpets and car seats were thrown away,
PBDE entered the rivers, the oceans and the atmosphere.
The Arctic, where all the world’s polar bears live, is one of
the great sinks of the planet. Chemical pollutants such
as PBDE are carried towards the Arctic Ocean by the
great rivers of Russia and Canada. PBDE already in the
sea is taken nor th by ocean currents and carried by the
wind. As it moves through the food chain from plankton
to predator, PBDE bioaccumulates and is biomagnied
so that longlived top carnivores such as the polar bear
accumulate the most concentrated amounts of them.
High amounts of PBDE have now been found in the body
tissue of polar bears and killer whales. The longterm
▲
Figre 2.2.17 Polar bears
environmental eect of PBDE is unknown, but it will
The new DDT could be polybrominated diphenyl ether
probably damage immune systems, brain functions and
(PBDE). It is manufactured in the United States and was
bone strength. It also messes up the polar bear ’s sex
widely used in the 1990s as a ame retardant to coat
hormones. One female bear on Spitzbergen had both
electrical appliances, sofas, carpets and car seats. The
male and female organs, a condition called imposex and
problem is that this chemical was designed to last the
often linked to chemical pollution.
The length of food chains
As
to
is
a
rule
the
next
used
to
the
of
in
thumb,
–
environment.
which
heat.
More
actually
eat
spiky.
before
level
it
to
trophic
states
is
–
lost
by
Some
can
the
that
in
is
the
the
a
energy
on
not
The
it,
or
is
the
at
very
of
to
and
more
it
in
in
level
of
nally
of
plant
dies
going
is
the
transferred
energy
lost
as
heat
thermodynamics
quality
some
ve
part
and
nally
material
because
energy
and
is
law
lower
and
trophic
major
second
energy
little
ecosystems
A
reject
all
one
alive
destroy
they
loss
in
10%.
degraded
eaten
90%
there
terrestrial
of
herbivores
trampling
is
is
is
organism
result
energy
because
means
of
efciency
keep
This
eaten.
next
levels
to
material
be
10%
trophic
respiration
(1.3)
or
the
only
it
is
and
from
available
aquatic
too
to
than
they
tough,
old
decomposes
one
after
trophic
about
four
ecosystems.
77
2
E c o s ys t E m s
Top
carnivores
trophic
erce
to
level.
to
a
are
large
E c o l o g y
vulnerable
There
animals
grow
are
a n d
is
only
rare.
size
It
so
is
and
because
much
hard
to
for
of
the
energy
them
maintain
to
their
loss
of
energy
available
and
accumulate
from
that
is
each
why
enough
big,
energy
bodies.
T 
mel f the strctre f  ecsste
A model is a simplied diagram that shows the structure
and workings (functions) of a system.
Copy and label the model (right) to show the relationship
between trophic levels.
Add arrows and names of the various processes.
▲
Figre 2.2.18
T 
Cstrctig  f eb fr ifrti
the water. The Azolla is an ecient nitrogen xer, and is
readily eaten by the ducks, as well as attracting insects
Make a list of all the organisms described in the
to be similarly enjoyed by the ducks. The plant is very
description below and construct a food web diagram to
prolic, doubling itself every three days, so it can be
show all feeding relationships.
harvested for cattlefeed as well. In addition, the plants
The Aigamo paddy farming system is a selfsustaining
spread out to cover the surface of the water, providing
agroecosystem based on rice, ducks (aigamo) and sh.
hiding places for another inhabitant, the roach (a sh),
The ducks eat up insect pests and the golden snails, which
and protecting them from the ducks. The roach feed
attack rice plants. They also eat the seeds and seedlings
on duck feces, on Daphnia (a crustacean) and various
of weeds, using their feet to dig up the weed seedlings,
worms, which in turn feed on the plankton. Both sh
thereby oxygenating the water and encouraging the roots
and ducks provide manure to fer tilize the rice plants
of the rice plants to grow more strongly. The ‘pests’ and
throughout the growing season, and the rice plants in
‘weeds’ are food sources for rearing the ducks. The ducks
turn provide shelter for the ducks.
are left in the elds 24 hours a day and are completely
The Aigamo paddy eld, then, is a complex, well
freerange until the rice plants form ears of grain in
balanced, selfmaintaining, selfpropagating ecosystem.
the eld. At that point, the ducks have to be rounded
The only external input is the small amount of waste
up (otherwise they will eat the rice grains) and are fed
grain fed to the ducks, and the output is a delicious,
exclusively on waste grain. There they mature, lay eggs,
nutritious harvest of organic rice, duck and roach. It is
and fatten up for the market.
amazingly productive. A two hectare farm of which 1.5 ha
The ducks are not the only inhabitants of this system.
are paddy elds can yield annually seven tonnes of rice,
The aquatic fern, Azolla, or duckweed, which harbours
300 ducks, 4,000 ducklings and enough vegetables to
a mutualistic bluegreen bacterium that can x
supply 100 people.
atmospheric nitrogen, is also grown on the surface of
78
2 . 3
F L o w S
o F
E n E R G y
a n d
m a T T E R
2.3 Fls f eerg   tter
sii ie:
appii  ki:
➔
Ecosystems are linked together by energy and
➔
alse quantitative models of ows of energy
matter ows.
and matter.
➔
The Sun’s energy drives these ows and
➔
Cstrct quantitative model of ows of energy
humans are impacting the ows of energy and
or matter for given data.
matter both locally and globally.
➔
alse the eciency of energy transfers
through a system.
➔
Clclte the values of both gross primary
productivity (GPP) and net primary productivity
(NPP) from given data.
➔
Clclte the values of both gross secondary
productivity (GSP) and net secondary
productivity (NSP) from given data.
➔
discss human impacts on energy ows, the
carbon and nitrogen cycles.
Kwee  ueri:
➔
As slr riti (insolation) enters the Ear th’s
➔
atmosphere some energy becomes unavailable
for ecosystems as the energy is absorbed
given period of time is measured as rcti it.
➔
by inorganic matter or reected back into the
Pathways of radiation through the atmosphere
rir rcti it (Gpp). npp = Gpp - R
➔
involve a loss of radiation through reecti 
Grss secr rcti it (GSp) is the total
energy / biomass assimilated by consumers and
bsrti as shown in gure 2.3.1.
➔
net rir rcti it (npp) is calculated
by subtracting respiratory losses (R) from gross
atmosphere.
➔
The conversion of energy into biomass for a
is calculated by subtracting the mass of fecal
Pathways of energy through an ecosystem
loss from the mass of food eaten. GSp = f
include:
ete - fecl lss
●
conversion of light energy to chemical
➔
energy
●
●
by subtracting respiratory losses (R) from GSP.
nSp = GSp - R
transfer of chemical energy from one trophic
level to another with varying eciencies
➔
reradiation of heat energy to the
atmosphere.
mxi sstible iels are equivalent to
the net primary or net secondary productivity of
overall conversion of ultraviolet and visible
a system.
light to heat energy by an ecosystem
●
net secr rcti it (nSp) is calculated
➔
Matter also ows through ecosystems linking
them together. This ow of matter involves
trsfers and trsfrtis
79
2
E c o s ys t E m s
➔
a n d
E c o l o g y
The crb  itrge ccles are used to
➔
illustrate this ow of matter using ow diagrams.
organisms (organic), soil, fossil fuels,
These cycles contain storages (sometimes
atmosphere and water bodies (all inorganic).
referred to as sinks) and ows which move
➔
matter between storages.
➔
➔
Strges i the itrge ccle include
Fls i the itrge ccle include nitrogen
xation by bacteria and lightning, absorption,
Strges i the crb ccle include organisms
assimilation, consumption (feeding), excretion,
and forests (both organic), or the atmosphere,
death and decomposition, and denitrication by
soil, fossil fuels and oceans (all inorganic).
bacteria in waterlogged soils.
Fls i the crb ccle include consumption
➔
H cti ities such as burning fossil fuels,
(feeding), death and decomposition,
deforestation, urbanization and agriculture
photosynthesis, respiration, dissolving and
impact energy ows as well as the carbon and
fossilisation.
nitrogen cycles.
Ke its
●
Almost all energy that drives processes on Ear th comes from the Sun.
●
This is called slr riti and is made up of visible wavelengths (light)
and those wavelengths that humans cannot see (ultraviolet and infrared).
●
Some 60% of this is intercepted by atmospheric gases and dust par ticles.
Nearly all the ultraviolet light is absorbed by ozone.
●
Most of the infrared light (heat) is absorbed by carbon dioxide, clouds and
water vapour in the atmosphere.
●
Both ultraviolet and visible light energy (shor t wave) are conver ted to heat
energy (long wave) (following the laws of thermodynamics).
●
The systems of the biosphere are dependent on the amount of energy
reaching the ground, not the amount reaching the outer atmosphere. This
amount varies according to the time of day, the season, the amount of
cloud cover and other factors.
●
Most of this energy is not used to power living systems, it is reected from
soil, water or vegetation or absorbed and reradiated as heat.
●
Of the energy reaching the Earth’s surface, about 35% is reected back into
space by ice, snow, water and land.
●
Some energy is absorbed and heats up the land and seas.
●
Of all the energy coming in, only about 1–4% of it is available to plants on the
surface of the Earth.
80
●
This energy is captured by green plants which convert light to chemical energy.
●
Then the chemical energy is transferred from one trophic level to the next.
2 . 3
F L o w S
o F
E n E R G y
a n d
m a T T E R
the fe f r rii rehi he Erh
total absorption
total reection 31%
69%
entering
reection by
solar
scatter 3%
radiation
absorption by
100%
clouds 19%
molecules and dust
1
7%
ground 9%
clouds
3%
ground
absorption
49%
land and ocean
▲
Figre 2.3.1 The fate of solar radiation hitting the Ear th
Our
It
Sun
has
helium
and
is
about
burned
it
and
takes
Earth.
The
up
4.5
billion
about
release
eight
half
energy.
minutes
energy
leaving
1
per
square
metre
(J
s
years
of
its
This
for
a
the
old
energy
photon
Sun
is
is
the
The
of
Earth’s
only
Earth
solar
way
in
photosynthesis
is
an
efcient
in
through
nuclear
packets
leaving
63
the
called
Sun
million
its
fusion
to
lifespan.
to
make
photons
reach
joules
per
the
second
).
The
1,400
J
solar
s
energy
reaching
the
top
of
the
2
m
(or
1,400
watts
per
second).
This
constant
which
by
is
in
2
m
is
halfway
about
1
atmosphere
and
hydrogen
life
green
converter,
can
plants.
the
turn
For
gures
solar
a
energy
crop
are
as
plant,
into
food
such
follows.
The
as
is
through
wheat,
plant
can
which
only
loss of energy
1000
in photosynthesis reactions
reected
500 not
500
50
308
air
(wavelengths
available
unsuitable)
400
absorbed by chloroplasts
leaf
oxidation in
92
mitochondria
glucose
37
ToK
55
net primary
What role does indigenous
production
knowledge play in passing
air
37
50
on scientic knowledge?
When is quantitative data
loss of energy
transmitted
superior to qualitative data
in respiration
in giving us knowledge
▲
Figre 2.3.2 Photosynthetic eciency of a crop plant. This is based on the input
about the world?
of 1,000 units of solar radiation
81
2
E c o s ys t E m s
a n d
E c o l o g y
absorb
about
40%
of
the
energy
that
hits
a
leaf.
About
5%
is
reected,
Ke ter
50%
the
lost
red
and
and
5%
blue
passes
straight
wavelengths
through
of
light
in
the
leaf.
But
plants
photosynthesis
and
only
use
reect
the
prctiit is the
other
colours
(which
is
why
plants
look
green).
So
of
the
40%,
just
over
this
is
conversion of energy into
9%
can
be
used.
This
is
the
GPP
of
the
plant.
Just
under
half
of
biomass over a given period
required
in
becomes
NPP
respiration
to
stay
alive
so
5.5%
of
the
energy
hitting
a
leaf
of time. It is the rate of
(new
plant
material).
growth or biomass increase
in plants and animals. It is
Of
measured per unit area per
of
all
it
the
solar
(GPP)
radiation
and
use
falling
some
of
on
that
the
to
Earth,
stay
plants
alive.
What
only
is
capture
left
over
0.06%
(NPP)
2
unit time, eg per metre
2
year. (m
per
is
the
amount
of
food
available
to
all
the
animals
including
humans.
1
yr
).
In
general
about
the
2–3%
aquatic
plants,
efciency
in
systems
though
zooplankton
of
terrestrial
as
it
water
is
absorbs
variable
feeding
on
conversion
systems
and
but
of
energy
even
more
there
of
the
are
to
lower
food
at
light
is
low
about
before
exceptions
1%
it
(such
at
in
many
reaches
as
the
marine
phytoplankton).
Pruivi
Grss refers to the total amount of something made as a result of an activity,
eg prot from a business or salary from a job.
net refers to the amount left after deductions are made, eg costs of production
or deductions of tax and insurance from a salary. It is what you have left and is
Ke ters
always lower than the gross amount.
Grss rctiit (GP) is
prir in ecology means to do with plants. Secr is to do with animals.
the total gain in energy or
Biss is the living mass of an organism or organisms but sometimes refers
biomass per unit area per
to dry mass.
unit time. It is the biomass
that could be gained by
Now we have these clear, we can put some together.
an organism before any
deductions.
net rctiit (NP) is the
Net
productivity
(NP)
results
from
the
fact
that
all
organisms
have
gain in energy or biomass per
to
respire
to
stay
alive
so
some
of
this
energy
is
used
up
in
staying
alive
unit area per unit time that
instead
of
being
used
to
grow.
remains after deductions
We
usually
talk
about
productivity
and
not
production
in
ecology
–
that
due to respiration.
way
we
know
the
area
or
volume
and
the
time
period
to
which
we
refer.
Grss rir rctiit
Primary
productivity :
autotrophs
are
the
base
unit
of
all
stored
energy
(GPP) is the total gain in
in
any
ecosystem.
Light
energy
is
converted
into
chemical
energy
by
energy or biomass per unit
photosynthesis
using
chlorophyll
within
the
cells
of
plants.
area per unit time by green
plants. It is the energy xed
(or conver ted from light to
chemical energy) by green
plants by photosynthesis.
Gross
the
is
primary
production
theoretically
the
amount
of
productivity
chain.
They
possible
sugar
to
x
(GPP) :
light
calculate
produced
plants
energy
a
are
and
plant’s
the
rst
convert
energy
it
organisms
to
uptake
sugars
by
in
so
it
measuring
(GPP).
But, some of this is used in
However
measuring
the
sugar
produced
is
extremely
difcult
as
much
respiration so...
it
82
is
used
up
by
plants
in
respiration
almost
as
soon
as
it
is
produced.
A
of
2 . 3
more
useful
way
of
looking
at
production
of
plants
is
F L o w S
the
o F
E n E R G y
a n d
m a T T E R
measurement
Ke ter
of
net
An
primary
ecosystem’s
productivity
NPP
is
the
rate
(NPP) .
at
which
plants
accumulate
dry
net rir rctiit
mass
2
(actual
in
plant
material)
photosynthesis
has
usually
two
measured
main
in
g
m
.
This
glucose
produced
(NPP) is the total gain in
energy or biomass per unit
fates.
area per unit time by green
●
Some
provides
for
growth,
maintenance
and
reproduction
(life
plants after allowing for
processes)
with
energy
being
lost
as
heat
during
processes
of
losses to respiration. This
respiration.
is the increase in biomass
●
The
remainder
represents
for
the
consumers
is
deposited
stored
dry
within
in
and
mass
the
–
around
this
store
cells
of
as
new
energy
is
material
and
potential
food
ecosystem.
of the plant – how much it
grows – and is the biomass
that is potentially available
to consumers (animals) that
So,
NPP
represents
the
difference
between
the
rate
at
which
plants
eat the plant.
photosynthesize,
accumulation
useful
of
measure
GPP
,
dry
of
and
mass
both
the
is
the
rate
at
usually
which
termed
production
and
they
respire.
biomass
the
and
This
provides
utilization
of
a
NPP =
resources.
GPP
R where
R = respiratory loss
NPP = GPP – R
glucose produced
▲
some glucose used to supply
remaining glucose available
energy to drive cellular
to be laid down as new
processes (respiration)
material – biomass (NPP)
Figre 2.3.3
The
of
during photosynthesis (GPP)
total
amount
energy
that
carnivores
●
lost
●
eaten
is
that
from
by
of
plant
available
feed
food
on
all
them.
chains
herbivores
material
to
as
it
It
has
dies
which
is
the
the
theoretical
animals,
two
and
means
both
amount
herbivores
and
the
fates:
decays
it
maximum
the
is
OR
removed
from
primary
productivity.
The
●
amount
Spatially:
tropical
●
of
some
to
warmth
vs
Many
changing
(see
produced
biomes
rainforest
Temporally:
linked
biomass
have
varies.
much
higher
NPP
rates
than
others
–
eg
tundra.
plants
have
availability
succession
seasonal
of
basic
patterns
resources
of
–
productivity
light,
water
and
2.4).
83
2
E c o s ys t E m s
a n d
E c o l o g y
Net secondary productivity (NSP)
As
with
make
●
plants,
new
Only
■
food
Some
Some
■
The
Some
of
is
of
the
goes
wall
is
into
the
herbivore
is
available
to
fates.
of
used
is
the
stored
as
in
be
to
the
alimentary
power
life
canal
(gut
processes
wall)
of
( assimilated
the
energy
used
ingested
of
in
be
dry
is
used
material
as
feces
no
waste,
mass
in
cellular
respiration
of
in
new
will
most
body
pass
animals
urine.
tissue.
straight
(egestion).
as
This
is
through
not
the
absorbed
energy.
herbivores
ingested
(net
the
secondary
energy
lost
productivity)
in
=
egestion
respiration
including
secondary
can
the
with
food
energy
processes.
nitrogenous
plant
animals
food
life
released
productivity
productivity
for
ingested
and
in
food
assimilated
energy
energy
gross
that
different
and
removed
provides
net
of
has
crosses
the
rest
herbivore
Total
it
absorbed
provide
■
and
that
is
energy
energy):
to
●
all
biomass,
animals
food
not
the
food
productivity
thought
of
in
that
is
(GSP).
the
egested
is
Therefore
same
way
as
the
net
net
measure
secondary
primary
productivity.
energy to drive cellular
processes (respiration)
total energy taken in
Ke ters
(food eaten)
new
biomass
waste
Grss secr rctiit
(feces and urine)
(GSp) is the total energy / biomass
assimilated (taken up) by consumers
Only
a
very
small
percentage
of
the
original
NPP
of
plants
is
turned
and is calculated by subtracting the
into
secondary
productivity
by
herbivores
and
it
is
this
secondary
mass of fecal loss from the mass of
productivity,
which
is
available
to
consumers
at
the
next
trophic
level.
food eaten.
This
GSP = food eaten
fecal loss
the
change
general
of
primary
conditions
productivity
of
energy
to
secondary
transfer
up
the
productivity
trophic
follows
levels.
Animals are known as heterotrophs or
Carnivores,
animals
that
eat
other
animals,
are
the
next
up
the
trophic
heterotrophic organisms to distinguish
ladder.
Secondary
consumers
are
those
that
eat
herbivores
and
tertiary
them from plants (autotrophs). Troph
consumers
are
those
whose
main
source
of
energy
is
other
carnivores.
is derived from the Ancient Greek word
The
ability
of
carnivores
to
assimilate
energy
follows
the
same
basic
path
for food, so plants are autofeeding
as
that
of
herbivores,
though
secondary
and
tertiary
consumers
have
and animals otherfeeding (hetero =
higher
protein
diets,
meat,
which
is
more
easily
digested
and
assimilated.
other) or feed on others.
Carnivores
net secr rctiit (NSP) is
●
On
●
They
●
Usually
they
is
by
average
they
assimilate
80%
of
the
energy
in
their
diets.
the total gain in energy or biomass per
unit area per unit time by consumers
egest
less
than
20%.
after allowing for losses to respiration.
have
to
chase
moving
animals
so
higher
energy
intake
There are other losses in animals as
offset
increased
respiration
during
hunting.
well as to respiration but respiration is
the main one.
●
Biomass
parts,
is
such
locked
as
up
bone,
in
the
horn
prey
and
foods
antler
–
–
so
non-digestible
they
have
to
skeletal
assimilate
the
nSp is calculated by subtracting
maximum
respiratory losses (R) from GSP
.
84
amount
of
energy
that
they
can
from
any
digestible
food.
2 . 3
F L o w S
o F
E n E R G y
a n d
m a T T E R
Herbivores
T thik bt
●
Assimilate
●
They
egest
60%.
●
They
graze
static
about
40%
of
the
energy
in
their
diet.
ntriet cclig 
Gersehl’s triet 
plants.
el
The diagram below shows the
Fw f eer  er
three major stores of nutrients
in ecosystems represented
Fl
Eerg s thrgh sstes
How much?
mtter ls s thrgh
Innite (the Sun is always
by circles and major ows
ecsstes (triets, x ge,
of nutrients between them
crb ixie, ter)
as arrows. What is really
clever about this model is
Finite
that the size of the circles is
shining somewhere)
proportional to the quantity of
When?
Once
Cycles and recycles repeatedly
Outputs
All organisms give out energy all
All organisms release waste
the time as respiration releases
nutrients, carbon dioxide and
heat
water
Degrades from higher to lower
May change form but does not
quality energy (light to heat) so
degrade
nutrients that are stored, and
the thickness of the arrows is
proportional to the amounts
of nutrients transferred. This
Quality
allows the nutrient cycles of
dierent ecosystems to be
entropy increases
easily compared.
Storages
Temporarily stored as chemical
Is stored long and shor t term in
energy
chemical forms
●
The biomass circle
represents nutrients
▲
Figre 2.3.4 Comparing energy and matter ows
stored in the forest
vegetation and animal life.
Transfers and transformations
●
Both
matter
Both
types
and
energy
move
or
ow
through
ecosystems
(see
The litter circle represents
1.2).
the nutrients trapped in
and
are
of
ow
therefore
use
energy
more
–
transfers,
efcient
than
being
simpler,
use
less
fallen leaves and dead
energy
organisms.
transformations.
●
The soil circle represents
Cycles and ows
the nutrients present
Energy
ows
radiation
through
and
nally
decomposers.
cycle:
and
to
nutrients
circulate
the
On
ecosystem
leaving
the
are
an
other
through
the
usually
biogeochemical
cycles .
heat
hand
absorbed
ecosystem,
as
by
one
organisms
the
direction,
released
chemical
trophic
via
in
levels
through
nutrients
from
and
detritus
starting
are
food
the
in
the
nally
chain.
solar
respiration
the
soil
as
in soil humus, ie
of
decomposing leaves and
biosphere
and
released
These
other dead organisms.
atmosphere
are
back
the
biomass
precipitation
Nutrient cycles
There
some
are
around
exist
only
40
in
elements
trace
that
amounts.
cycle
All
through
the
ecosystems,
biogeochemical
though
cycles
have
litter
both
organic
(when
the
(when
element
phases.
Both
are
organic
phase
the
is
in
vital:
element
a
is
simpler
the
in
a
form
efciency
of
living
organism)
outside
living
movement
and
inorganic
organisms)
through
soil
the
run-o
Yet
the
major
determines
reservoir
how
for
all
much
the
is
main
available
to
elements
living
tends
to
organisms.
be
leaching
outside
weathering
of
the
this
food
chain
inorganic
as
phase
inorganic
tends
to
molecules
be
much
in
rock
slower
and
than
soils.
the
Flow
in
movement
▲
Figre 2.3.5 Gersmehl’s
nutrient model
85
2
E c o s ys t E m s
a n d
E c o l o g y
of
these
nutrients
biogeochemical
and
phosphorus,
which
●
have
different
Energy
lost
●
to
of
which
matter
food
organic
phase.
carbon,
partially
The
nitrogen,
similar
routes
major
sulphur
and
all
of
as
nutrients,
Sun,
of
through
an
ecosystem
is
very
energy.
through
food
webs
and
is
eventually
are
nite
and
are
recycled
and
reused
(via
the
chain).
die
becoming
by
follow
such
the
eventually
up
the
water,
heat.
Organisms
taken
of
movement
from
as
and
decomposer
of
organisms,
those
characteristics:
the
travels
space
are
matter,
from
Nutrients
●
all
similar
Movement
●
through
cycles
and
are
plants.
decomposed
parts
These
of
living
are
the
and
nutrients
things
again,
are
released,
when
biogeochemical
they
are
cycles.
The carbon cycle
atmospheric carbon dioxide
combustion
respiration
higher
consumers
photosynthesis
fossil fuels and wood
primary
consumers
detritivores
detritus
fossils and
sediments
▲
Figre 2.3.6 The carbon cycle
Where is the carbon stored?
In
carbon
Organic
or
(with
Organisms
●
Fossilized
●
rocks
up
and
millions
●
The
the
life
or
of
oceans
shells
●
Soil.
●
A
forms,
small
xed
in
eg
carbon
fossil
sinks.
carbon
(biomass)
(simple
Locked
dioxide
complex
●
Inorganic
86
carbon
may
be:
molecules):
the
biosphere
fossil
–
living
plants
and
animals.
fuels.
molecules):
into
fuels.
These
solid
Most
forms
carbon
and
is
stored
stored
as
here
sedimentary
and
locked
up
for
years.
where
of
carbon
marine
proportion
is
dissolved
or
locked
up
as
carbonates
organisms.
is
carbon
dioxide
in
the
atmosphere
(0.37%).
in
2 . 3
F L o w S
o F
E n E R G y
a n d
m a T T E R
Carbon ows
T 
The
carbon
living
cycle,
systems
in
which
occurs
in
carbon
the
circulates
ecosphere.
through
Here
carbon
living
is
and
found
in
non-
four
Draw your own diagram of
main
storages:
the
soil,
living
things
(biomass),
the
oceans
and
the
the carbon cycle.
atmosphere.
Carbon
not
in
the
atmosphere
is
stored
in
carbon
dioxide
Include these ows and label
sinks
(soil,
biomass
and
oceans),
as
complex
organic
molecules
or
them:
dissolved
in
seawater.
photosynthesis
Carbon
cycles:
cycles
it
is
between
xed
by
living
(biotic)
photosynthesis
through
respiration.
Carbon
through
combustion
of
is
fossil
also
fuels
and
and
non-living
released
released
and
back
back
biomass.
(abiotic)
to
to
the
When
the
chemical
respiration
atmosphere
atmosphere
dead
feeding
organisms
death and decomposition
decompose,
when
they
respire
and
when
fossil
fuels
are
burned,
the
fossilisation
carbon
are
is
oxidized
released.
xation
–
By
and
to
carbon
dioxide
photosynthesis,
lock
it
up
in
and
plants
their
this,
water
recapture
bodies
for
a
vapour
this
time
as
and
carbon
–
glucose
heat
carbon
or
combustion
other
dissolving
large
molecules.
For each ow, draw:
When
plants
are
harvested
and
cut
down
for
food,
rewood
or
storages as boxes
processing,
burn
fossil
carbon
in
Carbon
the
carbon
fuels
the
can
and
is
cut
also
down
atmosphere
remain
released
trees,
and
locked
in
again
we
are
changing
either
the
cycle
to
the
atmosphere.
increasing
balance
for
long
the
of
we
amount
the
periods
As
carbon
of
arrows to represent the
of
sizes of the ow.
cycle.
time,
ie
in
Label biotic and abiotic
the
wood
of
trees
or
as
coal
and
oil.
phases.
Human
(carbon
activity
has
budget)
disrupted
through
the
balance
increased
of
the
global
combustion,
land
carbon
use
cycle
changes
and
deforestation.
The carbon budget
The
amount
idea
of
of
where
carbon
it
goes.
on
Earth
The
is
a
diagram
nite
of
the
amount
carbon
and
we
have
a
cycle
in
gure
gigatonnes
of
carbon
Global ows of carbon
rough
2.3.7
GtC gigatonnes carbon/year
shows
carbon
sinks
(storages)
and
ows
in
(GtC).
>100*
9
A
gigatonne
is
one
billion
tonnes
(10
tonnes).
atmosphere
5.5
750+
Humans and the carbon cycle
100
Our
annual
GtC.
About
current
20%
of
global
this
is
emissions
from
from
burning
burning
natural
fossil
gas,
fuels
40%
are
from
about
5.5
>100
biomass
coal
and
the
other
40%
from
burning
oil.
Another
1.6
GtC
are
deforestation.
So
7.1
GtC
enter
the
atmosphere
each
surface ocean
coal
and plankton
oil gas
1,720
4,000
added
650
through
year.
Only
soil 1,500
about
2.4–3.2
things.
GtC
Diffusion
of
of
this
stay
carbon
in
the
dioxide
atmosphere.
into
the
Some
oceans
and
is
taken
uptake
100
burning
up
by
by
living
oceanic
*deforestation
contributes
deep ocean
phytoplankton
accounts
for
2.4
GtC.
New
growth
in
forests
xes
about
0.5
about 1.6
40,000
GtC
a
year.
But
this
still
leaves
between
1
and
1.8
GtC
–
a
large
amount
–
▲
unaccounted
for.
We
are
not
sure
where
it
goes
because
of
the
Figre 2.3.7 The carbon cycle
complexity
with ow values
of
the
system.
The
●
atmosphere
●
standing
●
soils
●
oceans
Since
amounts
of
carbon
in
GtC
in
other
reservoirs
are:
750
biomass
650
1,500
the
1,720.
pre-industrial
period,
we
have
added
200
GtC
to
the
atmosphere.
87
2
E c o s ys t E m s
a n d
E c o l o g y
The nitrogen cycle
All
living
proteins
organisms
and
Nitrogen
nitrogen
is
is
need
nitrogen
as
it
is
an
essential
element
in
DNA.
the
most
abundant
unavailable
microorganisms
can
to
x
gas
plants
in
and
atmospheric
the
atmosphere
animals,
though
but
atmospheric
some
specialized
nitrogen.
nitrogen
in air
proteins
in animals
proteins
lightning
in plants
feeding
death
urea
death
nitrogen-xing
bacteria in soil
denitrifying
decay bacteria
bacteria
and fungi
▲
nitrates
nitrifying
ammonia
in soil
bacteria
in soil
Figre 2.3.8 The nitrogen cycle
Nitrogen
storages
or
sinks
are:
Flows
in
the
nitrogen
●
organisms
●
nitrogen
●
soil
●
nitrication
●
fossil
●
denitrication
●
the
●
feeding
●
in
For
fuels
atmosphere
water.
plants
to
take
up
nitrogen,
it
■
absorption
■
assimilation
■
consumption
excretion
●
death
be
in
the
are:
xation
●
must
cycle
and
decomposition.
form
of
ammonium
+
ions
(NH
)
or
nitrates
(NO
4
nitrogen
The
Animals
eat
plants
and
so
take
in
their
3
the
nitrogen
xation,
88
in
).
form
cycle
of
can
nitrication
amino
be
and
acids
thought
and
of
in
nucleotides.
three
denitrication.
basic
stages:
nitrogen
2 . 3
Nitrogen
xation:
when
atmospheric
nitrogen
(N
)
F L o w S
is
made
o F
E n E R G y
a n d
m a T T E R
available
2
to
plants
from
ve
through
gaseous
the
xation
nitrogen
By
nitrogen-xing
2.
By
nitrogen-xing
leguminous
sugars
with
nitrates.
or
Asian
or
water.
rice
even
By
ions
The
The
form
last
nitrogen.
can
be
This
carried
conversion
out
in
one
of
in
are
other
of
causing
into
are
soil
( Azotobacter).
the
bacteria
cause
root
of
been
algae)
the
nodules
the
provide
blue-green
have
in
provides
high
the
that
of
nitrogen
plant
live
in
productivity
productive
for
nitrogen-containing
oxidation
of
bacteria
gas
of
hundreds
fertilizers.
to
nitrate
soil.
process
Nitrogen
presence
plant
the
without
the
the
the
symbiotically
The
called
which
years
Haber
the
of
in
is
and
of
a
nitrogen-xing
hydrogen
iron
as
a
gases
catalyst
process
are
used
combined
(speeds
up
the
to
under
reaction)
ammonia.
two
processes
Nitrication:
and
also
fertilizers.
pressure
living
(sometimes
many
washed
industrial
make
bacteria
( Rhizobium ).
photosynthesis,
thousands
is
free-living
Cyanobacteria
elds,
lightning
which
to
from
cyanobacteria
soil
5.
ammonium
bacteria
plants
with
By
4.
atmospheric
ways:
1.
3.
to
of
able
to
convert
some
are
bacteria
convert
the
non-living
in
the
ammonium
nitrites
(NO
)
to
nitrogen
soil
to
are
xation.
called
nitrites
nitrates
nitrifying
bacteria
( Nitrosomonas)
(Nitrobacter)
while
which
are
then
2
available
to
be
absorbed
Denitrication:
waterlogged
process
gas
As
by
which
well
also
as
xation
escapes
supplies
nitrate
the
level)
nitrate
and
decomposition
uptake
soil
with
Important
among
(Pseudomonas
oxygen
denitricans ),
conditions,
nitrite
ions
in
reverse
to
this
nitrogen
atmosphere.
for
the
ions.
bacteria
(low
xation,
producing
roots.
ammonium,
nitrogen
These
plants.
much
fungi
ions:
ions
can
in
and
of
nitrogen
organisms
than
decomposition
bacteria.
ammonium
be
dead
Decomposition
more
organisms
others),
different
by
taken
They
ions,
up
by
dead
are
animals
break
nitrite
plants
of
nitrogen
down
ions
which
and
recycle
nitrogen.
Assimilation:
assimilate
in
to
nitrogen
worms
proteins,
nally
denitrifying
processes.
(insects,
plant
anaerobic
converting
provides
organisms
the
and
by
cells
acids
or
turns
and
blocks
it
of
Once
build
living
it
into
inorganic
then
DNA
these
and
organisms
more
nitrogen
join
these
to
taken
proteins.
contain
in
nitrogen,
molecules.
compounds
form
too
have
complex
into
Protein
more
Nucleotides
they
synthesis
complex
are
the
amino
building
nitrogen.
Humans and the nitrogen cycle
It
is
easy
When
for
humans
people
extract
nitrogen
sea
in
human
the
form
of
to
remove
from
the
sewage.
articial
alter
the
animals
cycle.
But
cycle
and
Much
people
fertilizers,
and
plants
can
made
of
this
also
in
upset
for
natural
for
is
nitrogen
Haber
balance.
humans,
nitrogen
add
the
the
food
later
to
process,
the
or
they
lost
to
cycle
by
the
in
planting
89
2
E c o s ys t E m s
a n d
E c o l o g y
leguminous
These
soil
crops
plants
condition
near
the
because
release
also
surface,
of
the
lack
ow
will
away
called
leaching
of
soil
affects
most
of
root
the
as
nodules
with
the
but
gas
and
nitrates
can
are
lead
into
through
into
to
If
to
a
air.
it
can.
lakes
down
called
such
then
The
waterlogged
detritus
Unfortunately
is
soil,
and
bacteria.
decompose.
becomes
This
porous
rivers,
they
break
bacteria
the
nitrogen-xing
when
cycle.
unable
certain
back
rainwater
the
containing
nitrogen
nitrogen
bacteria
oxygen
nitrogen
Excessive
wash
with
enrich
they
denitrication.
as
the
sandy
sea.
soil,
This
eutrophication.
T 
Copy the diagram of the nitrogen cycle and add these
Copy and complete:
terms to it:
Nitrogen xation is:
nitrogen xation, nitrication, denitrication,
Nitrication is:
decomposition, assimilation.
Denitrication is:
Assimilation (or protein formation) is:
Nitrogen gas (N
) in air
2
xation by the
conversion of nitrates
Haber process
to nitrogen by
denitrifying bacteria
xation by
nitrogen in
lightning
animal proteins
xation by bacteria in
root nodules of leguminous
plants
egestion
feeding
nitrogen in
plant proteins
excretion
absorption by
plant roots
decay by
bacteria
ammonium ions and
nitrates in soil
▲
90
Figre 2.3.9 The nitrogen cycle
death
is
2 . 3
F L o w S
o F
E n E R G y
a n d
m a T T E R
Energy ow diagrams
Energy
These
ow
of
ow
show
diagrams
the
diagrams
material
as
allow
energy
also
show
energy
to
easy
entering
loss
the
of
comparison
and
leaving
energy
of
through
decomposer
various
each
food
ecosystems.
trophic
level.
respiration
Energy
and
transfer
chain.
ow of energy and material through an ecosystem
sunlight
heat lost in
heat lost in
respiration
respiration
producers
consumers
heat lost in
respiration
energy
material
inorganic
decomposers
nutrient
pool
▲
Figre 2.3.10 Generalized energy ow diagram through an ecosystem
T 
1
The diagram below shows the ow of energy through
Gross primary productivity (GPP) is
a food web, and should be used for the three
A.
b
c.
B.
b
a.
C.
b.
D.
b
questions (right).
k
j
noitaripser
sresopmoced
carnivores
i
h
g
herbivores
2
f
c
d.
[1]
Net primary productivity (NPP) is
A.
b – c – d.
B.
d + e + f.
C.
e.
D.
e
e
d
producers
d.
[1]
b
c
3
The net productivity for the consumer community is
sunlight not used
sun
a
in photosynthesis
▲
Figre 2.3.11 Generalized energy ow diagram
through a food web
There
you
the
are
need
next
many
to
be
different
able
to
ways
to
interpret
draw
these.
energy
Some
ow
A.
e + h.
B.
e + h
C.
e -
g -
j.
D.
e -
g -
j -
diagrams
examples
are
g -
j -
k -
i -
k.
i.
[1]
and
given
in
pages.
91
2
E c o s ys t E m s
a n d
E c o l o g y
Assimilation and productivity eciencies
There
1.
are
two
What
the
2.
the
1.
an
much
of
organism
animal
How
into
put
2.
proportion
that
of
the
we
need
NPP
to
from
know
one
to
establish
trophic
level
these
is
efciencies.
assimilated
by
next?
How
For
quantities
in
How
into
raised
much
its
this
and
of
a
for
the
body)?
assimilated
how
much
meat
grass
This
is
turned
into
the
tissues
of
respired?
these
that
will
material
is
an
questions
animal
determine
are:
eats
how
can
many
it
assimilate
animals
the
(absorb
farmer
can
eld.
much
of
meat)?
what
On
a
is
assimilated
commercial
is
farm
used
this
gross
for
will
productivity
determine
productivity
×
the
(turned
prots.
100
___
Efciency
of
assimilation
=
food
eaten
net
productivity
×
100
___
Efciency
of
biomass
productivity
=
gross
productivity
Trophic eciency
The
efciency
ratio
of
considered,
quite
of
as
on
from
are
5%
to
mammals
of
0.1%
large
in
as
in
and
20%,
is
a
the
birds)
they
●
all
●
may
is
and
cannot
●
Heat
lost
●
Some
in
energy
at
rst
to
to
10%.
have
is
a
of
may
In
trophic
only
a
While
oceans,
the
of
10%
of
lose
than
a
range
of
small
efciency
rate
a
and
is
ow,
biomass
trophic
20%
(all
rule
generally
metabolic
so
is
not
energy
zooplankton
animals
rates
a
the
are
community
have
and
eg
consumed,
producer
A
high
efciency
assimilation
next,
things
efciencies
volume,
the
the
always,
primary
have
their
As
biomass.
Cold-blooded
occur
and
great
deal
feeding
consume
except
most
mammals
warm-blooded
of
on
and
animals.
because:
eaten
be
to
to
understanding
Trophic
20%
level
productivity
appear.
our
consumer
heat.
(if
it
were,
the
world
would
not
be
green
as
consumed).
inefcient
system
is
aid
ecosystem
slower
would
about
5%
into
trophic
primary
variations.
biomass.
everything
to
warm-blooded,
inefciencies
Digestion
one
they
compared
much
plants
be
as
only
respiration
have
Not
are
area
producer
Trophic
ie
to
helpful
grassland
phytoplankton
of
a
converted
surface
energy
average,
considerable
consumed
from
productivity
straightforward
generalization
there
transfer
secondary
extract
(food
all
is
the
lost
in
energy
feces
from
because
the
digestive
it).
respiration.
assimilated
is
used
in
reproduction
and
other
life
processes.
Energy budgets
For
of
an
individual
energy
This
is
its
entering,
energy
population
what
92
animal
of
stocking
silk
or
staying
budget.
worms
rate
of
population,
within
It
or
can
and
be
locusts
animals
per
we
can
leaving
measured
and
it
hectare
is
measure
the
in
they
animal
the
useful
can
the
or
quantities
population.
laboratory
for
farmers
use.
for
to
a
know
2 . 3
F L o w S
o F
E n E R G y
a n d
m a T T E R
T 
1.
Consider the assimilation eciencies in the table on
orgis
assiilti eciec
the right.
Carnivore
a.
90%
Why do carnivores have a relatively high
Insectivore
70–80%
Herbivore
30–60%
Zooplankton feeding
50–90%
assimilation eciency. (Think about the food
they eat.)
b.
Do you think ruminant herbivores would be at the
on phytoplankton
top or bottom of the range for herbivores? Why?
Giant panda
c.
20%
Why does the giant panda have such a low
2.
assimilation eciency? (Hint: its diet is mainly
Copy gure 2.3.13 and add the energy storages and
transfers in gure 2.3.12.
bamboo shoots.)
solar
energy
6
30.8 × 10
R ?
R 1
794
living plants
4659
3960
R 0.02
R 48
dead vegetation
305
still standing 3684
6053
10067
snails
sheep
dung
dung
8.7
301
132
inver tebrates
roots
0.09
10830
litter
5813
R 180
301
6053
1141
7
2
13
ear thworms
1136
?
R
145
soil organic
1663
matter including
decomposers 499000
▲
Figre 2.3.12 The energy budget in a sheepgrazed ecosystem
grass
▲
sheep
Figre 2.3.13
93
2
E c o s ys t E m s
a n d
E c o l o g y
T 
The clssicl eerg  exle
1.
Why does the width of the energy ow bands
become progressively narrower as energy ows
Siler Srigs, i cetrl Flri is famous amongst
through the ecosystem?
ecologists as the place where Howard T. Odum
researched energy ow in the ecosystem in the 1950s.
2.
Suggest an explanation for the limit on the number of
trophic levels to four or ve at most in a community.
Odum (1924–2002) was a pioneer ecologist working
on ecological energetics. This was the rst time an
3.
How is the energy transferred between each trophic
energy budget measurement was attempted when
level?
Odum measured primary productivity and losses by
4.
Insolation (light) striking leaves is 1,700,000 units
respiration. (Later, near the end of a long and illustrious
but only 410,000 are absorbed. What happens to the
career, he and David Scienceman developed the concept
unabsorbed light energy?
of eerg (embodied energy) which is a measure of
5.
A fur ther 389,190 units escapes from producers as
the quality and type of energy and matter that go into
heat. Why is this?
making an organism.)
6.
Account (mathematically) for the dierence
Figure 2.3.14 shows the energy ows and biomass
between gross and net primary productivity.
stores measured by Odum at Silver Springs. This
7.
Draw a productivity pyramid from the data given.
simple community consists of algae and duckweed
8.
(producers); tadpoles, shrimps and insect larvae
Would it be possible to draw a biomass pyramid from
the data given?
(herbivores); water beetles and frogs (rst carnivores);
small sh (top consumers); and bacteria, bivalves and
9.
Does the model suppor t the rst law of
snails (decomposers and detritivores). Dead leaves also
thermodynamics? Show your calculations.
fall into the water and spring water ows out, expor ting
10.
How does the diagram demonstrate the second law
some detritus.
of thermodynamics?
486
impor t
5060
D
460
insolation 1 700 000
gross production
2
1
light absorbed by
383
1478
producers
plants 410 000
3368
67
6
C
H
8833
20810
c
i
t
e
h
t
n
s
y
s
s
a
o
t
m
o
o
h
i
p
b
TC
plant
net plant
respiratory
production
biomass
2500
downstream
1890
389 190
11977
expor t
13
316
4600
light not absorbed
by plants 1 290 000
18 796
community respiration
2
▲
94
Figre 2.3.14 The energy ow values in Silver Springs community. Units kcal m
1
yr
(1kcal = 4.2 J)
2 . 3
F L o w S
o F
E n E R G y
a n d
m a T T E R
Human activities and ecosystems
Ke ter
A
process,
effect
or
anthropogenic
greenhouse
activity
derived
(‘anthro’
effect
is
meaning
anthropogenic.
anthropomorphic
which
animals,
inanimate
plants
or
from
is
giving
humans
human) .
Do
not
human
objects,
eg
is
known
The
this
or
(mSy) (see also 4.3) is the
with
characteristics
doll
mxi sstible iel
enhanced
confuse
your
as
to
your
largest crop or catch that can
other
be taken from the stock of a
pets.
species (eg a forest, a shoal
The concept of energy subsidy
of sh) without depleting
the stock . Taken away is the
Generally,
when
farming
or
diverse.
Usually,
and
often
that
may
humans
living
this
this
is
have
within
is
just
been
wheat
have
it,
on
one
an
we
tend
to
purpose.
species,
there
inuence
in
a
simplify
We
eg
on
cut
it
So
ecosystem,
and
down
wheat.
deciduous
an
make
forest
the
to
it
forest
it
increase in production of the
less
grow
complex
temperate
be
stock while leaving the stock
crops
food
to reproduce again. It is often
web
used in managing sheries.
becomes:
The MSY is equivalent to the
human
net primary or net secondary
or
productivity of a system.
improved
Much
of
simple
–
what
we
killing
compete
the
pasture
with
the
organisms
we
have
to
crops
we
–
so
to
use
the
is
rid
want.
Our
aimed
weeds
aim
our
is
means
brought
to
to
to
in
at
keeping
these
What
our
for
eat
the
the
of
them
or
NPP
happens
farming
varieties
fertilizers
things
either
maximize
maintain
improved
buy
as
prot.
sophisticated
articial
need
human
also
of
maximize
more
which
brought
getting
we
ever
we
cattle
agriculture
grow
Revolution
also
in
and
crops
become
agribusiness
Green
do
pests
grasses
is
that
practices
system.
rice
or
of
and
–
The
other
pesticides
to
kill
Practical
the
pests
to
which
they
were
Measure
All
farming
energy
that
practices
require
we
have
to
put
may
be
the
an
energy
into
the
subsidy
system
which
above
that
is
the
which
additional
comes
a
from
local
the
energy.
It
human
labour,
animal
labour
or
machines
to
and
other
power
systems
As
are
used
feed
tractors
more
in
food
energy.
people
has
to
communities
work.
power
by
or
to
from
have
animals.
food
add
to
irrigate
energy
MEDCs
as
a
make
is
or
the
chemicals
that
hunter-gatherer
All
put
we
subsidy
society
we
the
biomass
in
a
chain.
an
experiment
measure
productivity
dierent
ecosystems.
to
in
they
and
can
but
the
the
50
and
are
is
as
rising
their
1.
wind-
of
or
been an increase in
fossil
the impact of human
produce
activities on the
much
all
the
What are the two main
reasons why there has
subsidized
use
crops
times
it
from
animals,
major
T 
increases.
apart
these
on
use
Design
cane.
increased,
that
food
fertilizers
efcient
system
involves
to
is
in
thermodynamics).
draught
corn.
now
sugar
NPP
using
agricultural
sophisticated
more
of
energy
to
involve
grind
estimated
law
the
energy
eg,
subsidy
seems
make
some
density
more
energy
(rst
farming
cattle,
that
particularly,
became
an
may
is
population
complex,
little
for
result
production
farming
It
NPP
,
and
of
water
The
methods
more
to
machines,
for
high
somewhere
Commercial
feedstuffs
in
with
pump
crop.
groups
because
Subsistence
power
the
advantage
become
effort.
plows,
farming
The
water-power
human
fuels
larger
so
come
Hunter-gatherers
own
and
transport
productive
lived
more
more
energy
As
very
humans
needed
the
chemicals,
and
the
local
fuel
GPP
ecosystem.
Investigate
Sun’s
Work
susceptible.
environment over time?
time.
2.
Write down the three
Energy: yield ratio
trends that can be seen
In
economic
outputs
out
in
or
the
terms,
costs
form
sophisticated,
agriculture
crops
of
the
by
a
can
look
prots.
food.
ratio
(when
grown
we
and
land
It
at
we
seems
goes
is
So
subsistence
farming
can
that
down.
cleared
a
A
in
look
as
farmer)
slash
rainforest
may
as
energy
agriculture
simple
the
system
at
have
has
and
and
an
inputs
in
and
and
become
burn
then
in relation to the impact
energy
of human activities over
more
time on ecosystems.
type
a
variety
energy:yield
ratio
of
of
95
2
E c o s ys t E m s
a n d
E c o l o g y
1:30
as
or
40
work).
battery
system
the
The
not
issue
whether
rapidly
.
plant
a
of
egg
energy
or
goes,
others
species
in
ecological
large
is
can
–
by
from
take
so
We
are
has
reaching
subsidy
more
to
a
to
The
is
it
variety
likely
system
its
of
to
is
failure
input
10:1
in
to
as
through
food
fail
have
If
a
and
ecosystems
alters
and
chaos.
and
completely
.
resilient.
can
in
chains
in
foodstuffs.
system
result
is
protein
photosynthesis
will
for
the
energy
energy
the
energy
to
put
the
high
not,
stops
is
such
owing
does
of
reduce
that
energy
keep
If
unit
energy
thing
plant
less
wheat,
one
could
agriculture
and
and
role.
eg
this
producing
humans.
number
its
far
each
concentrated
complex
niche,
for
energy,
energy
energy
the
species
an
foods
that
sunlight
system
of
important
cereals.
is
the
energy
the
inuenced
ecosystem,
the
food
input
But
energy
Stopping
mean
of
production,
out.
remember
Blocking
natural
paths
high
natural
dies.
or
taken
lower
to
units
increasing
chicken
than
form
meat,
(30–40
With
there
the
In
energy
If
one
is
only
bigger
one
impact.
T 
From the data, write down word equations and calculate:
The data refer to carbon (in biomass) ows in a
freshwater system at 40°
N latitude:
2
1
g C m
a.
net productivity of phytoplankton
b.
gross productivity of zooplankton
c.
net productivity of zooplankton
yr
Gross productivity of
132
phytoplankton
d.
% assimilation of zooplankton
Respiratory loss by
e.
% productivity of zooplankton.
35
phytoplankton
Here are two more energy ow diagrams.
Phytoplankton eaten by
a.
31
For ecosystem I, copy and draw a rectangle on the
zooplankton
diagram to show the ecosystem boundary.
Fecal loss by zooplankton
6
b.
Explain why the storage boxes reduce in size as you
Respiratory loss by
go up the food chain.
12
zooplankton
c.
Name three decomposers and explain how they
lose heat.
R
4
ter tiary B
consumers
4
D
d
4
R
3
E
e
4
c
secondary B
consumers
3
o
D
3
R
m
2
heat loss
p
E
3
R
5
o
dead remains
primary B
consumers
2
s
feces etc.
R
D
2
1
e
r
E
2
s
respiratory
dead remains
loss
B
producers B
1
5
etc.
D
1
key to symbols
biomass of the various trophic levels
energy input
B
etc
1
area of box is propor tional to biomass
E
1
E
etc
energy ow through grazing chain
etc
energy ow to decomposers
etc
respiratory loss to abiotic environment
1
D
1
Sun
R
1
▲
96
Figre 2.3.15 Energy ow diagram of an ecosystem I
2 . 3
F L o w S
d.
o F
E n E R G y
a n d
m a T T E R
For ecosystem II, identify from the diagram the
solar radiation
atmospheric
letter(s) referring to the following energy ow
absorption/reection (A)
processes and explain what happens to this
photosynthesis (B)
energy at each stage as it passes through
the ecosphere:
species W
respiration
i.
loss of radiation through reection and
absorption
food consumed (C)
fecal loss (D)
ii.
absorbed (E)
conversion of light to chemical energy in
biomass
respiration (F)
species X
iii.
loss of chemical energy from one trophic
level to another
food consumed (G)
food consumed (H)
iv.
v.
species Y
eciencies of transfer
overall conversion of light to heat energy by
species Z
an ecosystem
▲
vi.
Figre 2.3.16 Energy ow diagram of an ecosystem II
reradiation of heat energy to atmosphere.
T 
ntriet cclig i terrestril ecsstes
Copy, ll the gaps and delete incorrect options in the paragraph below.
All living organisms need elements such as
and
. These are
needed to produce worms/minerals/growth/organic material. The availability
of such elements is nite – we cannot increase the amount. The plants take
up the nutrients from the soils, and once they have been used are passed
on to the carnivores/herbivores/photosynthesizers/producers and then the
which feed upon them. As organisms die, they
and nutrients are
returned to the system. As for all systems, there are inputs,
and
. Nutrients are stored in
, storages
main compar tments: the biomass
(total mass of living organisms), the soil and the
(the surface layer of
vegetation which may eventually become humus).
A model of the nutrient cycle is given below. Add the name of each of the
transfers of nutrients to the boxes.
input from
biomass
dissolved rainfall
soil
loss in
litter
run-o
▲
loss by
input from
leaching
weathered rock
Figre 2.3.17 Gersmehl’s model
97
2
E c o s ys t E m s
a n d
E c o l o g y
The nutrient cycle varies according to the climate and type of vegetation.
soil
The size of each of the stores and size of the transfer can be dierent. Using
the symbols given left (no resizing needed), copy and move them to make a
nutrient cycle diagram for
litter
1.
a deciduous woodland and
2.
a tropical rainforest.
Explain the size of the BIOMASS, SOIL and LITTER stores for each.
biomass
Grssl ecsste
(Redraw and resize the boxes to make the correct nutrient cycle diagram)
▲
Figre 2.3.18 Making
1.
Gersmehl’s model
In the ecosystem in gure 2.3.17, there are relatively large stores of
nutrients in the litter and soil compared to living things. Give three reasons
why this is the case.
2.
3.
What is the main nutrient ow from the soil? Why does this happen?
Is transpor t of minerals from one soil layer to another a transfer or a
B
transformation process?
B
4.
L
Look at the two nutrient models left, a tropical rainforest and a
continental grassland (prairie) ecosystem. Label each with its respective
L
ecosystem name.
S
S
5.
Copy and complete the table of comparisons between the two ecosystems:
Cris
Which ecosystem stores most
(a)
▲
(b)
Figre 2.3.19 Gersmehl’s
models for two dierent
nutrients in biomass?
Which ecosystem has most
undecomposed detritus?
ecosystems (see box to right)
Which ecosystem has least
humus?
In which ecosystem is plant
uptake of nutrients greater?
In which ecosystem is
decomposition slower?
Which ecosystem loses nutrients
from biomass quickest?
In which ecosystem are most
nutrients lost due to heavy rain?
In which ecosystem does rainfall
supply many nutrients?
98
Ecsste
Exlti
2 . 4
B I o m E S ,
Z o n a T I o n
a n d
S u C C E S S I o n
2.4 Bies, zti  scc essi
sii ie:
appii  ki:
➔
Climate determines the type of biome in a given
➔
Exli the distributions, structure, biodiversity
area although individual ecosystems may vary
and relative productivity of contrasting biomes.
due to many local abiotic and biotic factors.
➔
➔
alse data for a range of biomes.
➔
discss the impact of climate change
Succession leads to climax communities
that may vary due to random events and
on biomes.
interactions over time. This leads to a pattern of
➔
describe the process of succession in a named
alternative stable states for a given ecosystem.
example.
➔
Ecosystem stability, succession and
➔
Exli the general patterns of change in
biodiversity are intrinsically linked.
communities undergoing succession.
➔
discss the factors which could lead to
alternative stable states in an ecosystem.
➔
discss the link between ecosystem stability,
succession, diversity and human activity.
➔
distigish the roles of r and K selected
species in succession.
➔
Iterret models or graphs related to
succession and zonation.
Kwee  ueri:
➔
Bies are collections of ecosystems sharing
as changes in altitude, latitude, tidal level or
similar climatic conditions which can be
distance from shore (coverage by water).
grouped into ve major classes – aquatic, forest,
➔
grassland, deser t and tundra. Each of these
Sccessi is the process of change over time
in an ecosystem involving pioneer, intermediate
classes will have characteristic limiting factors,
and climax communities.
productivity and biodiversity.
➔
➔
Insolation, precipitation and temperature are the
gross and net productivity, diversity and mineral
main factors governing the distribution of biomes.
➔
The tricelllr el of atmospheric circulation
During succession the patterns of energy ow,
cycling change over time.
➔
explains the distribution of precipitation and
Greater habitat diversity leads to greater species
and genetic diversity.
temperature inuencing structure and relative
➔
r  K strtegist secies have reproductive
productivity of dierent terrestrial biomes.
strategies that are better adapted to pioneer and
➔
Climate change is altering the distribution of
climax communities respectively.
biomes and causing biome shifts.
➔
➔
Zti refers to changes in community along
an environmental gradient due to factors such
In early stages of succession, gross productivity is
low due to the unfavourable initial conditions and
low density of producers. The propor tion of energy
99
2
E c o s ys t E m s
➔
a n d
E c o l o g y
lost through community respiration is relatively
ecosystem.
low too, so net productivity is high, that is, the
factors,
system is growing and biomass is accumulating.
range
In later stages of succession, with an increased
depend
random
of
events
on
the
the
climatic
local
which
soil
can
and
occur
a
over
Human activity is one factor which can diver t
➔
be high in a climax community. However, this
the progression of succession to an alternative
is balanced by respiration, so net productivity
stable state, by modifying the ecosystem, for
approaches zero and the productivity:respiration
example the use of re in an ecosystem, use of
(P:R) ratio approaches one.
agriculture, grazing pressure, or resource use
In
a
and
complex
energy
ecosystem,
pathways
the
variety
contributes
of
to
such as deforestation. This diversion may be
nutrient
more or less permanent depending upon the
its
resilience of the ecosystem.
stability.
➔
of
These
proper ties
time.
consumer community, gross productivity may
➔
the
There
a
set
is
of
no
one
climax
alternative
community
stable
Ke ters
states
but
for
a
An ecosystem’s capacity to survive change may
➔
rather
depend on its diversity and resilience.
given
Bie
How many biomes are there?
A bie is a collection of
Opinion
differs
slightly
on
the
number
of
biomes,
which
is
because
they
ecosystems sharing similar
are
not
a
natural
classication
but
one
devised
by
humans,
but
it
is
climatic conditions.
possible
to
group
biomes
into
ve
major
types
with
sub-divisions
in
The bishere is that par t
each
type:
of the Ear th inhabited
by organisms. It extends
Aquatic
–
freshwater
and
marine
from the upper par t of the
Freshwater
–
swamp
forests,
lakes
and
ponds,
streams
and
atmosphere down to the
rivers,
bogs
deepest par ts of the oceans
Marine
–
rocky
shore,
mud
ats,
coral
reef,
mangrove
swamp,
which suppor t life.
continental
Deserts
Forests
–
–
hot
Each
of
–
–
these
the
We
shall
desert,
100
main
and
look
in
or
and
savanna
boreal
and
(taiga)
temperate
alpine.
will
have
biodiversity.
factors
tundra,
ocean
temperate
biomes
and
deep
cold
tropical
Arctic
productivity
are
and
tropical,
Grassland
Tundra
shelf,
governing
more
detail
temperate
characteristic
Insolation,
at
the
distribution
these
forest,
limiting
biomes:
deep
factors,
precipitation
ocean
of
tropical
and
and
temperature
biomes.
rainforest,
temperate
hot
grassland.
2 . 4
B I o m E S ,
Z o n a T I o n
a n d
S u C C E S S I o n
T 
Copy the tables and ll in the gaps
Cet
Lcl exle
Itertil/glbl exle
Species
Population
Community
Habitat
Ecosystem
Biome
Bie
ne exle
Tropical rainforest
Hot deser t
Tundra
Temperate forest
Deep ocean
Temperate grassland
30°N
tropic of Cancer
equator
tropic of Capricorn
30°S
tropical forest
savanna
deser t
▲
polar and high-mountain ice
temperate deciduous forest
chaparral
coniferous forest
temperate grassland
tundra (arctic and alpine)
Figre 2.4.1 Terrestrial biome distribution map
Why biomes are where they are
The
climate
and
so
is
what
geography
weather
–
the
lives
major
slope,
patterns,
two
factors
are
and
snowfall).
factor
where.
aspect
The
and
seasons,
most
that
other
determines
important
altitude.
extremes
important
–
of
what
factor
Climate
weather
temperature
is
grows
is
the
made
and
and
up
other
where
terrain
of
or
general
factors
precipitation
but
(rain
101
2
E c o s ys t E m s
a n d
E c o l o g y
The
temperature
is
hotter
nearer
the
equator
and
generally
gets
cooler
as
elsewhere on Ear th,
the rays hit the
we
go
towards
the
poles
(increase
latitude).
This
is
due
to
the
fact
the
suns
nor th
solar
Ear th at a more acute
rays
hit
the
Earth
at
a
more
acute
angle
and
so
are
spread
over
a
greater
B
energy
angle so are spread
surface
area.
You
can
see
this
effect
if
you
shine
a
torch
beam
directly
at
over a greater surface area.
an
object
which
is
at
in
front
of
the
torch
or
shining
it
at
an
angle.
solar
solar radiation hits the
equator
A
energy
Ear th at 90° angle so
Latitude
(distance
north
or
south
from
the
equator)
and
altitude
is most intense
(height
gets
▲
Figre 2.4.2 Solar radiation
hitting the Ear th
on
or
above
colder
Mt
as
sea
you
Ocean
biomes
currents
towards
Earth
is
called
cause
the
heat.
(water)
gives
solid
is
out
to
ocean
or
water
gives
out
around
in
the
well
degrees
once
break
changes
heat
the
to
the
Earth.
as
orbiting
on
its
round
the
gas
As
is
its
on
can
Sun
takes
and
in
Lucky
the
Sun,
365
this
high
is
–
to
low
us,
the
us
a
snow
alpine
the
to
that
to
heat
of
areas.
liquid
state
it
either
changes
as
more
molecules
from
energy
together.
(freezes),
distributes
occurs
the
Winds
transferring
water
that
the
snow),
solid
states
at
it
heat
naturally
within
the
normal
then!
Earth
(and
is
surface
for
state
in
change
three
for
the
and
As
takes
substance
the
energy
at
from
holding
this
generally
have
pressure
(ice
heat.
it
It
there
they
responsible
solid
changes
is
days
gives
heat
(condenses)
It
and
So
latitudes.
surplus
bonds
only
exist
Earth.
around
It
the
Andes
latent
liquid
biomes.
horizontally
that
it
and
altitude.
lower
(evaporates),
to
is
and
at
states
surroundings.
that
axis.
water
This
gas
are
from
three
molecular
Water
conditions
is
vapour).
to
from
its
It
heat.
increase
moving
blow
in
climate
distribute
Air
Winds
(melts)
atmosphere
climatic
As
to
in
they
winds
exist
or
Himalayas
poles.
(water
takes
liquid
needed
As
gas
latitude
the
currents.
can
inuence
though
and
the
wind.
Water
and
and
even
equator
both
increase
Kilimanjaro
polar
the
level)
a
rotates
quarter)
year
and
our
and
for
is
tilted
the
at
Earth
to
23.5
go
seasons.
spring in nor th
autumn in south
winter in nor th
summer in south
Sun’s rays
Sun
summer in nor th
winter in south
autumn in nor th
spring in south
▲
Figre 2.4.3 How the Ear th’s tilt causes seasons
Insolation,
(physical)
precipitation
factors
temperature
water
even
(deserts)
102
or
and
if
is
it
temperature
inuencing
causes
precipitation
and
increased
biomes
frozen
or
as
snows
ice
what
evaporation
evaporation
rains
or
are
is
a
also
lot
the
So
water
we
most
grows
the
important.
if
(tundra).
so
the
important
where.
may
evaporates
must
Increasing
relationship
Plants
also
abiotic
between
be
short
straight
consider
the
of
away
P/E
2 . 4
ratio
For
(precipitation
to
evaporation
ratio ).
B I o m E S ,
This
is
easy
Z o n a T I o n
to
a n d
S u C C E S S I o n
calculate.
example:
Tr: nr 
deser t: Jr
●
75 cm of snow falls/year
●
5 cm of rain falls/year
●
50 cm are lost by evaporation
●
50 cm are lost by evaporation
P/E ratio is 75/50 or 1.25
P/E ratio is 5/50 or 0.1
p/E rti is ch greter th 1
p/E rti is fr less th 1
●
●
It rains or snows a lot and
Water moves upwards through the
evaporation rates are low.
soil and then evaporates from the
surface.
●
Then there is leaching in the soil
●
when soluble minerals are washed
This leaves salts behind and
downwards.
the soil salinity increases to the
point that plants cannot grow
(salinization).
P/E
ratio
is
approximately
evaporation;
Make
sure
biomes
raw
in
the
you
have
Pole
in
or
winter,
the
so,
if
cannot
will
Productivity
temperatures
precipitation
is
is
towards
decline,
the
both
GPP
(gross
terrestrial
areas
latitudes),
long
rate
low
periods
tend
to
values.
Saudi
USA),
values
is
the
rainforest
were
if
lower.
and
South
greater
high
in
all
poles,
the
low
air
where
Arctic,
when
in
desert
of
even
areas
though
few,
values
–
for
were
these
in
the
close
to
as
much
(eg
as
are
those
and
of
webs
depend
store
other
is
are
as
and
thus
In
in
the
high
(permafrost),
and
low
and
air)
much
the
all
of
southwest
productivity
and
sunlight
temperate
variations
sub-Antarctic,
mid-latitude
(ie
grassland
in
sunlight
and
lower.
warm
high
temperate
and
productivity
become
places
of
lower,
regions
lowers
where
high
photosynthesis.
ground
be
is
amount
Sahara,
generalizations
Arctic
for
Australia,
may
favourable
be
South
energy
input
lower
would
and
may
equator),
values
and
the
factors:
the
food
darkness,
periods
forests
as
Different
capacity,
moisture
central
long
higher
sheltered,
and
frozen
temperatures
deciduous
the
adjacent
perpetual
(such
areas
moisture
However,
a
hold
All
ideal
NPP
permanently
is
same
food.
are
and
2.3.
at
initial
sunlight
photosynthesis
semi-arid
precipitation
In
in
the
(nearer
and
in
limiting
limited
photosynthesize
Antarctic
there
cannot
be
temperatures
can
the
photosynthesis
desert.
year,
productivity)
reduction
and
the
to
maximum
conditions
plants
due
enough
latitudes
These
which
primary
getting
through
high.
the
at
Georgia
productivity
problem
Temperate
considerable.
a
their
absence
abundant.
in
to
a
winter
severely,
supply
for
may
photosynthesize
Obviously,
Arabia),
(light)
heat
about
productivity
provide
of
a
on
productivity
and
is
fertile.
to
(cold
cause
of
limited
green
precipitation
and
section
source
temperatures,
in
precipitation
the
rich
plants
also
Moving
in
by
have
are
when
radiation
water
photosynthesis
1
be
amounts
energy
Solar
on
they
to
understand
supply.
organisms
tend
differing
materials
short
soils
if
it
are
Greenland
respectively
forest
have
–
been
recorded.
103
2
E c o s ys t E m s
a n d
E c o l o g y
Whittaker,
an
American
ecologist,
rst
plotted
biomes
against
T 
temperature
and
precipitation.
Reie qestis
1.
What is latitude?
2.
Does temperature
400
increase or decrease
tropical
with increasing (a)
rain
latitude, (b) altitude?
)mc( noitatipicerp launna
Explain why.
3.
Describe how the tilt of
the Ear th's rotational axis
causes dierences in the
amount of heat received
at the Ear th's surface.
4.
5.
forest
300
temperate
rain forest
200
tropical
seasonal
temperate deciduous
forest
forest
What are trade winds?
What causes high and
100
low air pressure?
taiga
savanna
temperate
grassland and deser t
tundra
subtropical deser t
0
20
30
10
0
–10
average temperature (°C)
▲
Figre 2.4.4 Diagram of annual precipitation and temperature showing biomes
Climate change and biome shift
With
increase
there
that
●
is
in
mean
evidence
the
climate
that
is
Temperature
global
biomes
changing
increase
of
temperature
are
in
moving.
these
1.5
to
and
changes
There
is
in
precipitation,
general
agreement
ways:
4.5
°C
by
2100
(according
to
the
IPCC)
●
Greater
●
More
●
Some
●
Stronger
These
are
warming
areas
can
than
drier,
happening
over
do
to
moves
summer
others
wetter
many
adapt
very
fast,
generations
to
fast
change
within
decades,
through
is
to
and
organisms
evolutionary
move
and
that
is
adaptation.
what
they
●
towards
●
higher
are:
the
up
towards
poles
where
mountains
temperature
104
winter
latitudes
doing.
These
●
higher
becoming
are
slowly,
they
in
at
storms.
changes
change
All
warming
the
about
3
equator
it
is
where
cooler
it
is
cooler
°C
where
it
is
wetter.
–
500
m
of
altitude
decreases
2 . 4
Examples
of
biomes
●
in
Africa
●
in
the
Arctic,
Plants
can
only
But
animals
But
there
seas
and
cities.
●
are
caused
may
hotspots
no
Equatorial
●
The
●
Madagascar.
●
The
North
one
exploitation
Drilling
The
of
for
decrease
●
Africa
in
–
to
are
becoming
savannas
eg
are
natural
cross
ones
such
these
to
dispersed
albatrosses,
as
a
could
high
wind
mountain
roads,
and
have
like
by
or
wildebeest,
ranges
agricultural
become
animals.
whales.
and
elds
and
extinct.
turnover
of
species
are:
called
land
–
the
third
pole
–
as
species
can
mass.
with
a
very
drought-sensitive
climate.
Great
live
Plains
in
changes
and
regions
can
also
Great
which
bring
Lakes.
are
new
vulnerable
to
opportunities
biome
for
resources.
oil
under
sea
could
the
Arctic
Ocean
is
becoming
possible
with
the
ice.
North-West
America
S u C C E S S I o n
region.
people
these
the
seeds
activities
sometimes
American
billion
as
predicted
These
than
Eastern
But
able
areas
a n d
shrubland.
distances,
migration
be
Mediterranean
changing.
●
–
higher
●
to
–
slowly
human
change.
woodlands
becoming
longer
to
by
not
is
Z o n a T I o n
are:
region,
very
migrate
Himalayas
move
Up
tundra
migrate
climate
The
Sahel
obstacles
ones
are
to
the
can
Animals
There
due
in
shifting
B I o m E S ,
Passage
become
a
for
ships
trade
between
route
the
without
North
icing
Pole
and
North
up.
T thik bt
H the tshere circltes: The tricelllr el f tsheric circlti
The equator receives most insolation (solar radiation) per
The air that blows to higher latitudes at 30°N and S forms
unit area on Ear th. This heats up the air which rises (hot
the winds known as the Westerlies and they collect
air rises because it is less dense). As it rises, it cools and
water vapour from the oceans as they blow towards the
the water vapour in the air condenses as rain. This causes
poles. At about 60°N and S, these winds meet cold polar
the afternoon thunderstorms and low pressure areas of
air and so rise as they are less dense. As they rise, the
the tropical rainforests. There is so much energy in this air
water in them condenses and falls as precipitation where
that it continues to rise until it is pushed away from the
the temperate forest and grassland biomes are found.
equator to nor th and south. As it moves away, it cools and
This is another low pressure area and associated with
then sinks (cooler air is more dense) at about 30°N and S
depressions and heavy cyclonic rainfall.
of the equator forming high pressure areas (more air). This
The air then continues to ow, some to the poles and
air is dry and this is where the deser t biome lies. Some
some back towards the equator. This air forms another
of the air then returns to the equator and some blows to
cell known as the Ferrel cell. The air that continues
higher latitudes. The air that blows towards the equator
towards the poles then descends as it gets cooler and
completes a circle or cell to end up where it star ted. This
more dense and forms a high pressure area at the poles,
movement of air is given the name ‘trade winds’ which
completing the polar cell. This then returns to lower
always blow towards the equator. At the equator, the nor th
latitudes as winds known as the Easterlies.
and south trade winds converge and rise again at the ITCZ
Three cells form between the equator and each pole,
(intertropical convergence zone). Here are the doldrums
hence the name tricellular model.
or area of little wind. The cell is called the Hadley cell.
105
2
E c o s ys t E m s
a n d
E c o l o g y
The winds do not blow directly nor th or south because
polar cell
the Ear th is rotating towards the East, ie if you viewed it
PFJ
+
from above the Nor th Pole, it would be turning counter
Ferrel cell
+
clockwise.
ST
J
polar
Because of this anything not xed on the Ear th (the
front
Hadley
oceans and the atmosphere) appear to veer to the right
cell
ITCZ
in the Nor thern hemisphere and left in the Southern. This
apparent deection is called the Crilis eect and it
Hadley
polar
cell
means that the trade winds, westerlies and other winds
front
+
ST
J
are deected to east or west.
Ferrel cell
Nor th of the equator, the trade winds blow from the
+
PFJ
nor theast and westerlies from the southwest: south
polar cell
of the equator, trade winds blow from the southeast,
westerlies from the nor thwest. This allowed sailing ships
▲
Figre 2.4.5 Idealized representation of the general
to cross the major oceans on trade routes as they could
circulation of the atmosphere showing the positions
nd the prevailing winds by altering their latitude.
of Polar Front; ITCZ (Inter Tropical Convergence Zone);
Subtropical Jets (STJ); Polar Front Jets (PFJ)
Some
biomes
in
more
detail.
Tropical rainforest
▲
Figre 2.4.6 A tropical rainforest in Borneo
What
Hot and wet areas with broadleaved evergreen forest.
Where
Within 5 degrees Nor th and South of the equator.
(distribution)
Climate and
limiting factors
1
High rainfall 2000–5000 mm yr
. High temperatures 26–28 °C and little seasonal variation.
High insolation as near equator. P and E are not limiting but rain washes nutrients out of the soil
(leaching) so nutrients may be limiting plant growth.
106
2 . 4
B I o m E S ,
Z o n a T I o n
a n d
S u C C E S S I o n
What’s there
Amazingly high levels of biodiversity – many species and many individuals of each species. Plants
(structure)
compete for light and so grow tall to absorb it so there is a multistorey prole to the forests with very
tall emergent trees, a canopy of others, understorey of smaller trees and shrub layer under this – called
stratication. Vines, climbers and orchids live on the larger trees and use them for support (epiphytes).
In primary forest (not logged by humans), so little light reaches the forest oor that few plants can live
here. Nearly all the sunlight has been intercepted before it can reach the ground. Because there are so
many plant species and a stratication of them, there are many niches and habitats for animals and large
mammals can get enough food. Plants have shallow roots as most nutrients are near the surface so they
have buttress roots to support them.
Net productivity
Estimated to produce 40% of NPP of terrestrial ecosystems. Growing season all year round, fast rate
of decomposition and respiration and photosynthesis.
Plants grow faster. But respiration is also high and for a large mature tree in the rainforest, all the glucose
made in photosynthesis is used in respiration so there is no net gain. However, when rainforest plants
are immature, their growth rates are huge and biomass gain very high. Rapid recycling of nutrients.
Human activity
The problem is that more than 50% of the world’s human population lives in the tropics and subtropics
and one in eight of us live in or near a tropical rainforest. With fewer humans, the forest could provide
enough resources for the population but there are now too many exploiting the forest and it does not
have time to recover. This is not sustainable. In addition, commercial logging of valuable timber, eg
mahogany, and clear felling to conver t the land to grazing cattle all destroy the forest.
Issues
Logging, clearfelling, conversion to grazing. Tropical rainforests are mostly in LEDCs and have been
exploited for economic development.
Examples
Amazon rainforest, Congo in Africa, Borneo rainforest.
30 m
20
10
0
30 m
▲
20
10
0
Figre 2.4.7 Tropical rainforest structure showing layers
107
2
E c o s ys t E m s
a n d
E c o l o g y
Deser ts
▲
What
Figre 2.4.8 A deser t in southwest Nor th America
Dry areas which are usually hot in the day and cold at night as skies are clear and there is
little vegetation to insulate the ground. There are tropical, temperate and cold deser ts.
Where (distribution)
Cover 20–30% of the Ear th’s surface about 30 degrees Nor th and South of the equator where
dry air descends. Most are in the middle of continents. (Some deser ts are cold deser ts, eg
the Gobi deser t.) The Atacama deser t in Chile can have no rain for 20 years or more. It is the
driest place on Ear th.
Climate and limiting
Water is limiting. Precipitation less than 250 mm per year. Usually evaporation exceeds
factors
precipitation – E>P
.
What’s there (structure)
Few species and low biodiversity but what can survive in deser ts is welladapted to the
conditions. Soils are rich in nutrients as they are not washed away. Plants are drought
resistant and mostly cacti and succulents with adaptations to store water and reduce
transpiration, eg leaves reduced to spines, thick cuticles to reduce transpiration. Animals
too are adapted to drought conditions. Reptiles are dominant, eg snakes, lizards. Small
mammals can survive by adapting to be nocturnal (come out at night and stay in a burrow
in the heat of the day, eg kangaroo rat) or reduce water loss by having no sweat glands and
absorbing water from their food. There are few large mammals in deser ts.
Net productivity
Both primary (plants) and secondary (animals) are low because water is limiting and plant
biomass cannot build up to large amounts. Food chains tend to be shor t because of this.
Human activity
Traditionally, nomadic tribes herd animals such as camels and goats in deser ts as
agriculture has not been possible except around oases or waterholes. Population density
has been low as the environment cannot suppor t large numbers. Oil has been found under
deser ts in the Gulf States and many deser ts are rich in minerals including gold and silver.
Irrigation is possible by tapping underground water stores or aquifers so, in some deser ts,
crops are grown. But there is a high rate of evaporation of this water and, as it evaporates,
it leaves salts behind. Eventually these reach such high concentrations that crops will not
grow (salinization).
Issues
Deser tication – when an area becomes a deser t either through overgrazing, overcultivation
or drought or all of these, eg the Sahel.
Examples
108
Sahara and Namib in Africa, Gobi in China.
2 . 4
B I o m E S ,
Z o n a T I o n
a n d
S u C C E S S I o n
Temperate grasslands
▲
Figre 2.4.9 Temperate grassland
What
Fairly at areas dominated by grasses and herbaceous (nonwoody) plants.
Where (distribution)
Climate and limiting
factors
In centres of continents 40–60° Nor th of equator.
P = E or P slightly > E. Temperature range high as not near the sea to moderate temperatures.
Clear skies. Low rainfall, threat of drought.
What’s there
Grasses, wide diversity. Probably not a climax community as arrested by grazing animals.
(structure)
Grasses die back in winter but roots survive. Decomposed vegetation forms a mat, high levels of
nutrients in this. Burrowing animals (rabbits, gophers), kangaroo, bison, antelopes. Carnivores –
wolves, coyotes. No trees.
Net productivity
Human activity
2
600 g m
1
yr
so not very high.
Used for cereal crops. Cereals are annual grasses. Black ear th soils of the steppes rich in organic
matter and deep so ideal for agriculture. Prairies in Nor th America are less fer tile soils so have to add
fer tilizers. Called world’s bread baskets. Plus livestock – cattle and sheep that feed on the grasses.
Issues
Dust Bowl in 1930s in America when overcropping and drought led to soil being blown away on
the Great Plains – ecological disaster.
Overgrazing reduces them to deser t or semideser t.
Examples
Nor th American prairies, Russian steppes in Nor thern hemisphere; pampas in Argentina, veld in
South Africa (30–40° South).
Temperate forests
dominant oak
dominant oak
codominant
codominant
ash
ash
sub dom.
oak
suppressed
oak
ash
sapling
in
hazel
hazel
gap
ivy
dog’s
mercury
moss-litter with herbs
in less dense shade
bramble
bare,
bracken,
(leaves)
bluebell
herb
▲
▲
Figre 2.4.11 Temperate forest
Figre 2.4.10 Temperate forest structure in Europe
109
2
E c o s ys t E m s
What
Where (distribution)
Climate and limiting
factors
a n d
E c o l o g y
Mild climate, deciduous forest.
Between 40° and 60° Nor th and South of the equator.
P > E. Rainfall is 500–1500 mm per year, colder in winter. Winters freezing in some (Eastern
China and NE USA), milder in western Europe due to the Gulf Stream. Temp range
30 °C to +
30 °C. Summers cool.
What’s there
Fewer species than tropical rainforests. For example in Britain, oaks, which can reach heights of
(structure)
30–40 m, become the dominant species of the climax vegetation. Other trees, such as the elm,
beech, sycamore, ash and chestnut, grow a little less high. Relatively few species and many
woodlands are dominated by one species, eg beech. In USA there can be over thir ty species
2
per km
. Trees have a growing season of 6–8 months, may only grow by about 50 cm a year.
Woodlands show stratication. Beneath the canopy is a lower shrub layer varying between 5 m
(holly, hazel and hawthorn) and 20 m (ash and birch). The forest oor, if the shrub layer is not
too dense, is often covered in a thick undergrowth of brambles, grass, bracken and ferns. Many
owering plants (bluebells) bloom early in the year before the taller trees have developed their
full foliage. Epiphytes, eg mistletoe, mosses, lichens and algae, grow on the branches. The forest
oor has a reasonably thick leaf litter that is readily broken down. Rapid recycling of nutrients,
although some are lost through leaching. The leaching of humus and nutrients and the mixing
by biota produce a browncoloured soil. Welldeveloped food chains in these forests with many
autotrophs, herbivores (rabbits, deer and mice) and carnivores (foxes). Deciduous trees give
way to coniferous towards polar latitudes and where there is an increase in either altitude or
steepness of slope. P >
Net productivity
E suciently to cause some leaching.
Second highest NPP after tropical rainforests but much lower than these because of leaf fall
in winter so reduced photosynthesis and transpiration and frozen soils when water is limiting.
Temperatures and insolation lower in winter too as fur ther from the Sun.
Human activity
Much temperate forest has been cleared for agriculture or urban developments. Large predators
(wolves, bears) vir tually wiped out.
Issues
Most of Europe’s natural primary deciduous woodland has been cleared for farming, for use as
fuel and in building, and for urban development. Some that is left is under threat, eg US Pacic
Nor thwest oldgrowth temperate and coniferous forests. Often mineral wealth under forests is
mined.
Examples
US Pacic Nor thwest.
Arctic tundra
Greenland
Europe
Asia
Nor th
America
Africa
South
America
Australia
▲
▲
110
Figre 2.4.12 Arctic tundra
Figre 2.4.13 Distribution of Arctic tundra
(shown in yellow)
2 . 4
What
B I o m E S ,
Z o n a T I o n
a n d
S u C C E S S I o n
Cold, low precipitation, long, dark winters. 10% of Ear th’s land surface. Youngest of all the
biomes as it was formed after the retreat of the continental glaciers only 10,000 years ago.
Permafrost (frozen soil) present and no trees.
Where (distribution)
Just south of the Arctic ice cap and small amounts in Southern hemisphere. (Alpine tundra is
found as isolated patches on high mountains from the poles to the tropics.)
Climate and limiting
Cold, high winds, little precipitation. Frozen ground (permafrost). Permafrost reaches to
factors
the surface in winter but in summer the top layers of soil defrost and plants can grow. Low
temperatures so rates of respiration, photosynthesis and decomposition are low. Slow
growth and slow recycling of nutrients. Water, temperature, insolation and nutrients can be
limiting.
In the winter, the Nor thern hemisphere, where the Arctic tundra is located, tilts away from
the sun. After the spring equinox, the Nor thern hemisphere is in constant sunlight. For nearly
three months, from late May to August, the sun never sets. This is because the Arctic regions
of the Ear th are tilted toward the Sun. With this continuous sun, the ice from the winter
season begins to melt quickly.
During spring and summer, animals are active, and plants begin to grow rapidly. Sometimes
temperatures reach 30 °C. Much of this energy is absorbed as the latent heat of melting of
ice to water.
In Antarctica, where a small amount of tundra is also located, the seasons are reversed.
What’s there (structure)
No trees but thick mat of lowgrowing plants – grasses, mosses, small shrubs. Adapted to
withstand drying out with leathery leaves or underground storage organs. Growing season
may only be 8 weeks in the summer. Animals also adapted with thick fur and small ears to
reduce heat loss. Mostly small mammals, eg lemmings, hares, voles. Predators – Arctic fox,
lynx, snowy owl. Most hibernate and make burrows. Simple ecosystems with few species.
Often bare areas of ground. Low biodiversity – 900 species of plants compared with 40,000
or more in the Amazon rainforest.
Soil poor, low inorganic matter and minerals.
Net productivity
Very low. Slow decomposition so many peat bogs where most of the carbon is stored.
Human activity
Few humans but mining and oil – see oil tars. Nomadic groups herding reindeer.
Issues
Fragile ecosystems that take a very long time to recover from disruption. May take decades
to recover if you even walk across it. Mining and oil extraction in Siberia and Canada destroy
tundra.
Many scientists feel that global warming caused by greenhouse gases may eliminate
Arctic regions, including the tundra, forever. The global rise in temperature may damage
the Arctic and Antarctic more than any other biome because the Arctic tundra’s winter will
be shor tened, melting snow cover and par ts of the permafrost, leading to ooding of some
coastal areas. Plants will die, animal migrating patterns will change, and the tundra biome
as we know it will be gone. The eect is uncer tain but we do know the tundra, being the most
fragile biome, will be the rst to reect any change in the Ear th.
Very large amounts of methane are locked up in tundra ice in clathrates. If these are released
into the atmosphere then huge increase in greenhouse gases (clathrates contain 3,000 times
as much methane as is in the atmosphere now and methane is more than 20 times as strong a
greenhouse gas as carbon dioxide).
Examples
Siberia, Alaska.
111
2
E c o s ys t E m s
a n d
E c o l o g y
Deep ocean
neritic
oceanic
epipelagic
littoral
200m
mesopelagic
bathyal
1000m
bathyal
bathypelagic
4000m
abyssopelagic
abyssal
6000m
oceanic divisions
hadal
10,000m
▲
▲
Figre 2.4.15 Deep ocean divisions
Figre 2.4.14 Deep ocean animals –
fangtooth sh, tubeworms
What
The ocean and seaoor beyond continental shelves.
Where (distribution)
65% of the Ear th’s surface. Most is abyssal plain of the ocean oor – averaging 3.5 miles deep.
Climate and limiting
Pressure increases with depth, temperature variation decreases to a constant −2
°C at depth.
factors
Light limiting below 1,000 m – there is none.
Nutrients – low levels and low primary productivity but some dead organic matter falls to
deep ocean oors.
What’s there (structure)
Top 200 m – some light for photosynthesis so phytoplankton and cyanobacteria live
here and they and algae are the main producers. They are eaten by zooplankton, sh and
inver tebrates, eg squid, jellysh.
200–1,000 m deep – as pressure increases with depth, sh here are muscular and strong
to resist pressure. Very little light reaches here so large eyes, reective sides and light
producing organs on their bodies. Many are red which absorbs shor ter wavelengths of light
that penetrate fur ther.
1,000–4,000 m deep – higher diversity here, always dark . Fish are black with small eyes,
bristles and bioluminescence – create own light to hunt or avoid predators. Very little
muscle, large mouths.
4,000 m to bottom – huge pressures, constant cold. Mostly shrimps, some sh, jellysh,
tubeworms on bottom.
Bottom surface – ne sediments made up of debris from above – plankton shells, dead
organisms, whale and sh skeletons. Also mud and volcanic rocks in midocean ridges.
Where volcanoes erupt, there are hydrothermal vent communities high in sulphides where
chemosynthetic bacteria gain their energy from the sulphur. These producers suppor t
communities of crabs, tubeworms, mussels, and even octopus and sh.
112
Net productivity
Low.
Human activity
Minimal but rocks rich in manganese and iron could be a resource.
Issues
Pollution from runo from rivers, sewage, ocean warming due to climate change.
Examples
Arctic, Atlantic, Pacic Oceans.
2 . 4
B I o m E S ,
Z o n a T I o n
a n d
S u C C E S S I o n
Comparison of biomes
Bie
net rir
al
are
rctiit
reciitti
10
6
2
1
1
r
g 
plt
me
ail
biss
biss
biss 10
2
k
9
 r
Slr
6
10
t
riti
2
t
2
kg 
w 
1
r
Tricl rifrests
2200
2000–5000
17.0
765
45
330
175
Teerte frests
1200
600–2500
12.0
385
32.5
160
125
Brel frests
800
300–500
12.0
240
20
57
100
Tricl grssls
900
500–1300
15.0
60
4
220
225
600
250–1000
9.0
14
1.6
60
150
8.0
5
0.6
3.5
90
24.0
0.5
0.02
0.02
75
V low
800–2000
Variable
(ss)
Teerte
grssl
Tr  lie
140
deser t
<250
90
<250
(rck , s, ice)
dee ces
20–300
Variable
352
1000+
tundra
low
ToK
B
Controlled laboratory
L
experiments are often
S
taiga
seen as the hallmark of the
B
scientic method. To what
extent is the knowledge
L
obtained by observational
S
natural experiment
less scientic than the
manipulated laboratory
B
experiment?
erutarepmet
maritime
L
forest
S
chaparral
steppe
B
B
B
deciduous
L
L
L
forest
S
S
S
selva
B
B
B
savanna
L
L
deser t
L
S
S
high
S
low
high
precipitation
▲
Figre 2.4.16 Nutrient cycling models for world biomes (after Gersmehl 1976)
113
2
E c o s ys t E m s
a n d
E c o l o g y
suei  zi
T 
Do
1.
What does deciduous mean?
2.
What is net primary productivity
not
confuse
Succession
Zonation
is
is
succession
how
how
an
an
with
zonation.
ecosystem
ecosystem
changes
is
in
changing
time.
along
an
(NPP)?
environmental
3.
gradient ,
eg
altitude.
Which biome has the highest
2
NPP per m
per yr and why?
Zonation, eg rocky seashore, mountain
Succession, eg terrestrial.
slopes.
4.
Which biome has the largest
NPP and why?
5.
Spatial and static.
Dynamic and temporal (takes place
over long periods of time).
Why is NPP low in tundra and
deser ts?
6.
Why are there no large
deciduous forests or tundra in
Caused by progressive changes
Mountains – changes in temperature.
through time, eg as vegetation
Seashore – changes in time exposure to
colonizes bare rock .
air / water.
the southern hemisphere?
7.
Caused by an abiotic gradient.
Why are trees in temperate
Sand
dune
colonization
is
unusual
in
that
the
succession
is
dynamic
biomes deciduous?
but
8.
one
also
observes
vegetation
zones
during
the
various
stages
of
How do the number of tree
theprocess.
species and their distribution
dier in temperate and tropical
Zonation
rainforests?
For
9.
What are the main factors
causing the distribution of
biomes?
10.
Which biome(s) are most
each
species,
boundary
many
limits
abiotic
important
there
and
and
ones
is
biotic
on
an
ecological
outside
these,
factors
mountains
●
Temperature
–
which
●
Precipitation
–
on
niche
the
that
(2.1).
species
inuence
That
cannot
these
niche
live.
limits.
has
There
The
are
most
are:
decreases
with
increasing
altitude
and
latitude.
threatened and why?
11.
mountains,
most
rainfall
is
at
middle
altitudes
so
Which biome(s) have been
deciduous
forest
grows.
Higher
up,
the
air
is
too
dry
and
cold
for
most changed by human
trees.
activity?
●
12.
Solar
insolation
–
more
intense
at
higher
pigment
in
their
altitudes
and
plants
have
to
What eect may climate change
adapt
–
often
with
red
leaves
to
protect
themselves
have on biome distribution?
against
●
Soil
too
type
deeper
tend
to
–
much
in
and
be
insolation.
warmer
more
zones,
fertile.
decomposition
Higher
up,
is
faster
decomposition
so
is
soils
slow
are
and
soils
acidic.
Ke ters
●
Zti is the change
in community along an
environmental gradient due
Interactions
between
somespecies
fungi
(2.1)
and
may
species
grazing
be
very
–
may
competition
alter
important
plant
in
may
crowd
composition.
allowing
trees
to
out
Mycorrhizal
grow
in
somezones.
to factors such as changes
Human
activities
alter
zonation.
Road
building
on
mountains
may
in altitude, latitude, tidal
allowtourism
level or distance from shore/
oragriculture.
coverage by water.
Sccessi is the process
of change over time in
an ecosystem involving
pioneer, intermediate and
climax communities.
114
into
previously
inaccessible
areas
or
deforestation
2 . 4
B I o m E S ,
Z o n a T I o n
a n d
S u C C E S S I o n
ice and snow
level aes morf edutitla gnisaercni noitanoz lacit rev
tundra
coniferous forest
temperate
deciduous forest
tropical
rain forest
ice and snow
tundra
coniferous forest
temperate
tropical
deciduous forest
rain forest
latitudinal zonation increasing latitude from the equator
▲
Figre 2.4.17 Zonation with increasing altitude on a mountain
splash zone
lichens and periwinkles
barnacles
high-tide zone
mussels
pink paint
red seaweeds
mid-tide zone
rock pool
brown seaweeds (kelp)
low-tide zone
▲
Figre 2.4.18 Zonation of species on a rocky shore due to increasing exposure to
air higher up the shore
115
2
E c o s ys t E m s
a n d
E c o l o g y
Graphical
representation
the
of
width
(see
the
sub-topic
‘kites’
of
zonation
corresponds
is
to
often
the
by
a
kite
number
of
diagram
that
where
species
2.5).
height above
shingle
char t datum (m)
large shallow rockpool
edge of ledge
sand
4
1
Enteromorpha sp.
Fucus spiralis
F
. vesiculosus
Arenicola marina
F
. serratus
Sargassum muticum
Littorina marlae/obtusata
Anemonia viridis
L. littorea
Chondrus crispus
Patella vulgata
Semibalanus balanoides
Laminaria digitata
Gibbula cineraria
abundance
shore distance
Laurencia pinnatida
scale
A
Nucella lapillus
▲
C
F
= 5m
O R
Figre 2.4.19 Kite diagram showing zonation of species on a rocky shore.
(For ACFOR key see 2.5)
Succession
Ke its
●
Succession is the change in species composition in an ecosystem over time.
●
It may occur on bare ground (rir sccessi) where soil formation
star ts the process or where soil already formed but the vegetation has
been removed (secr sccessi).
●
Early in succession, gross primary productivity (GPP) and respiration are
low and so net primary productivity (NPP) is high as biomass accumulates.
●
In later stages, while GPP may remain high, respiration increases so NPP may
approach zero and the productivity:respiration ratio (P:R) approaches one.
●
A climax community is reached at the end of a succession when species
composition stops changing. But there may be several states of a climax
community depending on abiotic factors.
●
The more complex the ecosystem (higher biodiversity, increasing age), the
more stable it tends to be.
●
In agricultural systems, humans often deliberately stop succession when
NPP is high and crops are harvested.
●
Humans also interrupt succession by deforestation, grazing with animals or
controlled burning.
●
Sometimes the ecosystem recovers from this interruption and succession
continues, sometimes the interruption is too great and the system is less
resilient and so succession is stopped.
●
Species biodiversity is low in early stages and increases as succession
continues, falling a little in a climax community.
116
●
The higher the diversity, the higher the resilience.
●
Mineral cycling also changes over the succession, increasing with time.
2 . 4
Primary
succession
occurs
on
a
bare
inorganic
B I o m E S ,
surface.
Z o n a T I o n
It
involves
a n d
S u C C E S S I o n
the
T 
colonization
either
of
created
newly
or
created
uncovered
land
such
by
as
organisms.
river
deltas,
It
occurs
after
as
new
volcanic
land
is
eruptions,
Review these terms:
on
sand
dunes.
GPP
, NPP
, respiration,
Bare
land
almost
anywhere
on
the
planet
does
not
stay
bare
for
very
species, biodiversity.
long.
an
Plants
entire
plant
community
results
in
very
a
is
quickly
community
replaced
natural
composition
of
start
a
by
to
colonize
develops.
another.
increase
in
community
the
This
This
change
process
complexity
over
bare
to
is
the
land
is
and
over
directional
succession.
structure
time
as
one
Succession
and
species
time.
Stages in primary succession
Figure
2.4.20
shows
the
stages
of
succession.
Stages
2,
3
and
4
are
intermediate.
Bare, inorganic surface
A lifeless abiotic environment becomes available for colonization by pioneer plant and animal
species. Soil is little more than mineral par ticles, nutrient poor and with an erratic water
supply.
Stage 1 Colonization
First species to colonize an area are called ieers adapted to extreme conditions.
Pioneers are typically r-selecte secies showing small size, shor t life cycles, rapid growth and
production of many ospring or seeds.
Simple soil star ts from windblown dust and mineral par ticles.
Stage 2 Establishment
Species diversity increases. Invertebrate species begin to visit and live in the soil increasing humus
(organic material) content and waterholding capacity. Weathering enriches soil with nutrients.
Stage 3 Competition
Microclimate continues to change as new species colonize. Larger plants increase cover and
provide shelter, enabling K-selecte secies to become established. Temperatures, sun and
wind are less extreme. Earlier pioneer rspecies are unable to compete with Kspecies for
space, nutrients or light and are lost from the community.
Stage 4 Stabilization
Fewer new species colonize as late colonizers become established shading out early
colonizers. Complex food webs develop.
Kselected species are specialists with narrower niches. They are generally larger and less
productive (slower growing) with longer life cycles and delayed reproduction.
Climax community
The nal stage or clix cit is stable and selfperpetuating. It exists in a steady
state dynamic equilibrium. The climax represents the maximum possible development that a
community can reach under the prevailing environmental conditions of temperature, light and
rainfall.
▲
Figre 2.4.20
117
2
E c o s ys t E m s
a n d
E c o l o g y
A
hydrosere
is
a
succession
in
water.
deep freshwater, no rooted plants
because of lack of light in deep water
community only microorganisms
and phytoplankton
sediments get carried into the pond
allowing rooted submerged and
oating plants to star t to grow
sediments continue to build up
reeds and grasses develop around
pond margin, trapping more sediment
a marsh community builds up around
the pond margins
reeds take over more of the ponds as
more silt builds up
as the soil around the edge dries from
waterlogged to damp, tree species
such as willow and alder become
established
▲
Figre 2.4.21 Succession in a lake
Ponds
rivers
lot
and
that
sinks
dead
lakes
open
to
the
organic
build
up
pond
slowly
climax
get
continuous
into
pond
lls
to
in.
This
communities
of
plant
to
the
the
sediment
sediment
Over
the
leads
pond
from
passes
communities
invade
eventually
of
of
this
sediments.
plants
around
disappearance
As
these
rooted
inputs
Some
bottom.
material
allowing
eventual
them.
to
the
margins
these
they
in
but
a
add
sediments
margins
as
establishment
and
and
through
develop
time
pond
streams
smaller
the
of
ponds
the
pond.
Secondary succession
time
agricultural land kept in
after being abandoned
with time small shrubs
eventually trees establish
an ar ticial seral stage
wild grasses from wind
star t to colonize the
leading to the development
blown and dormant
grassland
of a climax community on
crops like wheat act as
a
seed in the ground
grassland
mature soils
take over
▲
Figre 2.4.22 Stages of secondary succession in abandoned agricultural land
Where
as
version
118
an
already
following
of
re
established
or
ood
succession
or
community
even
occurs.
human
is
suddenly
activity
destroyed,
(plowing)
an
such
abridged
2 . 4
This
secondary
ready
to
succession
accept
dormant
seeds
shortens
the
left
occurs
seeds
in
the
number
of
on
carried
soil
in
from
stages
soils
by
the
the
that
the
are
wind.
previous
community
already
Also
Z o n a T I o n
are
often
This
through.
Changes occurring during a succession
During
a
succession
the
following
changes
S u C C E S S I o n
developed
there
community.
goes
a n d
raey rep ytivitcudorp ten
and
B I o m E S ,
occur:
time
●
The
size
of
organisms
increases
with
trees
creating
a
more
hospitable
pioneer
climax
community
community
environment.
▲
●
Energy
ow
becomes
more
complex
as
simple
food
chains
Figre 2.4.23 Productivity
become
changes in a succession
complex
●
Soil
depth,
cycling
●
food
all
humus,
and
increases
then
●
NPP
●
Productivity
and
GPP
falls
rise
:
productivity
ground,
it
from
a
low
seed.
It
accumulates.
of
plant
by
the
being
In
and
used
the
early
through
high,
In
later
climax
is
stages,
the
and
is
gross
productivity
proportion
is
low.
As
increases
the
respiration
Studies
Following
fall
as
usually
low
GPP
but
as
and
rates
net
with
increase
shown
that
the
trees
of
and
rise
to
which
in
the
a
due
so
of
being
xed
energy
to
the
energy
net
a
is
initial
lost
productivity
and
decomposer
maximum
equally
ratio
high
to
as
productivity
of
1.
the
is
climax
linked
to
biomass
Gross
tends
early
the
increase
decreases
and
in
rates
approaches
approaches
tends
growth
as
low
productivity
shrubs.
in
is
by
then
primary
to
be
stages,
woodland
and
percentage
(biomass)
within
mature
slows
energy
at
biomass
community
of
a
large
respiration
biomass
GPP
can
fall
as
biomass.
crop
peak
the
accumulating.
net
towards
NPP
as
too,
productivity
more
standing
growth
so
rapid
and
bare
starting
(stable
consumer
to
(P:R)
biomass
But
a
is
balanced
small
develops
reaches
low
increase
by
and
with
off
rate
colonize
are
proportion
productivity
primary
establishment
age,
The
producer,
stages
little
the
biomass
is
rst
heat.
continues
marked
productivity.
woodland
and
This
herbs
opportunities)
reached.
they
reached
productivity
respiration
early
community
as
and
levels
to
decomposers,
:
is
germinate
is
relatively
this
maturity.
grasses,
does
have
deciduous
to
is
of
so
–
is
primary
and
biomass.
equal
producers.
However,
pioneer
are
of
(lifestyle
plants
plants
plants
emitted
increased
by
When
many
primary
productivity
accumulation
time.
productivity
productivity
growth
stages
content
falls.
more
growing
an
niches
community
community
respiration
reaches
Early
as
and
density
community
and
not
climax
particularly
the
mineral
fall.
with
species),
with
succession,
through
more
ratio
are
gross
low
gross
the
capacity,
climax
approximately
community.
During
a
system
stages,
respiration
varies
respiration,
and
the
then
quickly
animal
community,
zero
rises
community
ie
and
there
When
in
conditions
is
as
producers
because
as
respiration
Primary
is
water-holding
increase.
Biodiversity
appear
webs.
and
the
climax
an
in
rst
succession
few
forest,
extended
to
centuries.
biomass
canopy
tends
crowds
out
119
2
E c o s ys t E m s
a n d
E c o l o g y
ground
and
as
cover.
more
root
Also
NPP
is
older
trees
allocated
to
become
less
photosynthetically
non-photosynthetic
structural
efcient
biomass
such
systems.
Erl stge
mile stge
Low GPP but high
GPP high
Lte stge
Trees reach their
percentage NPP
maximum size
Little increase in biomass
Increased photosynthesis
Ratio of NPP to R is
Increases in biomass as
roughly equal
plant forms become bigger
generalized graph of species diversity
following Mount St Helens eruption
▲
Figre 2.4.24 Biomass accumulation and successional stage
ytisrevid seiceps
Species diversity in successions
In
early
stages
community.
the
number
ever
totally
diversity
–
of
As
of
succession,
the
species
replaced
more
there
community
found
as
only
This
a
Very
tends
species
pioneer
The
to
within
subsequent
few
continues.
increase
few
through
increases.
succession
species.
are
passes
result
species
is
continue
the
stages
so
are
increasing
until
a
balance
years since eruption
is
▲
Figre 2.4.25 Species
reached
species
to
between
expand
possibilities
their
range
for
and
new
local
species
to
establish,
existing
extinction.
diversity changes in a
Evidence
following
the
eruption
of
the
Mount
St
Helens
volcano
in
1980
succession
has
provided
the
rst
but
after
10
ecologists
years
after
with
the
a
natural
eruption
laboratory
species
to
diversity
study
succession.
increased
In
dramatically
4
Practical
20
years
very
little
additional
increase
in
the
diversity
occurred.
Work
Disturbance
Analyse
data
on
4
dierent
Communities
are
affected
by
periods
of
disturbance
to
a
greater
or
biomes.
lesser
Investigate
succession
in
extent.
in
large
forests
trees
eventually
age,
die
and
fall
over
a
leaving
local
Even
a
gap.
Other
communities
are
affected
by
ood,
re,
landslides,
ecosystem.
earthquakes,
Investigate
zonation
in
a
local
effect
ecosystem.
of
within
and
hurricanes
making
the
gaps
surrounding
diversity
of
the
disturbance
and
other
available
natural
that
can
community.
be
This
hazards.
All
colonized
adds
to
of
by
both
these
have
pioneer
the
an
species
productivity
community.
disturbance
disturbance
primary
succession
pioneer
intermediate
climax
community
community
community
bare rock
secondary
succession
generated
disturbance can send any seral stage back to an earlier seral stage or create gaps in a later
community that then regenerate increasing both productivity and diversity of the whole community
▲
Figre 2.4.26 Eects of disturbance in a succession
4
Carey, S., J. Har te and R. del Moral. 2006. Eect of community assembly and primary succession on the
species–area relationship in disturbed systems. Ecography 29, pp866–872
120
Z o n a T I o n
other
suei   ue
grasses,
reduce
On
the
southern
coast
of
England
in
Dorset
its
Bay
where
sand
dunes
have
formed
since
the
16th
leaves
area.
which
Leaves
are
are
able
waxy
to
to
fold
to
reduce
and
can
be
aligned
to
the
wind
to
It
incorporates
silica
into
its
cell
structure
century.
to
give
As
a
a
the
as
leaves
result
sandy
support
of
soil
the
has
thrive
scrub
The
has
in
humus
grasses
elder,
oldest
and
and
climatic
the
species
will
ash
soil)
are
species
have
is
stages,
now
sea
so
As
be
–
rst
due
for
to
can
the
shaded
growing
vegetation
to
such
buckthorn
present.
will
able
Species
nodules
forest
declines
previous
This
and
root
woodland
climax
diversity
the
exibility.
bushes.
brambles
shorter
dunes
oak
from
and
developed.
nutrient-poor
the
for
strength
nitrogen-xing
develops,
nally
extra
now
‘pasture’
hawthorn,
(which
▲
S u C C E S S I o n
is
continued
direction.
be
have
surface
transpiration
Studland
a n d
pine
on
the
E S A C
B I o m E S ,
out.
and
Y D U T S
2 . 4
them;
area.
Here
competition
–
what?
Figre 2.4.27 Sand dunes at Studland Bay, Dorset, UK .
In
This
begins
colonizes
low
with
the
growing
with
a
–
waxy
submersed
a
bare
sand.
The
why?
coating
–
surface
of
pioneer
They
and
have
are
sand.
plants
fat
able
Vegetation
tend
eshy
to
to
be
survive
with
as
leaves
being
grass
with
the
on
the
its
vegetation
nal
climatic
temperate
one
is
in
colonizes
environment
climax
vegetation.
deciduous
in
dynamic
and
In
a
series
of
equilibrium
hence
the
UK
is
known
this
is
forest.
temporarily.
predominant
the
case,
The
climatic
As
Later,
every
stages.
seaward
plant
side
environmental
foredunes:
species
due
to
its
conditions.
mobile dunes
an object such
as a plant or
is
ability
It,
to
like
succession
vegetation
marram
cope
soil
develops,
cover,
acidity,
soil
moisture
there
depth
are
and
content
increases
humus
and
sand
in
content,
stability.
the
semi-xed dunes:
dune slack: once a hollow is
Scrub, health & woodland:
the dunes could be
formed, perhaps by blowout,
climax vegetation in the absence
20m high here
sand is removed by the wind until
of management/interference.
plants begin
rock causes
the damp sand near the water
to bind sand
sand to build up
on the lee side.
table can not be transported.
together
marsh plants
sandy beach,
tidal litter
increasing soil depth and quality
site number/description
distance from the sea (m)
strand line
embryo
fore dunes
white/yellow
xed dunes
dune slack
dune scrub
(1)
dunes (2)
(3)
dunes (4)
(5)
(6)
(7)
0–20
20–80
80–150
150–300
300–500
500–700
(400) variable
0–50
50–100
100–125
125–150
150–250
approximate age (years)
soil colour
soil surface pH
% calcium carbonate
yellow
woodland
(8)
(9)
700–2500
2500+
250–400
>400
grey
brown
8.5
8.0
7
.5
7
.0
10
8
8
5
2.5
5
10
20
>40
sea rocket,
sand,
marram,
marram,
harebell,
creeping
birch,
heather,
pines,
couch,
grass,
sand sedge
willow
willow,
brambles
gorse
oaks
lyme grass
sea holly
% humus
dominant plant species
yellow/grey
dune heath
<1
saltwor t
6.5
4.5
6.0
<0.1
1
common
sallow
▲
Figre 2.4.28 Diagram of idealized sand dunes
121
2
E c o s ys t E m s
a n d
E c o l o g y
Arrested and deected successions
Succession
eg
soil
This
other
natural
regular
its
of
reduced
plagioclimax
Why
do
think
eg
re
or
or
arrested
a
biodiversity.
want
the
climax
at
a
stage
as
Again
if
or
a
biotic
limiting
human
the
develop
:
This
their
will
be
as
lead
to
a
as
will
by
either
agriculture,
deected
farmland
a
heavy
which
affected
such
or
ceases
climatic
at
such
factor,
removed.
activity
the
crops
respiration
is
may
arable
abiotic
factor
activity
human
into
an
community
factor
community
or
pasture,
maintain
productivity
by
sub-climax
destruction.
such
will
to
if
or
landslide,
habitat
community
the
‘arrested’
waterlogging,
an
community
farmers
about
as
in
or
development
re
plagioclimax
with
such
circumstances
event,
use
stopped
results
continue
Under
a
be
conditions
grazing.
only
may
or
plantations
the
climax
community.
plagioclimax?
Clue
–
ratios.
Signicance of changes during succession
GPP
NPP
biodiversity
During
succession
mineral
initial
lost
is
through
high,
high
net
▲
ie
in
a
and
low
system
an
is
growing
of
is
productivity,
productivity
The
relatively
biomass
is
and
this
the
is
diversity
is
low
proportion
low
too,
so
gross
productivity
by
:
to
the
energy
productivity
In
later
productivity
balanced
and
due
of
net
accumulating.
community,
However,
zero
net
gross
producers.
and
consumer
approaches
and
stages
density
community.
productivity
gross
early
respiration
increased
climax
ow,
In
community
the
with
energy
change.
conditions
stages,
years
cycling
may
respiration,
respiration
be
so
(P:R)
Figre 2.4.29 Changes during
ratio
approaches
1.
Biodiversity
increases
during
succession
as
more
succession
species
arrive
reached.
but
increases
There
is
and
a
basic
productivity
increasing
for
a
and
simple
placed
systems
buffer
that
as
a
yield
a
as
on
a
and
elds.
as
environmental
we?
rights
Less
need
a
is
we
–
the
higher
need
Food
income
cycle,
be
balance
places
able
But
are
to
between
of
we
aims
have
natural
cycling,
aesthetic
mixture
to
more
monoculture
that
nutrient
provision,
a
of
leads
production
and
community.
natural
places,
to
is
succession
human
rates
system
controlled
climax
may
of
biodiversity,
ecosystem.
are
and
high
natural
productive
we
community
stages
process.
The
water
the
climax
early
achieve
carbon
waste
While
What
that
the
clean
provide.
quantity.
should
plants
stable
at
chains,
services
oceans,
We
left.
reach
in
a
succession
to
stratied
not
other
natural
food
weed
balance
systems
well
land,
–
does
if
slow
want
crop
longer
where
that
value
forests
natural
We
standing
be
succession
between
well-organized
system
productive
more
no
slightly
to
the
agriculture.
with
provide
of
quality
conict
in
tends
during
complexity,
maximizes
not
decreases
cycling
strongly
requirements
biomass
then
Mineral
as
climate
services
necessary
habitats,
grow
crops
human
on
rights
and
nd?
K-  r-rei' repruive reie
Species
can
r-selected
of
the
the
K-
122
roughly
species.
population
shape
and
their
be
of
the
into
and
growth
r
describe
the
next
into
are
curve.
exponential
r-strategies
genes
K
divided
and
r-strategists
two
variables
K
the
part
the
K-
is
of
the
approach
generation
and
that
carrying
growth
different
ensuring
or
K-
determine
capacity
and
the
and
r
shape
describes
curve.
species
the
‘take’
survival
to
of
getting
the
species.
2 . 4
Different
species
vary
in
the
amount
of
time
and
B I o m E S ,
energy
Z o n a T I o n
they
use
to
a n d
S u C C E S S I o n
raise
T 
their
offspring.
K-strategists,
There
eg
are
humans
two
and
extremes.
other
large
In 1980, Mt St Helens
mammals:
volcano erupted in
●
Have
●
Invest
small
numbers
of
offspring.
Washington State, USA.
large
amounts
of
time
and
energy
in
parental
care.
Research what has
happened to the vegetation
●
Most
offspring
●
They
are
●
Population
survive.
in the area since then. Star t
good
competitors.
here http://vulcan.wr.usgs.
their
sizes
are
usually
close
to
the
carrying
capacity,
gov/Volcanoes/MSH/
hence
Recovery/framework .html
name.
Sketch curves for gross
●
In
stable,
climax
ecosystems,
K-strategists
out
compete
r-strategists.
productivity, net productivity
r-strategists,
eg
invertebrates
and
sh:
and respiration as a function
●
Use
●
No
●
They
lay
●
They
reproduce
●
Are
●
Make
●
Because
lots
of
energy
in
the
production
of
vast
numbers
of
of time in one graph for Mt St
eggs.
Helens since 1980. Indicate
energy
is
used
in
raising
them
after
hatching.
the dierent succession
the
able
their
to
eggs
and
opportunistic
of
their
new
use
fast
in
habitats
of
stages in the graph.
forever.
with
unstable
rapidly.
short-lived
reproductive
capacity,
predominate
them
quickly.
colonize
carrying
leave
a
and
resources.
growth
population
crash
rates,
as
a
they
result.
may
exceed
They
ecosystems.
Ticl chrcteristics f r-  K- strtegists
r-strtegist
K-strtegist
Shor t life
Long life
Rapid growth
Slower growth
Early maturity
Late maturity
Many small ospring
Fewer large ospring
Little parental care or protection
High parental care and protection
Little investment in individual ospring
High investment in individual ospring
Adapted to unstable environment
Adapted to stable environment
Pioneers, colonizers
Later stages of succession
Niche generalists
Niche specialists
Prey
Predators
Regulated mainly by external factors
Regulated mainly by internal factors
Lower trophic level
Higher trophic level
Examples: annual plants, our beetles,
Examples: trees, albatrosses, humans
bacteria
It
a
is
important
continuum
of
these
to
of
appreciate
that
reproductive
K-
and
strategies
r-strategists
and
many
are
the
species
extremes
show
a
of
mixture
characteristics.
123
2
E c o s ys t E m s
a n d
E c o l o g y
Survivorship curves
type I
1000
sroviv rus fo noit roporp
)elacs gol( )dnasuoht rep rebmun ni(
typical for K-selected species.
100
they live for most of their life
span and mostly die later in life
t
y
p
e
10
I
I
typical for r-selected species: high
mor tality occurs in the very early
1
stages of the species’ life cycle.
type III
0
age
▲
A
a
Figre 2.4.30 Survivorship curves
survivorship
species.
gure2.4.30.
Curve
dying
II
at
species
is
shows
the
hypothetical
Note
rather
any
of
curve
Three
age.
that
rare.
It
the
It
fate
vertical
represents
occurs
of
a
group
survivorship
for
axis
is
in
individuals
are
shown
of
in
logarithmic.
species
example
of
curves
that
the
have
an
equal
hydrozoan
chance
Hydra
and
of
some
birds.
T 
Look at the diagram of a theoretical survival model of a small bird population.
deaths
eggs
200
100 eggs
and young
population pool
per year
birds of breeding age
100
deaths
T 
(input)
1.
50
100
Which kind of organisms
100 birds
per year
are rstrategists?
25
(output)
2.
12
0
List characteristics of
1
2
3
4
rstrategists shown by
age in years
the shape of the curve.
3.
Which species are most
reproduction
likely to be regulated by
▲
Figre 2.4.31 A theoretical survival model of a small bird population
densityindependent
factors, eg weather?
4.
1.
What is the life span of these birds?
2.
What is the potential natality?
3.
How many survivors after the rst year?
4.
What is the percentage mor tality at end of year 1?
5.
What is the percentage mor tality at end of year 2?
6.
What is the percentage mor tality at end of year 3?
7.
What would the survivorship curve for these birds look like?
Describe and explain the
shape of the survivorship
curve for Kselected
species.
124
2 . 5
I n v E S T I G a T I n G
E C o S y S T E m S
–
p R a C T I C a L
w o R K
2.5 Iestigtig ecsstes – prcticl rk
sii ie:
appii  ki:
➔
The description and investigation of
➔
desig and carry out ecological investigations.
➔
Cstrct simple identication keys for up to
ecosystems allows for comparisons to be
made between dierent ecosystems and for
eight species.
them to be monitored, modelled and evaluated
➔
Elte sampling strategies.
➔
Elte methods to measure at least three
over time, measuring both natural change and
human impacts.
abiotic factors in an ecosystem.
➔
Ecosystems can be better understood through
the investigation and quantication of their
➔
Elte methods to investigate the change
along an environmental gradient and the eect
components.
of a human impact in an ecosystem.
➔
Elte methods for estimating biomass at
dierent trophic levels in an ecosystem.
➔
Elte methods for measuring/estimating
populations of motile and nonmotile
organisms.
➔
Clclte and iterret data for species
richness and diversity.
➔
dr graphs to illustrate species diversity in a
community over time or between communities.
Kwee  ueri:
➔
➔
➔
The study of an ecosystem requires that it
include measurement of dry mass, controlled
be named and located eg Deiniker wald, Baar,
combustion and extrapolation from samples.
Switzerland, a mixed deciduous–coniferous
Data from these methods can be used to
managed woodland.
construct ecological pyramids.
Organisms in an ecosystem can be identied
comparison to herbarium / specimen collections,
quadrats for making actual counts, measuring
technologies and scientic exper tise.
population density, percentage cover and
percentage frequency.
Slig strtegies may be used to measure
➔
Direct and indirect methods for estimating
space, along an environmental gradient, over
the bce f tile rgiss can be
time, through succession or before and after a
described and evaluated. Direct methods include
human impact, for example as par t of an EIA .
actual counts and sampling. Indirect methods
include the use of ctre-rk-rectre with
Measurements should be repeated to increase
the application of the Lincoln Index.
reliability of data. The number of repetitions
required depends on the factor being measured.
➔
Methods for estimating the bce f
-tile rgiss include the use of
biotic and abiotic factors and their change in
➔
➔
using a variety of tools including kes,
Methods for estimating the biss and
energy of trophic levels in a community
➔
Secies richess is the number of species
in a community and is a useful comparative
measure.
125
2
E c o s ys t E m s
➔
a n d
E c o l o g y
Secies i ersit is a function of the number of
the result of the Simpson diversity index. Using
species and their relative abundance and can
its formula, the higher the result, the greater the
be compared using an index. There are many
species diversity. This indication of diversity is
versions of diversity indices but students are
only useful when comparing two similar habitats
only expected to be able to apply and evaluate
or the same habitat over time.
sui ee
All
ecosystem
investigations
experimentation
national
standards
Consider
if
you
●
Replace
●
Rene
●
Reduce
The
it
IB
it
follow
may
be
carefully
the
more
before
guidelines
stringent
in
the
than
designing
an
IB
your
animal
local,
experiment.
animal
by
using
number
states
of
that
to
cells,
alleviate
animals
you
plants
may
harm
or
or
simulations.
distress.
involved.
not
carry
out
an
animal
experiment
if
involves:
●
pain,
●
death
●
drug
the
If
check
experiment
the
policy
so
should
This
could:
the
the
policy.
undue
of
intake
or
damage
to
health
of
the
animal
animal
or
dietary
change
beyond
those
easily
tolerated
by
animal.
humans
and
the
stress
not
are
carry
blood-borne
involved,
out
you
must
experiments
also
that
have
involve
their
the
written
possibility
permission
of
transfer
of
pathogens.
tehique fr  ei
This
topic
number
you
●
to
collect
Where
to
itself
these
the
■
Transects
to
a
lot
of
the
traditional
underpin
various
relevant
collect
Quadrats
What
to
techniques
■
■
126
basic
understand
them
●
lends
of
methods
data
data
measure
Measuring
abiotic
X
Marine
X
Freshwater
X
Terrestrial
factors
for
a
environmental
many
of
of
data
wide
the
collection
range
studies
investigations.
of
you
can
and
a
Once
combine
investigations.
2 . 5
●
Measuring
I n v E S T I G a T I n G
E C o S y S T E m S
–
p R a C T I C a L
w o R K
biotics
Ke ter
■
Biomass
■
Catching
and
productivity
A qrt is a frame of
small
motile
animals
specic size (depending
X
Terrestrial
on what is being studied),
which may be divided into
X
Aquatic
subsections.
■
●
Keys
Measuring
abundance
■
Lincoln
■
Simpson
Index
diversity
index
Where  e he 
Quadrats
How
▲
many
quadrat
samples,
and
of
what
size?
Figre 2.5.1 Quadrats
The
size
being
of
the
quadrat
chosen
is
dependent
on
the
size
of
the
organisms
sampled.
Qrt size
Qrt re
orgis
2
0.01 m
10 × 10 cm
Very small organisms such as lichens on
tree trunks or walls, or algae.
2
0.25 m
0.5 × 0.5 m
Small plants: grasses, herbs, small
shrubs. Slow moving or sessile animals:
mussels, limpets.
2
Medium size plants: large bushes.
1 m
1.0 × 1.0 m
2
25 m
5.0 × 5.0 m
▲
Mature trees.
Figre 2.5.2
There
size
is
and
a
balance
time
to
strike
available
and
between
the
increasing
number
of
accuracy
times
a
with
quadrat
is
increasing
placed.
127
2
E c o s ys t E m s
a n d
E c o l o g y
These
20
will
vary
distribution.
depending
But
you
can
on
the
work
ecosystem,
out
how
size
many
of
organisms
samples
to
take
and
their
and
what
15
size
As
10
the
you
found.
quadrats
increase
When
should
the
this
be
quite
number
number
of
is
simply.
samples,
stable,
plot
you
the
have
number
found
all
of
species
species
in
the
5
area,
If
0
1
3
5
7
9
11
13
you
in
gure
increase
2.5.3,
the
eight
size
of
samples
the
are
enough.
quadrat
(eg
plot
number
from
side
length
10
cm
to
15
15
▲
so
Figre 2.5.3 Number of species
cm,
this
20
cm
number
and
so
reaches
on)
a
and
constant,
the
that
is
the
of
species
quadrat
size
found,
to
when
use.
and quadrat size
How to place quadrats
Quadrats
can
(according
15
1.
Random
your
9
16
2
1
26
be
to
a
quadrats
shoulder
4
10
1
7
22
27
2
5
11
18
23
28
The
3
6
12
19
24
7
13
20
25
8
may
but
14
2.
Figre 2.5.4
and
we
●
Map
●
Draw
●
Number
●
Use
out
a
a
or
continuously
or
systematically
be
do
placed
not
by
throwing
recommend
this
the
as
quadrat
it
could
over
be
Stratied
are
method
your
grid
random
study
over
each
random
–
you
(gure
may
2.5.4)
decide
is
to
where
use
to
both
random
throw.
number
tables:
area.
the
study
area.
square.
number
table
to
identify
which
squares
you
need
sample.
random
difference
edge of study area
not
conventional
to
▲
randomly
29
dangerous
1
placed
pattern).
within
sampling
an
area
is
to
used
be
when
sampled
there
and
is
two
an
obvious
sets
of
samples
taken.
This
study
types
taken
and
in
area
(gure
three
each
2.5.5)
separate
has
areas
to
two
be
distinctly
studied.
different
Samples
vegetation
need
to
be
area.
forest
●
Deal
●
Draw
●
Number
with
each
area
separately.
prairie
a
grid
for
the
each
squares
area.
in
each
area
(they
can
be
the
same
numbers
quadrats
or
●
Use
to
forest
▲
Figre 2.5.5
different).
a
in
number
each
table
to
identify
which
squares
you
need
area.
Transects
Continuous
Ke ter
random
sample
You
might
changes
and
use
along
systematic
this
an
to
look
sampling
at
is
changes
environmental
along
in
a
transect
organisms
gradient,
eg
as
a
zonation
line.
result
along
of
a
slope,
A trsect is a sample path/
a
rocky
shore
or
grassland
to
woodland,
or
to
measure
the
change
in
line/strip along which you
species
composition
with
increasing
distance
from
a
source
of
pollution.
record the occurrence and/
Transects
are
quick
and
relatively
simple
to
conduct.
or distribution of plants and
animals in a par ticular study
area.
NOTE
Many
obtain
128
line
transects
sufcient
(at
least
reliable
3,
data.
preferably
5)
need
to
be
combined
to
2 . 5
There
1.
are
Line
out
2
main
transect:
in
the
touching
2.
Belt
It
is
1.
In
a
belt
2.
In
the
this
an
is
may
be
of
the
a
a
string
are
strip
two
that
could
or
of
chosen
line
individuals
transect
E C o S y S T E m S
useful
to
tape
gradient
–
p R a C T I C a L
w o R K
you.
which
and
is
laid
species
recorded.
parallel
continuous
be
measuring
environmental
tape
which
continuous
is
or
laying
between
lines
of
string
by
transect
consists
transect:
apart,
of
direction
made
Transect
types
I n v E S T I G a T I n G
or
(line
width
through
transects,
are
the
usually
ecosystem.
0.5
or
1
metre
sampled.
interrupted.
or
belt
transect)
the
whole
line
or
sampled.
interrupted
points
along
horizontal
Quadrats
the
or
transect
line
or
vertical
are
placed
belt.
(line
intervals.
at
or
These
This
intervals
belt)
points
is
a
along
samples
are
form
the
are
usually
of
taken
taken
systematic
at
at
regular
sampling.
belt.
Wh  eure
Measuring abiotic components of the system
Ecosystems
terrestrial
of
can
be
roughly
ecosystems.
physical
(abiotic)
1.
Describe
and
2.
Describe
and
variations
in
divided
Each
factors
of
and
you
evaluate
methods
evaluate
how
abiotic
into
these
to
marine,
ecosystem
should
for
be
freshwater
types
able
measuring
measure
has
a
and
different
set
to:
these.
spatial
and
temporal
factors.
Marine ecosystems
Abiotic
factors:
salinity,
pH,
temperature,
dissolved
oxygen,
Normal seawater
35‰
Brackish water (Baltic Sea)
Between 1‰ and 10‰
Freshwater
0.5 ‰
The
salinity
can
be
determined
by
measuring
the
electrical
wave
action.
conductivity
Ke ter
or
the
density
Seawater
using
a
of
the
usually
pH
water.
has
a
pH
of
above
7
(basic).
The
pH
can
be
measured
Sliit is the concentration
of salts expressed in ‰
meter.
(par ts of salt per thousand
Many
meters
have
interchangeable
probes
and
so
can
be
used
to
par ts of water).
measure
a
number
of
abiotic
factors.
Temperature
Temperature
due
to
about
the
the
affects
fact
that
same
metabolic
rates.
may
a
have
as
the
the
So
metabolic
many
are
surrounding
changes
signicant
rates
in
impact
of
ectothermic
marine
(their
water).
temperature
on
some
organisms:
body
Lower
this
temperatures
caused
by
is
temperature
thermal
=
is
low
pollution
organisms.
129
2
E c o s ys t E m s
a n d
E c o l o g y
Dissolved oxygen
Solubility
●
of
oxygen
Temperature:
dissolved
oxygen
the
●
for
Dissolved
(A
in
series
the
Acid
of
an
then
well
can
added
calculated.)
by:
=
lower
organisms
changes
in
concentrations
rely
on
of
dissolved
temperature
will
impact
to
can
be
is
to
the
cause
measured
meter,
added
iodide
release
amount
titration
is
oxygen
to
the
ions
to
concentrations
oxygen-selective
which
in
or
a
can
give
to
a
and
thus
be
and
give
titration.
dissolved
can
results,
and
then
but
accurate
oxygen
precipitate.
measured,
which
quick
electrode
Winkler
golden-brown
oxygen,
order
by
sample
form
electrodes
labour
an
water
dissolved
calibrated
more
using
datalogging,
iodine
of
Oxygen-selective
and
low
organisms.
with
maintained
Winkler
marine
hence
electronic
reacts
proportional
be
this
marine
chemicals
water
is
for
to
affected
ecosystem.
oxygen
connected
is
temperatures
Many
respiration
pollution:
problems
water
higher
oxygen.
marine
Water
in
is
be
need
results.
to
The
intensive.
Wave action
Wave
to
action
the
is
water
important
surface.
concentrations
rocky
of
in
Areas
coastal
with
dissolved
zones
high
oxygen.
where
wave
organisms
activity
Typical
live
usually
examples
are
close
have
coral
high
reefs
and
coasts.
Freshwater ecosystems
Ke ter
Abiotic
factors:
turbidity,
ow
velocity,
pH,
temperature,
dissolved
oxygen.
Trbiit is the cloudiness of
Turbidity
a body of fresh water.
High
Low
turbidity
turbidity
The
turbidity
and
thereby
be
A
Secchi
disc
The
▲
cloudy
clear
water
important
depth
with
is
water
a
is
at
optical
white
heavy
because
which
limits
instruments
or
to
it
the
penetration
photosynthesis
or
by
black-and-white
ensure
that
the
can
using
disc
rope
a
occur.
Secchi
attached
goes
of
sunlight
Turbidity
can
disc.
to
a
vertically
graduated
down.
The
is:
1.
Slowly
2.
Read
3.
Slowly
4.
Read
5.
Calculate
lower
the
the
the
depth
raise
reliable
depth
the
stand
●
Always
wear
●
Always
work
disc
the
or
it
depth.
always
disappears
is
just
in
or
the
view.
rope.
again.
rope.
depth
procedure
sit
glasses
This
from
visible
graduated
standard
your
it
graduated
until
from
a
until
the
average
results
Always
disc
from
the
●
is
known
should
be
should
be
on
the
repeated
shady
in
the
of
same
the
Secchi
boat.
always
side
as
followed:
work
without
Figre 2.5.6 The Secchi disc
This
130
is
disc
procedure
For
=
the
measured
rope.
=
the
spot
boat.
3–5
times.
them.
depth.
2 . 5
I n v E S T I G a T I n G
E C o S y S T E m S
–
p R a C T I C a L
w o R K
Flow velocity
This
is
the
species
1.
Time:
low
2.
live
melt
ow
Depth:
of
3.
speed
can
the
1.
are
Flow
2.
in
on
be
oor
only
The
and
velocity
high
it
determines
varies
ow
which
with:
rates,
summer
drought
slowly
bend
for
than
generally
mounted
river
the
used
that
in
the
middle
a
clear
water,
ow
velocity:
and
can
be
unreliable
as
problems.
device
on
/
its
slower-moving
water.
expensive
has
as
shown
graduated
stream.
velocity
in
shallow
measuring
mechanical
the
has
fast-moving
electricity
and
impeller
is
held
facing
impeller
Repeat
more
The
stick
height
measured
shallow
in
at
water,
gure
and
of
the
the
different
as
you
2.5.7:
base
placed
impeller
depths,
must
be
can
BUT
able
it
to
impeller.
distance
d.
is
of
be
water
The
moving
gives
ow
Inside
are
simple
impeller
the
may
methods
with
adjusted
the
c.
a
the
see
is
Flow
spring
deeper
These
water
can
b.
river:
has
basic
meter:
The
the
water
the
bend
Impellers:
a.
in
water
area.
column.
three
mixing
the
certain
water
Surface
outside
which
a
rates.
water
Position
There
at
in
of
is
the
3–5
at
the
end
of
the
side
arm
and
lowered
into
upstream.
released
side
times
arm
for
and
is
the
time
it
takes
to
travel
the
measured.
accurate
results.
Impeller mounted on
a threaded side arm.
The side arm of xed length:
height can be adjusted.
The base of the graduated rod
is placed in the stream bed.
▲
3.
Figre 2.5.7 Impeller
Floats
The
easiest
object
preferably
and
to
be
only.
surface
to
measure
travel
partly
grapefruits
velocity
the
way
takes
ow
ow
certain
suitable
average
velocity
to
This
velocity
dividing
is
to
The
reduce
oats.
ow
by
velocity
distance.
submerged
make
The
a
the
measure
oating
the
effect
method
of
a
river
surface
the
object
of
the
gives
can
time
wind.
the
be
velocity
a
oating
should
Oranges
surface
estimated
by
ow
from
1.25.
131
2
E c o s ys t E m s
a n d
E c o l o g y
person 1 drops the oat above the rst marker
and shouts star t as it passes the marker
marker 1
marker 2
ideal distance = 10m
river owing in this direction
oat
person 2 star ts the stopwatch on command from
person 1 and stops it as the oat passes marker 2
and catches the oat
▲
Figre 2.5.8
This
should
be
WARNING:
repeated
This
3–5
method
times
gives
for
accuracy.
seconds
/
metre
NOT
metres
/
second
pH
pH
values
of
depending
with
For
a
pH
freshwater
on
range
surrounding
meter
or
temperature
from
soil,
datalogging
and
dissolved
moderately
rock
pH
and
acidic
vegetation.
to
It
slightly
can
be
basic,
measured
probe.
oxygen
see
marine
ecosystems
(p129).
Terrestrial ecosystems
Abiotic
slope,
factors:
soil
temperature,
moisture,
light
drainage
and
intensity,
mineral
wind
speed,
soil
texture,
content.
Air temperature
Temperature
simple
varies
liquid
(electronic)
temporally
thermometers,
thermometers.
temperature
continuously
temperature
probe.
and
spatially
min–max
The
latter
during
a
and
can
be
thermometers,
equipment
longer
time
can
as
measured
or
be
can
a
more
used
using
complex
to
measure
data-logging
Light intensity
This
can
varies
be
be
measured
with
taken
time
into
with
(sunny
electronic
period,
meters.
clouds,
time
The
of
fact
the
that
day,
light
intensity
season)
should
account.
Wind speed
There
●
A
are
a
variety
revolving
the
wind.
mounted
●
A
easy
By
to
a
the
anemometer
number
wind
use
is
a
and
related
to
of
or
to
consists
measure
of
per
Revolving
three
time
cup
wind
cups
period
speed:
that
is
rotate
counted
anemometers
can
in
and
be
hand-held.
calibrated
in
used
rotations
speed.
pressure
observation
then
132
to
techniques
permanently
ventimeter
reduces
●
cup
The
converted
of
the
tube
tube,
over
which
which
the
makes
a
wind
passes.
pointer
This
move.
It
is
inexpensive.
of
the
the
effect
Beaufort
of
the
Scale
wind
(a
on
scale
objects.
of
wind
The
observations
speed
from
0
to
are
12).
2 . 5
I n v E S T I G a T I n G
E C o S y S T E m S
–
p R a C T I C a L
w o R K
Rainfall
Rainfall
can
established
Many
easy
on
1.
be
schools
to
make
how
to
Place
collected
weather
will
and
make
your
obstacles
2.
Check
rain
a
are
may
gauge
a
case
of
Some
but
websites
you
have
spot
inuence
schools
collecting
station
suitable
the
every
gauge.
weather
Once
affect
graduated
rain
which
plenty
in
from
a
in
a
own.
gauge
away
–
have
there
your
that
rain
into
not
rain
somewhere
using
station
rain
that
made
in
of
can
give
rain
study
buildings,
are
you
is
easy.
very
advice
gauge:
area
trees
an
data
gauges
your
the
have
rainfall
–
and
other
rainfall.
24
hours
cylinder
–
and
at
the
record
same
daily
time
every
amount
of
day.
Pour
rainfall.
▲
Figre 2.5.9 Rain gauge
Soil
Soil
has
aspects
a
signicant
of
the
soil
impact
that
can
on
be
plant
growth
and
there
are
a
variety
of
measured.
Texture (Par ticle size)
Soil
is
made
distribution
up
of
of
particles
them
(gravel,
affects
a
soil’s
sand,
silt,
drainage
clay)
and
and
the
average
water-holding
size
and
capacity.
pr ticle
H t esre
Gravel: very coarse,
Measure individually – simple, but timeconsuming
coarse and medium
procedure
Gravel: ne and very ne
Sieved through a series of sieves with dierent mesh
sizes.
Sand: All sizes
Silt and clay
Sedimentation or optical techniques. Sedimentation
techniques are based on the fact that large par ticles
sink faster than small par ticles. Optical techniques
use light scattering by the par ticles (light scattering
is what makes suspensions of soil par ticles in water
look cloudy). Both sedimentation and light scattering
can nowadays be done using automated instruments
but are expensive for secondary school use.
Soil moisture
This
is
the
amount
of
water
in
the
soil.
It
can
be
measured
by
drying
soil
samples.
1.
Place
2.
Weigh
3.
Dry
Drying
In
●
a
sample
it
the
can
and
Set
the
burn
Leave
of
the
record
soil
the
in
a
crucible.
weight.
sample.
be
done
conventional
to
●
a
oven
off
for
becomes
in
to
105
organic
24
a
conventional
drying
oven
or
a
microwave
oven.
oven:
hours
constant.
°C;
hot
enough
to
dry
the
soil
but
not
so
hot
as
matter.
and
This
weigh
takes
the
sample,
several
repeat
this
until
its
mass
days.
133
2
E c o s ys t E m s
a n d
E c o l o g y
In
a
microwave
●
Place
●
Weigh
until
A
the
sample
the
its
oven:
sample,
mass
minimum
in
of
the
and
becomes
3–5
microwave
return
to
for
the
10
minutes.
oven
for
5
minutes
–
repeat
constant.
samples
should
be
tested.
Organic content
The
organic
stages
of
content
decay
and
●
Supplies
●
Holds
water
●
Helps
reduce
●
Increases
Organic
(like
Dry
the
2.
Heat
soil
to
a
is
plant
several
the
and
animal
residues
in
various
functions.
soil.
sponge).
compaction
and
crusting.
inltration.
can
sample
the
a
has
nutrients
content
1.
of
it
soil
at
be
as
determined
by
the
loss
on
ignition
(LOI)
method.
above.
high
temperatures
of
500
to
1,000
°C
for
several
hours.
3.
Weigh
the
sample
and
repeat
this
until
its
mass
becomes
constant.
Mineral content and pH
There
easy
in
is
to
a
many
Soil
pH
wide
range
measure
gardening
can
of
soil
through
also
be
nutrients
traditional
essential
soil
testing
for
a
kits
fertile
or
the
soil.
ones
These
are
available
centres.
measured
using
a
soil
testing
kit
or
a
pH
probe.
Measuring biotic components of the system
To
measure
●
Why
●
What
●
Why
●
What
So
walk
is
biotic
it
as
has
it
components
this
impact
around
do
your
a
playing
●
Is
there
a
footpath
●
Does
●
Is
ground
more
shady
does
and
people
not
observe
and
question.
there?
walking
institution’s
there
it
here
more
Is
difference
to
recently?
grow
●
the
need
is?
changed
does
we
here
grounds
or
have?
the
local
area.
eld?
on
soil
rather
than
concrete?
slope?
or
more
that
moist
make
to
in
the
one
type
area
and
than
another
number
of
and
species
what
living
there?
Measuring biomass and productivity
Plant biomass
Measuring
plant
it
take
is
best
very
134
to
difcult.
biomass
is
simple
above-ground
but
destructive.
biomass
as
trying
to
Generally
get
roots
speaking
etc.
can
be
2 . 5
For
low
vegetation
1.
Place
a
2.
Harvest
all
3.
Wash
to
4.
Dry
suitably
it
it
at
content
the
5.
6.
the
given
accurate
per
unit
result
For
trees
in
1.
Select
2.
Harvest
3.
And
can
(see
as
dry
–
p R a C T I C a L
w o R K
then
2.5.2).
in
that
area.
insects.
until
it
reaches
so
all
a
the
constant
water
weight.
should
be
Water
removed
and
weight.
this
be
gure
vegetation
enormously
can
the
and
any
results
area
quadrat
60–70°C
vary
For
species
sized
above-ground
about
E C o S y S T E m S
grasses:
remove
can
mass
The
/
I n v E S T I G a T I n G
should
be
repeated
3–5
times
so
that
a
mean
obtained.
be
extrapolated
to
the
total
biomass
of
that
ecosystem.
bushes:
the
tree
the
repeat
or
bush
leaves
steps
you
from
3–6
which
3–5
in
the
to
test.
branches.
above
method.
Primary productivity
In
aquatic
and
dark
ecosystems
bottle
productivity
has
given
The
the
1.
2.
of
us
a
aquatic
good
productivity
bottles.
Take
The
two
a.
One
b.
The
litre
the
the
Place
equal
4.
Both
bottles
should
5.
Allow
to
6.
Measure
original
the
is
amounts
must
be
the
light
the
dark,
In
terrestrial
(including
measure
the
phytoplankton).
productivity
calculated
ecosystems)
both
of
the
This
oceans
the
gross
and
from
the
oxygen
from
the
ecosystem.
is
light
and
net
simple
of
many
but
lakes.
concentrations
in
with
is
water
made
glass
of
or
clear
is
covered
concentration
an
oxygen
glass.
of
the
probe,
to
exclude
water
and
by
record
light.
chemical
it
as
mg
titration
oxygen
stand
the
of
be
plants
of
the
completely
same
lled
species
with
into
water
each
and
of
the
capped.
bottles.
(No
present.)
and
incubate
oxygen
laboratory
In
or
freshwater
to
is:
dark
oxygen
oxygen
In
of
and
used
water.
3.
air
lled
bottles
be
the
usually
method)
of
of
procedure
other
(Winkler
per
is
marine
can
plants
idea
bottles
of
Measure
(both
technique
bottle,
only
level
or
levels
of
in
the
outdoors
for
both
water.
in
the
photosynthesis
respiration
ecosystems,
several
hours.
bottles
The
and
ecosystem
and
compare
incubation
of
respiration
can
with
take
the
place
in
investigation.
have
been
occurring.
occurs.
you
can
do
a
similar
experiment
with
square
‘patches’:
1.
Select
2.
The
three
rst
equally
patch
measured
(see
(A)
sized
is
patches
harvested
with
similar
immediately
vegetation
and
the
(eg
grass).
biomass
above).
135
2
E c o s ys t E m s
a n d
E c o l o g y
3.
The
second
just
respiration).
4.
The
5.
After
C
third
a
are
patch
patch
(B)
(C)
suitable
is
time
harvested
is
covered
just
left
period
and
the
with
as
it
black
(no
photosynthesis,
is.
(depends
biomass
plastic
on
the
measured
season),
(as
patches
B
and
above).
2
6.
Now
GPP
,
NPP
and
R
can
be
calculated
(usually
per
m
).
Secondary productivity
In
a
typical
procedure
time
experiment,
is
period,
that
the
the
a
herbivore
food
and
remaining
the
food,
is
fed
with
a
herbivore(s)
the
known
are
herbivore(s)
amount
weighed.
and
the
of
After
feces
food.
a
are
The
suitable
weighed.
Catching small motile animals
These
small
are
more
animals?
identify
the
insects
you
Under
no
WARNING:
killed
count
problematic
Obviously
during
small
any
as
they
are
they
have
likely
to
move
to
catch
circumstances
investigation
–
be
around,
caught
–
have
should
there
are
any
so
how
rst.
a
key
be
ways
we
count
sure
handy
animal
humane
do
Make
to
you
help
stressed
to
catch
can
you.
or
and
animals.
Terrestrial ecosystems
There
is
a
range
1.
Pitfall
2.
Sweep
3.
Tree
of
safe
harmless
techniques
that
can
be
used
to
catch
insects:
traps.
nets.
beating.
WARNING:
●
Make
●
DO
or
The
NOT
a
do
Several
be
are
the
of
of
is
ideal
cannot
meat
not
fall
these
checked
number
handle
trap
that
decaying
insects
there
no
venomous
insects
insects
directly
–
in
move
your
the
local
insects
area.
with
tweezers
pooter.
pitfall
animals
by
sure
at
catching
away
(see
sweet
sugar
in
it
drown)
traps
and
can
be
species
and
and
(this
will
around
(every
6
other
2.5.10).
solution
placed
intervals
insects
gure
or
regular
that
for
y
fall
the
hours)
small
Insects
must
be
into
the
study
and
be
attracted
covered
so
the
trap.
area.
the
crawling
can
They
species
should
and
recorded.
cover over the trap to protect from rainfall
stones to
suppor t cover
small yogur t pot level with the
soil surface, with leaves or soil
▲
in the bottom
Figre 2.5.11 Sweep netting
▲
136
Figre 2.5.10 A pitfall trap
2 . 5
I n v E S T I G a T I n G
E C o S y S T E m S
–
p R a C T I C a L
w o R K
WARNING
●
DO
NOT
kill
●
the
DO
put
any
uid
in
the
bottom
of
the
trap
–
you
do
not
want
to
insect.
NOT
leave
the
traps
unchecked
for
more
than
24
hours.
Sweep nets
Sweep
nets
heights
These
and
in
of
various
order
can
then
numbers
to
be
sizes
catch
can
many
emptied
be
swept
through
grasses
at
various
insects.
into
a
large
clear
container
and
the
species
recorded.
Tree beating
This
method
can
nd
insects
in
tree
branches.
Simply
place
a
catching
tray
▲
beneath
that
a
falls
tree
branch
from
the
and
tree
gently
and
you
tap
can
the
log
branch.
the
The
species
tray
and
will
their
catch
Figre 2.5.12 Tree beating
anything
numbers.
suck here
Night-ying
sheet
is
Small
moths
hung
insects
and
will
the
and
be
attracted
moths
settle
invertebrates
to
on
can
a
light
this
be
behind
for
you
caught
which
to
with
a
white
rubber tubing
observe.
a
pooter
–
a
small
jar
rubber bung
with
and
two
the
gauze
tubes
animal
at
the
attached
(see
gure
is
into
the
end
pulled
of
the
2.5.13).
jar.
mouthpiece
You
You
suck
cannot
gently
swallow
it
on
as
one
tube
there
is
gauze tied
tube!
on to prevent
animal entering
animal
Aquatic ecosystems
in here
The
organisms
most
efcient
of
most
way
to
interest
catch
will
them
be
is
the
stream
through
kick
invertebrates
and
the
samples.
specimen
tube
Kick
sampling
is
another
simple
technique:
▲
●
Place
●
Shufe
●
Empty
●
Use
the
a
your
the
In
aquatic
into
to
three
times
systems,
nets
of
boats
or
running
is
also
You
loosens
effective.
may
caught
think
and
net
into
various
ensure
for
a
Figre 2.5.13 A pooter
you.
30
tray
insects
various
Some
is
good
mesh
invertebrates
water.
of
these
not
should
or
seconds.
lled
into
with
small
stream
plastic
water.
cups
and
which
always
and
sh.
plastic
sizes
the
to
do
are
not
their
can
can
be
be
T
urning
and
harm
kill
the
habitats
if
used
towed
effective.
net.
destructive
most
them
net
These
sieves
into
are
but
return
sizes
drift
methods
acceptable
results.
larger
Simple
invertebrates,
this
you
streambed
the
the
to
small
in
of
sort
plankton,
held
the
from
results.
catch
sampling
downstream
contents
your
Repeat
net
feet
pipette
record
●
sweep
to
behind
Kick
stones
the
over
organisms.
organisms
at
all
possible.
Keys
Once
are
you
have
called.
A
collected
(biological)
the
key
organisms,
is
used
to
you
may
identify
want
species.
to
nd
out
Ecologists
what
make
stream ow
they
keys
current carries
material into net
to
specic
to
help
groups
other
at
more
time
exact
and
people
dichotomous
examples
professionals
organisms,
interested
diagrammatic,
Look
of
use
than
of
Both
lines
invertebrates
‘spider’
keys.
statement
pictures.
the
soil
identify
published
paired
following
or
eg
or
and
Keys
a
Diagram
keys
keys
‘go
species.
key
are
to’
specic
come
paired
keys
because
used
in
by
numbers.
in
ecosystems,
two
formats,
statement
are
useful
printed
starting
but
descriptions
at
a
key.
the
top
are
▲
Figre 2.5.14 Kick sampling
each
137
2
E c o s ys t E m s
a n d
E c o l o g y
A
It
A
list
is
of
pond
from
paired
the
organisms
UK
in
a
temperate
Environmental
statement
key
has
no
ecosystem
Education
pictures
is
Centre
but
is
shown
in
more
in
gure
Canterbury,
accurate
2.5.15.
Kent.
.
animals with six legs
mayy nymph
damsely nymph
water beetle
saucer bug
dragony nymph
greater water
boatman
water stick insect
pond skater
beetle lar va
water scorpion
lesser water
boatman
caddisy nymph
animals with more than six legs
water spider
water mite
water louse
freshwater shrimp
animals with shells
rams horn snail
pond snail
pea-shell cockle
swan mussel
animals without shells
▲
138
midge eggs
phantom midge
midge pupa
bloodworm
leech
water worm
insect lar va
water ea
cyclops
algae
Figre 2.5.15 A picture key of pond animals
atworm
rat-tailed maggot
2 . 5
I n v E S T I G a T I n G
E C o S y S T E m S
–
p R a C T I C a L
w o R K
Measuring abundance
Having
established
what
organisms
are
where,
what
use
is
it?
4
Plants
There
are
a
number
of
ways
of
assessing
plant
species
abundance:
5
2
●
Density:
●
Frequency:
the
species
present
mean
number
of
plants
per
m
2
percentage
of
the
total
quadrat
number
that
the
3
was
in,
may
also
be
measured
within
the
quadrat.
1
●
Percentage
is
often
of
the
cover:
measured
coverage
because
instead
by
each
plants
of
spread
individual
species
and
it
out
and
grow
numbers.
sometimes
This
percentage
is
helps
an
if
cover
estimate
the
quadrat
▲
is
a
divided
forest,
100%
be
up
so
or
the
then
scale
by
it
this.
less
either
can
using
Species
percentage
much
estimated
and
for
be
if
is
on
overlap
within
bare
comparing
graded
gure
cover
there
by
may
a
a
or
scale
in
quadrat
ground.
the
lie
The
sample
from
0
may
be
5,
with
or
on
the
over
cover
gure
Figre 2.5.16
in
can
2.5.16
ACFOR
2.5.17.
percetge cer (%)
aCFoR scle
50
Scre
Abundant
5
25–50
Common
4
12–25
Frequent
3
Occasional
2
Rare
1
6–12
<6, or single individual
absent
▲
storeys
well
percentage
area
to
different
0
Figre 2.5.17 Percentage cover scales
Lincoln Index (capture, mark , release and recapture)
Sessile
or
limpets
Lincoln
move
slow
and
moving
barnacles.
Index
about
is
or
used
do
animals
More
to
not
can
be
mobile
estimate
appear
counted
animals
the
during
as
are
population
the
individuals,
harder
size
of
to
e.g.
assess
animals
and
the
which
day.
Method
1.
Establish
2.
Capture
will
a
Mark
have
each
of
the
them
example,
paint
(nothing
Release
allow
the
be
population.
of
animals;
The
you
actual
can
method
take
your
of
capture
pick
from
the
earlier.
must
higher
dog
can
the
size
organisms
this
to
area.
of
the
discussed
woodland
4.
on
marked:
expose
For
study
sample
depend
methods
3.
the
be
captured
done
predation
whelks
marked
on
a
in
a
levels
rocky
with
a
and
record
how
non-harmful
than
shore
spot
of
many
way
that
non-marked
or
woodlice
non-toxic
in
subtle
you
does
not
individuals.
a
coloured
bright).
captured
sufcient
time
individuals
to
remix
back
with
into
the
the
environment
and
population.
139
2
E c o s ys t E m s
a n d
E c o l o g y
5.
Take
of
are
if
a
second
organisms
marked.
this
sample
At
estimate
least
is
made
●
complete,
is
throughout
●
Marks
do
●
Marks
are
●
It
●
There
is
are
the
time.
Index
m
be
the
the
marked
fairly
marked
easily
the
rst:
count
count
how
sample
the
many
should
be
number
of
them
recaptured
accurate.
individuals
have
spread
to
nor
increase
predation
by
making
the
seen.
catch
every
immigration,
a
Lincoln
ie
between
Trapping
second
of
to
as
and
that:
harmful
easy
no
10%
way
sample
population.
more
equally
same
this
disappear.
not
population
●
the
not
individual
are
the
in
going
Assumptions
Mixing
in
captured
the
organisms
individual.
emigration,
times
does
of
births
or
deaths
in
the
sampling.
not
affect
their
chances
of
being
trapped
formulae
n
2
1
_
_
=
n
N
2
OR
n
×
n
1
2
_
N
=
m
2
Where
n
=
number
of
animals
rst
marked
=
number
of
animals
captured
and
released
1
n
in
the
second
sample
2
Ke ter
m
=
number
of
marked
animals
in
the
second
sample
2
N
=
Lincoln
Index
or
total
population
(the
gure
you
are
after)
Secies iersit is a
function of the number of
Simpson diversity index
species and their relative
Species
abundance.
numbers
diversity
of
is
the
number
individuals
of
each
of
different
species,
ie
species
species
and
the
richness
relative
and
species
evenness.
Ecologists
the
similar
time.
be
three
express
species
most
careful.
related
in
species)
The
to
the
value
ranges
a
1
is
1)
_
=
∑n(n
140
1)
to
number.
makes
it
The
higher
possible
ecosystems
turn
the
0
‘Simpson
index).
higher
from
a
whether
way
(Simpson’s
number
N(N
see
name
indices
which
and
to
in
This
diversity
are
into
a
to
the
number,
compare
changing
number
in
is
by
the
index.
reciprocal
equal
D
or
diversity
diversity.
common
diversity
Simpson’s
index
to
the
ecosystems
The
Simpson
But
try
greater
of
to
Here
lowest
value
1.
we
value
means
species
diversity
Index,
in
are
using
(when
more
the
index’
Simpson’s
of
Simpson’s
there
diversity.
sample.
actually
index
In
would
The
the
describes
diversity
be
just
highest
other
and
reciprocal
one
value
indices,
is
the
2 . 5
I n v E S T I G a T I n G
E C o S y S T E m S
–
p R a C T I C a L
w o R K
Where
D
=
Simpson
N
=
total
n
=
diversity
number
number
of
of
index
organisms
individuals
of
of
a
all
species
particular
found
species
Example
nber f iiils f secies
A
B
C
Ecosystem 1
25
24
21
Ecosystem 2
65
3
4
The
diversity
N
=
D
=
25
+
index
24
+
of
ecosystem
21
=
1
can
be
calculated
like
this:
70
70 × 69
____
=
(25
In
ecosystem
Both
are
A
×
high
value
ancient
prevent
Be
for
site.
like
Agricultural
Simpson
also
be
Note:
have
D
you
diversity
do
the
logged
land
to
not
index
so
as
a
to
is
diverse
low
for
also
D
is
most
in
so
(3)
by
are
for
in
D,
other
Arctic
often
in
used
and
1
is
often
these
higher.
a
stable
disturbed
values
farmers
species
and
for
in
low
as
tundra
there
system
measure,
found
results
and
slow
but
this
ecosystem
D
values
crops
for
growth
index
richness
diversity,
values
their
3.07
20)
1.22.
Pollution
values
as
animal
need
highly
extremely
low
is
×
species
low
between
sites
(21
species
forests.
has
+
index
same
contrast,
diversity
applied
23)
indicates
In
stable
The
×
distributed
though
and
(24
diversity
competition
careful
ancient
+
the
evenly
ecosystems
D.
2,
ecosystems
more
and
24)
may
for
try
to
(weeds).
represent
diversity
vegetation,
is
low.
but
it
can
populations.
memorize
the
Lincoln
Index
or
Simpson
formulae.
141
2
E c o s ys t E m s
a n d
E c o l o g y
W E I VE R
Explain what are the main
impacts of humans on ows
Evaluate the model of
of energy and matter in the
succession described here.
biosphere.
BIg QUEstIons
Ee 
e
Reeive quei
➔
Feeding
can
➔
we
What
relationships
decide
role
when
does
can
one
be
represented
model
indigenous
is
better
knowledge
by
different
than
play
in
models.
How
another?
passing
on
scientic
knowledge?
➔
When
is
quantitative
knowledge
➔
Controlled
of
by
the
about
of
➔
tropical
the
Why
study
142
do
we
when
experiments
natural
laboratory
rainforest
Earth,
therefore
use
superior
To
what
qualitative
are
often
extent
experiment
data
in
giving
us
is
less
seen
the
as
the
hallmark
knowledge
scientic
than
obtained
the
experiment?
biome
who
is
vital
should
internationally
making
to
world?
method,
observational
The
data
laboratory
scientic
manipulated
➔
the
to
the
decide
ecological
how
standardized
comparisons
across
equilibrium
humans
methods
international
of
use
it?
ecological
boundaries?
R E v I E w
W E I VE R
Q u I C K
Quik review
All
questions
are
The
diagram
and
should
worth
below
be
used
1
mark
shows
for
a
4.
complete
questions
1
food
and
web
is
organism
A.
A
producer
B.
A
primary
C.
A
secondary
D.
An
U?
2.
P
H
What
consumer
consumer
(carnivore)
autotroph
R
S
5.
F
L
G
E
The
diagram
food
web
for
below
a
lake
shows
part
of
an
aquatic
ecosystem.
T
N
freshwater turtles
large sh
O
1.
Which
are
producers?
small sh
A.
P
and
B.
P
,
C.
O,
D.
O
H,
H
R
and
F
tadpoles
N
and
T
water eas
rotifers
2.
Which
A.
G,
are
S,
secondary
R,
P
and
consumers?
F
algae
B.
H
and
C.
N,
P
What
L,
E
and
is
the
represented
D.
is
a
represent
diagram
different
photosynthesizing
and
in
this
number
food
of
trophic
levels
web?
O
Below
3
maximum
T
of
a
food
species
web.
of
organism.
The
organism.
Use
this
A.
Three
B.
Four
C.
Five
D.
Six
letters
S
for
is
a
questions
4.
R
S
T
U
3.
Which
organism
is
only
a
primary
consumer
(herbivore)?
A.
P
B.
T
C.
U
D.
S
143
B i o d i v e r s i t y
3
a n d
c o n s e r vat i o n
3.1 A todcto to bod st
sg :
appl  kll:
➔
Biodiversity can be identied in a variety of
➔
Dstgsh between biodiversity, species
forms including species diversity, habitat
diversity, genetic diversity and habitat diversity.
diversity and genetic diversity.
➔
➔
Commt on the relative values of
The ability to both understand and
biodiversity data.
quantify biodiversity is impor tant to
➔
Dscss the usefulness of providing numerical
conser vation eor ts.
values of species diversity to understanding
the nature of biological communities and the
conser vation of biodiversity.
Kwlg  ug:
➔
Bod st is a broad concept encompassing
➔
total diversity which includes diversity of
spcs, gtc d st and habtat d st.
➔
habitats in an ecosystem or biome.
➔
➔
and their relative propor tions (evenness).
➔
Quantication of biodiversity is impor tant
to conser vation eor ts so that areas of high
Communities can be described and compared
biodiversity may be identied, explored,
by the use of d st dcs. When comparing
and appropriate conser vation put in place
communities that are similar then low diversity
where possible.
could be evidence of pollution, eutrophication
or recent colonization of a site. The number
of species present in an area is often used to
indicate general patterns of biodiversity.
144
Gtc d st refers to the range of genetic
material present in a population of a species.
Spcs d st in communities is a product of
two variables, the number of species (richness)
Habtat d st refers to the range of dierent
➔
The ability to assess changes to biodiversity in
a given community over time is impor tant
in assessing the impact of human activity in
the community.
3 . 1
A n
i n T r O D u C T i O n
T O
B i O D i v e r S i T y
‘It should not be believed
tp f b
that all beings exist for the
You
may
think
animals
and
concept
than
ecosystem
diversity
biodiversity
that.
but
in
of
plants
in
Usually,
sometimes,
an
as
different
the
numbers
places.
high
But
diversity
particularly
unpolluted,
ancient
of
is
a
species
far
indicates
in
site
it
the
but
a
Arctic,
this
is
of
more
different
sake of the existence of
complex
man. On the contrary, all
healthy
there
because
may
be
low
the other beings too have
conditions
been intended for their own
are
so
harsh.
sakes and not for the sake
Biodiversity
diversity:
is
the
overall
genetic
term
diversity,
for
three
species
different
diversity
but
and
inter-related
habitat
types
of
of something else.’
diversity
Maimonides, The Guide for the
If
we
think
species
is
habitat.
about
more
important
Species
(variety)
and
biodiversity
than
diversity
number
of
then
the
spread
of
the
total
number
reects
this,
as
organisms
it
individuals
of
looks
(abundance).
between
individuals
at
both
Species
the
in
Perplexed 1:72, c. 1190
a
range
diversity
is
K tm
not
just
the
organisms
total
number
within
each
of
of
organisms
the
different
in
a
place
but
the
number
of
species.
Spcs dst in
Consider
the
examples
in
gure
3.1.1.
communities is a product of
two variables, the number
Fost A
Fost B
15 dierent species
15 dierent species
100 individuals of one species and one
Seven individuals of each of the
individual of each of the other 14 species.
15 species.
Total individuals = 114
Total individuals = 105
of species (richness) and
their relative propor tions
(evenness).
Greater number of individuals
TOK
Low species diversity because the
Greater species diversity – because
individual species may not be able to
the species are evenly spread and
breed = disappear
the populations more viable
The term ‘biodiversity’ has
replaced the term ‘Nature’ in
much writing on conservation
▲
Fg 3.1.1 Biodiversity in two forests
issues. Does this represent a
paradigm shift?
This
variation
such
as
coral
habitats
and
in
diversity
reefs
polar
and
alters
from
rainforests
regions
have
habitat
have
much
to
habitat.
Some
high
species
diversity.
lower
species
diversity
habitats
Urban
by
comparison.
K tm
Another
is
the
way
to
amount
measure
of
diversity
variation
that
is
to
exists
look
at
between
genetic
diversity
different
–
that
individuals
Gtc dst is the
within
different
populations
of
a
species.
A
small
population
normally
range of genetic material
has
a
lower
genetic
diversity
than
a
larger
one
because
of
the
smaller
present in a gene pool or
gene
pool.
population of a species.
Species
are
made
eachindividual
any
or
other
more
will
in
a
a
of
in
different
total
amount
need
conserved.
Not
all
entire
be
species
world
north-east
that
of
has
have
the
of
a
in
of
amount
seals
with
a
a
of
set
species
places,
genetic
on
small,
of
is
then
Therefore
different
exist
few
populations.
different
if
make-up.
diversity,
grey
England
And
different
genetic
same
and
slightly
species.
genetic
population
coast
individuals
populations
maximum
to
both
species
individual
different
have
up
Naturally,
genes
made
each
to
scattered
two
conserve
diversity.
Farne
of
population
populations
the
from
up
of
a
species
Almost
islands
the
the
off
the
populations
in
145
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
Grey seals have one large
population within which
individuals interbreed.
The whole population is adapted
to the same conditions so they all
have very similar genetic make-up
and low genetic diversity.
What may happen if disease
strikes?
▲
Fg 3.1.2 Grey seal
other
places.
genetic
This
Organisms
where
fox,
is
which
diversity
Each
as
we
within
Humans
can
engineering
even
plant
of
example
a
and
alter
genetic
right
of
an
organism
with
a
small
amount
of
Europe.
a
slightly
in
exists
many
different
include
Humans
also
the
European
have
high
red
genetic
populations.
genetic
make-up
so
there
is
more
species.
genetic
populations
diversity
with
genotypes
high-yielding
the
diversity
across
planet-wide
has
the
whole
breeding
‘gene
large
exist
identical
produces
strikes
an
found
population
variety
or
is
diversity.
has
–
clones.
crop
or
to
a
articially
loss
variation
This
animal
population
led
by
reduced
is
of
can
but
a
be
their
an
or
advantage
This
variety,
genetically
genotypes
disadvantage
susceptible.
genetic
breeding
in
if
if
it
disease
domestication
hence
the
and
importance
banks’.
POP E
For
many
conservationists,
more
genetic
variation
is
a
good
thing.
So
def
POP A
they
would
want
to
maximize
genetic
diversity.
That
means
having
abc
many
have
species
a
better
and
much
chance
of
variability
adapting
to
within
each
change
in
species.
their
Then
habitats.
species
But
POP G
that
could
mean
stopping
succession
as
species
diversity
falls
later
in
ghi
succession
▲
Fg 3.1.3 Red fox
Tropical
K tm
of
so
rainforests
ecological
level
(2.4)
niches
habitat
interfering
are
due
high
to
diversity
the
with
in
the
habitat
layering
(see
2.4,
of
natural
process.
diversity
the
as
forests.
there
Tundra
are
has
many
a
lower
biomes).
Habtat dst is the range
B –   f m hlh
of dierent habitats per unit
area in a particular ecosystem
or biome.
It
is
difcult
Biodiversity
equates
146
to
is
with
determine
often
high
used
if
as
one
a
ecosystem
ecosystem
measure
health.
as
is
more
high
healthy
biodiversity
than
another.
usually
3 . 1
A
habitat
●
with
resilience
some
high
and
will
genetic
●
some
plants
bring
them
●
high
diversity
could
bare
managing
●
some
an
does
stable
the
areas
to
the
to
result
of
T O
B i O D i v e r S i T y
of
insect
plants
attack,
present
of
which
disease
diseases
deep
always
i n T r O D u C T i O n
advantages:
range
roots
making
so
them
equate
can
to
having
fragmentation
richness
cycle
available
is
due
nutrients
for
a
other
healthy
(break
to
up)
pioneer
and
plants.
ecosystem:
of
a
habitat
species
quickly
be
difcult
tolerance
healthy
the
these
oods,
species
can
and
and
exception
not
when
grazing
requirements
to
have
surface
be
has
resistance
will
the
degradation
invading
●
there
to
due
drought,
so
biodiversity
diversity
or
stability
survive
●
But
biodiversity
A n
to
as
plant
species
have
different
grazing
communities
have
few
plant
species
so
are
rule.
d 
We
can
only
accurately
communities
within
compared
the
by
compare
an
use
two
ecosystem.
of
diversity
similar
ecosystems
Communities
indices
(see
can
or
be
two
described
and
TOK
2.5).
Biodiversity index is not a
When
be
comparing
evidence
site.
The
general
of
communities
pollution,
number
patterns
of
of
that
are
similar
eutrophication
species
present
biodiversity
but
in
or
an
only
then
recent
area
tells
is
us
low
diversity
colonization
often
part
used
of
to
the
of
could
a
measure in the true sense
of the word, but merely a
indicate
story.
number (index) as it involves
a subjective judgement
on the combination of two
It
is
important
to
repeat
investigations
of
diversity
in
the
same
measures; propor tion and
community
over
process
to
a
period
of
time
and
to
know
if
change
is
a
natural
richness. Are there examples
due
succession
or
due
to
impact
from
human
activity.
This
in other areas of the
could
either
increase
or
decrease
biodiversity
which
would
tell
us
if
subjective use of numbers?
conservation
efforts
are
succeeding
or
not.
Hp
Biodiversity
biodiversity
in
other
is
not
than
areas.
equally
others
There
–
are
distributed
more
on
species
hotspots
Earth.
and
where
Some
more
there
of
are
regions
each
also
have
species
more
than
unusually
K tm
high
A biodiversity hotspot is a
numbers
of
endemic
species
(those
only
found
in
that
place).
Where
region with a high level of
these
hotspots
are
is
debated
but
about
30
areas
have
been
recognized.
biodiversity that is under
●
They
other
●
They
include
●
tend
in
to
be
lower
They
are
been
lost.
The
ten
in
tropical
rainforest
but
also
regions
in
most
threat from human activities.
biomes.
factors
●
about
all
habitat
nearer
the
tropics
because
there
are
fewer
limiting
latitudes.
threatened
contains
areas
more
where
than
70%
1,500
of
the
species
of
habitat
plants
has
already
which
are
endemic.
●
They
cover
●
They
tend
only
to
2.3%
have
of
large
the
land
densities
surface.
of
human
habitation
nearby.
147
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
These
hotspots
about
60%
Critics
of
●
focus
●
do
●
focus
of
are
the
naming
on
not
shown
world’s
hotspots
vascular
represent
on
in
regions
say
plants
total
where
whether
that
●
do
not
consider
genetic
●
do
not
consider
the
they
and
threats
are
a
to
useful
and
is
between
have
they
ignore
very
can
still
them
high
be
they
species
misleading
contain
diversity.
because
they:
animals
diversity
habitats,
loss
or
usually
richness
forest,
have
been
lost
and
happening
diversity
value
model
unique
3.1.4;
so
that
species
ignore
But
gure
species
of
to
services,
focus
ecosystems
our
and
for
example
attention
the
species
on
water
resources.
habitat
within
destruction
them.
Caucasus
Mediterranean
South central
basin
China
California
Caribbean
Philippines
oristic
islands
Indo-Burma
province
Mesoamerica
Polynesia/
Micronesia
Brazil’s
cerrado
W. African
Western Ghats
forests
Tropical
and Sri Lanka
Choco/Darien/
Andes
Eastern arch &
Western Ecuador
Sundaland
coastal forests of
Wallacea
T
anzania/Kenya
New
Polynesia/
Madagascar
Central
Caledonia
Brazil’s
Micronesia
Succulent
Chile
Atlantic
karoo
Southwest
forests
Australia
Cape oristic
New Zealand
province
▲
Fg 3.1.4 World map of regions with biodiversity hotspots
Qu
Hotspot
Plat spcs
edmc plat
spcs
Atlantic Forest, Brazil
wold total
20,000
8,000
2.7
California Floristic Province
3,488
2,124
0.7
Cape Floristic Region, South Africa
9,000
6,210
2.1
13,000
6,550
2.2
6,400
1,600
0.5
10,000
4,400
1.5
Chilean Winter Rainfall – Valdivian Forests
3,892
1,957
0.7
Coastal Forests of Eastern Africa
4,000
1,750
0.6
East Melanesian Islands
8,000
3,000
1.0
Caribbean Islands
Caucasus
Cerrado
148
edmcs as a pctag of
3 . 1
Hotspot
A n
i n T r O D u C T i O n
Plat spcs
T O
edmc plat
spcs
B i O D i v e r S i T y
edmcs as a pctag of
wold total
Eastern Afromontane
7,598
2,356
0.8
Guinean Forests of West Africa
9,000
1,800
0.6
10,000
3,160
1.1
5,000
2,750
0.9
13,500
7,000
2.3
Irano-Anatolian
6,000
2,500
0.8
Japan
5,600
1,950
0.7
13,000
11,600
3.9
Madrean Pine–Oak Woodlands
5,300
3,975
1.3
Maputaland–Pondoland–Albany
8,100
1,900
0.6
Mediterranean Basin
22,500
11,700
3.9
Mesoamerica
17,000
2,941
1.0
5,500
1,500
0.5
12,000
3,500
1.2
New Caledonia
3,270
2,432
0.8
New Zealand
2,300
1,865
0.6
Philippines
9,253
6,091
2.0
Polynesia–Micronesia
5,330
3,074
1.0
Southwest Australia
5,571
2,948
1.0
Succulent Karoo
6,356
2,439
0.8
Sundaland
25,000
15,000
5.0
Tropical Andes
30,000
15,000
5.0
Tumbes–Choco–Darien
11,000
2,750
0.9
Wallacea
10,000
1,500
0.5
5,916
3,049
1.0
Himalaya
Horn of Africa
Indo-Burma
Madagascar and the Indian Ocean Islands
Mountains of Central Asia
Mountains of Southwest China
Western Ghats and Sri Lanka
▲
Fg 3.1.5 Biodiversity hotspots showing the total and endemic plant species
1.
How
many
2.
Why
is
3.
What
of
these
hotspots
can
you
locate
on
a
world
map?
Practical
the
number
of
plant
species
important
for
Investigate
are
the
criteria
for
dening
What
5.
For
is
an
what
endemic
reasons
do
think
biodiversity
differences
in
pools
and
riffles.
species?
you
the
hotspots?
in
4.
Work
biodiversity?
these
hotspots
are
threatened
Investigate
global
Investigate
plant
biodiversity.
areas?
in
two
local
biodiversity
areas.
Evolution/natural
selection
simulation.
149
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
3.2 Ogs of bod st
sg :
appl  kll:
➔
Evolution is a gradual change in the genetic
➔
expla how plate activity has inuenced
character of populations over many
evolution and biodiversity.
generations achieved largely through the
➔
Dscss the causes of mass extinctions.
mechanism of natural selection.
➔
Environmental change gives new challenges to
species, which drives evolution of diversity.
➔
There have been major mass extinction events
in the geological past.
Kwlg  ug:
➔
Bod st arises from evolutionary processes.
➔
Biological variation arises randomly and can
➔
populations of a species become isolated and
evolve dierently.
either be benecial to, damaging to, or have no
impact on the sur vival of the individual.
➔
Spcato is the formation of new species when
➔
isolato of poplatos can be caused by
environmental changes forming barriers such as
natal slcto occurs through the following
mountain building, changes in rivers, sea level
mechanism:
change, climatic change or plate movements.
●
within a population of one species there is
The surface of the ear th is divided into cstal,
genetic diversity, which is called variation
tctoc plats which have moved throughout
●
due to natural variation some individuals will
geological time. This has led to the creation of
be tter than others
both land bridges and physical barriers with
●
tter individuals have an advantage and will
evolutionary consequences.
reproduce more successfully
➔
●
The distribution of continents has also caused
the ospring of tter individuals may inherit
climatic variations and variation in food supply,
the genes that give the advantage.
both contributing to evolution.
➔
This atal slcto will contribute to evolution
➔
Mass x tctos of the past have been caused by a
of biodiversity over time.
combination of factors such as tectonic movements,
➔
Environmental change gives new challenges to
super-volcanic eruption, climatic changes (including
the species, those that are suited sur vive, and
drought and ice ages), and meteor impact all of
those that are not suited will not sur vive.
which resulted in new directions in evolution and
therefore increased biodiversity.
150
3 . 2
O r i G i n S
O F
B i O D i v e r S i T y
Hw w p fm
Charles
in
The
the
Darwin,
Origin
fossil
proposed
of
record,
mutations,
all
the
Species ,
discovery
supports
published
of
the
K tm
theory
the
of
in
evolution
1859.
structure
theory.
It
is
of
which
Evidence,
DNA
and
summarized
in
is
outlined
the
form
mechanisms
of
of
Spcato is the gradual
change of a species over a
long time. When populations
below.
of the same species
●
Each
individual
is
different
(except
identical
twins
who
have
the
become separated, they
same
genotype)
due
to
their
particular
set
of
inherited
genes
and
cannot interbreed and if the
tomutations.
environments they inhabit
●
Each
will
be
slightly
differently
adapted
(or
tted)
to
its
change they may star t to
environment.
diverge and a new species
forms. Humans can speed
●
Resources
are
limited
for
any
population
and
there
will
be
competition
up speciation by ar ticial
for
these
resources,
eg
for
food,
light,
space,
water.
selection of animals and
■
For
example,
othergiraffes
reach
an
to
the
a
giraffe
may
be
others
with
able
and
a
to
so
slightly
reach
get
longer
tree
more
neck
leaves
food.
This
than
that
are
gives
the
out
that
plants and by genetic
of
engineering but the natural
giraffe
advantage.
process of speciation is
a slow one. Separation
may have geographical or
■
These
small
differences
mean
that
some
individuals
will
be
more
reproductive causes.
successful.
pass
●
Over
their
time
They
will
genes
these
on
survive
to
changes
the
to
next
show
breed
more
than
others
and
so
generation.
and
the
whole
population
gradually
TOK
changes.
This
is
natural
environment
less
adapted
survive
–
selection
have
do
an
not
where
advantage
survive
‘survival
of
the
long
those
and
more
enough
ttest ’
is
adapted
ourish
the
to
and
to
reproduce.
term
you
their
reproduce
So
may
The theory of evolution by
but
the
have
those
ttest
natural selection tells us
that change in populations
heard.
is achieved through the
process of natural selection.
Over
many
generations,
if
a
population
is
separated
from
others
and
Is there a dierence between
isolated,
the
differences
may
increase
to
such
an
extent
that,
should
the
a convincing theory and a
populations
be
reunited,
they
will
be
unable
to
interbreed.
Then
a
new
correct one?
species
▲
has
and
speciation
has
occured.
Fg 3.2.1 Possible ancestors in evolution of Homo sapiens species
Isolation
or
formed
in
a
freely
may
body
but
be
of
they
synchronized
on
an
water
are
or
island
but
could
(lake
or
even
isolated
in
other
their
owers
be
pond).
ways:
mature
at
isolation
Some
their
on
a
mountain
populations
mating
different
mix
seasons
are
not
times.
151
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
Physical barriers
Species
is
split
or
can
by
ocean.
The
populations
the
two
Large
part
on
▲
both
to
can
birds
of
more
new
barrier,
will
the
split
in
species
for
the
barrier
develop
if
their
example
gene
will
not
a
pool:
be
population
mountain
the
genes
mixing
range
of
the
anymore
and
different
directions.
Examples
of
on
continents
that
once
barriers:
only
occur
(Africa,
However,
large
or
barrier
sides
Gondwana
the
two
physical
physical
ightless
America).
ago,
of
physical
due
of
into
kind
populations
speciation
1.
develop
some
because
ightless
those
Australia
birds
including
Gondwana
are
not
split
closely
New
up
a
were
Zealand,
very
long
South
time
related.
Fg 3.2.2 Large ightless birds (rhea, ostrich, emu, kiwi, tinamou, moa,
elephant bird, cassowary)
2.
Australia
At
that
the
(and
time,
same
prevailed
area.
and
happened
and
America).
cats,
3.
The
by
of
cichlid
of
cichlids
now
sh
of
152
the
in
enough,
grey kangaroo and joey
some
lakes
they
isolated
In
Lake
have
years
different
Fg 3.2.3 A marsupial – great
(bats)
Gondwana
placental
Africa,
marsupials.
mostly
(though
are
or
rare
were
East
in
a
in
the
In
long
time
placental
Australia
only
few
a
mammals
found
still
the
in
in
opposite
Australia
These
by
ago.
lived
mammals
survive
Australia.
introduced
Malawi
have
continue
populations
to
there
are
200
been
can
long
diverge
be
one
are
in
South
mammals
humans
too
as
the
the
from
small
the
170
(dogs,
largest
species
126
species
(99%
from
selection
So
of
are
species
isolated
different
As
are
Tanganyika
environments.
environments.
will
Africa
Victoria
Lake
probably
and
different
of
Lake
endemic);
populations
them–slightly
to
the
vertebrates.
formillions
▲
air
and
are
Guinea
mammals
from
early
rats).
in
(99%
the
marsupials
New
(seals),
and
off
and
America
outcompeted
(100%endemic);
These
South
Placental
sea
split
marsupials
Papua
rabbits
families
In
and
nearby
came
Antarctica)
both
endemic).
each
sh
have
population
other
and
other
pressures
within
adapted
is
large
populations
die
out.
but
3 . 2
Lake Tanganyika species
O r i G i n S
O F
B i O D i v e r S i T y
Lake Malawi species
Melanochromis auratus
Julidochromis ornatus
Psudotropheus microstoma
Tropheus brichardi
Ramphochromis longiceps
Bathybates ferox
Cyr tocara moorei
Cyphotilapia frontosa
Lobochilores labiatus
▲
Placidochromis milomo
Fg 3.2.4 Cichlid sh
Land bridges
These
allow
separated
Obviously
recently
allowed
moved
Land
species
for
a
that
is
invade
time
no
species
from
bridges
between
to
may
drift.
the
to
result
and
and
case
as
North
have
they
bridge
North
or
are
of
to
and
rather
South
now
joined
Central
the
America
different
by
America,
South.
were
species.
Bears
the
which
for
example
America.
from
the
lowering
include
Europe
Asia
areas.
land
the
South
Examples
England
America
to
new
therefore
formed
move
North
and
longer
(geologically)
continental
North
to
long
the
(now
(Bering
of
(now
under
seawater
levels
disappeared)
the
English
instead
land
of
bridges
Channel)
and
Straits).
Continental drift
Continental
During
their
different
food
supplies
Once
this
When
forced
A
snow
or
resulted
the
The
species
had
moved
a
in
globe,
new
the
changing
to
adapt
example
of
tropical
The
only
diverse
continents
and
the
was
the
and
have
in
moved
on
covered
and
the
and
to
therefore
increase
gradually
formed
of
an
changes
was
forest
remains
habitats.
conditions
resulted
are
climate
landscape
evolved.
and
climatic
this
southwards,
ice-covered
arrived
tree
over
dramatic
continent
and
also
zones.
Antarctica
species
some
has
drifting
climate
biodiversity.
the
drift
in
Antarctica.
by
forest.
disappeared,
new,
former
cold
adapted
forest
are
fossils.
153
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
Hw pl  u b
The
lithosphere
smaller
year.
the
ones
is
and
divided
these
into
drift
seven
around,
This
is
called
continental
plates
is
plate
tectonics.
large
tectonic
moving
drift
Where
and
the
at
the
plates
about
study
plates
50
of
meet,
and
to
the
many
100
mm
per
movement
they
of
may:
inner core
●
Slide
●
Diverge
past
each
other
(eg
the
San
Andreas
fault
line,
California).
outer core
mantle
slowly
(eg
the
apart).
mid-Atlantic
This
could
ridge
cause
where
the
the
physical
plates
are
separation
moving
of
crust
populations.
●
▲
Converge
–
these
convergent
plates
may:
Fg 3.2.5 Simplied
■
diagram of the Ear th
collide
of
■
the
and
both
be
Himalayas
collide
and
lighter
continental
ocean
the
one
trenches
Nazca
America
myriad
plate
and
new
forced
and
(the
heavier
plate.
and
the
Andes
This
as
is
a
form).
physical
plate)
sinks
subduction
island
Pacic
mountains
creates
oceanic
This
volcanic
under
the
upwards
Alps).
chains
meets
This
are
the
creates
(eg
underneath
zone
where
formed
west
land
formation
barriers.
(eg
coast
of
bridges
the
deep
where
South
and
niches.
Nor th American
plate
Eurasian
plate
Eurasian plate
Juan de
Fuca plate
Caribbean
plate
Arabian
Filipino
plate
plate
Cocos
Indian
plate
plate
African
Australian
Nazca plate
plate
Pacic plate
South American
plate
plate
Australian
Plate
Scotia plate
Antarctic plate
▲
154
Fg 3.2.6 The tectonic plates of the Ear th
3 . 2
O r i G i n S
O F
B i O D i v e r S i T y
To thk abot
Jgsaws ad cotts
Looking at a world map or a globe, we all notice that the
He was a car tographer and drew one of the rst atlases
west coast of the African continent and the east coast of
in 1570. Francis Bacon (1620), a British philosopher and
the South American continent appear to t together like
scientist, did too, as did Benjamin Franklin (USA), and
pieces of a jigsaw. Many others have noticed this in the
Antonio Snider-Pellegrini (France) who, in 1858 drew a
past, since the rst world maps were drawn. Abraham
map of how they may have tted together.
Or telius, from Antwerp, noticed (see gure 3.2.7).
▲
▲
Fg 3.2.7 Or telius’ world map in 1570
Fg 3.2.8 World map of 1320 possibly from Zhu Ziben
155
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
For at least a millennium, sailors have made long ocean
matched those in Nor th America. He proposed that this
voyages using the Sun and stars to guide them in
was because the continents had once been joined and
rudimentary navigation. There is debate about the dates
had oated apar t. This was thought outrageous and
of the earliest maps of the world but Zhu Ziben in the
criticism was heaped upon it. In 1930, Wegener died
Yuan Dynasty in China may have produced the map in
during an expedition to the Arctic and still few believed
gure 3.2.8 as long ago as 1320. This not only shows
his hypothesis. It took until the late 1960s for his idea to
the shape of the Ear th but also the continents including
be accepted when research was done on the deep ocean
Australia and Antarctica and the Americas.
oor vents at the edges of the plates.
In 1912, Alfred Wegener also noticed the jigsaw t of
If the shapes of the continents have been known by
the continents but additionally he noted that fossils
some for so long, why do you think Wegener was laughed
on the west coast of Africa were similar to those on the
at when he proposed that the continents move?
east coast of South America and coal elds in Europe
fossil evidence
Africa
of the Triassic
land reptile
India
Lystrosaurus
South America
Australia
Antarctica
fossil remains of
Cynognathus, a
fossil of the fern
Triassic land reptile
Glossopteris, found
approximately
fossil remains of the
3m long
freshwater reptile
Mesosaurus
▲
156
Fg 3.2.9 Fossil evidence for the continents being joined in the past
in all of the southern
continents, showing that
they were once joined
3 . 2
O r i G i n S
O F
B i O D i v e r S i T y
sml gup f ml
There
are
striking
continents
probably
●
and
think
Llamas
roles
–
and
years
meat,
milk
the
Kangaroos
the
rest
of
their
the
a
most
pouch
and
other
a
one
with
African
plant
to
to
the
it
the
are
that
the
a
on
various
few.
You
for
embryo
that
the
can
show
–
Australia
produces.
the
joey
–
are
All
in
are
are
for
do
areas
lay
in
grass
to
and
wombats
placental
mammals
(with
are
a
develop)
mostly
instead
of
conned
outcompeted
must
this
and
suckle
uterus)
eggs
have
to
the
broken
dominance.
example
similarity
about
for
these
mammals
the
Australia
another
much
(as
mammals
allow
cattle
eating
continues
They
and
that
marsupials
which
continents.
to
as
The
embryo
The
and
common
past.
marsupials
placental
on
animals
herbivores,
terms.
Their
suggests
the
similar
hump)
domesticated
pack
mammal.
others.
early
elephants
also
of
were
This
platypus)
the
other
areas
are
fullling
(one
cousins.
as
in
in
large
mother
food
are
most
role
types
duck-billed
seems
Indian
wealth.
both
Africa
Both
humans
evolutionary
young
in
of
three
provide
mainland
and
by
kangaroos
young
(eg
groups
species
animals
animals
in
distant
connected
are
that
in
are
ecological
The
of
camels
mammal.
used
They
milk
live
and
the
They
been
similar
meat.
which
two
from
of
Here
domesticated
indication
have
placenta
Australasia
●
to
are
birth
groups
unnoticed.
America,
are
world.
monotremes
giving
off
and
successful
in
both
humps).
an
full
young
are
South
must
it
between
gone
rabbit-sized
and
and
(having
a
the
converting
koalas)
in
ago
globe
not
others.
(two
was
5,000
of
has
camels
Asia
ancestor
●
of
llamas
central
similarities
this
and
between
there
are
continents.
a ll b bu h glgl ml
9
The
Earth
forms
4
are
billion
extinct.
about
thought
years
The
200,000
can
formed
ago.
appreciate,
at
a
To
if
have
Some
human
years.
appeared
to
65
this
you
billion
been
species
put
few
4.6
(4.6
simple
million
has
consider
seconds
to
10
cells
years
been
timescale
×
)
years
like
ago,
the
recognizably
into
a
geological
ago.
bacteria,
dinosaurs
human
perspective
time
as
The
a
rst
living
became
for
that
the
we
24-hour
life
about
last
humans
day,
humans
midnight.
Bkgu  m x
Background
we
10
think
and
we
do
species
know
are
what
geological
the
about
extinct
species
rate,
extinction
is
100
not
become
If
it
fossil
there
due
to
a
else
an
rapid
eruption,
is
is
the
species
year.
many
we
becoming
time
is
per
how
before
when
abrupt
change
meteorite
is
at
increase
ve
alive
rates
the
greater
results
have
so
record
and
between
because
species
We
from
many
the
will
background
occurred
ones.
natural
in
species
Some
than
extinction.
a
all
year
fossil
today.
disappear
of
of
per
exist.
major
perhaps
which
from
they
far
rate
species
extinctions
fossils
in
are
that
rate
been
climate,
impact)
a
Mass
have
suddenly
of
there
know
extinct
extinction
million
estimated
species
even
there
natural
per
This
happening?
and
record
and
rate
one
the
We
over
know
rock
think
disaster
species
this
from
strata
this
is
(volcanic
dying
out
as
157
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
Eons
Eras
Periods
Cenozoic
ciozoneC
500
Eras
0
ciozorenahP
0
Mesozoic
Paleozoic
50
Quar ternary
Ter tiary
Cretaceous
100
1000
ciozoseM
150
ciozoretorP
1500
Jurassic
200
Triassic
To thk abot
2000
250
nairbmacerP
Losom Gog
2500
Permian
Pennsylvanian
300
Mississippian
350
3000
naehcrA
ciozoelaP
Devonian
400
Silurian
3500
▲
Fg 3.2.11 Lonesome
Ordovician
450
George: born before 1912 –
4000
died 24 June 2012
naedaH
Losom Gog was the world’s
most famous reptile. He was
500
Cambrian
4500
over 100 years old and was a
Pinta Island giant tor toise from
the Galapagos Islands and the
▲
Fg 3.2.10 The geological timescale
last one of his subspecies. He
Geological Timescale copyright 2005–geology.com
was found in 1971 and no other
tor toise had been recorded on the
island since 1906. George’s fellow
they
cannot
survive
the
change
in
conditions.
Most
biologists
now
think
tor toises were taken for meat by
we
are
in
the
sixth
mass
extinction
–
called
the
Holocene
extinction
sailors or goats destroyed their
event
as
the
Holocene
is
the
part
of
the
Quaternary
geological
period
habitat and food source. He was
we
are
ice
age
in
now
(see
gure
3.2.10).
This
started
at
the
end
of
the
last
a symbol of what went wrong for
about
9,000
to
13,000
years
ago
when
large
mammals
such
as
many species whose fate is in the
the
woolly
mammoth
and
sabre-toothed
tiger
became
extinct
probably
hands of humans.
●
through
hunting.
While
may
But
the
rate
has
accelerated
in
the
last
100
years.
Do you think it matters that
it
be
due
to
climate
change,
the
big
difference
is
that
it
has
Lonesome George was the
been
caused
by
one
species
–
Homo
sapiens.
last of his kind? There are
We
think
there
are
about
5,000
mammal
species
alive
today.
Their
other subspecies of giant
background
extinction
rate
would
be
one
per
200
years
but
the
past
tor toise.
400
●
●
years
seen
89
mammalian
extinctions,
much
more
than
the
Is anyone to blame for this?
What could have been done?
background
rate.
endangered
or
have
158
have
such
Another
the
small
‘living
169
mammal
dead’.
populations
‘Living
that
there
species
dead’
is
are
listed
species
little
hope
are
they
as
critically
ones
will
which
survive.
Or
3 . 2
O r i G i n S
O F
B i O D i v e r S i T y
To thk abot
Bodst hadls
Scientists
(2007)
and
a
kinds
have
area,
WWF
the
threats
species
are
to
said
the
that
getting
it
is
13
of
species
2013:
harder
and
Figure
report
to
purple
sings
in
mean
the
discoveries.
harder
in
the
Nick
Programme,
like
the
detailing
survive,
new
and
Suriname
toad
a
bird,
Greater
Mekong
discoveries
many
of
in
the
new
conservation
The
world
Cox,
bad
of
2011.
group
news
is
conservation
manager
of
WWF-
said.
new
In
Frogs,
Sharks,
Glue-
Worms
more
3.2.12 The
carnivorous
new
sharks,
olinguito
mammal
the Americas
Two
coolest
that
species
biodiversity
is
Species
Velvet
frog
sustainability,’
Chocolate
Spitting
a
new
new
news
discovered
Walking
in
good
Mekong’s
the
a
in
beetles
to
126
struggling
environmental
Greater
bat
region’s
already
‘The
in
species
uorescent
dung
identied
warned.
and
of
new
a
devilish-looking
scientists
But
24
including
12
From
nd
since
the
Àrst
discovered
1978.
species
have
was
species
of
been
wobbegongs,
found
in
otherwise
Western
known
Australian
as
carpet
waters(2008)
Does it surprise you that we know so little about life on Ear th?
they
have
insect
for
The
last
You
may
K-T
ago.
and
In
a
species
owering
ve
mass
have
dinosaurs
the
lost
a
extinction
small
mass
of
some
extinct.
or
was
died
spread
them,
It
most
upon,
species
were
of
boundary.
plankton
depend
prey
This
extinction,
oceanic
they
a
extinctions
heard
became
this
that
plant,
for
over
example
500
million
the
one
the
but
about
large
most
a
pollinator
years.
when
Cretaceous–Tertiary
happened
out
for
predator.
particularly
the
of
a
65
animals
small
also
million
on
land
animals
the
called
years
and
and
sea
plants
159
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
survived.
view
●
A
is
causes
that
volcanic
now
●
The
now
a
erupted
meteor
atmosphere.
the
Yucatan
and
the
not
●
unable
rock
of
on
the
to
in
argued
about
for
years
but
the
general
by:
volcanoes
million
putting
of
years
huge
for
the
Mexico.
Deccan
the
time
amounts
The
underneath
the
at
impact
is
crater
object
of
plateau
of
the
dust
the
is
contains
extraterrestrial
in
K-T
into
high
km
in
levels
such
as
is
the
Chicxulub
180
what
boundary.
crater
in
diameter
of
iridium,
meterorites
a
but
earth.
climate
meteor
muchof
a
evidence
common
result
andthe
The
for
peninsula,
common
The
been
caused
impact
The
igneous
mineral
have
was
eruption:
India
And
it
change
impact
incoming
over
would
solar
photosynthesize
a
long
have
radiation.
and
so
period
caused
Plants
died
and
–
dust
the
eruption
clouds
would
food
to
have
webs
block
been
would
havecollapsed.
All
Mass
MyA
x tcto
(mllo as
the
mass
extinctions
Gologcal pod
now
5th
65
4th
199–214
3rd
in
the
table
below.
estmat of losss
ago)
6th
are
(a faml cotas p to 1,0 0 0 spcs)
Holocene
unknown
Cretaceous–Ter tiary
17% families and all large animals including dinosaurs
End Triassic
23% families, some ver tebrates
251
Permian–Triassic
95% of all species, 54% of families
2nd
364
Devonian
19% families
1st
440
Ordovician–Silurian
25% families
▲
Fg 3.2.13 The six mass extinctions
6
Geological time (10
600
500
400
300
years)
200
After
100
each
of
the
rst
ve
mass
extinctions,
there
was
a
burst
of
0
adaptiveradiation
of
the
remaining
species
which
adapted
to
ll
the
800
1. Late ordovician (
seilimaf fo rebmun
2. Late devonian (
12%)
14%)
4. Late triassic (
12%)
5. Late cretaceous (
ecological
niches
3. Late permian (
vacant.
But
this
is
all
within
a
geological
and
11%)
evolutionary
600
left
timescale
so
did
not
happen
overnight
but
over
tens
of
52%)
millions
more
years.
1
400
2
1
th xh m x
200
4
3
Many
scientists
believe
we
are
currently
in
the
sixth
mass
extinction.
0
y
i
t
r
a
r
e
T
e
o
s
u
r
C
c
a
t
e
J
r
u
s
a
c
i
s
i
r
T
s
a
c
i
s
r
e
P
i
m
a
n
C
a
m
i
r
b
a
n
This
is
extent
than
▲
caused
and
by
rate
happened
the
–
in
Fg 3.2.14 The ve major
We
extinction episodes of life
woolly
on Ear th shown by family
Mauritius.
One
diversity of marine ver tebrates
have
extinct
have
wiped
any
out
mammoths
gone
actions
humans
of
the
many
and
of
are
previous
large
ground
estimate
humans
pushing
is
that
between
and
mass
mammal
sloths,
25%
1985
far
to
greater
in
extinction
both
faster
extinctions.
and
all
be
animals
moas
of
and
may
more
ightless
in
New
plant
bird
species
Zealand,
and
animal
–
dodos
species
in
will
2015.
and inver tebrates (after
The
UN
estimated
that
12
October
1999
was
the
day
when
there
were
E. O. Wilson, 1988)
six
billion
Humans
do
well
160
alter
in
animals,
people
the
the
some
alive
on
Earth
landscape
on
environments
introduced
and
an
that
billion
unprecedented
we
species)
seven
create
but
most
on
scale.
(urban
do
12
rats,
not.
We
March
Some
2012.
organisms
domesticated
call
the
3 . 2
successful
species
But
we
to
ones
will
others,
should
10
weedy
probably
many
ask
million
is
species,
survive,
never
to
we
are
recover
animals
thrive,
identied,
whether
years
both
and
are
a
in
likely
weedy
and
the
to
die
species
biodiversity
plants.
current
after
out.
or
Many
mass
The
not.
past
O r i G i n S
It
mass
O F
B i O D i v e r S i T y
weedy
extinction.
question
has
Practical
R esearch
taken
5
Earth
Work
numb er
today
would
be
more
than
200,000
generations
of
humankind
and
been
about
7,500
generations
since
the
emergence
of
Homo
human
civilization
started
how
influenced
just
to
put
that
into
perspective,
only
The
and
is
direct
mass
periods
extinction
is
cause
caused
of
●
Overexploit
●
Introduce
●
Pollute
the
world’s
and
alien
the
are
in
few
called
species
–
Fund
the
The
and
of
ecosystem
in
the
–
–
with
in
and
as
using
named
examples.
years.
in
may
of
30%
oceans
have
kill
a
biotic
Humans
industry,
and
over
mass
cause
are
the
Report
a
on
grim
between
directly
the
or
indirectly.
produces
state
and
of
of
planet
1970
terrestrial
predators.
picture
living
agriculture.
harvesting.
natural
species
overall
and
causes
current
(www.panda.org)
painted
the
has
roads,
hunting
not
Planet
report
so
(abiotic)
The
millennia.
cities,
may
Nature
decline
health)
physical
of
we:
shing,
which
for
2012
not
because
which
–
to
(anthropogenic)
Living
temperate
due
millions
decades,
stress
environment
ecosystems.
of
humans
a
species
Worldwide
improvements
were
usually
environment
other
degradation,
losses
by
over
the
report
(measure
time,
ecosystem
Transform
periodic
extinctions
of
happening
●
WWF
,
activity
ago.
previous
extended
plate
evolution
500
species
generations
on
past.
sapiens.
biodiversity
And
species
the
there
has
have
of
in
extinctions.
Investigate
That
and
a
the
loss
index
2008.
ecosystems.
But
The
also
major
tropics.
temperate
terrestrial
freshwater
freshwater
marine
+31%
marine
61%
+5%
+36%
+53%
70%
62%
▲
Fg 3.2.15 The living planet index from 1970 to 2008 repor ted in the WWF
Living Planet Repor t 2012
The
Living
diversity.
It
Planet
Index
follows
measures
populations
of
trends
2,500
in
the
Earth’s
vertebrate
biological
species
(sh,
161
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
amphibians,
years ago
100,000
gives
a
Stage
Homo
to
40,000
●
1:
modern
sapiens
his
In
●
Australia,
North
Stage
were
●
of
2:
their
By
one
other
spread
in
from
all
around
the
world
and
so
biodiversity.
over
the
Neanderthal
megafauna
the
the
arrival
woolly
Earth:
man
(largest
ten
of
in
Europe
animals)
in
the
and
goods
carrying
humans
farmers
million
to
about
and
probably
led
disappeared
after
the
same
way
they
(how
support)
of
10,000
that
for
species
where
resulted
in
the
hunting
to
mastodons.
living
meant
other
capacity
can
and
humans
agriculture
species
environment
of
mammoths
became
to
environment
were
the
but
their
did
there
compete
manipulate
use.
they
could
individuals
local
when
not
could
own
living,
many
ago
Earth.
humans
food
for
years
on
of
a
environment
also
population
and
so
live
communities.
Humans
domestic
▲
of
importing
the
in
the
humans
exceed
●
mammals)
changes
humans.
invention
with
2,000
humans
America:
about
The
●
of
outcompeted
extinction
10,000
birds,
index
extinction.
arrival
12,500
reptiles,
numerical
concentrated
animals
and
on
using
consider
a
few
the
species
others
as
–
crop
weeds
plants
or
and
pests
(to
be
Fg 3.2.16 The two phases
eliminated).
of the sixth mass extinction
●
Humans
colonized
Madagascar,
larger
animals
disappeared
soon
after.
Natural selection
is an evolutionary driving
force, sometimes called
“sur vival of the ttest”.
What does this phrase
mean?
The theory of
Human impact
evolution tells us that change
has increased the rate
by which mass ex tinction has
in populations is achieved through
Origins of
occurred on a global scale.
the process of natural selection.
biodiversity
what are the consequences
what is the relation between
of this for (a) humans
a convincing theory and
(b) the Ear th?
a correct one?
Humans live
on most of the land area
of the Ear th. how have we
adapted to such a diverse
range of climatic
conditions?
▲
Fg 3.2.17 The origins of biodiversity
Only
in
reasons
162
Africa
for
did
that
the
may
large
be?
mammals
survive.
What
do
you
think
the
3 . 3
T H r e A T S
T O
B i O D i v e r S i T y
3.3 Thats to bod st
sg :
appl  kll:
While global biodiversity is dicult to quantify,
➔
➔
Dscss the case histories of three dierent
it is decreasing rapidly due to human activity.
species: one that has become extinct due to human
Classication of species conser vation status
➔
activity, another that is critically endangered, and a
can provide a useful tool in conser vation of
third species whose conservation status has been
biodiversity.
improved by intervention.
➔
Dscb the threats to biodiversity from
human activity in a given natural area of
biological signicance or conser vation area.
➔
ealat the impact of human activity on the
biodiversity of tropical biomes.
➔
Dscss the conict between exploitation,
sustainable development and conser vation in
tropical biomes.
Kwlg  ug:
➔
estmats of the total mb of spcs on
used to determine the conservation status of
the planet vary considerably. They are based
a species include: population size, degree of
on mathematical models, which are inuenced
specialization, distribution, reproductive potential
by classication issues and lack of nance for
and behaviour, geographic range and degree of
scientic research, resulting in many habitats
fragmentation, quality of habitat, trophic level
and groups being signicantly under-recorded.
and the probability of extinction.
The current rates of spcs loss are far greater
➔
most globally biodiverse areas and their
human inuence. The human activities that
unsustainable exploitation results in massive
cause species extinctions include habitat
losses in biodiversity and their ability to perform
destruction, introducing invasive species,
globally impor tant ecological ser vices.
pollution, overhar vesting and hunting.
➔
Topcal boms contain some of the
➔
now than in the recent past, due to increased
Most tropical biomes occur in Less Economically
➔
The itatoal uo fo Cos ato of
Developed Countries (LEDCs) and therefore there
nat (iuCn) publishes data in the rd Lst of
is conict between exploitation, sustainable
Thatd Spcs in several categories. Factors
development and conser vation.
tl wl b
How
many
species
straightforward
region
we
of
have
certainly
the
Earth
very
little
no
are
there
question
clear
and
idea
idea
as
on
logged
about
of
Earth
surely
how
we
and
today?
have
That
catalogued
many
groups
many
are
should
explored
of
what
just
is
there.
organisms
becoming
be
a
about
every
But,
there
in
are
fact,
and
extinct.
163
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
A
conservative
excluding
●
Most
●
2/3rds
●
50%
are
of
have
no
but
of
harder
Most
for
easy
to
eight
to
Beetles
to
original
forest
2
up
is
about
7
million
species
are
canopies
organisms
of
fall
are
to
are
One
way
rainforest
out
of
the
times
It
of
not
Earth.
group
trees
trees
and
quite
the
most
25%
a
collected
large
not
nd
identied
Earth
range
all
of
is
as
insects,
named.
have
are
been
about
estimates.
and
named
counted
named
species
is
insecticides.
and
as
there
insects
It
away.
and
than
think
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animals
plants
identied
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are
on
humans)
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organisms
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every
countries
organisms
our
easier
by
How
to
that
species
about
with
and
easier
found,
species.
is
of
grab
are
Many
destroyed
ones
been
with
nding
is
also
That
have
It
We
kilometres
science’.
smaller
more
million
or
species
to
or
is
humans.
kilometres.
animals
animals
have
and
of
furry
groups
on
the
insects
species.
by
square
square
million
known.
50
cleared
million
‘known
the
big
100
species
1
rainforests.
degraded
1.8
are
Big,
many
are
been
been
on
are
tropical
million
and
so
bacteria
there
are
million.
numbers
today
terrestrial.
about
18
the
birds
and
million
Beetles
1.4
are
have
(not
ones.
But
(Coleoptera)
species.
alive
mostly
logging
named,
and
that
there
ten
or
identify
fungi
most
depends
move.
think
so
species
tropics,
smaller
mammals
named
and
about
and
species
nematodes,
the
primary
cannot
Some
of
rainforests
the
between
relatively
they
of
described
estimate
the
burning
years
only
in
tropical
5–10
been
up
animals
are
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estimate
bacteria.
so
‘fogging’
Then
and
the
the
extrapolated.
Gops
Spcs fod
Total stmatd
Pctag
spcs
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ANIMALS:
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46,500
50,000
93
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200,000
35
840,000
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11
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750,000
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250,000
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200,000
20
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500,000
3
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70
256,000
300,000
85
Ar thropods: Insects
TOK
Fogging the canopy with
insecticide kills the insects
PL ANTS
there. Science can involve
▲
Fg 3.3.1 Numbers of identied species and total estimated species for
killing individuals to nd out
various groups
more for the greater good.
To what extent can this be
But
the
number
of
species
alive
on
Earth
has
not
been
constant
over
justied? Are there absolute
geological
time.
Some
become
extinct
while
others
evolve
into
new
species.
limits beyond which we
should not go?
Extinction,
species
and
164
when
dies,
the
is
a
average
a
species
natural
lifespan
ceases
process.
for
a
to
exist
after
Eventually
species
varies.
all
the
last
species
Most
individual
become
mammals
in
that
extinct
have
a
3 . 3
species
years
lifespan
or
made
more.
up
sudden
of
of
the
loss
one
The
of
million
rate
at
background
species
years,
which
some
extinction
occurs
in
arthropods
extinctions
a
rate
occur
and
relatively
is
ten
not
mass
short
of
T H r e A T S
T O
B i O D i v e r S i T y
million
constant
extinctions
and
is
when
a
time.
cu x 
How
large
this
taking
can
only
extinct
is
the
to
estimate.
long
rate
humans
the
is
think
of
that
species
These
Also,
before
extinction
We
loss
happen?
in
major
But
human
do
of
So
know
species
extinction
activities?
questions
time,
appeared.
we
cause
current
to
tricky
geological
humans
(3.2).
due
are
to
species
there
that
is
How
answer
evolved
a
habitat
natural
loss
long
is
because
and
we
became
background
caused
by
extinction.
rate
is
about
100
species
per
million
1
species
all
alive
than
E.O.
today)
Wilson,
rate
caused
could
be
species
But
areas
by
which
the
and
up
2%
habitat
there).
some
human
is
loss
like
to
the
may
remain
the
habitat
the
He
from
between
from
times
30,000
to
60,000
100–10,000
Harvard,
the
suggests
years.
in
The
thinks
background
that
rate
one
or
rates
are
the
So
news
is
preserve
and
eat
the
is
30–50
times
that
rate
per
estimated
(out
of
greater
the
and
cent
to
be
of
that
it
species
about
that
we
50%
of
all
rate
that
can
think
the
that
half
a
habitat
only
that
are
of
three
protecting
species
within
it.
evenly
of
make
(only
found
vulnerable
Those
to
and
we
us
or
others.
is
lost,
but
will
increase
some
vulnerable
dangerous
them
goes
50%
together
others.
habitat
fewer
to
very
endemic
than
in
distributed
Up
are
than
extinction
are
not
greater
particularly
extinct
those
far
which
are
are
is
areas.
areas
them
When
There
nearly
current
or
to
it
are
some
hotspots
reefs
become
linear.
half.
in
These
within
wear
Earth,
Species
30
Earth.
coral
to
or
not
when
the
(3.1).
vulnerable
other
the
of
on
species
likely
more
over
concentrated
area
many
Only
better
hotspots
are
land
hunt
rapidly.
could
hotspots
highly
more
be
in
there.
spread
rainforests
are
extinction
still
called
but
and
But
increase
1,000
100
equally
plants
crops
But
not
of
our
are
are
biologist
is
activities.
within
are
species
plants
and
range
rates.
extinction
Tropical
humans
year
well-known
of
Earth
animals
to
a
estimates
hour.
rate
only
a
Other
species
extinct
per
the
over
year
background
current
is
per
animals
the
and
species
extinction
rates
greatly.
only
5%
of
However,
the
remember
(3.1).
F h hlp  m b
Complexity of the ecosystem
You
may
complex
or
have
a
reduction
predator
is
studied
food
in
lost,
web,
its
food
the
webs
more
population
the
others
and
size.
will
food
resilient
ll
If
it
one
the
chains
is
to
type
gaps
the
of
left.
already.
loss
prey
This
of
or
The
one
more
species
food
resilience
source
of
or
more
1
Pim, S.L . and Raven, P
. Biodiversity: Extinction by numbers Nature 403, 843–845
(24 February 2000) | doi:10.1038/35002708
165
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
complex
overall.
communities
But
completely
it
may
but
the
and
not
be
ecosystems
good
for
community
is
a
good
species
thing
diversity
for
as
biodiversity
one
species
is
lost
continues.
Stage of succession
When
plants
species
a
climax
It
may
animals
it
at
community
fall
species
in
and
colonizing
slightly
diversity
young
is
vulnerable
the
increases
than
that
those
in
a
Species
reached
once
ecosystems
colonize
rst.
when
climax
as
bare
the
ones
land,
species
reached
So
are
are
but
may
more
few
time
is
until
stable.
normally,
communities
succession
which
there
with
composition
is
proceeds.
undergoing
older
of
increases
community
succession
are
piece
diversity
be
more
resilient
and
stable.
Limiting factors
If
it
is
difcult
materials
that
for
makes
abiotic
heat,
for
the
growth,
it
even
factors
organisms
eg
harder
required
nutrients),
water
the
may
for
life
system
is
in
is
an
ecosystem
limiting
result
are
in
in
likely
in
to
to
get
desert,
species
available
more
a
enough
then
any
disappearing.
abundance
manage
if
raw
change
If
the
(water,
one
is
light,
reduced.
Iner tia
Inertia
a
is
the
disruptive
planners
property
force.
know
of
Along
which
an
ecosystem
with
site
to
resilience
will
either
resist
and
resist
change
stability,
change
or
when
it
is
subjected
key
recover
to
to
helping
most
quickly.
F h l  l f b
Natural
hazards
impact
on
impact
is
are
be
the
so
often
bad
they
considered
considered
can
are
mitigate
naturally
environment
‘Acts
their
are
God’
effects
as
but
when
they
are
events
humans).
considered
disasters
of
occurring
(and
as
natural
they
are
to
a
may
stop
badly.
control
them
a
level
Natural
humans
the
have
certain
disasters.
impact
outside
unlikely
that
Above
of
negative
the
hazards
They
can
humans.
We
happening.
natal hazad
natal dsast
Volcanic eruptions
Eruption of Mount St Helens in Washington State, USA in 1980
Ear thquakes
Haiti 2010
Floods
Yangtze River oods in China that left 14 million people
homeless, the southern Asia oods of 2007
Wild res
Clear 4 million to 5 million acres (1.6 million to 2 million
2
hectares) of land in the USA every year
Hurricanes
▲
Hurricane Katrina in New Orleans, USA in 2005
Fg 3.3.2 Examples of recent natural hazards
Environmental
activity
and
oil
and
disasters
would
are
include
usually
loss
of
thought
tropical
of
as
caused
rainforest
on
a
by
human
massive
scale
spills.
2
http://www.ecoplum.com/greenliving/view/274?_dispatch=gcontents/view/274#sthash. JLzhn46v.dpuf
166
3 . 3
▲
Fg 3.3.3 Tsunami
▲
T H r e A T S
T O
B i O D i v e r S i T y
Fg 3.3.4 Forest re
wave –a natural hazard
The
of
major
cause
diversity
parts
of
the
original
●
In
on
habitat
most
In
the
●
In
Madagascar,
only
Loss
Habitat
a
piece
for
place
by
up
roads,
are
as
are
or
make
Local
areas,
●
is
of
habitat.
human
or
There
activities.
changed
most
is
In
of
loss
many
the
is
and
we
10%
of
reckoned
under
occur
lost
most
original
that
no
where
of
there
to
are
make
occur
forest
moist
protection.
and
likely
degradation
Bangladesh,
have
the
wildlife
rainforest.
only
highly
to
can
cover
forest
many
we
remains.
will
Madagascar
them
when
of
Climate
and
for
acid
the
and
is
endemic
be
the
species.
extinct.
develop
or
build
on
alters
of
to
of
the
the
degrade
of
and
The
they
There
the
temperature
that
between
or
as
habitat
possibility
range
elds.
ratios
light,
diseases
can
the
or
is
other
ecosystems.
area
of
area
each
landscape
modied
edge
spread
large
from
by
domestic
and
populations.
destroy
species
and
pest
habitats
that
a
pristine
include:
by
spraying
of
seabirds
emissions
or
in
pesticides
and
smaller
from
food
weather
can
may
drift
marine
factories
photochemical
waterways
accumulate
change
is
a
pipelines
Invasion
there
many
into
sea
support
deposition
lines,
uctuations
and
example
pollution
whereby
separated
degraded
higher
activities
to
These
kill
or
middle.
contact
fertilizers
can
with
greater
human
may
power
inhospitable
than
support.
process
fragments,
modied
increases
by
the
of
fences,
a
unsuitable
spills
to
is
islands
into
pollution,
lead
in
an
the
edge
caused
oil
habitat
factories,
come
them
Run-off
the
it
lemurs
smaller
the
chemicals
●
to
Lanka
high,
area
patchwork
Environmental
can
●
of
a
humans
species
ecosystem
●
Sri
primary
2020,
and
within
get
at
Pollution
and
loss
destroyed
are
region,
small
isolated
effects
humidity
species
the
habitat
towns,
fragments
wild
into
islands
edge
is
due
land.
fragments
act
by
where
their
Fragmentation
divided
levels
of
the
destruction
of
scale
have
Vietnam,
Mediterranean
of
large
humans
●
except
biodiversity
habitat.
population
and
of
and
Philippines,
human
left
loss
small
world,
natural
the
of
a
and
into
wild
species.
transport
smog.
cause
eutrophication,
toxic
chains.
patterns
and
shifts
biomes
away
from
equator.
167
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
Overexploitation
has
escalated
as
human
populations
have
expanded
TOK
and
technology
hunting
and
has
allowed
harvesting.
us
to
Chain
get
saws
better
have
and
better
replaced
at
hand
catching,
saws
in
the
There may be long-term
forests,
factory
ships
with
efcient
sonar
and
radar
nd
and
process
sh
consequences when
stocks
and
bottom
trawling
scoops
up
all
species
of
sh
whether
we
then
biodiversity is lost. Should
eat
them
or
not.
We
are
just
too
good
at
getting
our
food.
The
Grand
people be held morally
Banks
off
Newfoundland
were
one
of
the
richest
shing
grounds
of
the
responsible for the long-
world
but
are
now
shed
out.
If
we
exceed
the
maximum
sustainable
term consequences of their
yield
of
any
species
(the
maximum
which
can
be
harvested
each
year
actions?
and
not
replaced
by
sustainable
gure
is
and
improved
humans
lower
natural
(see
how
at
population
eating
real
bush
the
trade
we
different
growing
customs
being
meat)
or
the
poverty
that
the
and
the
what
mixed
more
is
this
with
and
environment.
practices
between
felling
population
knowing
mean
overexploit
choice
animal
is
rural
harvesting
level
it
●
potatoes
●
rubber
non-native
prevented
starvation
last
tree,
more
With
and
there
is
no
from
it
is
collectors
a
as
plants
and
Dutch
Elm
decimated
Sudden
●
Australia
toads,
thorns
of
environment
pet
different,
birds
and
have
their
Americas
the
trade.
exotic
As
for
animals
personal
pets.
to
wealth
Victims
of
this
reptiles.
done
own
species
this
crops
can
through
or
drastically
upset
colonization
of
livestock.
Europe
to
South-East
Asia.
large
over
to
Europe
owers.
many
areas
But
as
from
they
they
Nepal
have
by
plant
escaped
outcompete
into
the
native
toxic.
was
been
foxes,
starsh
came
from
imported
American
logs
to
Europe
and
populations.
death
also
name
well
the
imported
particularly
camels,
to
was
with
introduced
have
disease
the
to
Amazon
were
taken
elm
Australia
zoos.
the
disaster:
they
has
red
Sometimes
of
(exotic/alien)
bringing
the
are
oak
compete
and
Humans
from
and
●
natural
works:
trees
wild
new
primates,
Rhododendrons
the
the
demands
want
many
countries,
Sometimes
168
But
then
difculty
traditional
the
‘harvest’
ecosystem.
Sometimes
or
with
(wild
also
people
include
natural
●
densities,
The
and
subsistence
but
meat
Introducing
●
left.
hunting
ever-increasing
increases
a
is
8.4).
growth),
choice.
Nowadays
ll
of
a
overexploitation
and
much
methods
living
1.4
population
a
adapted
aggressive
species
is
this
unfortunate
blackberry,
just
in
few.
to
prickly
The
the
by
with
pear
rabbits,
and
different
environment
invasive
introduced
very
way.
the
cane
crown
ora
but
and
unable
of
fauna
to
species.
accident
or
escapes
from
gardens
3 . 3
Spread
of
disease
black-footed
1987
and
Diseases
versa,
a
the
of
to
be
across
examples
●
A
a
●
u
very
and
u
where
hit
can
are
one
barrier
is
kept
this
by
to
are
is
to
In
if
in
distemper.
zoos,
they
B i O D i v e r S i T y
of
distemper
species
together.
but
an
population
due
wild
high.
close
last
canine
reduced
species)
and
The
out
spread
densities
species
outbreak
pass
from
u)
since
mouth
hooves
rarely
to
haltthe
is
and
Diseases
mutate
ever-present
vice
disease
is
tend
they
threat.
can
Recent
and
species
are
2010
to
–
swine
u
is
endemic
in
pigs
and
can
humans.
virus
adapted
(H5N1)
has
to
both
spread
birds
and
through
humans
Asia
to
and
Europe
2003.
disease
(FMD)
sheep,
A
of
a
major
virus
deer,
outbreak
up
to
10
that
affects
goats)
in
and
the
million
UK
all
animals
spreads
in
2001
animals
to
with
easily,
led
try
to
to
FMD.
genetic
varieties
is
pigs,
slaughtering
agricultural
species
a
strain
humans.
spread
monocultures,
in
pigs
(cattle,
thegovernment
Modern
wiped
population
animals
(only
species
(avian
and
cloven
but
lion
biodiversity.
was
population
pathogenic
Africa
Foot
wild
T O
are:
swine
Bird
if
specic
the
sometimes
●
decrease
the
Serengeti
threat
species
infect
in
domesticated
particularly
constant
may
ferrets
T H r e A T S
practices
also
engineering
of
species
are
reduce
and
diversity
pesticides.
grown
with
Fewer
commercially
and
and
fewer
more
pest
removed.
To do
rabbts  Astala
followed killed o up to 500 million of the 600 million
rabbits. But the rabbits were not eliminated as a very few
Rabbits are not indigenous to Australia. In 1859, rabbits
were resistant to the virus. They bred and now rabbits
were introduced into Australia for spor t and for meat by
are again a problem with the population recovering to
shipping a few rabbits from Europe. With no predator
200–300 million within 40 years.
there, they multiplied exponentially and after ten years,
there were estimated to be two million. The rabbits ate
In 1996, the government released Rabbit Hemorrhagic
all the grass and forage so there was none for sheep and
Disease or RHD as a second disease to attempt to
the farming economy collapsed. Rabbits caused erosion
control the rabbits. But neither of these biological control
as the topsoil blew away but also probably caused the
measures has eliminated the rabbits.
extinction of many Australian marsupials which could
1.
What factors contributed to the success of the rabbits
not compete with them.
in Australia?
It was so bad that in 1901–7, Western Australia built
2.
What is a biological control measure?
3.
Research the introduction of cane toads and prickly
a rabbit-proof fence from nor th to south over 3200 km
long to keep the rabbits out. Other control methods are
pear (Opuntia) into Australia.
shooting, trapping and poisoning.
4.
What do all these three species have in common in
In 1950, the mxomatoss s was brought from Brazil
terms of being a pest?
to control the rabbits and released. The epidemic that
169
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
vulbl f pl f
Tropical
on
rainforests
Earth,
hectare
yet
of
40%
called
the
of
lungs
and
Fg 3.3.5 Tropical rainforest
covers
called
owering
the
Earth.
plant
of
mammals
animals
yet
of
of
one
size
in
on
They
they
are
the
richer
including
have
Malay
Malaysia’s
One
produce
sometimes
have
even
animals
Earth.
also
more
of
the
it.
and
area
have
which
to
plants
rainforests
genera
with
of
land
hence
areas
has
the
living
tropical
1,400
similar
species
use,
mahogany)
compared
all
6%
some
Malaysia
(eg
of
species
Overall
species
trees
300
that
diversity
Denmark,
of
have
hotspots.
Dipterocarp
species
may
oxygen
of
8,000
45
50%
only
habitat
are
importance.
▲
over
the
These
huge
contain
rainforest
rainforest
about
diversity
the
rain
155
high
species
than
others.
forests:
genera
enormous
Peninsula,
of
the
commercial
has
203.
in Malaysia showing canopy
And
they
have
been
lost
at
a
massive
rate
within
the
last
50
years.
They
and emergent trees
covered
cleared
will
be
up
by
of
biggest
14%
1.5
the
of
these
of
human
grow
is
hectares
is
At
rely
for
loss
of
is
cleared
It
is
and
because
written
does
and
not
grazing
urban
mean
time.
the
But
High
means
niches
means
that
both
that
the
The
fast
appear
(trees
or
in
Forest
are
does
so
food
can
living
are
be
and
of
respiration
and
leaf
of
very
other
litter.
had
is
the
time
fertile
plants).
at
Once
and
the
on
is
of
that
then
1,000
the
and
diverse
not
of
the
plants
of
cleared
much
it
is
forest
be
as
does
animals
well
as
regrow
biodiversity
all
year
year.
of
and
niches
year
lack
they
and
of
raw
different
round
Some
the
ways.
habitats
growth
rainforests
disturbance
means
biomass
nutrients
are
All
before
biodiversity.
the
ecological
by
area
pressures
may
many
many
soil
as
may
are
mean
complex.
decomposition
levels
in
for
the
recovered
limited
lack
more
the
be
present
allow
The
become
many
are
so
of
There
density
forest,
same
and
it
many
long
agriculture
for
to
of
as
as
that
managed
species.
time
terms.
most
land.
years
low
regrow
clearance
clearing)
A
the
nutrients
not
and
area
next
fully
next
logging
rainforest,
population
vulnerability
water
rapid
high
not
about
the
and
works
before
subsistence
of
the
they
is
is
tropics
small
to
impoverished
and
any
a
This
does
on
There
agriculture.
course,
rainforest
by
to
with
But
or
because
found
rate
be
up
geological
has
and
takes
light
lled
system
to
it
photosynthesis
these
grows
logging
grow
heat,
layers
Of
wet
been
activity.
timber
ranching
increasing
their
that
human
remaining
regenerate
forest
and
cleared
diverse
of
to
With
have
estimate
and
the
move
but
second.
clear
degradation
then
that
the
in
they
plantations,
(before
that
as
rainforests.
palm
to
live
1950
to
But
cultivation.
the
gradual
estimated
four
and
a
today.
then
forest
years).
nothing
oil
levels
that
The
the
biodiversity
forest
forest
materials.
soil
is
rainforests
provide.
old
it
primary
secondary
and
that
years
per
subsistence
shifting
100
about
development.
of
this
their
three
due
rainforests
threats
for
in
Some
years
cleared
humans
clearance,
is
is
sustainable
for
to
to
grasslands,
in
The
time
there
of
is
rates.
world
biggest
called
(up
spoken
the
surface
50
tropical
billion
or
is
forests
in
rainforests
two
again
another
in
the
two
This
land
rainforest
oil
not
the
enough
cleared
and
170
on
of
in
timber
population
crops
is
are
Earth’s
unprecedented
after
least
exhausted.
there
at
Earth’s
resource
people.
the
completely
commercially
is
of
humans
gone
Perhaps
50%
to
are
or
that
in
held
the
forests
standing
in
burned,
the
crop
plants,
fertility
not
the
reduces
3 . 3
rapidly
the
So
because
vegetation
more
the
is
forest
heavy
not
is
rainfall
there
cleared
to
to
washes
lock
get
up
the
the
the
nutrients
nutrients
short-term
nor
fertility
and
to
T H r e A T S
soil
away
protect
for
crop
the
T O
B i O D i v e r S i T y
and
soil.
growth.
Wh mk  p p  x
Some
the
species
same
others
of
are
more
ecosystem,
do
not.
vulnerable
some
These
species
factors
to
extinction
survive
make
a
than
habitat
species
more
others.
loss
or
likely
Even
in
degradation,
to
be
in
danger
extinction:
Narrow geographical range
If
a
species
only
the
habitat
has
the
species
in
so
many
lives
in
gone.
It
one
place
may
be
zoos
or
reserves
examples
of
species
Tamarin,
birds
on
oceanic
and
that
possible
but
lost
that
or
islands,
to
is
place
keep
not
the
threatened
sh
in
is
lakes
damaged
breeding
real
by
solution.
this
that
or
–
dry
destroyed,
populations
the
up,
There
Golden
of
are
Lion
lemurs.
Small population size or declining numbers – low genetic diversity
A
small
population
change
–
cannot
inbreeding
dead’
or
until
they
commonly
has
adapt
smaller
well.
populations
become
in
a
as
this
are
extinct.
category,
genetic
As
either
Large
eg
diversity
individual
snow
so
and
is
numbers
small
predators
leopard,
that
and
less
fall,
they
are
extreme
tiger,
resilient
there
is
the
to
more
‘living
specialists
Lonesome
George
are
(3.2).
Low population densities and large territories
If
an
to
individual
hunt
and
fragmentation
left
for
there
each
is
a
of
only
a
species
meets
can
restrict
individual
requires
others
or
its
if
of
a
the
large
territory.
they
city/road/factory/farm
are
territory
species
If
for
there
unable
splitting
is
to
up
or
range
breeding,
not
nd
the
a
large
each
over
then
enough
other
territory,
which
habitat
area
because
they
are
less
▲
likely
to
survive
as
a
species,
eg
the
giant
Fg 3.3.6 Island species
panda.
are prone to extinction eg on
Sipadan Island, Sabah
Few populations of the species
If
there
of
are
survival.
species
has
only
It
one
only
gone.
or
two
takes
e.g.
populations
that
one
left
then
population
to
that
be
is
their
wiped
out
only
and
chance
the
lemurs
A large body
As
we
10%
the
or
mentioned
of
the
environment)
terrestrial,
need
and
a
lot
of
tigers),
earlier
energy
they
food.
may
is
in
means
tend
a
on
that
to
They
be
the
passed
danger
to
the
large
have
also
book,
large
10%
next
top
rule
trophic
predators
ranges,
compete
to
the
with
humans
low
are
only
and
rare.
for
about
90%
is
Whether
population
humans
and
(where
level
food
are
hunted
for
the
population
lost
densities
(eg
to
aquatic
and
wolves
sport.
Low reproductive potential
Reproducing
time
to
slowly
recover.
seabirds,
produce
for
one
and
Whales
example
egg
per
infrequently
fall
into
gannets,
pair
per
this
means
category.
albatrosses
year,
and
do
or
Many
some
not
of
the
species
breed
until
takes
larger
of
a
long
species
penguins,
several
years
of
only
old.
171
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
Seasonal migrants
Species
that
migration
songbirds
routes
If
is
they
on
their
to
upriver
journey
to
tough.
only
and
habitats
get
there
prevent
African
do
southern
central
the
they
can
spawn,
Not
between
and
need
destroyed,
Barriers
swim
it
Canada
journey,
one
have
(swallows
between
hazardous
route.
migrate
at
to
often
Africa
south
and
have
end
no
of
food
completing
herbivores
long
Europe,
America)
both
nd
them
large
they
and
the
or
it
a
migration
habitat.
(salmon
following
the
trying
rains).
Poor dispersers
Species
Plants
That
that
can
takes
mean
the
ightless
cannot
only
a
long
plant
birds
introduced
move
rely
on
time
dies
of
hunters
and
out
New
easily
seed
climate
before
it
Zealand,
nor
to
y
new
dispersal
to
or
habitats
change
can
are
mostly
also
in
as
trouble.
to
biome
Non-ying
extinct
in
growth
resulting
move.
another
are
vegetative
move.
shift
animals,
they
may
eg
cannot
the
escape
island.
Specialized feeders or niche requirements
The
of
giant
panda
central
coastal
regions
sundew
(about
China.
or
The
of
2,000
koala
southern
pitcher
plant
left)
only
and
can
mostly
eats
western
only
eats
bamboo
eucalyptus
leaves
Australia.
survive
in
damp
Bog
shoots
and
in
lives
plants
forests
in
such
the
as
the
places.
Edible to humans and herding together
▲
Fg 3.3.7 Giant panda
Overhunting
especially
America,
if
it
under
as
such
all
so
demand
be
prone
on
the
172
▲
of
is
sh,
easier
threat
their
for
Populations
Fg 3.3.8 Tiger hunting
species
lives
ocks
to
can
in
eradicate
large
of
exploit
groups
passenger
the
a
–
species
herds
pigeons.
species
as,
of
quickly,
bison
Then,
once
in
with
located,
North
human
many
can
caught.
Also
▲
overharvesting
shoals
technology,
be
or
that
an
to
them
is
suffering
the
or
humans
parts
are
very
from
extinction.
organism,
greater
from
body
any
the
of
tigers.
in
Although
traditional
they
Chinese
are
not
edible
medicine
and
high.
Often
that
number
are
used
of
the
though,
nearer
to
increasing
Fg 3.3.9 Minke whale harvest
above
more
environmental
than
extinction
pressures
one
an
stresses
pressure
organism
there
are.
can
operates
becomes
3 . 3
T H r e A T S
T O
B i O D i v e r S i T y
Island organisms
Island
on
organisms
the
size
of
the
●
Populations
●
Islands
●
Genetic
●
Islands
dodo
Sadly,
be
tend
in
leopards,
live
in
many
The
of
vulnerable
to
extinction.
Dependent
to
degree
tends
be
to
of
be
endemic
low
vulnerable
which
they
to
have
example
of
species.
wolves)
and
no
an
small
unique
introduction
defense
of
island
of
mechanism.
species
that
of
carnivorous
these
attractive
populations.
non-native
became
extinction-prone
top
many
an
species.
island
Large
have
are
in
the
characteristics
same
groups
small.
species
mammals
characteristics.
food
source
extinct.
can
(tigers,
Species
(bison,
cod)
that
have
too.
genetic
in
the
is
viable
wild
no
diversity
growth
large
in
rate,
a
population
gure
the
carnivores,
minimum
have
that
number.
500
to
size
scientists
left,
habitat
which
many
big
that
depend
is
there
so
is
needed
and
on
rate
and
individuals
below
hunted
It
individuals
threats
Humans
levels,
is
magic
absolute
●
be
high
these
minimum
rate,
a
to
classic
bears,
there
For
a
the
large
survive
But
is
to
particularly
island:
diversity
many
found
be
tend
have
predators
The
can
so
of
is
a
species
conservationist
many
factors
reproduction,
to
consider.
such
as
mortality
on.
sometimes
animal
for
little
thought
hope
species
to
for
very
of
the
as
the
species.
endangered
eg:
There
may
today
(and
20th
be
400
an
tigers
estimate
in
of
Sumatra
40,000
in
and
about
India
3,500
alone
at
in
the
the
start
world
of
the
To thk abot
century).
What are the consequences
●
Some
700
blue
There
were,
whales
are
thought
to
live
in
the
Antarctic
oceans.
of extinction of tigers or blue
it
is
estimated,
250,000
about
60
years
ago.
whales? Do you think that
humans should try to protect
these and other iconic
th iUcn r L
species?
The
and
IUCN
Natural
Union.
It
universal
is
than
800
scientists
but
is
international
brings
of
mission
the
ensure
ecologically
experts
that
usually
agency,
together
from
is
world
to
to
any
Union
human
non-governmental
and
Union’s
to
International
Resources
an
and
throughout
and
the
declaration
assembly)
The
is
83
the
called
was
rights
countries
inuence,
of
the
natural
in
(NGOs),
in
by
of
Nature
Conservation
1948
the
government
and
(when
UN
the
general
agencies,
some
more
10,000
partnership.
encourage
the
World
adopted
110
organizations
181
Conservation
founded
was
states,
conserve
use
for
integrity
resources
and
and
is
assist
societies
diversity
equitable
of
nature
and
sustainable.
173
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
The IUCN Red List
ex tinct (EX)
The
ex tinct in the wild (EW)
IUCN
List
of
monitors
Threatened
the
state
Species
of
the
and
world’s
supports
species
the
through
Millennium
the
Red
Ecosystem
threatened categories
Assessment
critically endangered (CR)
assessing
adequate
as
new
well
as
World
educating
Heritage
the
public,
advising
governments
and
sites.
ex tinction
data
risk
endangered (EN)
The
vulnerable (VU)
Red
criteria:
List
determines
population
the
size,
conservation
degree
of
status
of
specialization,
a
species
based
distribution,
on
several
reproductive
evaluated
potential
near threatened (NT)
quality
and
of
behaviour,
habitat,
geographic
trophic
level
and
range
the
and
degree
probability
of
of
fragmentation,
extinction.
all
least concern (LC)
species
The
Red
under
Lists
varying
of
threatened
levels
of
species
threat
to
are
their
objective
survival.
lists
The
of
data
species
is
gathered
data decient (DD)
scientically
of
not evaluated (NE)
the
Red
There
▲
is
on
List
also
a
a
global
scale
categories
Red
List
and
which
of
species
assess
extinct
and
under
the
threat
relative
extinct
in
are
danger
the
wild
put
of
into
one
extinction.
species.
The
Fg 3.3.10 IUCN Red
lists
are
regularly
updated
and
inform
government
policies
on
trade
in
List categories
endangered
40,000
Practical
R esearch
of
three
that
to
the
has
that
is
and
a
case
different
b ecome
human
The
Work
extinct
activity,
critically
histories
species:
one
due
species
IUCN
Red
EXTINCT
(EX)
surveys
known
in
status
intervention.
has
IN
or
pressures
are
in
outside
economic
and
ecological
possible
facing
estimates
roles
listed
as
threatened.
there
is
is
no
reasonable
presumed
expected
doubt
Extinct
habitat
have
that
when
failed
the
last
exhaustive
to
record
an
WILD
or
(EW)
as
a
–
when
it
naturalized
is
known
only
population
(or
to
survive
in
populations)
an
past
range.
ENDANGERED
extremely
high
risk
of
(CR)
–
when
extinction
in
it
is
the
considered
to
be
wild.
the
(EN)
–
when
it
is
facing
a
very
high
risk
of
extinction
wild.
and
consequences
three
of
species
might
they
methods
(VU)
–
when
it
is
facing
a
high
risk
of
extinction
in
of
wild.
different
extinction
alive
vary?
used
rates
today.
Why
Evaluate
the
NEAR
THREATENED
criteria
but
does
not
Vulnerable
now,
threatened
category
(NT)
qualify
but
is
in
when
it
has
Critically
to
qualifying
close
the
–
for
near
been
evaluated
Endangered,
for
or
is
against
Endangered
likely
to
qualify
the
or
for
a
future.
ineach.
LEAST
DATA
make
a
CONCERN
DEFICIENT
direct,
distribution
NOT
the
or
(LC)
(DD)
indirect,
and/or
–
when
–
when
is
(NE)
–
widespread
there
assessment
population
EVALUATED
it
of
is
its
and
inadequate
risk
of
abundant.
information
extinction
based
to
on
its
status.
when
it
has
criteria.
*A taxon is a taxonomic unit, eg family, genus, species.
174
are
has
disappearance.
R esearch
and
these
List
the
the
their
of
Red
are:
taxon*
and/or
THE
VULNERABLE
the
A
40%
IUCN
impacting
in
species'
when
captivity
ENDANGERED
species
criteria
died.
the
CRITICALL
Y
ecological,
socio-political
the
about
The
b een
well
on
and
measures.
whose
improved
that
–
conservation
endangered,
conservation
the
List
has
cultivation,
Consider
it
and
individual.
another
species
by
on
individual
EXTINCT
third
species
not
yet
been
evaluated
against
1.
What
this
are
the
consequences
of
In
the
extinction
of
●
species?
your
The
cockatoos’
farming
judgement,
does
it
B i O D i v e r S i T y
Pressures
matter
if
it
habitat
during
recently
2.
T O
to
the
gravel
has
last
been
100
mines,
lost
years
to
and
rebreaks
wheat
more
and
becomes
agriculture.
Regeneration
of
mature
trees
for
extinct?
nesting
3.
How
and
much
effort
should
be
made
to
preserve
it
grow
is
slow.
they
are
As
the
grazed
young
by
trees
rabbits
begin
and
to
sheep.
why?
●
Nest
hollows
tidying
up
are
back
cleared
for
rewood
or
in
yards.
cul g p
●
Competition
nesting
1. Carnaby’s cockatoo
●
law
–
illegal
nests
is
is
invasive
species
for
the
sites.
Poaching
and
from
a
prized
specimens
robbing
lucrative
difcult
in
of
eggs
activity.
remote
for
and
bird
baby
E S A C
Questions for all case studies:
T H r e A T S
collectors
birds
Enforcement
Y D U T S
3 . 3
from
of
the
areas.
2. Raesia
▲
Fg 3.3.11 Carnaby’s cockatoo
Description
Carnaby’s
in
the
by
destruction
the
It
cockatoo
southwest
of
population
begins
is
of
its
size
breeding
a
large,
Western
habitat.
in
1950
when
black
bird
Australia
We
is
think
now
four
found
and
only
threatened
about
50%
of
left.
years
old
and
▲
produces
one
bird
only
from
two
eggs
each
each
nest
year.
survives
Fewer
each
Fg 3.3.12 Raesia ower
than
year
and
Description
the
death
extremely
Carnaby’s
rate
during
high.
They
cockatoos
the
rst
live
are
for
few
years
40–50
difcult
to
of
life
is
There
are
plant.
All
15–19
breed
in
of
by
their
law
population
and
are
is
declining.
ofcially
listed
as
They
are
which
are
of
this
found
tropical
in
the
parasitic
jungles
of
captivity
Southeast
and
species
years.
Asia.
protected
endangered
and
Ecological role
likely
to
continue
to
decline
in
numbers.
These
plants
female)
and
are
single
sexed
pollination
must
(either
be
male
carried
or
out
when
Ecological role
the
These
cockatoos
have
specialized
plants
They
breed
in
holes
in
mature
and
years
old)
salmon
gum
trees
using
the
holes
each
feed
in
open
heathland
on
seeds
and
in
the
same
area
must
same
time.
both
a
be
for
pollination
by
small
at
squirrels
and
The
seeds
rodents
and
are
they
reach
a
‘host’
vine.
Pressures
migrate
summer
female
insect
larvae.
They
Therefore
year.
must
They
(owering).
same
dispersed
breeding
bloom
(over
ready
100
in
habitat
male
requirements.
are
and
to
populated
autumn.
coastal
areas
in
late
The
rafesia
they
need
plants
very
are
specic
very
vulnerable
conditions
to
because
survive
and
175
3
B i o d i v e r s i t y
Y D U T S
carry
to
out
their
life
deforestation
habitat.
means
cycle.
and
Humans
less
a n d
They
logging
damage
chance
c o n s e r v at i o n
of
are
vulnerable
which
them
destroy
and
fewer
due
their
lost
at
wild
a
predict
plants
loss
breeding.
of
In
Sabah,
Sumatra
and
Sarawak
there
timber
are
rafesia
with
E S A C
one
There
are
many
locating,
protecting
and
being
set
up.
Education:
there
RAFFLESIA
’
is
Many
closer
by
researchers
to
the
2,000
year
and
2025
feel
the
they
due
to
the
for
all
direct
area
of
the
Asia
have
conversion
death
of
tigers,
fragmentation.
cannot
mate
been
to
this
This
with
destroyed
agriculture.
has
also
means
tigers
in
for
Along
caused
that
tigers
nearby
in
repeated
breeding
with
the
same
areas,
group
are
of
‘SA
VE
day.
monitoring
causing
programmes
per
extinction
across
or
the
1
habitat.
population
sanctuaries.
of
population
total
its
Forests
Method of restoring populations
rate
tiger
animals.
Over
time,
the
gene
pool
is
severely
campaigns.
weakened
and
and
tigers
are
born
with
birth
defects
mutations.
3. Tiger
Habitat
by
the
destruction
population
poaching.
worth
in
A
can
some
local
it
are
being
still
whiskers
is
sold
A
out
and
as
poached
other
for
used
luxuries.
a
is
in
A
to
sale
earn
kill
today
a
in
of
10
tiger,
parts
can
money.
skin
cause
to
be
one
tiger
than
years.
Even
tigers
bones,
sold
on
parts
Chinese
for
is
be
more
their
Tiger
sells
to
wild
because
traditional
tiger
major
estimated
The
can
of
primarily
human
equivalent
body
lot
the
second
prots
illegal
caused
of
tiger
people
now
market
commonly
▲
yield
though
black
LEDCs.
boned
been
growth
US$50,000–100,000.
skeleton
what
has
uncontrolled
the
are
medicine
or
US$15,000
Fg 3.3.13 A Siberian tiger in Philadelphia Zoo
while
only
one
US$1,250.
Description
One
of
Asia.
the
big
of
cats,
Carnivore.
regions
with
found
in
Territorial,
the
highest
eastern
solitary
human
and
and
endemic
on
penis
World
eats
various
deer
and
large
tiger
costs
bone
shocking
US$320
at
is
worth
still,
some
a
bowl
Taiwanese
Method of restoring populations
Recently,
carnivore,
soup
of
more
to
Earth.
Ecological role
Top
and
restaurants.
southern
populations
tiger
kilogram
Worse
herbivores.
have
begun
some
now
conservation
Wildlife
Fund
innovative
beginning
work
in
as
efforts
and
and
early
nearly
all
have
many
as
14
picked
other
aggressive
the
of
1970s.
the
up.
The
organizations
approaches,
The
WWF
countries
that
Pressures
tigers
At
the
beginning
of
the
20th
century,
it
that
there
were
around
100,000
Today,
the
number
is
less
than
have
8,000.
of
tiger
sub-species
has
reduced
been
includes
over
the
last
century.
Malaysia
has
from
8
about
600,
Russian
Bangladesh
have
about
has
200
300,
each.
while
Only
substantial
number
with
more
than
60
the
world
tiger
population.
The
Javan,
the
Caspian
20th
tigers
century;
have
Sumatran
before
Tiger
most
all
become
has
extinction.
a
researchers
maximum
Tigers
in
India
of
extinct
are
surveys
pushing
the
the
nding
illegal
use
international
and
for
the
trade
monitoring
enforcement
in
Chinese
of
tiger
alternative
efforts
of
tiger
tiger
parts,
laws
working
medicine
bone
and
community
other
products,
parts
supporting
where
tigers
are
most
in
anti-
danger,
during
using
state
of
the
art
ecology
methods
to
the
years
target
critical
Tigers
are
populations
of
tigers
in
certain
areas.
left
thought
to
also
now
covered
under
the
strictest
be
protection
176
conservation
Balinese,
believe
50
tiger
percent
and
the
strengthening
traditional
reduce
poaching
and
The
has
by
of
up.
Vietnam
India
to
a
Tiger
600,
with
and
as
to
controlling
Indonesia
set
supporting
populations,
5
such
The
treaties,
number
sites
wild
plan
tigers.
Conservation
was
Island
estimated
inhabit.
of
the
Convention
on
International
the
in
Endangered
value
and
Species
demand
for
(CITES).
their
parts
However,
enforcement
efforts
very
Pressures
difcult.
efforts,
the
future
of
the
saltwater
tiger
(leather),
look
bleak
and
most
of
the
efforts
going
do
not
seem
to
be
enough.
Many
feel
of
the
tiger
is
over
body
exploited
parts
for
through
poaching
and
smuggling.
It
was
illegal
hunted
sport.
Crocodiles
were
also
deliberately
killed
the
because
extinction
was
and
in
for
today
meat
really
hunting,
does
crocodile
Without
skin
conservation
B i O D i v e r S i T y
make
The
such
T O
of
attacks
on
humans.
inevitable.
Method of restoring populations
r p
To
a
1. Australian saltwater crocodile
restore
the
sustainable
wild
crocodile
use
hatchlings
captivity)
from
and
adults
offspring
at
farmed
they
This
are
policy
others
of
the
in
wild
now
was
a
of
and
tour
treating
of
eggs
them
in
(maintaining
and
harvesting
exploitation
the
hunting
to
of
and
see
of
wild
wild
crocodiles,
species.
supported
(SSC)
was
culling
The
areas
valued
raising
farming
age).
reduces
there
limited
(collecting
captivity
years
Visitors
Commission
with
ranching
animals
crocodiles.
so
4
populations
closed-cycle
breeding
of
policy
populations,
E S A C
Trade
T H r e A T S
Y D U T S
3 . 3
by
IUCN
crocodiles
the
but
Species
was
Survival
accused
by
inhumanely.
2. Golden lion tamarin
▲
Fg3.3.14 Australian saltwater crocodile
18
out
were
of
23
once
sufciently
species
species
of
endangered
to
are
be
crocodiles
but
removed
have
from
worldwide
since
the
recovered
list.
Many
thriving.
Description
The
5m
It
3
Australian
long.
lays
It
up
to
months
to
and
in
as
is
a
a
80
to
mature.
listed
is
saltwater
bulky
eggs
hatch.
The
each
The
protected
year
can
a
in
CITES
grow
broad
which
15
up
to
to
years
crocodile
Australia
which
up
snout.
take
take
saltwater
species
under
with
crocodiles
Australian
protected
endangered
crocodile
reptile
in
was
1971,
banned
trade
animals.
Ecological role
The
habitat
swamps
in
a
heap
pythons,
of
the
saltwater
rivers.
leaves.
dingoes
crocodiles
snakes,
of
and
eat
turtle
The
and
young
eggs
tadpoles,
crabs
crocodile
is
a
Nests
top
eggs
other
built
are
catsh.
sh.
The
on
food
small
crocodiles,
and
and
crocodile
are
is
estuaries,
river
for
animals.
mud
Baby
banks
goannas,
Older
crabs,
sea
crocodiles
Australian
eat
saltwater
predator.
▲
Fg3.3.15 Golden lion tamarin
177
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
Y D U T S
Description
Small
Description
monkey.
Endemic
rainforests
of
the
About
world.
captivity.
Life
Brazil.
Some
1,000
say
expectancy
to
Atlantic
Amongst
in
there
about
8
the
are
coastal
rarest
wild
only
The
animals
and
400
500
in
in
in
the
thylacine
appearance
wild.
years.
the
last
the
island
it
a
had
was
to
few
strong
a
marsupial,
wolf,
hundred
of
but
on
ghter
E S A C
than
the
in
it
a
that
but
The
During
only
prior
on
to
thylacine
could
known
in
tail.
found
Australia
jaws
other
rigid
was
mainland.
with
any
similar
with
years
Tasmania
existed
widely
a
open
mammal.
that
was
more
Thylacines
Ecological role
had
Omnivores.
Prey
to
large
cats,
birds
of
prey.
to
territorially
rainforest
in
in
family
the
groups
in
the
wild
in
a
life
expectancy
of
12–14
years
and
gave
birth
Live
2–4
young
a
year.
tropical
canopy.
Ecological role
The
thylacines’
habitat
was
open
forest
and
Pressures
grassland
Only
2%
of
their
native
habitat
is
left.
but
the
get
US$20,000
wild
well
as
and
their
habitat
per
skin.
food
Predation
source
is
not
became
restricted
to
dense
Poaching
rainforest
can
they
is
great
as
the
population
declined.
Thylacines
in
dependable
lived
in
They
were
rocky
outcrops
and
large,
hollow
logs.
as
nocturnal.
Their
typical
prey
were
small
destruction.
mammals
and
birds,
wallabies,
wombats
but
and
they
also
ate
echidnas,
kangaroos,
and
sheep.
Method of restoring populations
A
captive
for
the
breeding
last
40
programme
years
or
more.
(breeding
Over
150
in
zoos)
Pressures
institutions
Thylacines
are
involved
increase
to
the
in
this
genetic
wild
but
and
exchange
diversity.
with
only
Some
a
individuals
are
30%
habitat
is
threatened
and
of
Australia
hundreds
of
years
take
rate
seems
today
future
if
is
dingoes
extinct
on
the
there
predators
ago.
In
Tasmania
they
were
by
farmers
whose
stock
was
the
thylacine’s
(including
Private
and
government
bounties
were
paid
many.
unlikely
not
by
became
as
for
It
and
reintroduced
success
prey.
humans)
outcompeted
mainland
hunted
the
were
to
for
that
this
captive
uncertain
in
species
breeding.
the
would
The
be
alive
long-term
wild.
scalps,
leading
continued
(private).
hunting,
were
until
a
1910
There
was
poisoning
organized
severely
to
for
depleted
peak
kill
in
1900.
(government)
an
intense
and
trapping.
tourists’
and
killing
Bounties
1914
spree
Shooting
entertainment.
population
was
affected
by
parties
The
by
ex p
disease
1. Thylacine (Tasmanian tiger)
The
the
on
and
last
last
competition
wild
thylacine
captive
September
protected
in
endangered
animal
7,
1936.
1936.
in
It
1972
from
was
killed
died
The
was
and
settlers’
at
in
the
1930
Hobart
thylacine
classied
is
now
dogs.
was
by
listed
and
Zoo
legally
IUCN
as
as
extinct.
Consequences of disappearance
The
thylacine
unique
were
was
marsupial
no
dingoes,
a
carnivorous
family.
the
In
marsupial
Tasmania,
thylacine
was
a
from
where
a
there
signicant
predator.
Introduced
▲
of
178
dogs
Fg3.3.16 The last thylacine
the
thylacine.
have
taken
over
the
ecological
role
T O
B i O D i v e r S i T y
Pressures
In
1505
and
to
Portuguese
used
get
it
as
spices
source
colony
of
(jail)
for
monkeys
had
of
a
forest
Known
These
pigs
ate
and
by
extinct
eggs
used
and
also
dodo
voyages
dodo
as
monkeys
sailors
also
by
the
island
Mauritius
their
Crab-eating
stealing
plantations
be
on
Ate
and
dodo
food.
impact,
to
to
Later,
rats,
introduced
large
discovered
point
Indonesia.
meat.
and
sport
sailors
restocking
from
fresh
introduced.
them
a
as
a
a
penal
were
humans
killed
macaque
seem
eggs.
destroyed
E S A C
2. The dodo
T H r e A T S
to
have
Conversion
their
habitat.
1681.
Y D U T S
3 . 3
Consequences of disappearance
Island
▲
fauna
Became
Fg 3.3.17 Dodo
an
standing
Description
Large
ightless
bird
endemic
to
the
island
of
impoverished
icon
there
fear
of
due
and
had
no
fear
predators)
to
being
humans,
and
its
its
by
loss
of
apparent
clubbed
never
the
to
death
having
untimely
dodo.
stupidity
had
–
(just
as
it
need
extinction.
to
Very
Mauritius.
few
a
skeletons
common
remain
‘Dead
as
a
dodo’
is
now
saying.
Ecological role
No
major
need
of
predators
ight.
The
on
Mauritius
dodo
was
a
so
the
dodo
had
ground-nesting
no
bird.
To do
1.
What is bodst?
4.
List four examples of hma actt that threaten
species.
2.
What is an endangered species? List several
examples.
5.
Consider the case studies of organisms in the
previous pages and the list of characteristics that
3.
What are the t wo main reasons for extinction of
make species more prone to extinction. Make a
species?
table to compare the characteristics shared by
these species. What do they have in common?
179
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
3.4 C os ato of bod st
sg :
appl  kll:
➔
The impact of losing biodiversity drives
expla the criteria used to design and manage
➔
conser vation eor ts.
protected areas.
➔
The variety of arguments given for the
➔
ealat the success of a named protected area.
➔
ealat dierent approaches to protecting
conser vation of biodiversity will depend on
environmental value systems.
biodiversity.
➔
There are various approaches to the
conser vation of biodiversity, with associated
strengths and limitations.
Kwlg  ug:
➔
➔
Arguments about species and habitat preservation
Alternative approaches to the development of
➔
can be based on aesthetic, ecological, economic,
protected areas are species-based conser vation
ethical and social justications.
strategies that include
itatoal, gomtal ad o-
●
the Convention on International Trade in
gomtal ogazatos (nGOs) are
Endangered Species (CITES)
involved in conserving and restoring ecosystems
captive breeding and reintroduction
●
and biodiversity, with varying levels of
programmes and zoos
eectiveness due to their use of media, speed
selection of ‘charismatic’ species to help
●
of response, diplomatic constraints, nancial
protect others in an area (agship species)
resources and political inuence.
selection of ksto spcs to protect the
●
➔
Recent tatoal cotos o
integrity of the food web.
bod st work to create collaboration
Community suppor t, adequate funding and
➔
between nations for biodiversity conser vation.
proper research inuences the success of
➔
Conservation approaches include habtat
conser vation eor ts.
cos ato, spcs-basd cos ato and
The location of a conser vation area in a country
➔
a mixed approach.
is a signicant factor in the success of the
➔
Cta for consideration when dsgg
conser vation eor t. Surrounding land use for
potctd aas include: size, shape, edge
the conser vation area and distance from urban
eects, corridors, and proximity to potential
centres are impor tant factors for consideration in
human inuence.
conser vation area design.
The
relatively
together
concerned
species
180
new
experts
about
and
discipline
from
the
loss
communities
●
diversity
●
untimely
of
of
various
of
extinction
biodiversity
from
organisms
of
conservation
disciplines
and
in
and
extinction.
ecological
species
is
a
biology
the
last
want
Their
to
thing;
act
brought
are
years.
together
rationale
complexity
bad
has
twenty
is
All
to
that:
good
are
save
things;
3 . 4
●
evolutionary
●
biological
Some
adaptation
diversity
acronyms
to
has
help
is
good;
intrinsic
you
UN
United
IUCN
International
UNEP
United
CITES
Convention
UNDP
United
WWF
Worldwide
WRI
World
NGO
non-governmental
GO
governmental
MDG
millennium
make
C O n S e r v A T i O n
O F
B i O D i v e r S i T y
and
value
and
sense
of
we
this
should
try
to
conserve
it.
sub-topic:
Nations
Union
Nations
for
the
Conservation
Environment
Programme
International
Trade
of
Nature
TOK
on
in
Endangered
Species
Before you read the
Nations
Development
Programme
section on why to conserve
Fund
for
biodiversity, think about this
Nature
yourself for a few moments
Resources
Institute
and make a list of reasons
organization
why we should conserve and
reasons why we should not.
organization
These questions may help
development
goals
you make your lists:
●
There
are
social
and
many
reasons
to
conserve
Do humans need other
species? In what ways?
Wh  b?
biodiversity
–
economic,
ecological,
●
Do other species exist for
human use? Do they only
aesthetic.
exist for human use?
The value of biodiversity
●
Do other species have
a right to exist? Does
Direct
a great ape have more
Food sources
rights than a mosquito?
●
We
eat
other
species
whether
animal
or
plant.
Even
if
we
do
only
eat
●
a
small
number
of
food
crops,
there
are
many
varieties
of
Are your reasons based
these.
on rational thought or
●
We
need
to
preserve
old
varieties
in
case
we
need
them
in
the
future.
emotion or both? Does this
aect how valid they are?
●
Pests
●
Breeders
and
strains
diseases
are
from
only
can
wipe
one
which
step
they
out
non-resistant
ahead
may
of
nd
the
strains.
diseases
resistant
and
require
wild
genes.
To do
For
In
example,
the
1960s,
wheat,
wheat
rice
and
stripe
maize
rust
provide
disease
one
wiped
half
out
a
of
the
third
of
world’s
the
food.
yield
in
1.
the
US.
It
was
the
introduction
of
resistant
genes
from
a
wild
strain
Read the reasons to
of
preserve biodiversity
wheat
in
Turkey
that
saved
the
crops.
Maize
is
particularly
vulnerable
below. List each under
to
disease,
as
it
is
virtually
the
same
genetically
worldwide.
A
perennial
the headings: economic,
maize
was
found
in
a
few
hectares
of
threatened
farmland
in
Mexico.
ecological, social and
The
plants
contain
genes
that
confer
resistance
to
four
of
the
seven
aesthetic reasons. Do
major
maize
diseases
and
could
give
the
potential
of
making
maize
a
some t in more than
perennial
crop
that
would
not
need
sowing.
one column?
2.
Under the same
Natural products
headings list reasons
●
Many
of
the
medicines,
fertilizers
and
pesticides
we
use
are
derived
NOT to preserve
from
plants
and
animals.
biodiversity. Discuss
●
Guano
is
a
fertilizer
high
in
phosphate
which
is
seabird
droppings.
your list with your fellow
students.
●
Oil
palms
give
us
oil
for
anything
from
margarine
to
toiletries.
181
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
●
Rubber
cotton
●
(latex)
from
Honey,
or
is
from
cotton
beeswax,
rubber
plants,
rattan,
trees,
silk
linen
from
natural
from
ax,
rope
from
hemp,
silkworms.
perfumes,
timber
are
all
from
plants
animals.
Indirect
Environmental services
We
are
(8.2).
the
just
If
a
beginning
value
natural
can
capital
●
Soil
●
Fertilization
●
Ecosystem
aeration
materials.
release
●
Soil
●
Climate
●
Waste
as
is
or
the
of
disease
catastrophe.
from
were
affected
the
to
environmental
then
and
store
need
recycled
and
as
we
services
could
quantify
less
by
replaced
or
the
and
recycles
tissues.
terrestrial
vegetation
species
to
varied
a
serious
insects.
They
ecosystem.
cover.
decomposers.
as
may
be
some
with
stability
their
on
respiration.
of
possible,
likely
in
depend
vegetation.
and
many
as
human)
by
it
for
by
rainforests
followed
tropical
environment
protected
of
crops
productivity
habitat
or
food
and
multi-layered,
was
by
the
are
and
stable,
animal
islands,
This
of
preservation
Natural,
tropical
plantations.
down
our
organisms
resources
more
(plant,
value
processes,
some
carbon
40%
by
of
gives
all
semi-natural
environment
these
worms.
capture
regulated
example,
natural
on
which
broken
on
pollination
captures
water
monetary
biodiversity.
productivity
Agriculture
For
and
Plants
●
is
of
give
placed
depends
oxygen
and
to
be
possible,
render
affected
other
forest
single
by
the
spread
environmental
was
removed
species
damage
and
the
–
when
coconut
the
islands
storms.
Scientic and educational value
We
investigate
encyclopaedia
species
that
should
know.
and
of
are
research
life
the
diversity
www.eol.com
named
on
the
of
intends
Earth.
We
plants
to
do
and
animals.
document
this
because
all
the
we
The
1.8
million
believe
we
Biological control agents
Some
use
of
species
of
living
chemicals,
eg
things
help
myxamatosis
us
control
disease
invasive
and
rabbits
species
in
without
the
Australia.
Gene pools
Wild
animals
genetic
and
plants
are
sources
of
genes
for
hybridization
and
engineering.
Future potential for even more uses
With
to
new
early
If
should
the
get
to
come,
biodiversity.
warning
them.
182
discoveries
appreciate
system.
birds
out.
They
Miners
died,
they
Indicator
there
can
used
knew
species,
will
be
to
take
there
eg
be
many
more
environmental
canaries
was
lichens,
a
toxic
can
into
gas
show
practical
monitors
the
mines
around
air
reasons
as
an
with
and
quality.
they
3 . 4
C O n S e r v A T i O n
O F
B i O D i v e r S i T y
Human health
●
The
●
A
rst
rare
has
species
recently
value
●
antibiotics
The
in
yew
been
the
rosy
with
of
(such
penicillin)
(Taxus)
found
treatment
periwinkle,
as
to
of
from
produce
certain
from
the
the
a
were
obtained
Pacic
Northwest
chemical
forms
of
from
that
of
may
fungi.
the
USA
prove
of
cancer.
Madagascan
forest,
is
curing
children
leukaemia.
Human rights
If
biodiversity
their
native
continue
to
is
protected,
lands.
live
If
in
we
indigenous
preserve
them
and
the
people
can
rainforests,
continue
to
make
continue
to
indigenous
a
live
in
tribes
can
livelihood.
Recreational
Many
people
national
nance
take
parks,
to
an
vacations
go
skiing,
area
and
in
areas
scuba
of
diving
provides
outstanding
and
hiking.
natural
This
beauty
brings
and
extra
employment.
Ecotourism
Biodiversity
places
and
is
often
living
the
subject
things
in
of
them
aesthetic
for
interest.
spiritual
People
rely
on
wild
fullment.
Ethical/intrinsic value
Each
species
Biodiversity
has
a
right
should
responsibility
to
act
be
to
exist
–
preserved
as
stewards
a
bioright
for
of
its
the
unrelated
own
sake
to
and
human
humans
needs.
have
a
Earth.
Biorights self-perpetuation
Biologically
reducing
diverse
the
need
ecosystems
for
future
help
to
preserve
conservation
their
efforts
on
component
single
species,
species.
c  p f b
Many
people
different
use
Conservation
from
reserves
consider
They
and
these
two
terms
interchangeably
but
they
do
have
meanings.
biologists
or
from
harvesting
recognize
that
development
is
or
it
do
not
necessarily
interacting
hunting
is
very
needed
of
with
species
difcult
to
help
want
other
to
as
to
long
exclude
people
exclude
organisms.
out
as
it
is
will
even
sustainable.
humans
of
humans
They
from
poverty.
But
habitats
they
K tms
want
a
the
development
conservation
people
of
the
from
not
biologist
by
be
would
ecotourism
public
to
or
opening
it
at
the
look
expense
for
ways
management
up
to
access
of
(an
a
to
of
the
create
reserve
environment.
income
to
allow
anthropocentric
for
So
local
education
viewpoint).
Cos ato bolog is
the sustainable use and
management of natural
resources.
Preservation
nature
for
exploit.
should
So
the
more
its
Deep
be
own
preserved
even
has
ecocentric
worth,
ecologists
virus
should
option
it
of
not
causes
than
not
argue
regardless
though
difcult
an
intrinsic
green
smallpox
biologists
a
biology
as
that,
their
be
viewpoint
a
resource
whatever
value
or
destroyed
disease
which
in
puts
that
the
humans
cost,
usefulness
according
humans.
value
can
species
to
to
on
humans.
preservation
Preservation
is
often
Ps ato bolog
attempts to exclude human
activity in areas where
humans have not yet
encroached.
conservation.
183
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
Efforts
to
conserve
and
preserve
species
and
habitats
rely
on
citizens,
To do
conservation
Because
organizations
conservation
is
and
governments
mostly
seen
as
for
to
the
act
in
various
‘public
good’,
ways.
politicians
Look back in sub-topic
act
to
change
public
policy
to
align
with
conservation
aims.
There
will
1.1 to nd a pioneer
be
tension
between
what
is
seen
as
good
for
the
economy
and
human
conservationist and a
needs
and
good
for
the
environment
but
the
two
can
coincide
and
this
pioneer preservationist. With
is
being
recognized
more
and
more.
A
report
on
climate
change
(The
which one do you agree?
Stearns
of
GDP
Review
per
activities
There
little
is
or
in
a
order
can
perhaps
have
thinking
‘Think
rst
an
a
or
in
environmental
packaging
may
not
some
and
be
form
or
of
as
conscience
fossil
is
1970s
fuel
able
development
impacting
the
–
1992)
revenue
example
of
have
it
this.
There
organizations
to
have
changed
less
is
one
a
slogan
is
as
at
you
save
a
as
an
may
the
have
as
help
a
whale
local
but
group
last
few
It
can
in
decades.
was
then.
using
nature
you
may
happened
was
in
have
that.
individual
heard.
it
whether
can
think
The
have
in
1%
on.
not
group.
today
home,
to
do
changes
true
that
mitigation
individual,
But
environment
acting
can,
spoil
–
a
to
the
heaps
and
and
has
of
the
be
been
the
Your
less
plastic
reserve.
act
to
that
has
a
You
save
after
is
to
conservation
have
but,
in
all
mine
not
without
biodiversity
though.
extracted
seed
and
national
they
environment
grass
present
applied
within
‘greenwash’
restored
adding
of
generations
people
mining
can
needs
impression
on
When
the
future
local
danger
give
areas
of
can
impact
nothing.
economically
bulldozing
a
and
later
place
of
major
change
GDP
just
specic
meeting
Providing
when
the
needs
projects.
practices
a
in
issue.
member
and
to
20%
you,
proposed
climate
biodiversity.
(WRI/IUCN/UNEP
is
in
starts
or
in
global
a
for
locally’
early
a
both
acting
government)
of
that
is
locally
effect
personally
Sustainable
negatively
effect
act
the
drop
what
globally
globally,
used
a
UK
invested
thinking
on
and
the
be
avoid
larger
about
for
should
in
impact
and
locally
2006
to
danger
no
You
act
in
annum
park
is
an
Greenwash
changed
fact,
the
their
they
minerals
closure.
But
just
enough.
How conservation organizations work – IGOs, GOs and NGOs
Organizations
environment
and
regional
also
fall
into
that
may
and
work
be
local
three
composed
●
also
●
eg
of
called
the
●
highly
●
research,
●
eg
of
of
large
the
both.
depending
answering
a
are
their
and
national
international
on
(IGOs)
to
biodiversity
There
the
branches
organizations.
constitution
and
They
funding.
–
group
of
member
states
(countries)
organizations
organizations
and
funded
by
a
(GOs)
–
national
government
bureaucratic
regulation,
Environmental
Protection
184
preserve
or
organizations
and
or
global
IPCC.
Governmental
part
ofces
international
UN,
●
conserve
or
categories
Intergovernmental
●
to
local
monitoring
Protection
Department
of
and
Agency
China.
control
of
the
activities
USA
(EPA),
Environmental
3 . 4
Non-governmental
●
not
part
●
not
for
●
may
●
some
●
very
●
eg
be
of
a
organizations
(NGOs)
C O n S e r v A T i O n
O F
B i O D i v e r S i T y
–
government
prot
international
run
by
or
local
and
funded
by
altruists
and
subscriptions
volunteers
diverse
Friends
of
the
Earth,
Greenpeace.
To do
Whch s whch?
Consider these logos of some international agencies and organizations that do
environmental work . Work out which organization it is from the logo and then
do research to nd out:
1.
Is it an IGO, GO or NGO?
2.
What are its main aims?
3.
How does it accomplish these aims?
N
▲
G
Fg 3.4.1 some conservation organization logos
The organizations you have investigated operate in dierent ways. In their
dealings with people, some work at government level whilst others work with
local people ‘in the eld’. To bring about change, some work conservatively by
careful negotiation, whilst others are more radical and draw attention to issues
using the media.
4.
Place the organizations shown in gure 3.4.1 on the following axes and add
others that you know of locally and nationally.
desk-based
research
radical
conser vative
in the eld
▲
Fg 3.4.2
185
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
Comparison
of
IGOs,
GOs
iGO ad GO
Use of media
●
Media liaison ocers prepare and read
and
nGO
●
written statements
●
Control /works with media (at least one
NGOs
Use footage of activities to gain media
attention
●
TV channel propagates the ocial policy
Mobilize public protest to put pressure on
governments
in even the most democratic regimes)
●
Gain media coverage through variety of
so communicates its decision/attitudes/
protests (eg protest on frontlines /sabotage);
policies more eectively to the public
sometimes access to mass media is hindered
(especially in non-democratic regimes)
●
They both provide environmental information to the public of global trends, publishing ocial
scientic documents and technical reports gathering data from plethora of sources
Speed of response
●
Considered, slow – they are bureaucratic
●
Can be rapid – usually its members already
and can take time to act as they depend
have reached consensus (or else they
on consensus often between diering
wouldn’t have joined in the rst place)
views
●
Directed by governments, so sometimes
may be against public opinion
Political diplomatic
●
Considerable – often hindered by
●
political disagreement especially if
constraints
Unaected by political constraints – can
even include illegal activity
international
●
●
Idealistic/driven by best conservation
Decisions can be politically driven rather
strategy/often hold the high moral ground
than by best conservation strategy
over other organizations/may be extreme in
actions or views
Enforceability
●
International agreements and national or
●
regional laws can lead to prosecution
Public image
●
Organized as businesses with concrete
public opinion to pressure governments
●
allocation of duties
●
No legal power – use of persuasion and
Can be confrontational/radical approach to an
environmental issue like biodiversity
Cultivate a sober/upright/measured
image based on scientic/businesslike
approach
●
Both lead and encourage par tnership between nations and organizations to conserve and
restore ecosystems and biodiversity
Legislation
●
Enforce their decisions via legislation
●
(may even be authoritarian sometimes)
Serve as watchdogs (suing government
agencies/businesses who violate
environmental law)
Agenda
●
Both seek to ensure that decisions are applied
●
Provide guidelines and implement
●
international treaties
Use public pressure to inuence national
governments/lobby governments over
policy/legislation
●
Buy and manage land to protect habitats,
wildlife etc.
●
Both may collaborate in global, transnational scientic research projects, both may provide
forum for discussion
186
3 . 4
C O n S e r v A T i O n
iGO ad GO
●
Funding
O F
B i O D i v e r S i T y
nGO
Fund environmental projects by monies
●
Manage publicly owned lands
●
Fund environmental projects by monies
coming from national budget
coming from private donations
●
Extent of inuence
●
Global or national in extent
Focus more on local and/or national
information, aiming at education, producing
geographically
learning materials and oppor tunities for
schools and public
Monitoring
●
IGOs monitor regional and global trends
●
NGOs also monitor/research species and conservation areas at a variety of levels
activities
th g w – l  
b
No
nation
today
Authoritarian
information
human
than
●
age
rights
ever
can
nation
and
and
to
states
ignore
are
freedom
on
of
democracy
the
the
rest
of
decline
information
mean
that
the
and
via
the
world.
the
the
rise
of
the
worldwide
individual
has
web,
more
power
before.
International
and
afford
its
huge
cooperation
number
of
was
formalized
specialist
with
agencies
the
which
United
have
a
Nations
major
impact.
●
UNEP
set
●
UNEP
drove
of
CFCs.
and
●
of
the
intergovernmental
Montreal
the
EU,
these
are
the
are
impacts,
eg
Institutional
but
the
say
they
will
by
of
(an
down
or
Union,
are
by
the
on
climate
phasing
with
OPEC
working
the
name
(IPCC).
production
economic
to
for
out
change
groupings
but
a
sustainable
few
–
and
development
to
wanting
may
even
NGOs,
often
but
are
started
now
as
grassroots
having
global
WWF
.
inability
people
it,
for
together
individuals)
Greenpeace,
deliver
panel
protection.
(locally
inertia
power
slow
African
complemented
movements
Protocol
getting
organizations
environmental
They
and
the
Countries
ASEAN,
some
up
be
going)
change,
able
reverse
get
to
and
stop
has
voting
the
degradation
been
of
swing
our
a
for
of
block
to
change
politicians
the
planet
that
pendulum
by
human
activities.
Timeline of key dates for biodiversity conser vation
1961
World
Wildlife
1966
Species
1973
Convention
Fauna
Fund
Survival
and
on
up
by
IUCN
Commission
the
Flora
set
International
and
Julian
published
Trade
of
Huxley
Red
Data
Endangered
Lists
Species
of
(CITES).
1980
World
Conservation
1980
Brandt
Commission
Strategy
published
–
beginnings
of
sustainable
development
187
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
1982
UN
World
Charter
1987
Brundtland
for
Nature
Commission
sustainable
development
1991
Caring
the
1992
Earth
for
Summit
Convention
Declaration
Earth
2000
UN
Rio
on
Council
de
to
Global
Millennium
World
A
Our
Common
Strategy
Janeiro
Biological
leading
development
2002
Earth:
on
for
produced
Summit
and
rst
Agenda
(CBD)
(biodiversity
Biodiversity
–
Sustainable
Diversity
BAPs
Future
and
action
dened
Living
21,
the
Rio
plans)
Strategy
the
MDGs
(millennium
goals)
Summit
on
Sustainable
Development
held
in
Johannesburg
2005
World
Summit,
2010
International
2012
Rio+20
–
New
Year
UN
of
York
Biodiversity
conference
on
sustainable
development
(UNSD)
The World Conser vation Strategy (WCS) and subsequent
milestones
The
WCS
was
published
ground-breaking
approach
national
of
the
to
conservation
and
maintain
●
preserve
●
ensure
living
genetic
1982,
UN
UNEP
which
the
to
rst
Its
and
WWF
presented
time.
balance
ecological
aims
It
a
in
called
for
development
were
processes
1980.
united,
It
was
a
integrated
international,
with
conservation
to:
and
life
support
systems;
diversity;
adopted
national
the
for
efforts
sustainable
countries
IUCN,
resources.
essential
the
addressing
In
regional
world’s
●
Many
by
achievement
utilization
the
WCS
of
and
species
and
developed
ecosystems.
their
own
strategies
for
issues.
World
Charter
for
Nature
was
adopted
which
had
as
its
principles:
●
Nature
●
The
shall
genetic
population
●
viability
sufcient
shall
be
All
of
a
188
the
life
their
and
and
way
its
essential
Earth
forms,
survival,
both
shall
wild
and
land
the
habitats
organisms,
maintain
to
that
processes
not
be
and
to
shall
not
this
be
impaired.
compromised;
domesticated,
end
as
they
the
rare
well
are
sea,
shall
protection
samples
of
as
of
or
the
must
necessary
all
integrity
the
land,
by
subject
be
be
at
habitats
of
different
shall
these
to
types
of
species.
and
be
managed
productivity,
those
to
given
marine
man,
sustainable
coexist.
be
shall
endangered
the
utilized
optimum
endanger
which
and
special
representative
to
resources
as
with
Earth,
to
and
atmospheric
species
on
all
conservation;
areas,
Ecosystems
such
for
the
of
ecosystems
achieve
of
and
safeguarded.
areas
unique
respected
levels
least
principles
●
be
other
but
not
to
in
ecosystems
or
3 . 4
●
Nature
other
In
1991,
was
It
be
Caring
updated
stated
the
shall
hostile
the
secured
of
degradation
caused
by
warfare
O F
B i O D i v e r S i T y
or
activities.
for
and
the
Earth:
launched
benets
benets
against
C O n S e r v A T i O n
of
in
A
65
Strategy
sustainable
sharing
resources
for
Sustainable
Living
countries.
use
more
of
natural
equally
resources ,
amongst
the
and
world
population.
1992: Rio Ear th Summit
World
21–
of
leaders
and
the
the
agreed
Earth
strategy
national
was
planning.
to
the
conservation
●
the
sustainable
●
the
equitable
The
Global
main
biological
use
of
sharing
its
of
development
Biodiversity
countries
three
of
implementation
governments
of
integrate
objectives
the
agenda
–
Strategy .
biodiversity
Agenda
The
into
aim
their
were:
variation;
components;
benets
Agenda
national,
have
implement
document.
sustainable
and
arising
out
of
the
utilization
of
resources.
international,
to
a
help
The
●
genetic
on
Council
the
Such
regional
legislated
plan
or
locally,
programmes
21
was
and
advised
as
intended
local
levels.
that
local
recommended
are
known
as
to
involve
Some
action
national
authorities
in
Chapter
Local
take
28
Agenda
of
21
at
and
state
steps
the
or
LA21.
2000 UN Millennium Summit: Millennium Development Goals (MDGs)
Largest-ever
bound
and
illiteracy,
The
aim
gathering
of
measurable
environmental
was
to
achieve
world
goals
leaders
for
degradation
the
goal
who
combating
by
and
agreed
to
poverty,
a
set
of
hunger,
discrimination
time
disease,
against
women.
2015.
2002: The Johannesburg Summit on sustainable development
Supposed
of
its
to
consolidate
the
Rio
Earth
Summit
but
little
action
came
out
deliberations.
2005 World Summit, New York
Outlined
each
a
series
country
natural
resources
strategies
have
Integrating
was
not
of
global
prepare
its
for
been
written
case
few
as
with
decades
for
national
long-term
conservation
the
priorities
own
a
action,
and
strategy
for
human
result
of
welfare.
the
development
recommended
the
National
international
is
now
a
that
conservation
high
of
conservation
meetings.
priority
–
this
ago.
2010 Biodiversity target
Adopted
2010;
by
was
EU
heads
shown
to
of
state
have
in
2001
largely
to
halt
biodiversity
decline
by
failed.
2013, Rio+20
How
to
build
sustainable
we
a
green
economy
development
and
resulted
how
in
a
to
improve
non-binding
cooperation
paper
‘The
for
future
want’.
189
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
apph  
To do
There
Focs o th WWF ad
Gpac
are
based
three
and
involves
a
basic
approaches
mixture
research,
of
both.
adequate
to
conservation:
Conservation
funding
and
is
the
species-based,
more
successful
support
of
the
habitat
when
local
it
community.
Go to www.panda.org and
www.greenpeace.org/
Species-based conservation
international/
This
Find out
type
look
at
of
conservation
conserving
species-based
1.
2.
the
focuses
habitat
conservation
in
on
conserving
which
it
lives.
the
species
Here
are
but
ve
does
not
examples
of
approaches.
What WWF stands for.
Why do you think WWF
1. CITES (the Convention on International Trade in Endangered
has a panda as their logo?
Species of Wild Fauna and Flora)
3.
For both WWF and
Greenpeace, nd out:
a.
Who they are.
Many
this
What they do.
c.
Where they work .
d.
How they work .
that
4.
5.
is
an
are
their
becoming
international
problem.
write
b.
species
CITES
Governments
own
national
international
threaten
their
trade
survival.
elephants
to
Find the nearest WWF
CITES
dramatically
project to where you live.
animal
What are Greenpeace’s
The
main bodst
threatened
has
turtles,
imports
species
endangered
agreement
(eg
are
in
orchids
to
reduced
by
to
in
or
by
of
its
of
international
governments
voluntarily
aims.
wild
CITES
Its
and
aim
animals
are
to
is
and
have
to
to
ensure
plants
threatened
trade.
address
does
species
not
from
mahogany.
the
trade
animal
the
CITES
support
specimens
tortoises)
are
up
to
Covered
grouped
they
sign
laws
because
between
CITES
international
in
endangered
parts
(eg
species
elephant
Appendices
tusk,
according
of
both
rhino
to
live
horn).
how
trade.
campaigns?
Appendix
6.
Choose one and identify
threatened
I
–
species
with
cannot
be
traded
internationally
as
they
are
extinction.
one aspect (eg whales)
Appendix
II
regulations
ensuring
–
species
can
be
traded
internationally
but
within
strict
from question 5. Describe
its
sustainability.
an action Greenpeace has
taken to draw international
Appendix
attention to the issue.
needs
The
the
orchids
is
–
appendices
(whales,
It
III
a
Since
species
and
many
and
5,000
animal
it
has
included
other
some
at
of
whole
species
been
one
can
and
of
or
be
request
to
of
as
of
corals,
then
exploitation.
cetaceans
cacti
and
species.
species
effective
which
illegal
primates,
voluntarily
plant
most
country
parrots,
populations
done
a
prevent
such
turtles,
28,000
the
help
groups,
sea
species
what
the
countries
porpoises),
separate
example
1975,
of
include
dolphins
great
About
a
cooperation
to
conserve
are
on
its
international
species.
lists.
wildlife
TOK
conservation
agreements
in
the
world.
There are various
2. Captive breeding and zoos
approaches to the
conservation of biodiversity.
Zoos,
How can we know when we
of
aquaria
should be disposed to act on
breed
what we know?
straightforward
species,
wiped
the
in
Programmes
expensive
190
to
other
course
they
saving
A
a
best
in
facilities
keep
captivity
every
or
a
keep
species
keep
many
species.
their
into
DNA,
the
examples
Even
it
wild
if
is
if
they
not
can
a
they
are
habitat.
populations
few
horse
The
breeding
cannot
reintroduce
reintroduce
difcult.
USA.
of
to
native
Przewalski’s
hope
captive
they
have
process
their
and
Wyoming,
best
of
species
out
condor,
and
but
in
are
Mongolia
programmes
species
that
or
establish
successful,
is
and
are
eg
for
in
the
ones
ferret
worthwhile
wild
are
Californian
black-footed
highly
extinct
new
the
or
in
in
and
the
severe
3 . 4
decline.
to
Success
support
extra
out
they
Oman
or
are
tamarin
rallying
more
care
in
to
point
has
is
the
for
given
of
money,
wild
after
Rare
It
plants
conditions.
can
is
be
it
the
in
Zoos
are
Most
to
see,
very
and
are
not
the
Frozen
that
is
are
become
then
breed
there
are
Frozen
in
extinct
in
zoos
many
Ark
a
animal
at
so
wild
been
oryx
a
in
unnecessary
successful
used
to
and
them
the
in
humans.
socialize
to
jump
once
to
to
farms
live
with
in
the
successfully.
controlled
planted
its
native
keep
and
that
out,
habitat
species
aquaria,
keep
these
and
the
are
look
plants
in
sperm,
to
In
eggs,
nature
process.
from
animals
pools
–
for
killer
embryos,
for
this
one
skin)
long-term
animals
reserves.
For
pay
species.
theory,
raised
the
we
programmes
gene
temperature
°C).
megafauna
cetaceans
invertebrate
animals
cruelty.
what
after
the
large
when
with
breeding
widen
be
this
justied
treated
to
as
the
low
−196
is
or
zoos
(eg
could
in
to
and
reintroduced
involved
way
need
best
tissue
at
make
this
bear)
keep
very
less
get
species
cages
other
sh
has
Arabian
an
seedlings
only
centres
may
many
the
be
issues
Project
each
nitrogen
in
or
The
runs
golden
banks.
small
and
the
Brazil
climb
to
need
herbivores.
game
polar
the
to
B i O D i v e r S i T y
tribes.
as
collectors
sometimes
public
(frozen
liquid
the
seed
worms.
of
not
by
zoos,
in
rhino,
and
how
O F
people
may
supply
of
the
become
raising
by
eaten
and
Aquaria
stores
cryopreserved
up
of
of
seen
Often
has
do
after
in
and
with
are
local
food
Forest
perseverance
educational
animals
success.
often
the
or
have
porpoises,
zoos
storage,
have
to
hippo,
beetles
exchange
reproductive
gardens
and
taught
Then
animals
their
Bedouin
reintroduce
gone.
press
local
many
or
to
Coast
animal
dug
connement
open
many
and
–
the
and
if
to
animals
reintroduction
reintroduction
be
and
incentives
Released
unethical.
to
plants
has
bad
elephant,
well,
whale
a
close
to
the
be
impossible
botanic
had
in
zoos
(giraffe,
other
The
Atlantic
and
or
have
may
are
recaptured
reintroduced
captivity
have
kept
run
captivity
habitat
arboretums,
be
successful
patience
these
Sometimes
not
there
dying.
where
utans
be
But
by
may
those
in
outcompeted
because
are
takes
years
of
people
poorly
are
orang
other.
even
employment
waste
each
if
programme.
remaining
local
programmes
programmes
or
danger
Many
Orphaned
likely
reintroduction
feeding
or
lion
a
C O n S e r v A T i O n
which
material
In
and
practice,
example,
see
the
http://www.frozenark.org/.
3. Botanical gardens and seed banks
The
largest
Kew,
and
about
some
and
They
banks
are
the
plant
are
future.
species.
and
them
gene
use.
the
of
garden
grow
these
botanical
species
future
There
10%
1,500
classify
Seed
for
botanical
London.
seed
are
and
out
where
seeds
are
If
the
in
bank
the
plant
bank
plants
should
Royal
Botanical
(10%
of
stored,
is
way
which
of
are
contain
wild.
only
and
species
in
the
the
seeds
preserving
widely
many
and
many
up
be
of
varieties
world
but
are
identify
years.
insurance
to
for
variation
just
of
policy
100,000
preserved
genetic
are
the
in
total)
conservation.
for
an
may
the
grown
more
dry,
Gardens
world’s
plants
and
and
wild,
the
Around
grow
education
frozen
plant
lost
the
not
extinction,
a
is
in
they
world’s
of
is
the
species
research,
species
danger
seed
crop
for
world
plant
threatened
gardens
carry
are
Some
the
and
banks
The
in
25,000
the
a
few
of
a
varieties
species.
191
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
There
are
seed
international
the
seeds
maintain
many
seeds
seed
bank.
they
tend
A
seed
Diversity
built
frozen.
banks
A
the
Crop
been
around
them,
countries.
Global
has
in
banks
collections.
within
This
through
is
As
to
the
world,
in
in
as
need
Svalbard,
as
permafrost
or
is
levels
yet
may
net
no
and
that
of
of
is
seeds
funded
owns
by
loss
to
of
to
from
the
government
power
against
who
technology
contain
Norwegian
needs
safety
national
some
Norway
the
so
for
high
MEDCs
well
ultimate
strife
holding
concern
they
be
bank
Trust
the
civil
the
major
keep
other
and
the
seed
war.
4. Flagship species
These
▲
species
capture
our
Most
the
are
charismatic,
imagination.
instantly
Look
back
at
recognized,
the
WWF
popular
logo
in
and
gure
can
3.4.1.
Fg 3.4.3 Seeds for storage
of
agship
species
are
large
and
furry
but
they
may
not
have
in a seed bank , Kew Gardens
a
signicant
community
What
the
they
●
if
●
they
take
they
Sometimes
use
to
other
be
gain
is
are
that
(see
may
disappeared,
the
rest
of
the
and
to
be
are
used
protect
under
to
the
more
ask
for
habitat
funds
from
which
will
threat.
species:
others
extinct,
with
the
local
umbrella
conserve
same
they
used
agship
called
to
the
appeal
then
conict
are
keystone
instant
over
If
affected.
become
in
support
in
little
naming
to
be
ecosystem.
species
priority
these
species
both
of
were
may
be
funds
other
Disadvantages
they
the
have
these
the
●
in
would
do
public;
include
role
that
habitat
below)
–
and
message
peoples,
species
species,
those
umbrella,
eg
–
in
the
eg
that
the
we
have
man-eating
one
and
under
is
that
failed
tigers.
conservationists
return
it
greatly
umbrella.
lemurs
of
A
helps
species
the
can
Madagascar.
5. Keystone species
▲
Fg 3.4.4
A
keystone
structure
All
species
of
species
the
are
environment
They
act
means
far
like
that
greater
Loss
of
the
ecosystem
species.
The
the
their
The
in
plays
not
that
in
it
for
they
some
an
arch,
of
the
researchers
tend
to
herbivores
their
far
would
in
are
a
maintaining
bigger
the
effect
arch
ecosystem
to
keep
in
abundance
holding
an
is
have
can
a
their
keystone
and
role
the
live.
have
of
from
greatly
predator
the
critical
they
proportional
population
small
a
which
regardless
keystone
imbalance
which
in
disappearance
characteristics
without
that
others,
difculty
A
one
equal
and
small
or
ecosystem.
▲
not
than
than
is
ecosystem
species
than
as
a
have
the
increase
and
an
destroy
of
the
other
keystone
or
all
species.
engineer
population
eat
This
impact
biomass.
loss
the
predator
herbivore
or
could
identifying
their
biomass.
together.
can
numbers
more
on
or
the
in
in
the
check,
producers
Fg 3.4.5
so
causing
the
loss
of
all
food
in
the
ecosystem.
Examples:
●
Sea
the
otter
oats
192
eating
urchins
away.
sea
need
urchins
only
eat
in
the
kelp
forests.
holdfast
If
there
(anchor)
of
are
the
no
sea
kelp
otters,
and
it
3 . 4
C O n S e r v A T i O n
O F
B i O D i v e r S i T y
To do
To do
While we can watch stunning wildlife documentaries on DVD, they are not
Choose an animal species
the same as being there and watching a real elephant feed. If you believe
that is thatd. Browse
that animals and plants provide you with a service, then zoos, aquaria and
the Red Lists or WWF if
botanical gardens are there for humans to enjoy.
you cannot make up your
mind. Find the following
Is keeping animals just so humans can go and look at them a pointless
information:
exercise?
●
Download image(s) of
Or does it have value in itself?
your chosen species.
Do we have the right to capture and cage other species even if we treat them well?
●
What is the Red List
If it is a choice between allowing a species to become extinct in the wild or
category of your species?
keeping the last few individuals in a zoo, which is right?
(It must be Cr, en or vu.)
●
●
Beavers
are
swampy
beaver
●
area.
and
Elephants
and
engineers,
then
Swamp-loving
its
in
making
dams,
the
the
African
grasses
can
dams
which
species
habitat
then
turn
move
a
stream
in.
into
Without
species? Find a map if
the
possible.
changes.
savanna
are
also
engineers,
removing
trees
●
●
in
the
conservation
success
conservation
for
of
the
area
consideration
Many
land
land,
was
protected
that
in
far
degraded
●
within
distance
else
or
nature
wanted.
from
some
high
way.
a
country
effort.
from
conservation
away
in
is
conservation
areas
no-one
land
area
and
may
centres
land
are
use
for
important
set
been
up
on
population
haphazard
reserves
may
not
have
been
large
Threats facing your
species (ecological,
factor
social and economic
the
pressures on the
factors
species).
were
have
human
The
signicant
design.
reserves
It
a
Surrounding
urban
area
is
in
the
poor
density
nature
of
past
●
on
this
or
land
meant
enough
or
inappropriate
Suggested conservation
strategies to remove
agricultural
threat of extinction.
that
that
●
early
In which CITES Appendix
is your species?
Designing protected areas
a
Estimated current
population size?
grow.
Habitat conservation
Where
What is the global
distribution of your
a
to
Pay par ticular attention
the
to how local people and
needs
of
the
species
they
were
aiming
to
protect.
UNESCO’s
Man
and
government actions are
the
Biosphere
programme
(MAB),
started
in
1970,
created
a
involved in helping your
world
network
of
international
reserves,
now
with
480
reserves
in
species to recover.
over
are
100
their
countries.
The
MDGs
and
sustainability
and
conservation
Present your assignment to
aims.
your class and hand out an
Questions
that
conservationists
now
ask
themselves
when
planning
a
information sheet.
protected
●
How
large
need
●
Is
it
the
area
are:
should
protection
better
edge
●
How
●
What
●
If
●
Should
to
there
have
be
the
one
to
protect
middle
larger
of
or
the
a
species?
large
many
Are
there
species
that
reserve?
smaller
reserves?
What
about
effects?
many
is
it
in
the
are
individuals
best
be
an
endangered
species
must
be
protected?
shape?
several
they
of
reserves,
joined
by
how
close
corridors
or
should
they
be
to
each
other?
separate?
193
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
The
or
large
or
several
small
debate
is
known
as
the
SLOSS
debate
(single
large
small).
Sgl lag (SL) Or
Sal small (SS)
Contains sucient numbers of a large
Provide a greater range of habitats
wide-ranging species – top carnivores
Minimizes edge eects
More populations of a rare species
Provides more habitats for more species
Danger of a natural or human-made disaster (re, ood, disease) wiping out
the reserve and its inhabitants is reduced as some reserves may escape
the damage
Both used for education and so fur ther long-term goals of conservation through education
The
consensus
requirements
Sometimes
size,
edge
ratio
is
Edge
is
a
in
only
effects
as
But
links
a
a
specific
protected
the
conventions
area
on
over
their
Evaluate
the
of
that
have
past
b een
decades.
successfulness.
be
to
the
success
protected
of
Investigate
and
so
than
that
the
to
size
nothing.
the
and
protect.
But,
whatever
circumference
to
area
(where
ones
increased
factors
a
There
large
is
as
from
eg
Dividing
be
it
national
up
is
the
easier
as
a
by
avoided
parks
each
more
effect,
determined
should
habitats
more
for
is
and
or
with
has
fences,
this
governments
there
is
less
There
precipitation.
one
as
there
some
the
available
possible
and
present
competition.
wind
circular
area
if
and
what
meet
species
habitat
predation
well,
edge
two
are
least.
and
to
pylons,
put
But,
parks
roads,
fragments
opposition
is
Long
road
than
the
and
from
land.
are
to
strips
move
of
protected
from
land
reserve
to
may
link
reserve
reserves.
and
so
These
increase
gene
pool
or
allow
seasonal
migration.
This
worked
the
well
in
to
design
The
named
two
and
the
parks
at
have
other
animals
Exotic
in
or
were
least
35
linked
species
disadvantages
and
the
it
may
corridor
invasive
be
as
may
a
7,700
bird
a
easier
which
species
by
of
is
use
disease
for
to
in
corridor
several
y
park
one
poachers
harder
also
ha
it
get
to
from
reserve
and
protect
into
a
to
may
hunters
than
reserve
the
via
corridors.
MAB
core
reserves
reserve
have,
which
is
if
possible,
buffer
transitional.
zones.
Some
This
farming,
is
a
zone
around
extraction
of
the
resources,
eg
selective
logging,
and
experimental
research
and
on
two
to
the
natural
used
wide
corridors
spread
reserves.
where
a
area.
evaluate
But
kill
the
in
the
buffer
zone.
protected
The
core
reserve
disturbance
194
the
is
sometimes,
which
Rica
park.
the
areas.
are
area.
owned
kilometres
conservation
the
Evaluate
manage
better
minimized
on
there
and
international
biodiversity
adopted
criteria
in
individuals
Costa
named
and
is
it.
R esearch
and
depend
reserve
example
size
evaluate
possible
be
will
the
Work
allow
of
small
that
ecotones
shape
across
Corridors
Investigate
have
the
farming
privately
Practical
or
boundary).
there
abiotic
irregular
habitat.
at
the
there
so
reserves
railways,
rail
is
should
occur
in
practice,
are
small
near
ecotones
change
in
large
species
low.
change
thin
that
the
effects
opportunists
a
is
of
is
should
undisturbed
be
safer
and
there.
species
that
cannot
tolerate
can
go
3 . 4
Better
Worse
C O n S e r v A T i O n
O F
B i O D i v e r S i T y
WHY ?
bigger better than smaller, includes
A
more species, allows bigger populations,
more interior per edge
intact better than fragmented; larger single
B
population, no dispersal problem, more
interior per edge
To do
1.
What is meant by the word
close better than isolated; easier to disperse
cos ato?
C
among patches, allows easier recolonization
in case local patch loses all individuals
2.
Here are ways to conserve
species on the edge of
extinction. Explain how this
clumped better than in a row; shor ter
can be done with named
D
distance to other reser ves
examples. You may need to
look up some on the web.
a)
Legislation and
connected with corridors better than not
E
conserving habitats.
connected; facilitates dispersal
round better than any other shape;
b)
Zoos and captive breeding.
c)
Flagship species.
d)
Nature reserves.
F
decreases amount of edge
▲
Fg 3.4.6 Possible shapes of protected areas
195
3
B i o d i v e r s i t y
a n d
c o n s e r v at i o n
W E I VE R
Discuss in what ways
Discuss in what ways
To what ex tent can
might our approaches
your EVS inuences
conser vation restore
to conser vation alter
your attitude towards
habitats and species?
biodiversity in the future.
conser ving other species.
BiG QUestions
B 

Comment on the factors
that may make your own
To what ex tent is loss of
EVS dier from that of
biodiversity sustainable?
others with respect to
conser vation.
r qu
➔
The
term
“Nature”
issues.
➔
“biodiversity”
in
much
Does
this
Biodiversity
has
writing
represent
index
is
not
replaced
on
a
a
the
➔
term
conservation
paradigm
measure
the
it
of
a
word,
involves
a
but
merely
subjective
a
number
judgement
exposure
the
to
unique
of
the
Are
two
there
measures;
subjective
use
examples
of
other
The
theory
of
by
➔
natural
has
to
us
that
change
in
populations
a
difference
correct
➔
the
process
between
a
natural
is
impact
may
biodiversity
be
morally
long
term
is
Is
responsible
Should
for
the
theory
and
a
➔
➔
people
long
be
scale.
Why
is
of
their
Why
is
There
are
various
conservation
we
of
approaches
be
of
the
formerly
populations?
increased
have
the
rate
occurred
at
In
which
and
science
in
Why
does
regions
are
the
a
highest
why?
of
taxonomy
species
the
important
in
extinction?
scientic
conservation
conservation
to
collaboration
of
biodiversity?
to
can
act
on
create
need
to
involve
meaningful
and
the
local
sustainable
change?
the
How
disposed
to
we
know
what
Why
are
NGOs
important
in
global
conservation
we
agreements,
assessing
global
status
of
species’
know?
numbers
196
which
on
actions?
biodiversity.
should
some
were
term
➔
when
human
international
community
➔
has
rates
the
important
➔
consequences
that
populations.
there
consequences
lost.
altered
that
extinctions
understanding
when
conditions
those
achieved
selection.
convincing
of
selection
one?
There
held
of
regions
factors
different
mass
extinction
through
the
globalization
to
Human
global
tells
environmental
and
of
numbers?
evolution
different
selection
and
areas
some
➔
natural
the
proportion
in
distinct
within
(index)
on
unique
richness.
evolved
true
environmental
combination
population
have
through
How
as
human
populations
were
sense
the
characteristics
shift?
in
Within
and
inuencing
governments?
W E I VE R
R E V I E W
Quk w
1.
The
of
table
bird
below
species
tropical
gives
found
South
the
at
approximate
different
number
altitudes
A
B
in
America.
large
small
reser ve
reser ve
1
Alttd (m)
nmb of spcs
several
0–500
2000
500–1000
1950
1000–1500
1550
1500–2000
1100
2000–3000
950
3000–4000
500
one large
2
small
corridors
3
no corridors
4
4000–5000
200
Data from a diagram in Gaston K and Spicer J, Biodiversity: an
For
each
pair
(1)
to
(4),
explain
why
the
areas
Introduction, Blackwell Science, 1998
represented
a)
Describe
and
between
altitude
explain
shown
in
b)
Dene
habitat
the
c)
Outline
the
and
better
relationship
number
of
table.
and
species
characteristics
should
have
nature
reserve
if
it
is
column
A
conservation
might
than
be
the
considered
areas
in
B.
[4]
[3]
diversity
diversity. [2]
3.
three
for
column
species
in
to
be
that
an
designated
Outline
three
tropical
rainforests
reasons
for
the
relative
value
of
area
in
contributing
to
global
a
biodiversity.
or
similar
protected
area.
4.
d)
An
area
of
forest
has
been
made
a
The
table
several
It
is
surrounded
towns.
Describe
by
farmland
some
of
below
gives
the
number
of
owering
nature
plant
reserve.
[3]
[3]
species
for
several
tropical
regions
in
the
with
Americas,
together
regions
km
with
the
area
of
each
of
the
the
2
changes
that
following
its
might
occur
protection
in
in
the
this
in
area
way.
[2]
rgo
e)
Briey
or
describe
nature
and
a
named
reserve
explain
that
how
it
protected
you
has
have
been
Sfac aa
 km
its
managed
of spcs
to
biodiversity.
7,050,000
30,000
383,000
40,000
1,000,000
10,000
2,500,000
19,000
[3]
Nor thern Andes
Atlantic coastal
2.
a)
Explain
the
term
total mb
studied
Amazon Basin
protect
estmatd
2
area
biodiversity.
[2]
forests of Brazil
b)
List
four
arguments
for
the
preservation
Central America
of
biodiversity.
[2]
including Mexico
c)
Describe
the
the
processes
formation
of
new
that
may
lead
to
species.
[3]
Data from: Andrew Henderson and Steven Churchill, ‘Neotropical
plant diversity’, Nature (1991), Vol. 351, pp. 2
1–22. © Nature
d)
Discuss
the
relative
disadvantages
of
a
advantages
and
species-based
a)
conservation
strategy
compared
to
Which
species
use
of
reserves.
The
diagram
below
shows
the
layout
Which
conservation
reserves.
The
“islands”
areas
containing
surrounded
affected
by
per
unit
by
human
region
per
Explain
numberof
area?
has
the
[1]
lowest
numberof
unit
the
area?
range
of
biodiversity
[1]
shown
protected
in
ecosystems
greatest
reserves
c)
represent
the
of
species
various
has
[4]
b)
e)
region
the
the
data
above.
[2]
unprotected
activities.
197
W at e r ,
f o o d
p r o d u c t i o n
4
s y s t e m s
a n d
s o c i e t y
4.1 Itodctio to t ssts
sg :
al  kll:
➔
The hdologicl ccl is a system of water
➔
Discss human impact on the hydrological
ows and storages that may be disrupted by
cycle.
human activity.
➔
Costct and ls a hydrological cycle
diagram.
Kwlg  g:
➔
Sol ditio drives the hydrological cycle.
➔
Fresh water makes up only a small fraction
movement), precipitation, melting, freezing,
ooding, surface run-o, inltration, percolation
and stream-ow or currents.
(approximately 2.6% by volume) of the Ear th’s
water storages.
➔
➔
deforestation and urbanization have a signicant
Stogs in the hydrological cycle include
impact on surface run-o and inltration.
organisms and various water bodies, including
oceans, groundwater (aquifers), lakes, soil,
rivers, atmosphere and glaciers and ice caps.
➔
Flos in the hydrological cycle include
evapotranspiration, sublimation, evaporation,
condensation, advection (wind-blown
198
H cti vitis such as agriculture,
➔
Oc cicltio ssts are driven by
dierences in temperature and salinity. The
resulting dierence in water density drives the
ocean conveyor belt, which distributes heat
around the world, and thus aects climate.
4 . 1
I n T r O D u C T I O n
T O
w a T e r
th eh’ w bg
The
Earth
From
of
is
space
the
not
the
Earth’s
referred
to
as
presence
of
water
surface
is
the
covered
K t
‘Blue
on
by
S y S T e m S
Planet’
Earth
is
without
very
due
obvious.
reason.
About
70%
The t bdgt is a
quantitative estimate of the
water.
amounts of water in storages
●
About
●
97%
2.6%
of
all
water
is
fresh
water
and
and ows of the water cycle.
Fresh
of
the
water
●
About
●
30.1%
●
Water
about
is
water
in
68.7
in
on
quite
%
of
the
planet
is
ocean
water
(salt
water).
supply.
water
is
in
the
polar
ice
caps
and
glaciers,
water.
surface
of
the
short
this
ground
0.3%
on
the
of
the
Earth
in
lakes,
rivers
and
swamps
is
only
total.
To do
You
may
think
the
atmosphere
holds
a
lot
of
water
but:
Using the data given,
●
Only
0.001%
of
the
total
Earth’s
water
volume
is
as
water
vapour
in
construct a table to list fresh
the
atmosphere.
water storages on Ear th in
●
According
to
atmosphere
a
depth
of
the
US
rained
2.5
Geological
down
at
Survey,
once,
it
if
all
would
of
the
only
water
cover
in
the
the
ground
decreasing order of size.
to
cm.
Distribution of Ear th’s water
fresh water 3%
other 0.9%
rivers 2%
surface
water 0.3%
swamps 11%
ground
water
30.1%
saline
lakes
(oceans)
ice caps
87%
97%
and
glaciers
68.7%
freshwater
Ear th’s water
fresh surface
water (liquid)
Fig 4.1.1 Distribution of Ear th’s water
The
turnover
leave
that
times
part
of
●
In
●
Icecaps
●
Groundwater
●
Rivers
●
Atmosphere
So
the
water
oceans,
can
renewable
it
16,000
12–20
be
(time
the
it
takes
system)
takes
are
37,000
for
a
very
molecule
of
water
to
enter
and
variable.
years
years
300
years
days
only
9
days.
considered
resource
either
depending
on
a
renewable
where
it
is
resource
stored.
or
See
a
non-
Figure
4.1.2.
199
4
W AT E R ,
F O O D
P R O D U C T I O N
S YS T E M S
A N D
S O C I E T Y
Renewable
Middle ground
Non-renewable
Atmosphere
Groundwater aquifers
Oceans
Rivers
An aquifer is a layer of porous rock, sand
Icecaps
or gravel underground that holds water.
In aquifers, it takes longer than a human
lifetime to replenish the water extracted
Water can easily slide from being renewable to being non-renewable if poorly managed
Figure 4.1.2 Status of water storages
The water (hydrological) cycle
Energy
water
from
cycle.
solar
The
radiation
water
cycle
and
the
drives
force
the
of
gravity
world’s
drive
weather
the
systems.
clouds &
water vapour
transpor t
condensation
water storage
in ice and snow
precipitation
evapotranspiration
surface
evaporation
water
run-o
in

lt
r
a
t
io
n
management
boundary layer
(and exchange with
p
e
r
c
o
la
t
io
m
n
o
is
t
u
r
e
free atmosphere)
s
o
il
soil
heterogeneity
ocean
stream ow
water table
river discharge
groundwater ow
bedrock
Figure 4.1.3 The water cycle
The
water
between
cycle
the
consists
various
of
storages
storages.
of
These
water
ows
and
may
transformations.
Transfers,
200
when
●
Advection
●
Flooding
●
Surface
it
stays
in
the
(wind-blown
run-off
same
state,
movement)
are:
the
be
ows
of
transfers
water
or
4 . 1
●
Inltration
or
●
and
percolation
water
runs
into
and
through
T O
w a T e r
S y S T e m S
soil
rocks)
Stream
ow
and
Transformations,
current.
when
●
Evapotranspiration
●
Condensation
●
Freezing
The
(when
I n T r O D u C T I O n
storages
–
–
into
oceans,
●
soil,
●
groundwater
●
lakes,
●
rivers
●
atmosphere,
●
glaciers
and
–
changes
liquid
water
solid
include
●
it
to
vapour
snow
state
to
water
to
and
or
from
liquid
water,
are:
vapour
liquid
ice.
the:
(aquifers),
streams,
and
and
ice
caps.
To do
1.
Draw a systems diagram of the water budget and cycle showing the
storages and ows given in the table. Make your storage boxes and width
of ow arrows correspond to the propor tions of these volumes. Label all
storages and ows.
Stogs
Snow and ice
Ground water and aquifers
Lakes and rivers
Oceans
Atmosphere
Soil
3
wt vol (k
3
× 10
)
27,000
9,000
250
1,350,000
13
35,000
Flos
Precipitation over oceans
385
Precipitation over land
110
Ice melt
2
Surface run-o
40
Evapotranspiration from land
70
TOK
The hydrological cycle is
Evaporation from sea
425
represented as a systems
model. To what extent
can systems diagrams
2.
There are six storages of water shown in the diagram. List them in order of
decreasing size (largest size rst) and calculate the percentage of the total
hydrosphere stored in each.
eectively model reality,
given that they are only
based on limited observable
features?
3.
Which of these storages can humans use and what percentage of all water
is this?
201
4
W at e r ,
f o o d
p r o d u c t i o n
s ys t e m s
a n d
s o c i e t y
H   h w l
Humans
change
the
1.
Withdrawals
2.
Discharges
–
agriculture,
3.
Changing
a.
b.
–
by
the
cities
concreted
by
Diverting
b.
Aral
sea
last
●
of
50
pollutants
which
to
water
roads
facilitate
barrages
or
are
and
in
water,
of
agriculture
eg
water
and
chemicals
can
ow
and
channelling
large
more
and
sections
diverted
sections
rapid
dykes,
of
away
by:
industry.
from
where
rivers
it
ows:
underground
or
ow
of
rivers
through
making
in
concrete
sensitive
areas.
reservoirs.
rivers:
from
–
towards
changes
intense
lowered
important
areas
to
avoid
caused
irrigation
the
sea’s
dams
by
has
level
to
storage.
humans:
almost
(it
improve
has
stopped
shrunk
river
in
area
ow
by
into
90%
the
in
the
years).
Ganges
basin
absorbed
●
irrigation
movement
areas.
diverted
major
Sea
and
the
damage.
Some
Examples
are
use,
straightening
to
rivers
Many
at
interrupt
sewage.
building
dams,
ood
●
speed
in
With
a.
adding
In
and
domestic
fertilizers,
channels
4.
for
Canalizing:
c.
landscape
Run-off
by
–
deforestation
increases
ooding
as
precipitation
is
not
vegetation.
from
urbanized
areas
causing
local
ooding.
To do
Urbanization and ash oods
Observe and record on your
journey to school what the
More
surfaces of the land you
ever
and
more
cover are made of. Could
inltrate
they absorb water? What
being
has been done to channel
impermeable
before.
humans
Flash
the
soil
and
hard-baked
live
oods
in
runs
hot,
surfaces
in
in
occur
off
dry
cities
and
when
on
the
areas
there
rainfall
surface.
but
more
or
are
more
of
snowmelt
This
and
could
more
be
it
us
than
cannot
is
due
to
due
to
land
cities.
the water and to where?
In
Manila,
after
capital
record
of
the
Philippines,
50%
of
the
city
was
ooded
in
2012
rainfall.
To do
Go to http://www.fao.org/nr/water/aquastat/countries_regions/jordan/index.stm
Read the information on Jordan and answer these questions.
a.
Describe where most of the population live and explain why.
b.
Summarize the agricultural industry of Jordan.
To sch
Investigate two other
c.
List the water supply sources available to Jordan. Explain which are
examples (one local, one
sustainable.
global) of where human
d.
Describe the political and the environmental issues around Jordan’s
activity has signicantly
water supplies.
impacted surface run-o
and inltration of water.
202
e.
Explain the water management strategies that Jordan is adopting.
4 . 1
I n T r O D u C T I O n
T O
w a T e r
S y S T e m S
o   g b
Ocean
They
currents
move
found
on
Ocean
of
the
are
surface
the
global
currents
Earth’s
an
an
in
water
and
deep
role
atmospheric
deects
vertically
have
and
names,
horizontally.
and
they
are
water.
important
400m
both
some
understanding
(upper
rotation
of
directions
and
have
Without
understand
Surface
movements
specic
currents
energy.
The
in
the
distribution
currents
we
cannot
exchanges.
ocean)
and
global
ocean
energy
of
them
in
of
are
moved
increases
their
by
the
wind.
circular
movement.
Deep
of
●
water
ocean
They
(b)
●
are
and
to
also
cause
called
the
differences
thermohaline
oceanic
in
water
currents,
conveyor
density
belt
make
(gure
caused
by
(a)
up
90%
4.1.4).
salt
and
water
can
hold
less
salt
than
cold
water
so
is
less
dense
rises.
●
Cold
●
When
●
due
and
temperature.
Warm
it.
currents,
currents
water
warm
These
When
holds
are
cold
more
water
salt,
rises,
is
cold
denser
has
to
so
sinks.
come
up
from
depth
to
replace
upwellings.
water
rises,
it
too
has
to
be
replaced
by
warm
water
in
downwellings.
●
In
this
way,
water
circulates.
d
l
o
c
Ocean
m
ra
w
Atlantic
Pacic
Ocean
Indian
Ocean
rm
wa
ld
co
Fig 4.1.4 The great oceanic conveyor belt
203
4
W at e r ,
f o o d
p r o d u c t i o n
s ys t e m s
Cold
ocean
a n d
s o c i e t y
currents
run
from
the
poles
to
the
equator,
for
example:
To do
1.
●
the
Humboldt
●
the
Benguela
Current
(off
the
coast
of
Peru)
Explain how the issues of
Current
(off
the
coast
of
Namibia
in
southern
Africa).
freshwater availability are of
relevance to sustainability
Warm
currents
ow
from
the
equator
to
the
poles,
for
example:
or sustainable development.
2.
●
the
Gulf
●
the
Angola
Stream
(in
the
North
Atlantic
Ocean)
With reference to a named
Current
(off
the
coast
of
Angola).
ecosystem, to what extent
have the solutions emerging
from water resources been
Ocean currents and climate
directed at preventing
Water
causes of environmental
raise
impacts or problems, limiting
that
the extent of impact from
As
these causes, or restoring
moderate
a
has
the
a
higher
specic
temperature
water
masses
result,
land
of
heat
close
winters
heat
unit
up
to
and
a
and
seas
cool
capacity
of
matter
cool
and
(the
by
down
oceans
amount
1
°C)
more
has
a
of
than
slowly
mild
heat
land.
than
climate
needed
This
to
means
landmasses.
with
summers.
systems in which impacts
Ocean
currents
also
affect
local
climate:
have already occurred?
●
3.
The
warm
Gulf
Stream/North
Atlantic
Drift
moderates
the
In what ways might the
climate
of
Northwestern
Europe,
which
otherwise
would
have
a
solutions to freshwater
sub-arctic
climate.
resource use alter your
predictions for the state of
●
The
cold
Benguela
Current,
under
the
inuence
of
prevailing
2
human societies and the
southwest
winds,
moderates
the
climate
of
the
Namibian
desert.
biosphere some decades
●
The
Humboldt
Current
impacts
the
climate
in
Peru.
from now?
(see
ENSO
below).
E. Greenland
Labrador
er
ing
Irm
Alaska
Oyashio
N. Atlantic drift
N. Atlantic
N. Pacic
drift
N. Pacic
Canary
California
Gulf stream
Kuroshio
N. Equatorial
N. Equatorial
N. Equatorial
N. Equatorial
Equatorial counter
Equatorial counter
Equatorial counter
Equatorial counter
S. Equatorial
S. Equatorial
S. Equatorial
S. Equatorial
Humboldt
Brazil
W. Australia
Benguela
S. Pacic
E. Australia
Agulhas
S. Atlantic
S. Indian
S. Pacic
Antarctic circumpolar
Antarctic circumpolar
Antarctic subpolar
Antarctic circumpolar
Antarctic subpolar
warm currents
Fig 4.1.5 The ocean currents
2
http://www.pbs.org/edens/namib/ear th2.htm.
204
4 . 1
I n T r O D u C T I O n
T O
w a T e r
S y S T e m S
To do
el niño Soth Oscilltio (enSO)
usually occurred just before Christmas. Because the
reversal of sea and air currents is caused by the changed
The El Niño Southern Oscillation (ENSO) is a
pressure dierence, the whole phenomenon is often
phenomenon in the Pacic Ocean that has global
called ENSO: El Niño Southern Oscillation. El Niño events
consequences. Normally, air pressure in the eastern
occur about every two to eight years and last for about
Pacic Ocean (South America) is higher than that in
two years. They may be either weaker or stronger. Strong
the western Pacic Ocean (Australia, Indonesia). This
El Niño years are usually followed by several years of ‘La
results in the trade winds that blow westward for most
Niña’, when the ocean temperature of the eastern Pacic
of the year. The trade winds blow the warm surface
is unusually cold after being unusually hot in the El Niño
water westward.
years, as the system swings back and for th.
convective loop
El Niño has local and global eects. Local eects include
collapse of anchovy sh stocks, massive death of sea
birds and storms and ooding in the coastal plain of Peru.
The anchovy shery o the coast of Peru is extremely
rich because of the occurrence of an llig when
equator
cold nutrient-rich waters come up from the ocean depths.
Normally, productivity in oceans is quite low because
of one of two limiting factors: light level and nutrient
concentration. In the upper water levels light intensity
is high, but nutrient levels are low and limit productivity.
thermocline
120°E
The available nutrients are taken in by phytoplankton
80°W
and travel down the food chain. Dead organisms that are
not eaten by some other organism sink and the nutrients
Fig 4.1.6 Trade winds blowing warm surface
stored within them end up on the ocean bottom. The lower
waters of the Pacic westward in a non-ENSO year
water layers are therefore nutrient-rich. But here, the
In some years however, the pressure dierence across
absence of light makes photosynthesis impossible. West
the Pacic Ocean is reversed.
of the Peruvian coast, the prevailing eastern trade winds
push the surface water westward. This water is replaced
by cold nutrient-rich water from the deep Hboldt
Ct, which originates in the Antarctic region and
follows the South American coast to the nor th. The
appearance of nutrient-rich water at the surface allows
for high productivity, hence the high numbers of sh and
equator
their predators, the seabirds. During El Niño events, the
upwelling disappears and the sh and seabirds starve.
During El Niño events the Peruvian coastal plain is
subject to severe storms, accompanied by excessive
thermocline
rainfall. This is caused by the warm, extremely moist air
being forced upward by the Andes Mountains.
120°E
80°W
The warm ocean water that moves east during El Niño
Fig 4.1.7 An ENSO year when the winds blow
events contains tremendous amounts of energy. The
eastward across the Pacic
amount of energy is large enough to alter major air currents
These pressure reversions are the Southern Oscillation.
The changed pressure dierence alters both the
like the jet streams and, as a consequence, El Niño aects
global weather. Examples of these changes are:
directions of the wind and of the warm surface current.
●
Droughts in Australia, Indonesia, the Pacic Nor thwest
This phenomenon was rst discovered by Peruvian
of the United States and British Columbia (Canada).
shermen, who called it ‘El Niño’, the Boy Child, as it
Forest res are common in these areas.
205
4
W at e r ,
●
f o o d
p r o d u c t i o n
s ys t e m s
a n d
s o c i e t y
Heavy storms often resulting in ooding in California
think it may stop completely in a few decades. Melting
and the Midwest of the United States, Central Europe
of the Greenland ice sheet may be adding so much fresh
and eastern Asia.
water to the Nor th Atlantic that the saltiness of the Nor th
Atlantic Drift is reduced and the sinking and return of the
●
Absence of the monsoon in India. The Indian
water to the Gulf of Mexico is slower. If this were the case,
population depends on the monsoon rains for its
climate in Western Europe would be getting cooler but it
food production.
is warming instead.
While ENSO is a natural phenomenon, its eects are
The Nor th Atlantic Oscillation (NAO) is a weather
exacerbated by human pressures on the environment.
phenomenon in the Atlantic as ENSO is in the Pacic. In
high index NAO years, there is low pressure over Iceland
Th Glf St/no th atltic Oscilltio
and high over the Azores so westerly winds blow and
The Gulf Stream is a current in the Atlantic Ocean that
winters are mild and summers cool and wetter. In low
comes from the Gulf of Mexico across the Atlantic, where
index NAO years, the pressure dierences are lower, the
it is known as the Nor th Atlantic Drift to western Europe.
westerlies reduced and winters are colder and summers
It carries warm waters in a current about 100 km wide
have heat-waves. There is also an inuence on eastern
and 1000 m deep on average. It makes Nor thern Europe
Nor th America from the NAO.
warmer than it otherwise would be. As this water ows,
Research the latest data on ENSO and NAO. Find out if
some evaporates so its saltiness increases. By the time
there is an ENSO event now. What is the reduction in the
it reaches nor th of Britain and Scandinavian coasts, it
Gulf Stream current now?
is so much saltier, and so much more dense, than the
surrounding sea water that it sinks and returns in the
conveyor belt as the Nor th Atlantic Deep Water back to
where it star ted.
There is some evidence that the Gulf Stream current is
slowing down, possibly due to global warming. Some
If human activity is altering climate, as most scientists
believe, we are also exacerbating the eects of ENSO
events as we put more pressure on the natural systems.
If the Gulf Stream were to stop suddenly (which we
think has happened in the past), what would be the
implications?
206
4 . 2
a C C e S S
T O
F r e S H w a T e r
4.2 accss to fsht
sg :
al  kll:
➔
The supplies of freshwater resources are
➔
evlt the strategies which can be used to
inequitably available and unevenly distributed,
meet increasing demand for freshwater.
which can lead to conict and concerns over
➔
Discss, with reference to a case study, how
water security.
shared freshwater resources have given rise to
➔
Freshwater resources can be sustainably
international conict.
managed using a variety of dierent approaches.
Kwlg  g:
➔
accss to an adequate supply of freshwater
➔
varies widely.
➔
wt slis c b hcd through
reservoirs, redistribution, desalination, articial
recharge of aquifers and rainwater harvesting. wt
Clit chg may disrupt rainfall patterns and
cosvtio (including grey-water recycling) can
fur ther aect this access.
help to reduce demand but often requires a change
➔
As population, irrigation and industrialization
in attitude by the water consumers.
increase, the dd fo fsht icss.
➔
➔
The sccit of t socs can lead to
Fsht slis  bco liitd
conict between human populations par ticularly
through contamination and unsustainable
where sources are shared.
abstraction.
W   l 
K oits
These facts are from the World Water Council:
●
1.1 billion people live without clean drinking water.
●
2.6 billion people lack adequate sanitation (2002, UNICEF/WHO JMP 2004).
●
1.8 million people die every year from diarrheal diseases.
●
3,900 children die every day from waterborne diseases (WHO 2004).
●
Daily per capita use of water in residential areas:
●
■
350 litres in Nor th America and Japan
■
200 litres in Europe
■
20 litres (or less) in sub-Saharan Africa.
Over 260 river basins are shared by two or more countries mostly without
adequate legal or institutional arrangements.
●
Quantity of water needed to produce 1 kg of:
■
wheat: 1,000 l
■
rice: 1,400 l
■
beef: 13,000 l.
207
4
W at e r ,
f o o d
p r o d u c t i o n
s ys t e m s
Although
a n d
there
is
s o c i e t y
a
lot
of
water
on
Earth,
most
of
it
is
saline.
We
can
To do
remove
terms
1.
the
of
salt
from
energy
water
(especially
in
desalination
burning
fossil
plants
fuels)
but
are
the
large
costs
and
in
it
is
only
Assuming there are 6.6 billion
currently
possible
in
wealthy
countries
which
are
water-stressed
and
people alive on Ear th, what is
near
the
with
desalination
sea,
for
example
Israel,
Australia,
Saudi
Arabia.
A
major
issue
the percentage of the world’s
is
that
salt
is
a
by-product
and
is
often
returned
to
population that have no clean
the
ocean,
increasing
the
density
of
the
water
which
then
sinks
and
drinking water?
damages
2.
ocean-bottom
ecosystems.
Unless
we
can
nd
the
technology
to
How many children die
desalinate
water
cheaply,
it
is
not
a
viable
proposition
at
the
moment.
per year from waterborne
The
freshwater
available
to
us
is
limited
and
the
UN
has
applied
the
diseases?
term
3.
‘Water
Crisis’
to
our
management
of
water
resources
today.
There
What is the percentage
is
not
enough
usable
water
and
it
can
be
very
polluted.
Up
to
40%
of
of daily per capita use of
humans
alive
today
live
with
some
level
of
water
scarcity.
This
gure
water in sub-Saharan Africa
will
only
increase.
compared with that in Japan
and Nor th America?
4.
How many days of water
Humans
use
fresh
●
domestic
●
agriculture
●
industry
●
hydroelectric
●
transportation
●
marking
water
purposes
–
for:
water
used
at
home
for
drinking,
washing,
cleaning;
use by one person in Europe
–
irrigation,
for
animals
to
drink;
would it take to produce one
–
including
manufacturing,
mining;
kilogram of beef?
5.
How many kilograms of wheat
power
generation;
would be produced by the
(ships
on
lakes
and
rivers);
equivalent of one year of
the
boundaries
between
nation
states
(rivers
and
lakes).
water consumption by one
person in sub-Saharan Africa?
The
WHO
have
21
says
than
for
this
this
Water
how
a
is
it.
water
not
Egypt,
the
for
enough
there
is
Adding
story,
and
As
but,
water
you
and
see
international
Many
major
●
The
●
The
Iraq
One
and
the
been
it,
is
not
uneven.
for
that
humans
water
as
and
are
half
a
for
water
of
not
its
so
much
soil
will
become
a
it
is
is
but
of
diverted
to
to
than
grow
worldwide,
does
in
not
and
run
through
basin
is
Euphrates
pollutes
and
it
have
Australia
agriculture.
salinization
major
less
more.
and
water
for
and
it
Agenda
far
higher
basin
used
erosion
to
there
enough
as
should
but
far
but
times
need
food
is
have
irrigation
we
is
day
access
region
tens
there
has
Murray–Darling
change,
is
water
than
the
in
human
per
areas
much
expands,
is
climate
how
rates
it
in
world
other
water
it
more
the
uses
usage
and
of
each
water
issue
for
to
the
nations
organizations.
River
water?
increasingly
of
enough
that
fresh
several
shared
rivers
by
countries.
19
carry
countries
water
that
and
is
81
million
extracted
people.
by
Iran,
Syria.
country
owns
have
Tigris
of
that
rivers
Danube
–
imports
scarcity
can
measure
be
states
of
whilst
population
food,
grow
droughts
Much
Agriculture
human
example,
to
a
livestock
like
20litres
minimum
may
use.
of
40litres.
distribution
water
Organization)
just
There
for
use.
food
that
be
recommended
non-domestic
more
Health
minimum
should
use
domestic
208
to
scarcity
we
provide
is
(World
access
–
the
Another
will
next
continue
needed
and
country
Tragedy
to
be
of
the
suffers,
fought
increasingly
the
Commons.
over
scarce.
question
And
water
as
it
so
is
who
wars
becomes
4 . 2
a C C e S S
T O
F r e S H w a T e r
sbl  hw  g
Sustainable
resources
use
of
resources
exploited
extraction
and
and
full
allows
full
recovery
of
natural
the
replacement
ecosystems
of
the
affected
by
their
use.
little or no water scarcity
physical water scarcity
approaching physical
water scarcity
economic water scarcity
not estimated
Fig 4.2.1 World map of water scarcity
Sources
of
reservoirs
extracted
An
freshwater
and
directly
aquifer
two
layers
lled
lakes)
is
of
a
from
layer
Water
the
ow
of
surface
by
surface,
surface
in
aquifers
or
porous
rock
this
is
is
via
rock
of
only
extremely
(rivers,
aquifers.
wells
(holds
(does
inltration
but
freshwater
underground
impermeable
continuously
reaches
are
and
not
from
limited
slow
can
sandwiched
water
precipitation
in
streams,
water
be
aquifers.
water)
let
The
through).
where
the
between
They
are
porous
rock
areas.
(horizontal
ows
can
be
as
1
slow
as
1–10
metres
unsustainably.
recharge
never
Many
source
relled.
per
is
aquifers
no
These
century).
longer
can
are
As
also
exposed
never
be
a
result,
‘fossil
at
used
the
aquifers
aquifers’
surface
–
and
are
often
meaning
so
they
used
the
are
sustainably.
All water on Ear th
recharge area for
unusable 99%
ar tesian well
ar tesian
surface water
well
spring
water usable by humans 1%
water table
groundwater 99%
upper aquitard
ar tesian aquifer
lower aquitard
lakes 0.86%
Fig 4.2.2 Aquifer structure
rivers 0.02%
Fig 4.2.3 Water to humans
1
M.B. Bush, Ecology of a Changing Planet, 3rd ed., Prentice Hall, Upper Saddle River, 2003, pages 187–188.
209
4
W at e r ,
f o o d
p r o d u c t i o n
s ys t e m s
Global
a n d
freshwater
s o c i e t y
consumption
is
increasing
strongly
because
the
human
TOK
population
This
is
increasing
increased
and
freshwater
because
use
leads
the
to
average
two
types
quality
of
of
life
problems:
is
improving.
water
scarcity
Aid agencies often use
and
water
degradation.
Degradation
means
that
water
quality
deteriorates,
emotive adver tisements
making
it
less
suitable
for
use.
Let’s
have
a
more
detailed
look
at
the
around the water security
problems
related
to
freshwater
use
and
possible
solutions:
issue. To what extent
can emotion be used to
Issues:
manipulate knowledge and
●
Climate
change
may
be
disrupting
rainfall
patterns,
even
changing
actions?
monsoon
●
Low
water
USA,
once
when
●
Slow
it
deltas
enters
because
the
the
rates
from
Freshwater
becomes
●
Irrigation
by
the
of
●
the
it
the
used
be
of
supplies.
Colorado
more
making
river
River
than
a
navigation
rivers
even
results
in
tiny
the
stream
impossible.
in
shallower
exhausted.
anymore,
damaged
taken
aquifers
well
sedimentation,
and
may
extend
in
when
are
too
fast;
and
irrigation
for
so
means
strongly
the
soil
is
affects
shrinking
this
causes
a
cone
of
unusable.
degradation,
minerals
(salty)
simply
unusable.
soil
in
This
which
away.
contaminated
used
saline
The
much
courses
being
been
Dissolved
too
of
especially
evaporates
remain
further
in
the
in
before
top
agriculture.
it
layer
This
dry
is
of
areas.
absorbed
the
soil,
process
is
salinization
Fertilizers
and
can
results
water
crops.
making
called
often
not
shallow
be
the
●
is
Mexico,
are
has
making
Much
of
cannot
exhaustion
streams.
now
lower
aquifers
water
and
inequality
sea.
Buildings
the
Pumping
rivers
river,
already
into
aquifer
further
Gulf
in
the
further
agriculture.
●
the
ow
makes
the
in
major
Underground
that
causing
levels
a
water
which
●
rains,
and
pesticides
used
in
agriculture
often
pollute
streams
rivers.
●
Industries
release
●
Industries
and
Warm
water
aquatic
pollutants
electricity
can
hold
organisms
craysh)
stations
are
the
surface
release
dissolved
take
negatively
changes
plants
less
that
into
their
affected.
species
water
warm
oxygen
oxygen
Warm
water
than
from
water
composition
in
bodies.
into
cold
the
water,
water
outow
the
rivers.
so
(sh,
from
power
water.
Solutions:
●
●
Increase
■
reservoirs
■
redistribution
■
desalination
■
rainwater
■
articially
Reduce
supplies
plants
recharging
use
of
dishwashers
by:
removing
harvesting
domestic
showers,
210
freshwater
salt
systems
–
from
large
seawater
and
small
scale
aquifers.
freshwater
and
toilets.
by
using
more
water-efcient
4 . 2
●
Wash
cars
car
the
in
in
car
street
washes
also
with
reduces
a
closed
water
pollution
by
system.
Not
a C C e S S
washing
T O
F r e S H w a T e r
the
Practical
oil.
Unequal
●
Grey-water
recycling
–
grey
water
is
water
from
showers,
laundry,
kitchen
sinks
etc.
which
can
be
access
reused
on
site
cause
WCs,
garden
Irrigation:
selecting
drought
resistant
crops
can
reduce
the
that
irrigation.
crops;
canals
cattle
and
(Some
grazing
trickle
areas
may
may
be
systems
simply
better.)
instead
be
unsuitable
Closed
of
pipes
spraying
for
instead
water
can
who
Alternatively
using
subsurface
drip
●
Reduce
the
amount
possible
amount
Replace
chemical
nutrients
is
at
of
pesticide
the
most
fertilizers
slower
and
and
fertilizer
appropriate
with
more
organic
likely
to
of
examples
Prevent
●
Use
over-spray,
eg
spraying
pesticide
both
has
arisen
selective
pesticides
instead
of
(using
the
smallest
our
●
●
control
Industries
can
treatment
plants.
Regulate
of
the
remove
water
the
can
pollutants
Often,
they
are
from
used
to
meet
demand
for
freshwater.
–
the
absorbed
fertilizer
generic
cooling
their
forced
temperatures
warm
be
supplies.
release
by
the
of
Investigate
crop
plants.
water
directly
in
a
that
(b)
pesticide,
or
the
you
volume
use
indirectly
(a)
per
of
directly
day.
stream.
this
with
other
users
use
and
globally.
measures.
maximum
releasing
conict
water
strategies
be
increasing
locally
biological
over
the
can
Compare
highly
R esearch
reduce
time).
or
not.
where
open
and
●
and
irrigation.
used
ones
be
have
two
which
●
an
freshwater
growing
Evaluate
evaporation.
have
of
need
those
for
b etween
irrigation.
abundance
●
freshwater
conict
for
countries
ushing
to
baths,
can
household
Work
of
water,
by
wastewater
law
released
cooling
to
do
cooling
towers
with
water
so.
water.
that
Instead
evaporate
used.
To thik bot
G t
If you live in a house with running water, only puried and treated freshwater enters
your home in one pipeline. This water is used for all the many processes in the
home that need water. But it does not all have to be as clean as our drinking water.
Black water or sewage contains human waste and may carry disease-causing
bacteria and other organisms (eg worms).
Grey water can be very lightly used water. Do you keep the tap running
when you clean your teeth or run a glass of water? If so, most of this water
is perfectly clean yet goes down the pipes and mixes with black water in
a shared sewerage system. All this water is then cleaned to the highest
standards before being recycled back into our piped water system.
This is a crazy waste of clean water and the two types, black and grey could be
separated before they leave our homes. Grey water could be used to irrigate
gardens, clean cars, ush WCs and anywhere that requires water but not drinking-
quality water. It must be used at once though to avoid build-up of bacteria.
W w
The
scarcity
populations
of
water
resources
particularly
where
can
lead
sources
to
are
conict
between
human
shared.
211
4
W at e r ,
f o o d
p r o d u c t i o n
s ys t e m s
a n d
s o c i e t y
Y D U T S
though
1. The geopolitics of Israel’s water
June.
there
The
can
rainy
be
occasional
season
begins
rainy
days
around
through
October.
shor tage
Despite
Golan
SYRIA
the
shortage,
the
amount
the
peace
of
water
Israel
will
supplied
probably
to
Jordan
not
reduce
according
to
International border
Heights
Coastal
treaty
between
the
countries,
Schor
said.
aquifer
Mountain
aquifer
Jordan’s
drought
Water
a
is
much
worse
than
Israel’s,
he
said.
Haifa
is
contentious
E S A C
of
the
disputes
to
overcome
In
an
Israeli
issue
and
in
the
dry
Palestinian
region,
and
negotiators
one
hope
Sea of Galilee
reviR nadro
J
Tel Aviv
in
talks
to
work
out
a
peace
agreement.
JORDAN
will
effort
launch
to
a
stem
a
serious
conservation
shortage
campaign,
of
water,
Israel
targeting
mostly
n
a
e
household
Jerusalem
use.
As
part
of
the
efforts,
Israel
has
in
n
a
r
r
e
t
i
recent
weeks
reduced
by
more
than
50
percent
the
a
e
s
d
e
drinking
M
water
supplied
to
farmers,
increasing
their
Gaza
need
for
recycled
water,
Schor
said.
Water
ofcials
will
Be’er Sheva
this
weekend
debate
raising
the
cost
of
drinking
water
Dead Sea
in
another
Israel
has
attempt
two
to
cut
household
desalination
plants
use,
that
he
said.
supply
about
EGYPT
one-third
of
water
needed
households,
Schor
said.
by
municipalities
Three
other
plants
and
scheduled
Fig 4.2.4 Aquifers of the region
to
be
The
completed
next
one
is
by
2013
due
to
will
be
double
that
operational
in
amount.
2009.”
Water shor tage looms in Israel after prolonged
1.
drought, but supply to Jordan continuing
List
Israel’s
(ows)
International
Herald
March
2008.
21st,
Tribune.
Posted
on
is
suffering
2.
its
greatest
What
drought
in
the
of
its
the
and
main
will
summer,
Authority
has
to
the
source
have
drinking
an
to
ofcial
spokesman
stop
stop
water
pumping
said
Uri
pumping
sources
from
by
from
the
Wednesday.
Schor
about
40
the
said
Sea
percent
of
when
of
of
3.
Water
are
its
—
it
will
have
to
step
already-depleted
aquifers,
bearing
rock.
bad,’
seams
Schor
aquifers,
of
said.
the
‘As
of
extraction
more
water
water
growth
brings
Schor
got
and
a
of
large
desire
the
is
policy
water
of
in
very,
go
most
Israel’s
quality
5.
Since
of
life
How
he
not
grow
much
of
the
food
it
water
Can
cycle
the
reasons
for
neighbouring
strained
countries
could
in
any
needs,
short
Israel
term
solve
and
the
these
long
for
farming
should
be
some
they
In
countries
sea
share
your
the
in
water
212
rainy
winter
season
that
Israel
Critics
uses
a
heavily
this
water
problems
in
both
the
but
region
can
others
afford
cannot,
to
should
the
to
what
water
would
be
management
a
in
sustainable
this
part
of
world?
To do
Research the water politics of the Nile basin in Nor th-
east Africa. The Nile ows through 10 countries which
all extract water from it.
event
they
drastically
ends
relations
over
water?
opinion
solution
Evaluate the claims of Egypt and Sudan for their
say
curtailed.
2.
Israel’s
explain
term?
use of Nile water.
irrigation
you
diagram?
50–60
said.
receiving
Israel
If
1.
does
your
gardens,
that
agriculture
water,
are
desalinate
very
the
about
areas,
that
of
down.’
and
fourth
only
environmental
water?
from
population
lawns
the
with
note
rates.
in
of
—
water-
from
will
from
water
was
rain,
average
proportion
subsidized
to
winter
average
government
stems
improvement
This
than
percent
of
an
greater
said.
less
problem
long-term
overuse
supplies?
6.
Israel’s
the
of
terms
between
Israel
Galilee
situation
pump
the
demands
drinking
underground
‘The
we
quality
up
in
What
the
water
and
one
end
4.
of
(stores)
past
this
decade
sources
water.
on
problems
“Israel
water
this
month,
Suggest solutions to the tensions.
4 . 2
Behind
2. China’s Three Gorges dam update
100
a C C e S S
the
and
building
drinking
There
is
much
is
this
Ba
the
water
people
dead
toxic
dam
and
algal
dammed
it
by
F r e S H w a T e r
historical
their
the
increase
so
and
The
buried
Pollution
for
dam,
metres
ooded.
T O
and
make
minimal
blooms
here
cofns
wastes
rose
in
up
sites
3,000
caves
materials
the
to
were
years
on
ago
cliffs.
used
waters
sewage
and
by
cultural
settled
in
may
level
and
in
unsuitable
treatment
eutrophication
in
may
the
waters.
a
risk
of
power
destroyed,
power
energy
from
by
long
dam
terrorism
generation
transmitted
security
one
is
or
lost.
distances
to
as
well.
means
Having
that,
if
earthquake,
It
also
where
has
it
is
to
all
be
used.
Fig 4.2.5 Yangtze River and Three Gorges dam,
China–where do you think the dam is located?
To thik bot
The
Three
Yangtze
Gorges
River,
hydroelectric
China
was
one
dam
of
on
the
the
largest
To have information is useful. To turn it into knowledge
engineering
projects
and
the
largest
power
station
is dicult. This information age feeds us a massive
in
the
world.
Its
estimated
cost
was
US$30
billion
glut of information, but for all this information there
and
it
opened
in
2012.
The
hydroelectric
power
is also a vast amount of misinformation. As a critical
produced
from
the
dam
could
provide
9%
of
all
thinker, always be aware of what is not written as
China’s
output
so
the
saving
in
carbon
emissions
much as what is written. Omitting essential facts that
would
be
huge.
Up
to
a
quarter
of
a
million
do not suppor t the case you are arguing for is an easy
workers
built
the
dam
and
1.3
million
people
thing to do. Consider either the Three Gorges dam
were
resettled
as
the
ood
waters
covered
their
or any other project to manage water (eg the Aswan
homelands.
Apart
from
electricity
generation,
the
dam, Aral Sea, Ogallala Aquifer).
dam
is
designed
to
stop
the
river
ooding.
These
Either
oods
the
have
past
drowned
100
Wuhan
for
years
up
and
to
1
million
ooded
the
people
major
in
city
of
months.
Put together a case FOR the project and AGAINST
the project using the information you research.
You can omit some facts and exaggerate others.
Criticisms
of
the
dam
are
that
it
will
cause
Pseudoscience does just this.
environmental
archaeological
and
silt
The
Siberian
degradation,
sites,
refugees,
threaten
some
destroy
wild
OR
species
up.
Set up a class debate for and against the project.
their
winter
oods.
extinct
water
The
in
the
silt
only
but
silt
the
as
Upstream
habitat
Yangtze
ow
affected
Crane
wild
the
get
increases
liable
to
Yangtze,
it
the
due
dam,
caught
the
does
make
the
erosion.
is
is
River
to
endangered
wetlands
dolphin
pollution
The
that
is
and
the
dam
probably
and
Yangtze
loss
of
sturgeon
is
well.
of
means
critically
downstream.
will
may
is
built
increasingly
siltation
behind
danger
not
of
ow
will
the
clogging
Shanghai,
a
without
silt
This
the
downstream.
downstream
on
increase
dam.
at
bed
river
the
and
mouth
replacement
Lack
of
more
of
may
from
not
turbines
banks
this
as
the
erode
upstream.
213
4
W at e r ,
f o o d
p r o d u c t i o n
s ys t e m s
a n d
s o c i e t y
4.3 atic food odctio ssts
sg :
al  kll:
➔
Aquatic systems provide a source of food
➔
Discss with reference to a case study the
production.
controversial har vesting of a named species.
➔
Unsustainable use of aquatic ecosystems can
➔
evlt strategies that can be used to avoid
lead to environmental degradation and collapse
unsustainable shing.
of wild sheries.
➔
➔
exli the potential value of aquaculture for
Aquaculture provides potential for increased
providing food for future generations.
food production.
➔
Discss a case study that demonstrates the
impact of aquaculture.
Kwlg  g:
➔
➔
Dd for aquatic food resources continues
➔
to increase as human population grows and diet
changes to shing methods have led to
changes.
dwindling sh stocks and damage to habitats.
Photosynthesis by phytoplankton suppor ts a
➔
highly diverse range of food webs.
➔
national, local and individual) through policy,
Aquatic (freshwater and marine) ora and fauna
legislation and changes in consumer behaviour.
➔
The highest rates of odctivit are found
and is expected to continue to rise.
lligs and nutrient enrichment of surface
waters occurs.
➔
Issues around aquaculture include loss of
habitats, pollution (with feed, antifouling agents,
Har vesting some species can be controversial
antibiotics and other medicines added to the sh
eg seals and whales. Ethical issues arise over
pens), spread of diseases and escaped species
bioights, rights of indigenous cultures and
(some involving genetically modied organisms).
international conser vation legislation.
‘ The world has quietly
aclt has grown to provide additional food
resources and suppor t economic development
near the coast or in shallow seas where
➔
usstibl xloittio of aquatic systems can
be mitigated at a variety of levels (international,
are har vested by humans.
➔
Developments in shig it and
m    wb
entered a new era, one where
Marine
ecosystems
(oceans,
mangroves,
estuaries,
lagoons,
coral
reefs,
there is no national security
deep
without global security. We
and
ocean
oor)
are
usually
very
biodiverse
and
so
have
high
stability
resilience.
need to recognize this and
Some
to restructure and refocus
our eorts to respond to this
new reality.’
are
oceans
food
214
is
where
sources
descends
Lester R. Brown
more
productivity
productive
in
light
are
from
coastal
does
than
regions
not
above
reach
chemotrophs
above.
others.
One
the
have
(2.2)
and
half
of
marine
continental
low
productivity
dead
organic
shelf.
as
the
matter
Deep
only
that
4 . 3
The
continental
oceans.
It
is
Where
important
●
It
●
Upwellings
has
of
●
Countries
The
(eg
of
of
under
Arctic.
The
all
can
the
more
extension
shelf
exists
of
it
productivity
ENSO)
shallow
claim
shelf
or
Sea
shelf.
steeply
it
bring
continents
creates
under
shallow
but
15%
of
its
nutrient-rich
coast
to
so
theirs
nearly
exploit
km
but
the
seas
S y S T e m S
and
water.
area.
water
1600
at
km
remarkably
and
up
to
the
the
Isles
the
constant
from
one
almost
stops
and
150
plate
Shelf
mainland
about
zero
tectonic
Siberian
and
shelf
at
photosynthesize.
harvest.
where
for
British
which
can
varies
Sumatra
the
depth
producers
to
80
of
between
The
is
as
seas
averages
west
another)
North
continental
slopes
4.1
the
Chile
sliding
the
p r O D u C T I O n
shelf.
reaches
width
coast
oceanic
(see
continental
Light
is
F O O D
because:
50%
●
shelf
continental
a q u a T I C
in
is
the
Europe
the
sea
is
bed
metres.
To do
The
UN
Convention
continental
shelves
on
as
the
Laws
belonging
of
to
the
the
Sea
(UNCLOS)
country
from
in
1982
which
designated
they
extend.
Research the maritime
It
also
designated
a
200
nautical
mile
(370
km)
limit
from
the
low
water
claims of your own country
mark
of
a
shore
as
an
exclusive
economic
zone
belonging
to
that
country.
and compare them with
Outside
that
are
international
waters
which
no
one
country
controls.
This
Ecuador and Peru in gure
has
huge
impact
on
shing
these
areas,
who
is
allowed
to
sh
there,
who
4.3.1. Why is this impor tant
controls
this
‘tragedy
of
and
who
cleans
it
up
when
there
is
a
pollution
problem.
(See
economically?
the
commons’,
later
in
this
section.)
PANAMA
Cocos Island
Malpelo
COSTA RICA
Island
COLOMBIA
COLOMBIA
Galapagos
R
O
D
A
U
C
E
Islands
ECUADOR
ECUADOR
BRAZIL
Ecuador & Peru
maritime claims
PERU
internal waters (claimed)
PERU
territorial waters (claimed)
AIVILOB
exclusive economic zones
maritime boundaries
C
IH
EL
claimed by Peru,
not recognized by Chile
disputed between Peru and Chile
CHILE
Fig 4.3.1
Phytoplankton
and
are
99%
of
the
primary
Zooplankton
eat
the
and,
the
are
most
single-celled
important
productivity
also
oat
phytoplankton
between
oceans.
them,
in
the
and
these
organisms
producer
(2.3
sea
their
in
and
and
2.4).
are
waste
organisms
that
the
can
oceans,
They
photosynthesize
producing
oat
single-celled
(dead
support
organic
the
in
the
sea.
animals
matter
complex
–
that
DOM)
food
webs
Fig 4.3.2 Phytoplankton
of
and zooplankton range in size
from 1 μm to 10 mm
215
4
W at e r ,
f o o d
p r o d u c t i o n
s ys t e m s
Marine
organisms
●
Benthic
●
Pelagic
the
a n d
–
–
s o c i e t y
can
living
living
be
on
classied
or
in
the
surrounded
as:
sea
by
bed
water
from
above
the
sea
bed
to
surface.
fh – l g  hg
K t
About
A sh exists when sh
90%
Fisheries
of
shery
activity
is
in
the
oceans
and
10%
in
freshwater.
include
are harvested in some way.
●
shellsh:
●
some
oysters,
mussels
and
molluscs
(including
squid)
It includes capture of wild
sh (also called capture
vertebrates:
eels,
tuna
etc.
shing) and aquaculture or
Up
to
half
a
billion
people
make
a
livelihood
in
sheries.
sh farming.
Three
rest
of
billion
us
Fish
are
a
Fish
are
high
vitamins
of
very
to
the
depleted
or
gain
15%
of
20%
our
important
in
protein,
(A,B,D)
According
70%
people
about
the
that
too
low
food
low
(Food
sheries
to
their
for
in
humans
FAO
world’s
of
protein
intake
from
sh
and
the
protein.
allow
humans.
saturated
need
and
are
for
a
fats
Agriculture
fully
and
healthy
(under
various
Organization),
exploited,
recovery
contain
diet.
in
decline,
drastic
limits
more
than
seriously
to
allow
a
1
recovery).
The
technology
cannot
has
nd
aquaculture
or
global
sh
improved.
catch
has
catch
no
Demand
enough
increased
is
sh.
is
longer
high
They
increasing
and
are
no
rising
longer
even
but
though
shermen
there.
But
greatly.
100
note: 2011 is an estimate;
90
2012 is a projection.
wild catch
80
70
snot noillim
60
farmed sh
50
40
30
20
10
0
1950
1960
1970
1980
1990
2000
2010
Fig 4.3.3 World wild sh catch and sh farming
K t
1950–2012
aclt is the farming
of aquatic organisms in both
Aquaculture
coastal and inland areas
Human
diets
are
changing
and
many
people
in
MEDCs
are
becoming
involving interventions
more
health
more
fish
conscious,
eating
less
meat
from
terrestrial
animals
and
in the rearing process
and
vegetables,
as
this
change
lowers
saturated
fat
intake.
to enhance production.
Saturated
fat
intake
is
linked
to
cholesterol
(FAO http://www.fao.org/
aquaculture/en/)
1
http://www.american.edu/ TED/ice/cansh.htm
216
build-up
in
arteries
4 . 3
and
increased
worldwide,
per
y e a r.
and
the
These
most
wild
have
just
take
of
more
better
used
to
be
comes
has
and
about
we
20
higher
reached
have
sustainable
strokes.
kg
from
technology
because
a
attacks
eats
fish
fishing
and
than
population
heart
extra
caught
there
of
person
figures
the
better
not
risk
each
over
yield
of
meat
and
that
is
not
of
for
fish
because
Either
or
S y S T e m S
meat
lower
is
though
them
p r O D u C T I O n
average
kg
and
fish.
exploited
8
This
even
the
F O O D
on
and
farms.
limit
find
N o w,
fish
for
fish
its
to
a q u a T I C
humans
they
we
enough
are
cannot
as
human
grows.
70
60
50
beef
snot noillim
40
30
farmed sh
20
10
0
1950
1960
1970
1980
1990
2000
2010
Fig 4.3.4 World farmed sh and beef production,
1950–2012
From
than
gure
beef
farmed
than
are
sh
wild
not
4.3.4,
you
production
were
caught
sh
sustainable,
Ways
which
Fishmeal
wasted
sh
uses
in
the
●
Livestock
●
United
States
species
of
cobia,
get
and
for
this
sustainable.
●
enough
that
66
rst
is
farmed
million
2012.
cannot
farming
more
in
the
Now,
time
we
since
continue
becoming
trimmings
sh
tons
and
so
may
we
the
more
scraps
production
(60
million
eat
more
started
sustainable
more
of
farmed
shing.
challenge
which
was
tonnes)
is
to
If
sh
these
make
sh
are:
would
have
been
past.
poultry
processing
Department
carnivorous
arctic
see
2011:
produced
farming
in
can
in
char,
sh
of
–
from
is
substituted
Agriculturehas
white
yellowtail,
nutrients
waste
sea
Atlantic
bass,
that
walleye,
salmon
alternative
proven
and
sources
for
shmeal.
eight
rainbow
coho
without
trout,
salmon–can
eating
2
other
Figure
4.3.5
farmed
most
sh.
of
sh.
that
shows
China
is
carp
waste
provides
Asian
countries
healthy
source
the
relative
produces
or
catsh.
fertilizer
and
of
is
for
of
protein
importance
62%
These
the
rice.
mutual
for
of
the
all
are
of
China
farmed
grown
This
benet:
sh
in
system
the
as
rice
is
a
producer
worldwide
paddies
used
system
in
and
many
produces
of
and
their
SE
rice
and
a
farmer.
2
http://science.kqed.org/quest/2014/02/13/vegetarian-farmed-sh-may-be-key-to-sustainable-
aquaculture/
217
4
W at e r ,
f o o d
p r o d u c t i o n
s ys t e m s
a n d
s o c i e t y
Fishery food supply (kg/capita)
40
aquaculture
35
capture
30
25
20
15
10
5
WORLD
CHINA
WORLD E XCLUDING CHINA
0
70
80
90
00
10
70
80
90
00
10
70
80
90
00
10
Fig 4.3.5 Relative contribution of aquaculture and capture sheries to
food sh consumption
To do
1.
But
other
aquaculture
carnivores
and
are
Mangrove
swamps
fed
systems
on
are
less
shmeal
or
efcient.
sh
oil
Shrimp
produced
and
salmon
from
wild
are
sh.
Describe the ‘tragedy of
have
been
replaced
by
sh
farms
–
in
the
Philippines
the commons’.
2.
two-thirds
of
the
Impacts
sh
mangroves
have
been
lost
in
40
years.
State two reasons why
of
farms
include:
we are overshing the
●
loss
●
pollution
oceans.
3.
Why has the world sh
What actions can
habitats
(with
medicines
catch stalled?
4.
of
●
spread
●
escaped
of
feed,
added
to
antifouling
the
sh
agents,
antibiotics
and
other
pens)
diseases
be taken to reverse
species
including
genetically
modied
organisms
which
may
overshing?
survive
5.
to
interbreed
with
wild
sh
What actions can
●
escaped
species
may
also
outcompete
native
species
and
cause
the
you take?
population
to
crash.
To thik bot
atltic slo d sh fig
uneaten food, feces and chemicals used to treat them
enter the oceans. Sea lice are a problem in the farms and
www.atlanticsalmontrust.org
escape of some farmed salmon which then interbreed
with wild salmon reduces the genetic tness of the wild
stock as farmed salmon are bred for sh farm life, not the
wild. Because of this, the ability to survive of the salmon
population in the wild is reduced.
As wild stocks of many sh species decline, sh farming
has increased. Although there are environmental
Fig 4.3.6 Atlantic salmon
problems created by keeping sh of one species in
Wild Atlantic salmon live in the Nor th Atlantic and Baltic
seas. Due to overshing at sea and in rivers where they go
to spawn, the commercial market for wild salmon crashed.
Now they are farmed in sh farms (a form of aquaculture).
Although commercially successful, these farms create
pollution as the sh are kept in high densities and their
218
high densities, the benets of not chasing sh stocks
across the oceans are large. Some have likened shing
in the seas to hunting on land. We now get most of our
terrestrial meat from farmed livestock and little from
hunting. It makes economic sense to do the same with
our aquatic meat supply.
4 . 3
a q u a T I C
F O O D
p r O D u C T I O n
S y S T e m S
Unsustainable wild shing industry
World
sheries
estimates
We
are
that
so
good
populations
specimens,
them
to
were
75%
at
can
we
thought
sheries
nding
be
and
depleted
then
mature
once
of
catch
and
are
to
be
catching
very
inexhaustible
under
threat
sh
quickly.
smaller
and
of
that,
Once
smaller
but
now
the
FAO
over-exploitation.
once
we
found,
catch
ones
and
the
do
sh
larger
not
leave
reproduce.
100
pelagic marine sh
demersal marine sh
other marine sh
80
freshwater/diadromous sh
molluscs
60
crustaceans
aquatic plants
other
40
20
0
1950
1960
1970
1980
1990
2000
2010
Fig 4.3.7 Global wild sh capture in million tonnes, 1950–2010, as repor ted
by the FAO
Fish
stocks
are
overshing
nding
●
–
and
a
catching
Commercial
navigation
●
Fishing
eets
●
entire
Within
a
supply
●
All
to
sh
eet
there
vessels
and
drag
huge
in
wars
taken
far
their
we
over
number
a
cry
primitive
for
When
is
talk
fuel
of
1970s:
of
This
be
larger
exploited
We
are
by
just
too
good
at
scale.
the
latest
satellite
technology
and,
freezing,
a
will
with
they
the
over
energy
of
stay
technology,
military
modern
can
GPS
quality.
refrigeration
at
sea
for
weeks
or
to
the
catch
organisms
in
shing
at
an
vessels,
sea.
area,
not.
seabed
shing
resources,
virtually
ethos
clearcutting
of
equipment
are
and
rights
foreign
‘Cod
we
However
crises
shing
all
three
all
or
including
it.
shermen
to
land
a
going
sh
community.
supplies.
and
banned
the
vessels
process
hunter-gatherer
international
led
take
simple
or
of
that
species
over
with
family
suite
ships
gear
nets
shing
Iceland
waters.
by
scanning
target
from
wars
and
over
the
craft
own
serious
place
blast
will
shing
Trawlers
this
industrial
informed
nding
factory
are
of
an
being
level.
season.
they
sea
on
is
pressure,
unsustainable
become
whether
catch
●
sh
have
under
an
including
Indiscriminate
●
at
shing
and
techniques,
an
resource
shing
near
in
vessels
Wars’
usually
there
war
the
last
from
between
thinking
are
a
events
60
that
have
years.
shing
Britain
about
signicant
in
Icelandic
and
Iceland.
219
4
W at e r ,
f o o d
p r o d u c t i o n
●
s ys t e m s
1994:
a n d
British
shermen
●
1995:
and
shing
a
mesh
in
the
the
cut
smaller
Eventually,
war
and
the
Bay
turbot
Estai,
Estai
shermen
the
Canada
recovered
size
turbot.
turbot
was
The
Canadians
French
tuna
when
boat,
waters.
and
for
there
Spain
s o c i e t y
(also
red
it
than
net
the
that
Canada
result
called
halibut)
and
chased
trawl
from
competed
with
it
from
when
war
captured
it
was
being
found
permitted
and
this
Spain
an
agreed
increased
crew
national
and
and
between
the
seabed
was
Spanish
Biscay.
upon
having
its
of
on
into
had
a
of
Spanish
but
net
the
solution
regulation
a
international
pursued
it
caught
a
Canada
of
the
with
smaller
to
the
sheries.
What happens to the sh?
TOK
The
Inuit people have an
20
world
million
sh
catch
tonnes
is
are
just
not
over
wild
90
sh
million
but
tonnes
from
per
year
aquaculture
of
(sh
which
about
farming).
historical tradition of
●
15%
of
animal
protein
eaten
by
humans
comes
from
sh.
In
Japan
whaling. To what extent
nearly
half
About
a
of
the
animal
protein
in
the
diet
is
sh.
does our culture determine
●
or shape our ethical
quarter
products
judgements?
●
About
20
marine
shing
sh,
to
boats.
whales,
This
sh
quotas.
thrown
back
pie
chart
are
…
Most
the
are
and
are
of
catch
to
feed
goes
may
back
be
these
too
are
–
sh
meal
unwanted
into
the
porpoises,
legally
into
and
sh
oil
us.
‘by-catch’
thrown
by-catch
that
into
to
global
tonnes
that
dolphins
allotted
a
the
animals
million
animals
albatrosses),
Draw
of
feed
small
or
even
to
sh
oceans
wrong
and
dead
the
species
dying
or
when
other
the
(non-target
seabirds
catch,
and
from
such
sh
as
over
they
are
seas.
illustrate
these
values.
i  l
To thik bot
Colls of th nfodld cod sh
stocks in the Nor th Sea and to Scotland’s west are on the
verge of collapse.
For centuries the Newfoundland cod shery was one of
the world’s most productive sheries, yielding 800,000
The deterioration of oceanic sheries can be reversed.
tons of sh and employing 40,000 people at its peak
Granting shers an ownership stake in sh stocks is one
in 1968. Then its stocks plummeted as a result of
way to help them understand that the more productive
overharvesting and habitat damage. In 1992, the shery
their shery is, the more valuable their share. For
was closed in an eor t to save it. But it may have been
example, shers in Iceland and New Zealand have used
too late: two decades have passed, but stocks have not
marketable quotas, allowing them to sell catch rights,
recovered.
since the late 1980s. The upshot is smaller but more
protable catches and rebounding sh populations. The
This collapse was local in scale, but the issue is much
classic ‘tragedy of the commons’ problem is aver ted.
larger. Nor th Atlantic Ocean sheries operating now catch
220
half what they did 50 years ago, despite tripling their
Because of the complexity of marine ecosystems,
eor ts. So many popular species – such as cod, tuna,
some scientists are pushing for management of whole
ounder and hake – are now in serious decline. Cod
ecosystems rather than single species. In addition,
4 . 3
a q u a T I C
F O O D
p r O D u C T I O n
S y S T e m S
studies have shown that well-positioned and fully
thus does not relieve pressure on marine stocks. Proper
protected marine reserves, known as sh parks, can
labels are needed to allow consumers to make wise
help replenish an overshed area. By giving sh a
purchasing decisions. The Marine Stewardship Council, a
refuge to breed and mature in, reserves can increase the
new independent international accreditation organization,
size and total number of sh both in the reserve and in
has thus far cer tied seven sheries as being sustainably
surrounding waters. For example, a network of reserves
managed with minimal environmental impact.
established o St. Lucia in 1995 has raised the catch
The capacity of the world’s shing eet is now double
of adjacent small-scale shers by up to 90 per cent.
the sustainable yield of sheries. Myers and Worm
Preservation of nursery habitats like coral reefs, kelp
from Dalhousie University believe that the global sh
forests and coastal wetlands is integral to keeping sh in
catch may need to be cut in half to prevent additional
the sea for generations to come.
collapses. Reducing by catch, creating no-take sh
Consumers can promote healthy shery production by
reserves, and managing marine ecosystems for long-
eating less sh and buying seafood from well-managed,
term sustainability instead of shor t-term economic gain
abundantly stocked sheries. The Seafood Lover ’s Guide
are all policy tools that can help preserve the world’s sh
from Audubon’s Living Oceans programme is one valuable
stocks. If these are coupled with a redirection of annual
reference. Chilean seabass stocks are on the verge of
shing industry subsidies of at least $15 billion to
collapse and illegal shing abounds, so it makes the list
alternatives such as the retraining of shers, there could
of sh to avoid. The list also distinguishes between wild
be a big payo. It is dicult to overestimate the urgency
Alaska salmon, which comes from a healthy shery, and
of saving the world’s sh stocks. Once sheries collapse,
farmed salmon, which is fed meal made from wild sh and
there is no guarantee they will recover.
Fish
stocks
are
shrinking
because:
To do
●
industrialized
nations
US$50
a
billion
year,
subsidize
their
modern
eets
by
an
estimated
and
Ethical issues arise
●
demand
outstrips
supply.
over biorights, rights of
indigenous cultures and
international conservation
th g  h 
legislation. Discss with
This
the
is
if
metaphor
needs
seen
we
as
the
This
(be
it
the
individual
belonging
can.
resource
of
illustrates
is
to
all,
because
sh,
tension
and
we
the
timber,
between
how
all
they
tend
to
advantage
minerals,
can
the
be
exploit
to
the
apples)
common
in
it
conict.
and
If
a
and
resource
over-exploit
individual
is
good
greater
of
taking
than
the
it
the
reference to a case study the
controversial harvesting of a
named species. For example,
whales, seals, tuna.
cost
For a really chilling look at
to
the
individual
In
the
short
as
the
cost
is
spread
amongst
the
whole
population.
the causes and problems of
term
it
is
worth
taking
all
the
sh
you
can
because,
if
overshing check out the
you
do
not,
someone
and
not
and
philosophers.
else
will.
This
assumes
that
humans
are
selsh
documentary End of the Line.
altruistic
authorities
any
which
individual.
conserve
the
Exploitation
commons.
amongst
were
shed
it
The
caused
solution
limits
This
has
the
may
is
much
often
amount
be
by
of
permit,
debate
amongst
regulation
and
common
good
set
or
limits
by
economists
legislation
available
by
to
cooperation
to
resource.
of
The
the
and
the
oceans
Grand
richest
by
is
Banks
shing
eets
from
a
good
off
the
grounds
Spain,
example
coast
on
of
of
Earth.
Portugal,
the
tragedy
Newfoundland
Since
England,
the
of
the
were
1400s,
France,
once
they
and
later
221
4
W at e r ,
f o o d
p r o d u c t i o n
s ys t e m s
a n d
Newfoundland,
early
there
So
1990s,
had
far,
Canada,
sh
been
there
s o c i e t y
stocks
closed
has
been
Russia,
crashed
in
an
little,
and
and
attempt
if
any,
the
by
to
United
1995,
conserve
recovery
States,
cod
of
and
the
sh
and
others.
ounder
remaining
Th uitd ntios Covtio o th Ls of th
international waters
over decades that attempts to dene the rights and
responsibilities of nations with respect to the seas and
marine resources. Most, but not all, countries have
continental shelf
signed and ratied the convention. It denes these
categories of waters:
●
Internal waters – next to a country’s coastline where
foreign ships may not travel and the country is free to
set its own laws and regulate use.
exclusive economic zone
(200 nautical miles)
●
Territorial waters – up to 12 nautical miles (just
over 22 km) from the coastline where foreign ships
can transit on ‘innocent passage’ but not spy, sh or
pollute. In island states, eg the Maldives, a boundary
200
contiguous zone
line is drawn around the whole archipelago.
nautical
(12 nautical miles)
miles
territorial waters
●
Beyond the territorial waters is another 12 nautical
(12 nautical miles)
miles of contiguous zone where a state can patrol
smuggling or illegal immigration activities.
internal waters
●
baseline
In the exclusive economic zones (EEZs), the state
has sole rights to exploit all natural resources.
Foreign nations may overy or navigate through this
land
zone. If a country’s continental shelf is greater than
200miles from its coast, it also has exclusive rights
to exploit this.
The international seabed authority, created by the
UN, controls and monitors seabed exploitation in
Fig 4.3.8 Ocean zones according to UNCLOS
Questions
international waters.
Do you think that UNCLOS was a good idea?
Landlocked states are given a right of free access to and
Why would some nations not sign up to it?
from the sea under UNCLOS rules.
What would have happened without UNCLOS?
222
the
stocks.
numbers.
To do
S (unCLOS) is an international agreement written
In
shing
4 . 3
a q u a T I C
F O O D
p r O D u C T I O n
S y S T e m S
To thik bot
wht ot to t from the Marine Conservation Society www.mcsuk .org
Scis
rso
alttivs
Atlantic cod (from
Species listed by World Conservation Union IUCN.
Line caught sh from Icelandic
overshed stocks)
Some stocks close to collapse eg Nor th Sea
waters
Atlantic salmon
Wild stocks reduced by 50% in last 20 years
Wild Pacic salmon. Responsibly
and/or organically farmed salmon
Chilean seabass
Species threatened with extinction by illegal
(Patagonian toothsh)
shing, also high levels of seabird by-catch
None
Dogsh/spurdog
Species listed by IUCN
None
European hake
Species heavily overshed and now scarce
South African hake (M.capensis)
European seabass
Trawl sheries target pre-spawning and spawning
Line caught or farmed seabass
sh also high levels of cetacean by-catch
Grouper
Many species are listed by IUCN
Haddock (from
Species listed by IUCN
overshed stocks)
Ling (Molva spp)
None
Line caught sh from Icelandic
and Faroese waters
Deep-water species and habitat vulnerable to
None
impacts of exploitation and trawling
Marlin
Many species are listed by IUCN
Monksh
Long-lived species vulnerable to exploitation.
None
None
Mature females extremely rare
Nor th Atlantic halibut
Species listed by IUCN
Line caught Pacic species. Also
farmed N Atlantic halibut
Orange roughy
Very long-lived species vulnerable to exploitation
None
Shark
Long-lived species vulnerable to exploitation
None
Skates and rays
Long-lived species vulnerable to exploitation
None
Snapper
Some species listed by IUCN, others over-
None
exploited locally
Sturgeon
Long-lived species vulnerable to exploitation.
None although this species is
5 out of 6 Caspian Sea species listed by IUCN
now farmed
Swordsh
Species listed by IUCN
None
Tuna
All commercially shed species listed by IUCN
‘Dolphin friendly’ (EII monitored)
except skipjack and yellown are over-shed
skipjack or yellown. Preferably
pole and line caught
Warm-water or tropical
High by-catch levels and habitat destruction
Responsibly farmed prawns only
prawns
Fig 4.3.9 What not to eat
Source: Marine Conser vation Society
223
4
W at e r ,
f o o d
p r o d u c t i o n
To thik bot
s ys t e m s
free market – in a global
context – have we the
right to criticize or control
those who use technology
and labour eciencies to
produce more food at less
cost? Without intensive
s o c i e t y
mx bl l (msy)
A
In a world committed to a
a n d
sustainable
income
stock
that
or
its
yield
can
amount
that
the
amount
of
sustainable
crucial
year
that
for
be
water
the
taken
stored.
that
–
the
is
how
in
year
of
is
each
For
–
sh
without
and
the
the
of
impaired
capital,
yield
highest
what
natural
the
of
original
an
permanently
ventures,
stock.
in
ie
depleting
Sustainable
commercial
interest
not
natural
without
year
depleting
many
harvest
increase
each
replenishment.
permanently
amount
so
can
yield
without
is
exploited
potential
the
taken
(SY)
be
is
amount
In
size
it
can
be
is
maximum
that
sheries,
subsequent
aquifer
decreasing
can
this
taken
is
in
be
a
any
years.
agriculture, we could not
carrying capacity of environment (K)
feed the human population.
K
dN
N
= rN
(
Why does food harvesting
)
K
dt
)N( ezis noitalupop
/ production need to be
ethical?
What do we actually mean
What is Fair trade? Does it
e yie
ld
ab
c
in
u
a
r
v
e
(MSY)
fully shed
maximum sustainable
dleiy
by ethical food?
s
yield, or MSY (K/2)
intensively
over shed
shed
?
depleted
help farmers out of pover ty
moderately
or does it make consumers
shed
in MEDCs feel better or both?
time (t)
The
carrying
its
reproductive
●
its
longevity
●
the
indigenous
breeding
(either
new
population
Research how two
contrasting sheries
have been managed and
relate to the concept of
capacity
●
Each
To do
then
from
there
is
larger
a
net
to
/
than
This
for
population.
the
depends
new
habitat
the
number
in
If
the
on
is
ecosystem.
size
the
is
enter
the
number
leaving
population.
population
number
/
individuals
immigrants).
increase
the
species
of
year,
or
new
remain
this
same.
each
resources
season
size
for
strategy
offspring
is
initial
shing eor t or shing mor tality
If
(dying
the
population
recruited
or
difference
harvested
maximum
to
the
emigrating),
the
in
population
population
sustainable
yield
will
(MSY)
sustainability eg cod
SY
sheries in Newfoundland
total biomass at time t + 1
___
total biomass at time t
___
energy
energy
=
and Iceland. Issues that
Or
should be covered include:
SY
=
annual
growth
and
recruitment
annual
death
and
emigration
improvements to boats,
shing gear (trawler bags),
In
practice,
harvesting
the
maximum
sustainable
yield
normally
leads
to
detection of sheries via
population
decline
and
thus
loss
of
resource
base
and
an
unsustainable
satellites. Management
industry
or
shery.
There
are
several
reasons
for
this.
aspects should include:
●
use of quotas, designation
The
population
(modelled)
of Marine Protected
measured
Areas (exclusion zones),
dynamics
rather
than
of
the
the
target
species
species
numbers
are
being
normally
predicted
quantitatively
(counted).
restriction on types and size
●
It
●
Estimates
is
often
impossible
to
be
precise
about
the
of shing gear (including
mesh size of nets).
224
are
made
on
previous
experience.
size
of
a
population.
4 . 3
●
The
model
does
not
allow
for
monitoring
of
a q u a T I C
the
F O O D
dynamic
p r O D u C T I O n
nature
S y S T e m S
of
To do
the
harvest
targets
in
terms
reproductive
of
age
and
females
sex
this
ratio.
will
If
have
the
a
harvest
much
primarily
greater
impact
Research the history and
on
future
recruitment
than
the
targeting
of
mature
or
old
males.
current state of one of these
Targeting
young
immature
sh
will
also
equally
impact
on
future
sheries:
recruitment
●
Disease
So
if
poor
A
you
may
extract
safer
Sustainable
maximizes
much
/
population
Fishing
if
population
size.
●
Pacic wild salmon
●
Nor th Sea herring
●
Grand Banks sheries
●
Peruvian anchovy
●
Or any other that is near
population.
at
the
MSY,
are
are
often
quota
adopt
This
than
other
set
is
as
set
the
you
will
deplete
harvesting
usually
between
margin
there
The
to
(OSY).
safety
year.
is
difference
quotas
per
the
overall
a
population
in
years.
Yield
size
thus
harvest
approach
the
greater
and
strike
recruitment
much
eet
rates
a
total
MSY
requires
less
and
but
still
percentage
a
an
revenue
may
environmental
as
of
weight
or
of
Optimal
effort
total
have
than
cost.
an
pressures
not
has
impact
within
proportion
catch
MSY
It
of
a
the
number
and
a
to where you live.
on
system.
OSY
of
per
sh.
ex-stl stios
The Inuit are indigenous aboriginal people of Nor thern Canada. The data below
come from a study of a Inuit sh farming community. The Inuit sh in the open
sea but have also sectioned o a large fjord (a long narrow inlet of the sea) which
they use for farming salmon and shrimps. The shrimps eat microscopic plants in
the sea called phytoplankton. Salmon and kawai (a wild sh) both eat shrimps.
Figure
1
2
all its i kJ 
Insolation on fjord
Insolation on open sea
Farmed shrimp consumed by Inuit
Gross primary production by phytoplankton
185,000.0
1,972,000.0
26.0
3,470.0
Shrimp consumed by kawai
847.0
Respiratory loss by kawai (open sea)
572.0
Shrimp consumed by salmon (farmed)
461.0
Respiratory loss by salmon
410.0
Kawai consumed by Inuit
6.2
Salmon consumed by Inuit
4.3
Energy used in managing salmon farm
4.1
Energy used in shing for kawai
6.7
Energy used in managing shrimp farm
Energy used in other human activities including
1

14.0
12.5
trading furs
225
4
W at e r ,
f o o d
Practical
Discuss
case
Work
with
study
harvesting
Discuss
a
p r o d u c t i o n
(a)
reference
the
of
a
case
demonstrates
s ys t e m s
to
Use
a n d
the
s o c i e t y
data
in
gure
1
to
complete
study
the
diagram
below.
[6]
a
Sun
controversial
named
the
species.
that
impact
of
aquaculture.
Investigate
selected
Evaluate
can
be
shing
rates
in
countries.
strategies
used
to
unsustainable
that
avoid
shing.
847
farmed shrimp
26
shing for kawai 6.7
(b)
(i)
Dene
what
productivity
(ii)
State
how
rates
(c)
Using
or
the
of
the
kawai
by
the
term
gross
primary
[1]
differs
from
net
primary
(NPP).
factors
gross
data
is
meant
GPP
productivity
(iii)Identify
is
(GPP).
in
more
[1]
other
primary
gure
than
insolation
which
affect
productivity.
1,
efcient
determine
at
[2]
whether
converting
food
salmon
into
biomass.
[3]
(d)
Compare
(e)
Calculations
systems
that
food
to
(f)
the
efciency
of
with
terrestrial
food
farming
source
farm
for
ways
might
production
226
and
on
the
eating
the
production
production
data
in
shrimp
Inuit.
food
is
Suggest
gure
the
systems.
1
would
most
why
the
[3]
suggest
energy
Inuit
efcient
continue
salmon.
Suggest
system
based
aquatic
in
[1]
which
differ
system.
this
from
a
indigenous
large-scale
food
production
commercial
food
[3]
4 . 4
w a T e r
p O L L u T I O n
4.4 wt olltio
sg :
al  kll:
➔
Water pollution, both groundwater and surface
➔
als water pollution data.
➔
exli the process and impacts of
water, is a major global problem the eects of
which inuence human and other biological
eutrophication.
systems.
evlt the uses of indicator species and
➔
biotic indices in measuring aquatic pollution.
evlt pollution management strategies with
➔
respect to water pollution.
Kwlg  g:
➔
There are a variety of freshwater and marine
➔
olltio socs
➔
by assaying the impact on species within
the community according to their tolerance,
Types of tic olltts include organic
diversity and relative abundance.
material, inorganic plant nutrients (nitrates
and phosphates), toxic metals, synthetic
➔
➔
etohictio can occur when lakes, estuaries
compounds, suspended solids, hot water, oil,
and coastal waters receive inputs of nutrients
radioactive pollution, pathogens, light, noise and
(nitrates and phosphates) which result in an
biological (invasive species).
excess growth of plants and phytoplankton.
A wide range of parameters can be used to
➔
Dd zos in both oceans and freshwater
directly test the quality of aquatic systems,
can occur when there is not enough oxygen to
including pH, temperature, suspended solids
suppor t marine life.
(turbidity), metals, nitrates and phosphates.
➔
A biotic idx indirectly measures pollution
Biodgdtio of ogic til utilizes
➔
Application of gure 1.5.6 to water pollution
management strategies includes:
oxygen which can lead to anoxic conditions
●
and subsequent anaerobic decomposition
reducing human activities producing
pollutants (eg alternatives to current
which leads to formation of methane, hydrogen
fer tilizers and detergents);
sulphide and ammonia (toxic gases).
●
➔
Biochicl ox g dd (BOD) is a
reducing release of pollution into the
environment (eg treatment of wastewater to
measure of the amount of dissolved oxygen
remove nitrates and phosphates);
required to break down the organic material in a
●
removing pollutants from the environment
given volume of water through aerobic biological
and restoring ecosystems (eg removal of
activity. BOD is used to indirectly measure the
mud from eutrophic lakes and reintroduction
amount of organic matter within a sample.
of plant and sh species).
➔
Some species can be indicative of polluted
waters and be used as idicto scis
227
4
W at e r ,
f o o d
p r o d u c t i o n
s ys t e m s
Water
a n d
pollution
s o c i e t y
kills
over
14,000
people
per
day
(nearly
10
people
every
K t
minute)
wt olltio is the
Nearly
through
half
a
waterborne
billion
people
disease
do
not
and
have
poisoning.
access
to
clean,
safe
drinking
water.
contamination of bodies of
Water
pollution
affects
MEDCS
as
well
as
LEDCs.
water by pollutants either
directly or indirectly.
t  w ll
Both
sea
and
Pollutants
1.
freshwater
can
2.
point
3.
organic
4.
direct
or
(created
algal
source
or
become
polluted.
be:
anthropogenic
eruptions,
can
or
by
human
activities)
or
natural
(eg
volcanic
blooms)
non-point
source
(1.5)
inorganic
indirect.
T
polltt
exl
ects
Organic
Sewage
Human waste
Eutrophication (p233)
Animal waste
Manure
Biological detergents
Washing powders
Food processing waste
Fats and grease
Pesticides from agriculture
Insecticides, herbicides
Chemicals from industry
PCBs, drugs, hormones
Smell
Loss of biodiversity
May be carcinogenic, growth-promoting
hormones
Inorganic
Pathogens
Waterborne and fecal pathogens
Disease
Invasive species
Cane toads
Decimates indigenous species
Nitrates and phosphates
Fer tilizers
Eutrophication, changes biodiversity
Phosphates
Washing detergents
Heavy toxic metals
Industry and motor vehicles
Bioaccumulation and biomagnication in
food chains, poisonous
Hot water (thermal
Power stations
pollution)
Oil
Changes physical proper ty of water, kills
sh, changes biodiversity
Industry
Floats on surface, contaminates
seabirds, reduces oxygen levels
Radioactive materials
Nuclear power stations
Radiation sickness
Light
Cities, hotels on beaches
Disrupt tur tle nesting sites
Noise
Aircraft
Upset whale navigation, change plant
growth, upset bird cycles
Both
Suspended solids
Silt from construction sites
Solid domestic waste
Household garbage
Damage corals and lter feeders
Plastics are especially bad – suocate,
cause starvation (Great Pacic Garbage
Debris
Trash, shipwrecks
Patch)
228
4 . 4
Sources
of
freshwater
pollution
w a T e r
p O L L u T I O n
include:
TOK
1.
Agricultural
run-off,
sewage,
industrial
discharge
and
solid
domestic
waste.
A wide range of parameters
Sources
of
marine
pollution
include:
are used to test the quality
2.
Rivers,
pipelines,
operational
and
the
atmosphere
accidental
and
human
activities
at
sea,
both
discharges.
of water and judgements
are made about cause
and eect. How can we
mg w ll
know cause and eect
relationships, given that
Water
pollution
can
be
measured
directly
or
indirectly
by
sampling.
we can only ever observe
See
sub-topic
2.5
for
this.
correlation?
1. Biochemical oxygen demand
K t
Biochicl ox g dd (BOD) is a measure of the amount of dissolved
oxygen required to break down the organic material in a given volume of water
through aerobic biological activity by microorganisms.
2. Biotic indices and indicator species
K ts
Idicto scis are plants and animals that show something about the
environment by their presence, absence, abundance or scarcity.
A biotic idx indirectly measures pollution by assaying the impact on species
within the community according to their tolerance, diversity and relative abundance.
Indicator
warning
example,
they
are
species
signs
canaries
more
monoxide,
die
and
are
that
so
the
were
sensitive
methane).
warn
most
something
the
If
once
than
were
time
to
change
changed
down
humans
in
to
have
taken
gases
miners
sensitive
may
coal
in
them
they
an
mines
poisonous
present
for
so
in
the
to
are
the
early
ecosystem.
in
Britain
gases
mine
For
because
(carbon
the
bird
would
escape.
To do
Four factories discharge euent containing organic matter
1.
into rivers. The table shows the volume of discharge into
Explain whether these pollution data are for point
sources or non-point sources.
the river and the resulting biological oxygen demand.
2.
Which pollution source, point source or non-point
source, is easier to regulate?
Fcto
Vol of t/
1
BOD/g l
1
Explain your choice.
10 0 0 l d
3.
A
14.0
Which factory is adding most to the BOD of the river
27
into which it discharges?
B
1.0
53
C
3.0
124
4.
If factory C discharges water at a temperature of
50 °C, give three possible eects on the organisms
D
0.8
33
in the river.
229
4
W at e r ,
f o o d
p r o d u c t i o n
A
s ys t e m s
B
a n d
s o c i e t y
C
D
E
1
1
1
1
1
2
2
4
2
3
2
3
4
3
4
3
2
4
5
5
3
5
A
5
B
C
6
D
E
organic discharge
Fig 4.4.1 Inver tebrates found in fresh water
A
biotic
index
ecosystem
mayy nymph
stoney nymph
by
Figure
4.4.1
and
at
various
The
pollutants
is
above
4.4.2
and
sensitive
(1–10)
some
points
are
a
gives
measure
of
the
invertebrates
point
directly
a
abundance
typical
below
not
that
and
source
measured
of
that
their
quality
living
might
sewage
but
the
species
be
outfall
effect
on
in
of
an
it.
found
above
pipe.
biodiversity
(left)
at
to
shows
various
are
some
points
used
decreases
to
in
typical
below
estimate
oxygen
a
invertebrates
point
levels
source
of
that
pollution,
concentration
in
might
sewage
as
they
water,
be
found
outfallpipe.
are
caused
by
freshwater shrimp
the
action
presence
oxygen
of
of
of
is
time
aerobic
certain
used
pollution
Biotic
sample
BOD.
is
calculate
a
as
they
species
biotic
decompose
that
can
index,
a
organic
tolerate
matter.
various
The
levels
semi-quantitative
of
estimate
levels.
indices
as
to
bacteria
indicator
based
BOD
collected
on
indicator
gives
a
species
measure
whereas
of
indicator
are
usually
pollution
species
at
give
used
the
a
at
the
instant
summary
same
a
water
of
bloodworm
water louse
recent
A
history.
diversity
Simpson’s
and
rat-tailed maggot
no life
Fig 4.4.2
index
can
diversity
polluted
also
compare
index).
What
two
bodies
values
might
of
water
you
(see
expect
2.5
for
for
clean
water?
eh
Eutrophication
ecosystem.
230
scale
presence
shows
Invertebrates
sludgeworm
a
measured.
Figure
caddisy lar va
is
the
is
more
It
is
can
common.
when
be
a
excess
natural
nutrients
process
are
but
added
to
an
anthropogenic
aquatic
eutrophication
4 . 4
When
it
is
severe,
it
results
in
dead
zones
in
oceans
or
w a T e r
p O L L u T I O n
freshwater
To do
where
there
is
not
biodegradation
enough
of
oxygen
organic
to
support
material
uses
life.
up
In
less
oxygen
severe
which
cases,
can
lead
evlt the uses of indicator
to
anoxic
(low
oxygen)
conditions
and
then
anaerobic
decomposition.
species and biotic indices in
This
can
release
methane,
hydrogen
sulphide
and
ammonia
which
are
measuring aquatic pollution.
all
toxic
gases.
Impacts of eutrophication
K t
Anthropogenic
covered
by
eutrophication
green
algal
scum
leads
and
to
unsightly
duckweed.
rivers,
They
also
ponds
give
off
and
lakes
foul-smelling
etohictio can occur
gases
like
hydrogen
sulphide
(rotten
egg
smell).
Other
changes
include:
when lakes, estuaries and
coastal waters receive
●
oxygen-decient
●
loss
●
death
of
higher
●
death
of
aerobic
●
increased
(anaerobic)
water
inputs of nutrients (nitrates
of
biodiversity
and
shortened
food
chains
and phosphates) which
plants
(owering
plants,
reeds,
result in an excess growth of
etc.)
plants and phytoplankton.
The
excess
organisms
turbidity
nutrients
●
detergents
●
fertilizers
●
drainage
●
sewage
●
increased
from
–
invertebrates,
(cloudiness)
are
nitrates
intensive
of
and
sh
amphibians
water.
phosphates
livestock
and
rearing
and
they
come
from:
units
To do
erosion
of
topsoil
into
the
water.
Draw an annotated systems
These
sources
may
be
point
sources,
for
example
wastewater
from
cities
diagram to illustrate
and
industry
and
run-off
or
animal
feedlots,
overows
from
storm
drains
or
sewers,
eutrophication. Indicate
from
construction
sites.
Harder
to
identify
are
the
sources
of
on your ow diagram an
pollution
from
non-point
sources.
These
may
be
run-off
from
crops
and
instance of positive feedback.
grassland,
landll
urban
sites
or
run-off,
old
leaching
from
septic
tanks
or
leaching
from
mines.
The process of eutrophication
1.
Fertilizers
2.
High
(as
3.
levels
of
Algal
blooms
More
that
more
5.
Algae
6.
But
is
algae
food
die
river
so
and
there
are
lake.
particular
allow
algae
to
grow
faster
of
algae)
that
block
out
light
to
plants
die.
more
them.
in
or
limiting).
(mats
which
mean
on
the
often
form
them,
feed
into
phosphate
phosphate
beneath
4.
wash
food
They
are
are
then
for
the
food
to
fewer
decomposed
by
zooplankton
sh
which
zooplankton
aerobic
and
small
multiply
to
eat
as
the
animals
there
is
algae.
bacteria.
Fig 4.4.3 Algal bloom in a
dies
there
as
is
food
not
enough
chains
oxygen
collapse.
in
the
water
so,
soon,
everything
village river in the mountains near
Chengdu, Sichuan, China
231
4
W at e r ,
f o o d
p r o d u c t i o n
s ys t e m s
7.
Oxygen
on
8.
the
a n d
levels
lake
Eventually,
blue
s o c i e t y
fall
or
lower.
river
all
life
bed
is
Dead
and
gone
organic
turbidity
and
the
material
forms
sediments
increases.
sediment
settles
to
leave
a
clear
lake.
Fig 4.4.4 Dead sh resulting from toxins or oxygen depletion in Lake Binder, Iowa.
Photo credit: Dr. Jennifer L. Graham, U.S. Geological Survey
Fig 4.4.5 A red tide in the Gulf of
Mexico
The
by
Gulf
of
excess
Mexico
nitrates
has
and
agriculture.
One
trading
voluntary
the
and
as
most
on
those
a
that
can
higher-cost
could
It
is
a
reduce
allow
sources
of
to
to
nutrients
of
at
could
and
low
a
to
their
new
who
USA
of
of
in
scheme
credits
pollution
revenue
implement
use.
both
It
nds
industry
which
to
trading,
basin
nutrient
nutrient
use
sell
caused
River
strategy
Nutrient
meet
the
trading
cost
create
others
is
nutrient
quality
to
in
Mississippi
reduction
options.
pollution
and
zone
the
this
reduce
water
reduction
manner
dead
from
proposed
ways
entrepreneurs,
reduction
largest
market-based
type
nutrient
cost-effective
farmers,
solution
cost-effective
farms.
the
phosphates
allows
those
facing
therefore,
targets
in
a
opportunities
low-cost
for
pollution
practices.
Red tides
In
coastal
waters,
sometimes
species
as
the
caused
can
lakes
water,
produce
make
or
damaging
Fig 4.4.6 Eutrophication in the Caspian
Sea (lighter areas of algal bloom)
232
excess
slow
toxins
moving
which
be
numbers
nutrients.
bloom
which
water
to
these
red.
sh
of
phytoplankton)
phytoplankton
This
and
can
be
are
are
a
dangerous
accumulate
in
shellsh,
ill.
bodies,
a
If
looks
kill
severely
leads
can
(large
seriously
which
eutrophication
water.
the
humans
changes,
downstream
clean
by
blooms
dinoagellate,
algae
which
In
of
algal
eutrophication
reduces
temporary
followed
by
a
leads
biodiversity.
reduction
recovery
in
and
In
to
a
fast
series
of
moving
biodiversity
restoration
of
4 . 4
w a T e r
p O L L u T I O n
Eutrophication management strategies
Sttg fo dcig olltio
exl of ctio
Altering the human activity
1.
producing pollution
Ban or limit detergents with phosphates (it is there to improve the performance
of the detergent in hard water areas).
2.
3.
Use ecodetergents with no phosphates or new technology in washing machines.
Plant buer zones between the elds and water courses to absorb the excess
nutrients.
Regulating and reducing the
4.
Stop leaching of slurry (animal waste) or sewage from their sources.
5.
Educate farmers about more eective timing for fer tilizer application.
Treat wastewater before release to remove phosphates and nitrates.
pollutants at the point of
Diver t or treat sewage waste eectively.
emission
Minimize fer tilizer dosage on agricultural lands or use organic matter instead.
Clean up and restoration
Pumping air through the lakes.
Dredging sediments with high nutrient levels from the river and lake beds.
Remove excess weeds physically or by herbicides and algicides.
Restock ponds or water bodies with appropriate organisms.
Fig 4.4.7 Table of replace, regulate and restore models of pollution management for eutrophication
To do
Practical
Countries
1.
Work
with
limited
access
Copy the table of strategies and actions on eutrophication and add a third
to
clean
water
often
have
column, entitled Evaluation. Complete this column.
higher
2.
incidences
of
water-
Eutrophication can occur by point source river pollution due to nutrient
borne
illnesses.
R esearch
input from an outfall pipe discharging sewage.
one
3.
Copy the axes in gure 4.4.8 and draw curves to show changes in detritus
example
solutions
of
this
b eing
and
the
adopted.
(sewage), turbidity (suspended solids), bacterial growth, BOD, oxygen
With
respect
to
measuring
concentration, inver tebrate and sh biodiversity, clean water species.
aquatic
pollution,
compare
a
Make a key to your curves.
polluted
4.
Complete another copy of gure 4.4.8 to show the eects of high nutrient
levels, eg from over-fer tilized elds, being washed into a stream. Draw
curves to show changes in nutrients (nitrate and phosphate), algal growth
site
(eg
and
an
unpolluted
upstream
downstream
of
a
and
point
source).
(bloom), detritus increase (due to higher plant death), bacterial growth,
Evaluate
the
uses
of
indicator
BOD, oxygen concentration, inver tebrate biodiversity, clean water species.
species
5.
Make a key to your curves.
and
measuring
Analyse
from
a
aquatic
water
intensive
the
indices
data
source.
impact
agriculture
aquatic
in
pollution.
pollution
secondary
Investigate
local
biotic
of
on
a
ecosystem.
distance downstream
outfall
Fig 4.4.8
233
4
W at e r ,
f o o d
p r o d u c t i o n
s ys t e m s
a n d
s o c i e t y
W E I VE R
Discuss the possible sustainable
Comment on how global sheries
solutions to our freshwater
can be sustainably managed.
crisis.
BiG Questions
W,  
  
To what ex tent are our solutions
Evaluate the hydrological cycle
to ocean pollution mostly aimed
as a model.
at prevention, limitation or
restoration?
rv q
➔
The hydrological cycle is represented as a systems
model.
➔
To what extent can systems diagrams
Some rivers ow through more than one country.
How might this lead to international disputes?
eectively model reality, given that they are only
➔
Dierent countries have dierent access to
based on limited observable features?
freshwater how can this cause conict between
➔
countries?
Aid agencies often use emotive adver tisements
around the water security issue. To what extent
➔
Countries with limited access to clean water
can emotion be used to manipulate knowledge
often have higher incidences of waterborne
and actions?
illnesses. Explain why this is the case and
➔
➔
234
Inuit people have an historical tradition of
discuss whether responsibility for reducing
whaling. To what extent does our culture
these lies with the country or the international
determine or shape our ethical judgements?
community.
A wide range of parameters are used to test the
➔
Fish and many other species do not respect
quality of water and judgements are made about
natural boundaries and for successful
cause and eect. How can we know cause and
management of marine and some freshwater
eect relationships, given that we can only ever
sheries par tnership between dierent nations
obser ve correlation?
is required. How can this work? Who decides?
Assuming
qick vi
level
All
questions
are
worth
1
The
amount
of
hydrosphere
A.
3%.
B.
6%.
C.
10%.
D.
20%.
water
as
present
freshwater
is
in
outputs,
percentage
by
oceans
A.
90%.
B.
is
of
A.
P
+
B.
I
C.
(S
D.
I
+
the
Earth’s
I
what
E
surface
P
+
+
Which
a
there
rise
are
a
fall
other
in
the
inputs
is
the
value
of
R?
S
+
E)
P
+
row
in
E
×
+
(I
E
S
+
P)
S
correctly
order
of
shows
the
decreasing
storages
of
the
size?
L arGeST
SmaLLeST
Oceans
A.
Ground
Glaciers
Lakes,
water
and ice
rivers and
caps
atmosphere
Groundwater
70%.
C.
50%.
D.
45%.
Which
of
the
proportion
Oceans
following
of
the
contains
world’s
the
Lakes,
Glaciers
rivers and
and ice
atmosphere
caps
greatest
freshwater?
Lakes,
C.
Oceans
Ground
Glaciers and
water
ice caps
Glaciers
Ground
Lakes,
and ice
water
rivers and
rivers and
A.
nor
no
covered
about
B.
3.
neither
and
approximately
water
The
is
lake,
the
6.
2.
there
the
mark
or
1.
of
W E I VE R
R E V I E W
Organisms
atmosphere
B.
The
C.
Ice
atmosphere
Oceans
D.
caps
and
glaciers
caps
D.
4.
Streams,
Which
to
an
of
rivers
the
overall
and
following
increase
atmosphere
lakes
is
in
most
the
likely
Earth’s
to
lead
7.
Which
of
the
following
statements
is
correct?
freshwater
A.
Less
than
0.1
%
(by
volume)
of
the
Earth’s
storages?
water
A.
Removal
B.
Melting
C.
Increase
of
oceans
over
polar
in
ice
increase
rates
in
from
C.
the
5.
Discovery
The
diagram
outputs
of
hydrological
The
is
precipitation
in
cycle
is
independent
of
energy.
main
ice
reservoir
caps
and
of
the
Earth’s
freshwater
glaciers.
continents
D.
D.
The
solar
caps
evaporation
causing
the
freshwater.
forests
B.
of
is
of
new
below
water
underground
represents
from
a
lake
the
over
aquifers
inputs
a
Only
abiotic
hydrological
storages
are
involved
in
the
cycle.
and
period
of
time.
P = precipitation (rain, snow)
falling on the surface of the lake
I = inow from
lake
E = evaporation from the
surface of the lake
R = run-o in a stream
streams
owing out of the lake
S = loss by downward movement into the rocks
235
5
Soil SyStemS and S o c i e t y
5.1 Itoctio to oi te
Sg s:
apps  sks:
➔
The soil system is a dynamic ecosystem that
➔
Otie the transfers, transformations, inputs,
has inputs, outputs, storages and ows.
outputs, ows and storages within soil systems.
➔
The quality of soil inuences the primary
➔
Expi how soil can be viewed as an ecosystem.
➔
Cope and cott the structure and
productivity of an area.
proper ties of sand, clay and loam soils, with
reference to a soil texture diagram, including
their eect on primary productivity.
Kwg  ursg:
➔
The soil system may be illustrated by a oi
➔
poe that has a layered structure (horizons).
➔
Soil system toge include organic matter,
weathering and nutrient cycling.
➔
organisms, nutrients, minerals, air and water.
➔
Tfotio include decomposition,
The structure and proper ties of , c
and o oi dier in many ways, including:
mineral and nutrient content, drainage, water-
Tfe of material within the soil including
holding capacity, air spaces, biota and potential
biological mixing, leaching (minerals dissolved
to hold organic matter. Each of these variables
in water moved through soil) contribute to the
is linked to the ability of the soil to promote
organization of the soil.
primary productivity.
➔
There are ipt of organic material including
leaf litter and inorganic matter from parent
material, precipitation and energy. Otpt
include uptake by plants and soil erosion.
236
➔
A oi tex te tige illustrates the dierences
in composition of soils.
5 . 1
I n T r O d u C T I O n
T O
s O I l
s y s T E m s
‘ Too many people have
Wh s s?
lost sight of the fact that
Soil
is
gases
a
complex
and
liquids
ecosystem.
which
It
forms
is
made
the
up
habitat
of
minerals,
for
many
organic
animals
material,
and
plants.
productive soil is essential
to the production of food.’
We
tend
mud
or
to
take
the
●
Plants
grow
soil
animals
the
or
Soil
is
below
As
food
a
as
●
it,
in
soil
and
that
for
as
and
granted,
transfer
but
it
is
more
than
just
of
mentioned
atmosphere,
the
the
both
four
also
the
pedosphere
and
lithosphere
and
hydrosphere
and
(soil
is
and
the
(In
than
that
lter
fact
the
upon
grow
chemistry
any
of
affecting
lithosphere
in
some
above
nutrients
for
soil.
directly
in
that
water
that
the
plants
that
life
the
biomass.)
depend
passes
water.
between
where
ecosystems
ground
atmospheric
interactions
take
temperature
soil
and
processes
and
soil
place.
of
the
Earth
lithosphere
sphere).
acted
the
plants
mineral
so
the
spheres
hydrosphere,
eat
ultimately
plants.
organisms.
heat
affect
part
the
processes
either
greater
altering
can
depends
enormous
Soils
are
is
water
moisture.
We
for
eaten
many
an
often
we
have
biomass
act
turn
consume
atmospheric
forming
the
we
holding
soils
store
which
in
habitat
through
Soils
that
ground
well
upon,
●
us
H H Bennett, 1943
All
●
around
dirt.
●
●
soil
This
upon
and
and
is
a
in
sub-topic
biosphere.
thin
bridge
inuenced
by
1.2:
the
However
between
the
there
is
biosphere
atmosphere,
lithosphere.
stoge
●
Organic matter, organisms, nutrients, minerals, air and water.
Tfe witi
●
Biological mixing, translocation (movement of soil par ticles
in suspension) and leaching (minerals dissolved in water
te oi
moved through soil).
●
Ipt
Organic material including leaf litter and inorganic matter
from parent material, precipitation and energy.
Otpt
●
Uptake by plants and soil erosion.
Tfotio
●
Decomposition, weathering and nutrient cycling.
▲ Fige 5.1.1 The components of the soil system
What is soil made from?
Soils
are
made
up
of
●
Mineral
particles
●
Organic
remains
●
Water
●
Air
four
main
mainly
that
components:
from
have
the
come
underlying
from
the
To o
rock.
plants
and
animals.
Make a systems diagram
within
spaces
between
soil
showing the relation
grains.
between soil, the biosphere,
also
within
the
soil
grains.
hydrosphere and
It
is
also
typically
contain
a
habitat
with
a
for
plants
50:50
variable
mix
amounts
and
of
of
animals.
solids
water
and
and
Soil
pore
is
a
highly
spaces.
The
porous
pore
medium
spaces
atmosphere. Add ows and
storages to your diagram.
air.
237
5
S o i l
S yS t e m S
a n d
S o c i e t y
It
0
1
is
the
exact
mix
of
these
four
portions
that
give
a
soil
its
character
2 mm
plant
but
it
is
not
just
these
that
make
a
soil
what
it
is.
The
soils
within
any
root
environment
Climate,
on
and
are
parent
within
the
rock
it
result
of
a
material,
and
time
all
mix
the
of
complex
shape
contribute
of
to
the
and
soil
forming
land,
the
affect
the
processes.
organisms
nished
living
soil.
passages for
air and water
par t of a worm
Fctio
Cotitet
Fctio
Rock
Insoluble – eg
par ticles
gravel, sand, silt,
●
provides the skeleton of the soil
●
derived from the underlying rock or
clay and chalk .
from rock par ticles transpor ted to the
sand
Soluble – eg mineral
environment, eg glacial till.
par ticle
salts, compounds of
nitrogen, phosphorus,
soil animals
potassium, sulphur,
magnesium etc.
▲
Fige 5.1.2 Cross-section of soil
Humus
Plant and animal
matter in the process
●
gives the soil a dark colour.
●
as it breaks down, it returns mineral
of decomposition.
nutrients back to the soil.
●
absorbs and holds on to a large amount
of water.
Water
●
Water either
dissolved mineral salts move through the
soil and so become available to plants.
seeping down from
precipitation or
●
moving up from
rapid downward movement of water
causes leaching of minerals.
underground sources
●
rapid upward movement can cause
by capillary action.
salinisation
●
large volumes of water in the soil can
cause waterlogging leading to anoxic
conditions and acidication.
Air
●
Mainly oxygen and
Well-aerated soils provide oxygen for
the respiration of soil organisms and
nitrogen.
plant roots.
●
Soil
Soil inver tebrates,
organisms
microorganisms and
large par ticles of dead organic matter are
broken down by soil inver tebrates like
worms = smaller par ticles.
large animals.
●
smaller par ticles are decomposed by
soil microorganisms thus recycling
mineral nutrients.
●
larger burrowing soil animals (eg moles)
help to mix and aerate the soil.
▲
Fige 5.1.3 Table of constituents of soil
TOK
What does a soil look like?
The soil system may be
represented by a soil prole.
Since a model is strictly
speaking not real, how can it
lead to knowledge?
If
you
dig
trench
a
surface
towards
that
have
chemical
238
a
prole,
in
the
cross-section.
the
created
and
ground,
This
underlying
the
soil,
physical
the
prole
its
side
of
changes
base
rock.
mineral
characteristics
the
as
It
is
it
a
trench
goes
record
composition,
such
as
pH
creates
down
of
the
organic
and
a
from
soil
the
processes
content,
moisture.
and
5 . 1
I n T r O d u C T I O n
T O
s O I l
s y s T E m s
Horizons
In
cross-section
organic
move
upwards.
(zones/levels)
The
top
lower
is
layer
layers
derived
sorted
or
soils
material
down
–
These
that
of
the
the
layers
soil
is
so,
it
and
dissolves
minerals
in
water
are
formed
irrigation
water
them
ows
and
from
and
down
called
in
downwards.
in
rocks.
In
soil,
is
O
is
to
this,
as
materials
horizons
dry
colder
minerals
when
either
and
the
doing
the
also
wetter
and
soil
When
where
This
are
up
where
at
upwards.
surface,
the
material
climates,
evaporating
the
whilst
materials
particles
evaporates.
In
dissolving
material
inorganic
moves
water
leaching
The
hot,
them
time
distinctive
Within
water
the
into
over
mineral
soil.
carrying
layers
takes
and
organic
salinization .
the
This
modied
soil
the
water
soil
when
is
material.
(P <E),
lower
behind
is
rich
of
by
the
in
translocation.
minerals
left
sort
often
weathering
as
which
downwards
visible
inorganic
Precipitation <Evaporation
surface
prole
often
of
are
known
a
(washes)
processes
are
consist
from
and
have
leaches
happens
climates,
transporting
P>E.
leaf litter
mineral horizon at the surface showing organic
A
matter enrichment
subsurface horizon showing depletion of organic
E
matter, clay, iron, and aluminium compounds
subsoil horizon showing enrichment of clay material,
B
iron, aluminium, or organic compounds
▲
O
Horizon:
the
will
A
soil.
start
to
and
often
Upper
hard bedrock
soluble
reduces
the
organic
peat
and
rapidly
number
dead
In
ne
of
through
are
of
and
soil
soils,
partially
mineral
In
of
die
different
newly
and
kinds
this
is
brown
added
end
of
up
on
top
animals
or
black
up
organisms,
eventually
by
which
lead
to
material
organic
web
roots.
results
the
matter
decomposition
organic
food
plant
humus
organic
Often
conditions,
decomposer
taken
where
decomposed
particles.
normal
the
then
can
many
layer
that
material.
dark
layer .
uppermost
organisms
and
many
from
layer
that
matter
the
with
a
an
from
bacteria
layer.
humus
minerals
contain
comes
forms
mixed
the
decomposes
of
R
fungi,
Humus
incomplete
–
soils
this
decompose
up.
formed
–
There,
Horizon:
is
Many
material
builds
is
horizons of loosened or unconsolidated material
Fige 5.1.4 A soil prole
organic
of
C
in
is
matter
releasing
Waterlogging
a
build-up
formation
of
soils.
239
5
S o i l
S yS t e m S
a n d
S o c i e t y
B
Horizon:
tends
salts
C
R
to
be
can
be
Horizon:
all
This
soils
horizons
distinct
is
the
layer
Parent
be
in
is
all
where
the
this
In
weathered
(bedrock
three
some
above.
minerals
In
and
particular
organic
clay
matter
and
iron
horizon.
A,
distinguished
layering.
soluble
layer
mainly
material
contain
can
layer
from
deposited
horizon:
Not
C
This
deposited
B
and
while
cases
or
we
in
rock
other
C
from
cannot
soils
dig
the
soil
forms.
medium).
horizons;
other
which
sometimes
there
deep
may
enough
only
not
to
two
be
nd
the
layer.
precipitation
energy
organic material
inltration
leaching
uptake
decomposition
soil
weathering and
nutrient cycling
soil movement
parent material
▲
Fige 5.1.5 The soil system
Soil structure
The
on
mineral
size:
soil
portion
sand,
particles
proportions
silt
and
of
< 0.002 mm
soil
clay.
soil
silt
can
be
Most
divided
soils
texture
and
clay
therefore
particles.
Clay
Silt
0.05–2 mm
Sand
up
consist
P tice
0.002–0.05 mm
▲
240
the
sand,
P tice iete
of
and
Fige 5.1.6 Sandy, clay and loam soil types
into
of
a
three
particles
mixture
depends
on
of
the
based
these
relative
5 . 1
I n T r O d u C T I O n
T O
s O I l
s y s T E m s
100
0
1
90
0
2
80
0
3
70
clay
0
4
60
0
5
silty
50
0
6
clay
sandy
40
clay
silty clay
loam
0
7
clay
loam
sandy clay
30
0
loam
8
20
loam
0
9
sandy loam
silt loam
10
1
0
2
0
3
0
4
0
5
0
6
0
7
0
0
8
sand
9
0
1
0
0
sand
0
0
1
silt
loamy
percent sand
▲
Fige 5.1.7 A soil texture triangle
The
proportion
also
contain
stones),
It
is
of
each
particles
but
these
possible
to
are
feel
of
these
that
not
the
are
particles
larger
considered
texture
of
gives
than
in
moist
2
a
soil
mm
its
in
texture.
diameter
description
soil
if
you
of
rub
soil
it
Most
soils
(pebbles
and
texture.
between
your
ngers.
●
Sandy
●
Silty
soils
better
●
Clay
Most
soils
soils
It
is
is
mesh
feel
size
–
a
then
get
soil
rst
a
like
and
apart
wet
can
mixture
clay
or
the
mm,
of
silty
soil
clearer
sample
2
fall
easily.
talcum
powder
and
hold
together
soils.
sticky
sandy
to
a
and
slippery
feel
present
out
gritty
sandy
contain
as
possible
drying
are
than
described
size
soils
is
be
different
clays.
said
picture
and
to
of
passing
then
5
rolled
mm
If
the
it
soil
a
be
up
a
a
ball
particles
fairly
equal
easily.
and
can
portion
be
of
each
loam.
soil
proportions
through
and
into
nally
a
series
0.005
of
mm
of
soil
sieves
–
particles
of
by
decreasing
separating
Practical
What
soil
into
its
portion
of
clay,
silt
and
sand
particles.
Alternatively
you
can
value
sample
of
soil
in
a
jam
jar,
ll
it
with
water,
shake
it
vigorously
then
to
settle
out.
The
heaviest
particles
will
settle
rst
(sand)
and
the
will
settle
last
play
in
can
the
you
causes
approaches
to
resolving
ner
the
particles
at
leave
and
it
systems
place
identify
a
Work
the
issues
addressed
in
soil
(clay).
conservation?
Soil
texture
is
an
important
property
of
a
soil,
as
it
determines
the
soil’s
In
fertility
and
the
primary
productivity.
This
is
exemplied
in
gure
what
ways
solutions
Loam
soils
are
ideal
for
systems
agriculture.
your
●
The
sand
particles
ensure
good
drainage
and
a
good
air
supply
to
The
clay
retains
water
and
supplies
nutrients
–
so
they
are
and
The
silt
they
particles
can
be
help
worked
to
hold
the
sand
and
clay
particles
the
in
societies
predictions
human
for
soil
alter
the
societies
and
state
the
fertile.
biosphere
●
explored
the
of
roots.
might
5.1.8.
together
and
some
decades
from
now?
easily.
241
5
S o i l
S yS t e m S
a n d
S o c i e t y
s oi
C oi
lo oi
100
15
40
Silt
15
20
Clay
70
40
Composition (%)
Sand
Mineral content
High
High
Intermediate
Potential to hold organic matter
Low
Low
Intermediate
Drainage
Very good
Poor
Good
Water-holding capacity
Low
Very high
Intermediate
Air spaces
Large
Small
Intermediate
Biota
Low
Low
High
Primary productivity
Low
Quite low
High
▲
Fige 5.1.8 Comparison of three soil types
Porosity, permeability and pH
Related
to
a
(porosity)
the
soil
lots
of
of
as
a
micropores.
ll
these
water’s
effect
with
a
the
can
a
the
Soils
and
clay
but
of
that
clay
a
total
to
a
a
to
also
space
between
liquids
ne
the
large
so
These
that
it
minerals
but
As
high
the
are
lock
to
has
soils
up
water
fewer
large
for
well.
dissolved
minerals
Strangely
the
fertility.
acidity,
soil
the
have
too
access.
low
have
made
molecules
trapping
drain
also
through
texture
space
water
sandy
roots
encourage
characteristics.
as
soils
can
plant
pore
spaces
sandy
particles
pass
particle
surface
contrast,
space.
for
clay
can
clay
permeability
In
work
in
very
low
hard
of
and
combined
means
it
rich
soils
chemical
in
adhere
clay
is
gases
particles.
smaller
of
amount
with
results
making
soil
features
on
the
which
properties
pores
be
is
at
pores
permeability
between
These
the
adhesive
low
This
spaces
around
macropores
result
ease
microscopic
lm
The
texture
the
(permeability).
many
easily
soil’s
and
which
absorbs
has
more
a
great
water
+
clay
soil
particles
water
also
tightly
reduces
potassium,
Along
ions
the
the
these
Europe
iron
ions
needle
242
where
more
ll
the
loss
acid.
in
of
death.
soil
positive
particles
other
and
positive
ammonium
important
iron
start
to
hydrogen
makes
ions
to
be
the
that
lost
nutrients,
become
ions
more
soil
can
(H
bind,
through
as
).
more
soil
This
binds
acidic.
It
allowing
leaching.
pH
available
decreases,
to
plants.
toxins.
soils
rain
in
of
and
and
This
with
these
plant
acid
the
of
up
clay
amount
are
Acidication
soil
to
aluminium
of
to
magnesium
with
of
Both
begin
has
had
caused
turn
causing
has
a
major
by
impact
industrial
meant
damage
to
more
on
forestry
pollution
available
evergreen
has
in
Northern
made
the
aluminium
forestry
and
through
5 . 1
I n T r O d u C T I O n
T O
s O I l
s y s T E m s
S susb
Fertile
soil
replaced
is
a
non-renewable
resource .
Once
it
is
lost,
it
cannot
be
quickly.
potash: for
ower head
Soil
formation
takes
a
very
long
time.
The
natural
soil
renewal
rate
or fruit
1
is
about
1
conditions
per
tonne
(wet,
y e a r.  A n d
weathering
present.
soils
soil
So
regain
yr
is
only
occurred
their
in
temperate
what
formation
renewable
ha
this
has
1
this
and
As
therefore
the
fine
actually
resource/natural
ecosystems
climate),
after
f e r t i l i t y.
and
natural
equivalent
initial
a
and
is
the
consequence,
soil
should
to
chemical
material
represents
under
be
best
0.05–0.1
and
soil
mm
physical
organisms
natural
soil
the
use
rate
often
considered
a
at
are
which
exceeds
non-
nitrate: for
leaf and
capital.
stem
Fertile
soil
has
enough
nutrients
are
there
many
can
are
be
have
nitrates,
leached
to
be
nutrients
of
replaced
soil
in
healthy
phosphates
micronutrients
out
for
or
that
and
agricultural
also
when
soils
growth.
potassium
plants
removed
plant
via
a
need.
crop
is
chemical
The
(NPK)
These
main
and
nutrients
harvested.
fertilizer,
They
phosphate:
for root
growing
system
legumes
matter
(2.1),
(eg
crop
manure,
rotation
or
through
the
application
of
organic
compost).
▲
Fige 5.1.9
To o
1.
A
yield comparison
B
cereal production per capita
10
500
NPK fer tilizer
8
400
6
300
gk
ah/t
no fer tilizer
4
200
2
100
0
1950
▲
0
1960
1970
1980
1990
2000
1950
1960
1970
1980
1990
2000
Doublecropping results in a trial at
World cereal production is unable to
the IRRI research farm, Philippines.
keep up with population growth.
Fige 5.1.10 Signs of fatigue of soils
Source: V Smil, Feeding the world, 1998
Graph A in gure 5.1.10 shows the harvest from one eld of a crop in the
Philippines over 25 years. With or without fer tilizer, yields fall over this
time. Graph B shows that the annual yield of cereal crops per capita is not
increasing. Explain what these graphs tell us about:
a)
carrying capacity
b)
sustainability.
243
5
S o i l
S yS t e m S
a n d
S o c i e t y
2.
Study the table below.
nPP ccot
nPP coe
Pg/
consumed by
0.8
nPP oite
croplands
Pg/
nPP ot
15.0
deforestation
humans
consumed
Pg/
10.0
for crops
2.2
conver ted
10.0
deser tication
4.3
occupation
2.6
pastures
by domestic
animals
wood used by
2.4
humans
tree plantations
2.6
occupied lands
0.4
res, forage,
3.0
human
wood
Total (4%)
5.2
land clearing
10.0
Total (31%)
41.0
Total (13%)
16.9
One estimate of total Net Primary Production (NPP) of the whole world is
132 Pg/yr. Column 1 gives actual consumption. Column 2 gives the productivity
of agricultural systems, and column 3 annual losses to nobody’s benet, but
deforestation in column 3 produces land for column 2.
Total NPP sequestered by humans is 58 Pg/yr or 39% of total NPP
.
Sources: Olson J S et al, Carbon in live vegetation of major world ecosystems. 1983.
Oak Ridge Nat Lab. Vitousek P M et al: Human appropriation of the products of
photosynthesis. 1986. Bioscience 36: 368–373.
15
▲
Fige 5.1.11 Data on NPP of the world. (1 Pg (petagram) = 10
g)
Note that the terrestrial NPP of 132 Pg carbon/year quoted above diers from
most sources which estimate world NPP at 50 Pg carbon per year. The diculty
in calculating NPP is that it is a turnover factor. Satellite images can look at the
green colour of chlorophyll and make an estimate of the standing crop in green
leaves, but not NPP
.
The consequences of the data:
●
For 5.2 Pg/yr in direct consumption (col 1), humans are prepared to lose
16.9 Pg/yr permanently (in col 3). The seriousness of the situation is par tly
hidden by increasing agricultural yields, while not showing the amount of
degradation of the seas.
●
Net eciency of human agricultural systems is 5.2/41 = 13%.
●
Of the 132 Pg/yr world NPP
, humans claim 58 (=
41+16.9) for themselves.
The rest is for all other species.
●
Of the remaining 80–90 Pg/yr, humans claim by deforestation a large share
of 10 Pg/yr.
How much should we leave alone as natural ecosystems for the millions of
other species?
What actions can we take to make this more sustainable?
244
5 . 2
T E r r E s T r I a l
F O O d
P r O d u C T I O n
s y s T E m s
a n d
F O O d
C h O I C E s
5.2 Teeti foo poctio te 
foo coice
Sg s:
apps  sks:
➔
The sustainability of terrestrial food production
ae tables and graphs that illustrate the
➔
systems is inuenced by socio-political,
dierences in inputs and outputs associated
economic and ecological factors.
with food production systems.
➔
Consumers have a role to play through their
Cope  cott the inputs, outputs and
➔
suppor t of dierent terrestrial food production
system characteristics for two named foo
systems.
production systems.
➔
The supply of food is inequitably available and
Ete the relative environmental impacts of
➔
land suitable for food production is unevenly
two named food production systems.
distributed, and this can lead to conict and
dic the links that exist between socio-
➔
concerns.
cultural systems and food production systems.
Ete strategies to increase sustainability in
➔
terrestrial food production systems.
Kwg  ursg:
➔
Te tibiit of teeti foo poctio
➔
te is inuenced by factors such as scale,
industrialization, mechanization, fossil fuel
Ct coice may inuence societies to
har vest food from higher trophic levels.
➔
use, seed/crop/livestock choices, water use,
Terrestrial food production systems can be
cope  cotte according to inputs,
fer tilizers, pest control, pollinators, antibiotics,
outputs, system characteristics, environmental
legislation and levels of commercial versus
impact and socio-economic factors.
subsistence food production.
➔
➔
Icee tibiit may be achieved by
Ieqitie exit i foo poctio 
●
Altering human activity to reduce meat
itibtio around the world.
consumption and increase consumption
➔
Foo wte is prevalent in both LEDCs and
of organically grown, locally produced,
MEDCs but for dierent reasons.
➔
terrestrial food products.
Socio-economic, cultural, ecological, political
●
and economic factors can be seen to inuence
assist consumers in making informed food
choice of food production systems.
➔
choices.
As the human population grows, along with
●
urbanization and degradation of soil resources
and national food corporations’ standards
capita ecee
and practices.
The yield of food per unit area from lower trophic
●
levels is greater in quantity, lower in cost and
Monitoring and control by governmental and
intergovernmental bodies – multinational
the ibiit of  for food production per
➔
Improving the accuracy of food labels to
Planting of buer zones around land suitable
for food production to absorb nutrient run-o.
may require fewer resources.
245
5
S o i l
S yS t e m S
a n d
S o c i e t y
‘Abundance does not
Ke poit
spread, famine does.’
●
There is enough food in the world but an imbalance in its distribution.
●
Terrestrial and aquatic food production systems have dierent eciencies.
●
Dierent food production systems have dierent impacts and make
Zulu proverb
‘This is a sad hoax, for
industrial man no longer eats
dierent demands on the environment.
potatoes made from solar
●
Food production is closely linked with culture, tradition and politics.
●
Our current use of soil to produce food is not sustainable.
energy; now he eats potatoes
partly made of oil’.
Howard T. Odum, an American
ecologist, referring to the common
perception that modern agriculture
has freed society from limits
imposed by nature, when in fact
it is highly dependent on non-
renewable fossil fuels (1971).
deitio
▲
●
Fige 5.2.1 Wheat and rice – two staple crops for human populations
lEdC – le ecooic
eeope cot:
Sustainability
a country with low to
many
factors
of
terrestrial
listed
in
food
gure
production
systems
is
inuenced
by
5.2.2.
moderate industrialization
and low to moderate
tps f frg sss
average GNP per capita.
Subsistence
●
farming
is
the
provision
of
food
by
farmers
for
their
own
mEdC – moe ecooic
families
or
the
local
community
–
there
is
no
surplus.
Usually
mixed
eeope cot: a
crops
are
planted
and
human
labour
is
used
a
great
deal.
There
are
highly industrialized
relatively
low
inputs
With
capital
of
energy
in
the
form
of
fossil
fuels
or
chemicals.
country with high average
low
input
and
low
levels
of
technology,
subsistence
farmers
GNP per capita.
are
●
unlikely
to
produce
much
more
than
they
need.
They
are
vulnerable
agibie: the
to
food
shortages
as
little
is
stored.
Cash
cropping
is
growing
crops
for
business of agricultural
the
market,
not
to
eat
yourself.
production including
Commercial
farming
takes
place
on
a
large,
prot-making
scale,
farming, seed supply,
maximizing
yields
per
hectare.
This
is
often
by
a
monoculture
of
one
breeding, chemicals for
crop
or
one
type
of
animal.
High
levels
of
technology,
energy
and
agriculture, machinery,
chemical
input
are
usually
used
with
corresponding
high
outputs.
food harvesting,
distribution, processing
and storage.
●
Coeci gicte
(o fig): large scale
production of crops and
Farming
farming
lower
more
may
uses
inputs
also
and
intensively
Animal
be
more
feedlots
described
land
with
a
as
corresponding
with
are
high
extensive
lower
density
outputs.
levels
of
or
of
intensive.
stocking
Intensive
input
and
or
farming
output
per
Extensive
planting
uses
unit
and
land
area.
intensive.
livestock for sale.
Pastoral
●
sbitece gicte
(o fig): farming for
self-suciency to grow
enough for a family.
246
is
not
soils
to
crops
farming
suitable
eat
and
to
fertilize
to
the
for
is
directly
animals
the
or
to
and
crops
animals.
raising
crops.
is
and
animals,
Arable
feed
a
to
usually
farming
animals.
system
improve
in
is
grass
Mixed
itself
soil
on
growing
where
structure
and
crops
farming
animal
and
on
on
has
land
both
waste
some
that
good
crops
is
used
are
fed
5 . 2
Fcto
T E r r E s T r I a l
F O O d
P r O d u C T I O n
s y s T E m s
a n d
F O O d
C h O I C E s
Wic i oe tibe?
Coeci fig: ot i mEdC
sbitece fig: ot i lEdC
Agribusiness
Commercial farming is epitomized by many of the
Subsistence agriculture tends to be
(commercial vs
practices in this column but could still function with more
more associated with this side of the
subsistence)
environmentally sound practices.
equation.
Large-scale farming tends to rely heavily on machinery,
Small-scale farming tends to be more
chemicals and extensive use of fossil fuels.
labour intensive but may still rely on
Scale of farming
chemicals to boost production.
Industrialization
Mechanization
MEDCs have many people working in industry and so they
LEDCs have limited industry so job
must be provided with food from large-scale commercial
oppor tunities are limited and people
farming.
may have to grow their own food.
Use of lots of heavy machinery can damage the soil and
Use of draft animals (donkeys, oxen) or
uses a lot of fossil fuels.
human power is less stressful on the soil
and can add manure. They are powered
by plants so no burning of fossil fuels.
Fossil fuel use
A heavy dependence on fossil fuels is using a nite
Use of manual labour or draft animals
resource which produces large amounts of pollution.
does not cause these problems.
Seed/crop/
Farming systems sometimes grow crops or keep animals
Selecting organisms that are indigenous
livestock choices
that are not indigenous to the area and this can create the
is less likely to create these problems.
need for irrigation, glass houses, impor ts of feedstus.
Water use
Some agricultural systems have very heavy water
Also requires water which can be used
demands and require large-scale irrigation solutions which
unsustainably.
diver t water from people and may cause localized water
supply problems and a drop in the water table.
Fer tilizers, pest
Growing the same crop continuously on the same land
Crop rotation, biological pest control and
control
requires chemicals to suppor t the soil and control pests.
other environmentally sound practices
These often make their way into the local ecosystems –
cause fewer problems but many
terrestrial and aquatic.
subsistence farmers use large amounts
of pesticides if they can aord them.
Antibiotics
Keeping animals in close quar ters (often inside) causes
Free range animals tend to be healthier
the spread of diseases and this requires large amounts of
and in less need of antibiotics.
antibiotics, often used routinely. If these make it into the
local ecosystem they can cause super-bugs.
Legislation
Pollinators
Large-scale commercial interests are controlled by
Small-scale operations often go un-
legislation so may pollute less.
noticed by legal bodies.
Many commercial crops, eg almonds in California, require
With a more biodiverse farm, pollinators
pollination by bees and other insects. Honey bee hives are
have dierent habitats and there are
brought in to provide this but honey bee colony collapse
usually enough insects to pollinate
disorder is killing many bees. Some crops have no
crops.
pollinators left and humans have to do this by hand.
▲
Fige 5.2.2 Factors inuencing sustainability of agriculture
Figure
notice
5.2.2
that
shows
many
the
of
two
these
extremes
factors
are
of
any
situation
inter-related
but
and
you
difcult
should
to
separate.
247
5
S o i l
S yS t e m S
a n d
S o c i e t y
F fs
To e
Malnutrition
soe bic foo fct (fo
a
diet
that
is
is
an
umbrella
unbalanced.
term
for
Nutrients
‘bad’
may
nutrition
and
it
is
the
result
of
be:
1
me  Ket)
●
●
Lacking
●
Excessive
–
undernourishment,
usually
a
lack
of
calories.
Wheat is a staple food for
–
overnourishment,
usually
too
many
calories
leading
to
over one third of the world’s
obesity.
population (bread and pasta).
●
●
Unbalanced
–
the
wrong
proportion
of
micro-nutrients.
Wheat, rice, maize (coarse
2
grains), potato, barley, sweet
The
potato, cassava, sorghum
people
and millet are the staple
suffer
carbohydrate foods for most
of
humans.
children
Food
in
the
from
the
leads
●
and
98%
to
Agriculture
world
do
Organization
not
get
enough
undernourishment.
are
and
in
Asia,
infants.
permanent
Africa
or
Chronic
damage:
(FAO)
estimates
energy
About
2%
Oceania.
from
of
Of
these
these,
undernourishment
stunted
growth,
that
their
are
in
about
during
mental
925
food
–
million
they
MEDCs.
200
Most
million
childhood
retardation
are
years
and
social
Grain production provides
and
developmental
disorders.
Many
people
are
also
suffering
from
an
half the human population’s
unbalanced
diet
–
their
food
contains
enough
energy,
but
lacks
essential
calories.
3
nutrients
●
World food production is
concentrated in the Nor thern
hemisphere temperate zones.
Hunger
these
sixth
●
Site
millions
of
of
like
die
proteins,
year
children
the
and
certain
www.thehungersite.com
each
are
vitamins
world
from
under
about
starvation
the
age
(approximately
minerals.
of
or
of
the
malnutrition
ve.
13%)
10%
According
How
not
can
having
to
the
undernourished
and
we
three
justify
enough
quarters
about
food
a
when
There are 23 billion livestock
there
are,
apparently,
large
surpluses
stored
in
MEDCs?
animals on Ear th.
Food
●
is
potentially
one
of
the
most
important
resource
issues
facing
global
There are 1 billion pigs and 3
society
today,
alongside
potable
water
(drinking
water).
As
populations
billion ruminants.
increase,
●
as
global
trade
expands
and
as
market
choice
develops,
Livestock need 3.5 billion
greater
and
greater
demands
are
being
made
on
food
supplies
and
food
hectares of land.
production
●
Crops take up 1.5 billion
hectares of land – about 11%
of the total land area.
●
There are 13.5 billion hectares
of land on Ear th, but 90% of this
is too dry, wet, hot, cold, steep
or poor in nutrients for crops.
on
an
industrial
science
have
production
In
many
foods
foods
are
advances
of
food
choice
mean
In
in
and
all
has
the
that
is
agricultural
the
last
has
preference
New
Zealand
years
cheap.
in
lamb,
and
agricultural
too.
than
Modern
and
Most
most
operated
technology
practice
rather
disappeared
round.
systems
increased
relatively
year
50
agricultural
population
produce
available
systems
primarily
agribusiness.
cost
of
of
are
human
the
out
freely
–
huge
then
Seasonality
transport
●
but
These
scale
made
MEDCs,
purchase
need.
systems.
people
basic
nutritional
MEDCs.
Exotic
technology
beans
from
and
Kenya,
dates
In Africa, only 7% of the total
from
Morocco
and
bananas
from
the
Windward
Islands
can
be
bought
in
land area is cultivated.
almost
●
any
MEDC
supermarket
anywhere
in
the
world,
all
year
round.
LEDCs have 80% of the world’s
In
LEDCs,
many
populations
struggle
to
produce
enough
food
to
human population and eat
sustain
their
population.
There
may
be
political
and
economic
agendas
56% of the world’s meat.
as
●
well
as
The human population has
Cereals
increased by 70% in the last
to
30 years but world food
crops
production has increased
However
by 17%.
arable
feed
simple
can
be
environmental
grown
indigenous
can
be
is
as
occupy
in
export
populations
grown
they
land
for
nite
limitations
cash
land
and
–
that
revenue
cash
crops:
on
be
hemp,
used
production.
generation
cropping.
coffee,
could
food
Crops
ax
for
and
food
rather
other
than
than
food
biofuels.
production
and
supply.
1
Myers N. and Kent J. 2005. The New Atlas of Planet Management. University of California Press.
2
W. P
. Cunningham, M. A . Cunningham and B.W. Saigo. Environmental Science, 7th Ed. McGraw-Hill
Higher Education, New York 2003, 231.
3
For more information see Cunningham et al., pages 231–235.
248
5 . 2
The
1.
choice
of
Climate
where
to
2.
food
and
on
Islam
Political
to
–
what
or
in
Socio-economic
eat
is
through
but
most
some
can
P r O d u C T I O n
determined
determine
irrigation
crops
religions
eating
pork,
foodstuffs
discourage
this
F O O d
conditions
proscribe
governments
encourage
and
this
climate
religious
determine
–
grow
adapt
the
Judaism
production
4.
we
ecological
We
alter
and
and
traditions
3.
local
Earth.
articially
Cultural
that
T E r r E s T r I a l
we
subsidize
their
are
by
many
what
and
will
using
grown
proscribe
Hindus
s y s T E m s
C h O I C E s
factors:
grow
without
not
F O O d
greenhouses
certain
do
a n d
this.
foods,
eat
beef.
eg
Our
prefer.
or
put
production,
tariffs
eg
on
the
EU
some
foods
manipulates
way.
–
market
forces
determine
supply
and
demand
in
To o
a
free-market
beans
and
prices
fall
economy,
prices
rise,
eg
if
there
farmer
may
is
go
a
short
into
supply
this
crop,
of
almonds
supply
or
increases,
Consider your own food
and
then
they
may
stop
growing
it.
choices. Which of the factors
We
and
all
need
some
available.
of
food
us
But
nourishment
anything
–
it
often
many
to
about
supplies
of
keep
it?
take
Is
us
us
it
for
the
fuel
granted
have
that
the
nowhere
healthy
anyone’s
and
we
fact
near
need
that
to
food
enough
energetic.
live
Why
is
is
and
listed (left) determine what
breathe
you eat? Are there other
readily
food,
this?
let
factors involved as well?
alone
Can
we
do
fault?
To e
Te iig cot of foo
because there are more of us but because many of us
eat more meat.
There will be billions more human mouths to feed in the
next 50 years so an increase in the demand for food is not
April
June
going to go away. Human population is now over 7 billion
2011
250
2008
Index: January 2002 = 100
and is predicted by the UN to be 8 billion in 2025 and 9.2
December
200
2008
in 2050. Because it is protable at the moment, there is
a massive increase in growing crops for biofe (living
150
plants conver ted to fuel to replace fossil fuels) and this
up 130 %
up 60 %
100
uses land that would otherwise be used to grow crops for
down 33 %
food. We cannot have it both ways as crop land is limited.
50
In 2008, there were food riots (for example in Burkina
0
2002
Faso, Egypt and Bangladesh) when people protested
2003
2004
2005
2006
2007
2008
2009
2010
2011
about the rising price of food. In Haiti, the poorest
▲
Fige 5.2.3 World food prices 2002–2011
country, the government was over thrown due to the high
While there is still enough food, we need to review the
cost of food. According to the FAO, 37 countries are facing
strategies on global food production.
food crises. Food costs a higher propor tion of income for
the poor than for the rich. For 100 million people or more,
1.
What has happened to food prices now? Do your own
research on this.
this could mean starvation and many are going without
meals because they cannot aord them.
2.
Do your own research on biofuels and read the
section in sub-topic 7.1 on them.
The World Food Programme could only buy half as
much food in 2008 as in 2007 with the same amount of
a.
Evaluate the costs and benets of growing
money. Wheat and soya prices, rapeseed oil and palm oil
biofuels on agricultural land.
prices spiked but have fallen back again (gure 5.2.3).
b.
Which countries are most likely to see an
Biofuels are one of the reasons for this as farmers get
increase in the production of biofuels and what
subsidies for growing them so do not put their crops
impact will that have?
into the food chain. The increasing wealth of India and
China means that more people can aord and want more
meat to eat so demand for meat has not just increased
3.
Is the country in which you live a net impor ter or
expor ter of food?
249
5
S o i l
S yS t e m S
a n d
S o c i e t y
F pru  srbu ru h wr
Let’s
look
rst
at
agricultural
production.
180
160
USA
Australia
Brazil
E27
China
Russia
Canada
India
Ukraine
140
120
100
80
60
40
1992
1995
1998
2001
2004
2007
2010
2013
2016
2019
To o
▲
Fige 5.2.4 Agricultural production in key producers 1992–2019
Compare and contrast the
(2004–6 = 100 on y axis)
agricultural production
Source: OECD/FAO
trends shown in gure 5.2.4.
So
why
you
is
there
search
of
food
of
Science
to
available
the
go
such
round.
suggests
each
a
difference
internet
day
or
The
that
for
in
world
textbooks,
American
there
every
is
an
agricultural
many
will
Association
average
human
on
the
of
say
for
the
2,790
planet
production?
that
there
If
plenty
Advancement
calories
–
is
23
of
percent
food
more
4
than
in
1961
actually
so
kept
many
and
up
enough
with
problems
to
world
with
feed
everyone.
population
famine,
hunger
Food
growth,
and
production
so
why
are
has
there
still
malnutrition?
Poitic of foo pp
To tik bot
If
excess
under
food
the
is
not
power
of
paid
the
for,
does
exporting
this
put
the
country?
receiving
What
country
impact
does
forever
this
food
There are many factors that
have
on
the
local
farmers
and
the
economy?
What
happens
when
may be considered but is
corrupt
governments
do
not
distribute
to
those
who
need
the
food,
the main one distribution? It
and
who
decides
who
needs
the
food
anyway?
These
are
some
of
the
is well known that countries
questions
that
need
to
be
considered
where
the
issues
involved
in
the
like the USA, Canada and
imbalance
in
global
than their indigenous
All
need
population needs.
diets
food
supply
are
concerned.
Australia have more food
people
of
people
to
in
eat.
However,
MEDCs
and
huge
those
in
differences
exist
between
the
LEDCs.
Consider who should pay to
mEdC
lEdC
3314
2666
USA 3774
Eritrea 1512
ship the excess foods from
Average energy intake: cal/cap/day (calories per
where they are stored to
capita per day)
countries like Bangladesh,
Ethiopia and Sudan, and is it
Major types of food (% of total calorie intake)
the type of food they want?
meat
12.9
7.3
1.4
0.9
37.3
56.1
What impact would this have
sh
on the local farmers and the
cereals
markets?
▲
Fige 5.2.5 Average energy intake per day in MEDCs and LEDCS
4
http://atlas.aaas.org/index.php?par t=2&sec=natres&sub=crops
250
5 . 2
To
start
global
answering
pattern
availability
called
low
in
of
these
world
MEDCs
income
T E r r E s T r I a l
issues,
food
and
food
it
is
LEDCs
–
P r O d u C T I O n
necessary
supply.
decient
F O O d
Figure
those
to
5.2.6
with
countries
have
an
shows
low
food
s y s T E m s
overview
per
capita
supplies
a n d
of
F O O d
C h O I C E s
the
calorie
are
(LIFDCs).
To o
daily calorie
intake per capita
less than 1,890
1,890
2,1
70
2,1
70
2,390
2,390
2,620
2,620
2,850
2,850
3,050
3,050
3,270
3,270
3,480
3,480
3,770
no data
in kcal/person/day
▲
Fige 5.2.6 Per capita calorie consumption worldwide
Look at the key for the map in gure 5.2.6.
Comment on the distribution of LIFDCs in the world.
What are the common factors for these countries?
What food issues do countries with high per capita calorie consumption face?
Recent doubts
So
far
pace
us
in
the
with
(see
8.1).
efciency
As
we
and
history
of
population
But
and
the
very
adapt
more
and
more
land,
of
1.1
and
they
The
global
billion
are
per
grain
of
living
getting
harvest
hectare
Revolution
limit
some
allow
of
the
demand
are
us
NPP
more
food
the
doubting
to
feed
on
a
Earth
meat,
supply
has
Malthusians
we
that
world
to
technology,
of
9
human
must
kept
amongst
be
billion.
needs,
reaching
use
the
growth.
The
yields
will
more
population,
confounding
recently,
innovation
degrade
limits
human
growth,
as
the
of
poverty
grain
have
per
As
may
slowed
benets
productivity.
produced
in
appear
to
be
increasing
not
decreasing
hungrier.
have
the
capita
still
increasing
rate
been
human
(see
be
their
of
realized
and
population
gure
but
increase
annual
since
we
the
may
increases,
be
grain
Green
near
there
is
a
the
fall
in
5.2.7).
251
5
S o i l
S yS t e m S
a n d
S o c i e t y
3 billion tons
grain production
1,000 pounds
grain production per capita
per person
3 year moving average
750
World
2
World
500
Asia and
Oceania
1
250
Americas
Europe
Africa
196
1
▲
1970
1980
1990
2000
196
1
2009
1970
1980
1990
2000
2009
Fige 5.2.7
To tik bot
B et is any wild animal killed for food. In some
countries, this is called game, in others, hunting wild
animals. The term bush meat is highly politicized as
many see it as illegal hunting, par ticularly in Central and
West Africa and tropical rainforests. Although bush meat
can be many species, the emotive element focuses on
the killing of the Great Apes for meat, often orphaning
their young.
Trade
that
in
bush
logging
easier
for
meat
roads
hunters
is
increa sing.
bu ilt
and
into
the
the
high
T he
reas on s
fores ts
price
of
mak e
meat
a re
access
in
markets.
The cane rat is a large rodent pest of crops in West
Africa and this is hunted for bush meat . Now, some
farmers are successfully star ting to farm cane rats for
meat in Benin and Togo.
▲
Fige 5.2.8 A cane rat
a brf hsr f gruur
TOK
Livestock farming – why farm animals?
Consumer behaviour plays
Man
has
been
associated
with
animals
for
longer
than
he
has
been
an impor tant role in food
farming
cereals.
rst
dog,
Animal
domestication
came
before
crop
farming,
production systems. Are
the
then
sheep,
goats,
pigs
and
cattle
were
domesticated
there general laws that can
and
used
to
full
a
variety
of
needs.
Dogs
were
used
as
hunting
describe human behaviour?
companions
dog
was
hunted
a
more
horses,
and
as
252
also
as
a
wild
ultimately
source
prey
convenient
donkeys,
beasts
clothing
and
and
and
of
of
and
and
yaks,
even
then
camels
their
herding
food.
more
burden.
decorations.
as
In
Sheep,
animals.
goats
corralled
reliable
and
they
antlers
pigs
of
cultures
probably
were
food.
(and
provided
and
some
domesticated
source
llamas
addition
bones,
and
and
In
teeth
are)
wool
had
to
Cattle,
a
provide
reindeer,
used
and
value
the
were
as
food
hides
as
for
tools
5 . 2
Livestock
human
living
are
a
useful
digestion
in
T E r r E s T r I a l
means
systems
Mediterranean
digesting
vegetation
on
as
farms
a
way
scrub
that
of
of
(grass)
is
F O O d
converting
into
forests
plant
valued
waste
to
on
and
and
scrub
pigs
a n d
unsuitable
Sheep
woody
humans;
products
s y s T E m s
material
protein.
browse
unpalatable
processing
P r O d u C T I O n
for
trees
often
producing
C h O I C E s
goats
and
were
F O O d
kept
valuable
protein.
Growing crops
In
arable
that
has
planted
by
farming,
been
into
plowing
species)
altered
bare
grown
their
Fertilizers
are
acidic
lime
most
has
often
nutrients
than
season
the
crop
soil
and
the
minerals
it
had
Crop
crops
every
water
If
is
the
year,
a
as
a
the
way
of
be
has
of
a
(broken
(all
be
of
soil
plant
the
soil
of
up)
one
limiting
soil
over
is
are
too
are
quantities
in
of
amount
time
biomass
plant.
that
varieties
greater
have
the
the
biomass
a
net
The
loss
soil
the
other
is
been
whether
At
the
end
from
the
eld,
of
to
of
biomass,
more
soil
loss
nitrogen
with
The
from
that
of
addressing
rotation
may
into
usually
of
in
the
supply.
been
add
that
owering,
volumes
extracted,
beans)
or
used.
plants
food
are
monoculture
magnitude
body
sown
seeds
possible.
extract
system.
is
as
of
large
removal
crop
peas,
in
they
are
a
growth
may
general
There
from
one
beans,
fourth
They
the
another
–
are
The
conditioned
Conditions
orders
produce
harvested
requires
rotation
(soya
often
deliberately
previously
high
encourage
ecosystem.
and
been.
or
as
irrigation
species.
is
is
are
vegetation.
plants
density.
hungry’
to
plants
been
The
rate
minerals
heads
crop
natural
has
high
to
added,
selected
Harvesting
that
growth
indigenous
of
the
over).
‘nutrient
seed
of
in
added
and
genetically
tubers,
soil
(digging
and
so
seeds
cleared
impoverished
fertility
soil
the
the
nutrients,
is
reduced
fertility.
soil
so
than
again.
Leguminous
may
be
grown
crops.
253
5
S o i l
S yS t e m S
a n d
S o c i e t y
Y D U T S
P  – rfrs  ur shppg
E S A C
▲
Fige 5.2.9 Oil palm
The
oil
West
to
South
grown
in
palm
Africa
is
East
for
its
Malaysia
a
and
tropical
Central
Asia
oil.
and
in
the
Half
the
palm
tree
America
early
indigenous
but
1900s.
of
the
large
rest
are
in
to
●
lubricants
●
biofuel.
imported
Here
it
plantations
Indonesia
and
is
are
What
The
South
East
Asian
countries.
In
Indonesia,
do
you
of
land
occupied
by
palm
oil
plantations
in
benets
the
last
10
years
and
is
still
palms
to
Friends
of
the
Earth,
an
for
palm
rainforest
loss
oil
in
is
the
most
Malaysia
signicant
and
oil
is
high
in
saturated
fats
and
room
temperature.
It
is
found
and
in
palm
plantations
are
in
bring
an
and
exports.
income
for
a
Growing
a
few
subsistence
large
oil
plantations
much
needed
and
processing
employment.
cause
oil
palm
plantations
often
replace
Indonesia.
rainforest
and,
in
Malaysia
and
Indonesia,
semi-solid
primary
at
oil
employment
provide
tropical
Palm
of
can
However,
of
oil?
NGO,
plants
demand
palm
increasing.
farmer
According
contains
has
oil
doubled
that
the
providing
area
use
other
1
in
10
rainforest
has
been
cleared
for
oil
palm.
food
Often
this
forest
is
on
peat
bogs
which
are
then
products:
drained
●
cooking
oil
and
processed
foods:
chocolate,
bread,
crisps
maintain
and
cosmetics
(lipsticks),
detergents
and
Sunlight
Soap
and
other
monoculture
are
used
animal
on
the
species.
of
oil
palms,
plantations
Animals
that
herbicide
and
these
were
rainforest,
such
as
elephants,
move
into
the
Palmolive)
plantations
254
lost.
soaps
the
(eg
the
pesticides
poison
●
habitats
margarine
To
●
and
seeking
food
and
are
killed
as
pests.
in
5 . 2
T E r r E s T r I a l
F O O d
P r O d u C T I O n
s y s T E m s
a n d
F O O d
C h O I C E s
cprg frg sss
Fig te
siftig ctitio
Cee gowig
rice gowig
ho ticte 
iig
Wee
Amazon rainforest
Canadian Prairies
Tpe
Extensive
Extensive
Intensive
Intensive
Subsistence
Commercial
Subsistence
Commercial
Low – labour and hand
High use of
High labour, low
High labour and
tools
technology and
technology
technology
Ipt
Ganges Valley
Western Netherlands
fer tilizers
Otpt
Low – enough to feed
Low per hectare but
High per hectare,
High per hectare and
the family
high per farmer
low per farmer
per farmer
Eciec
High
Medium
Eioet ipct
Low – only if enough
High – loss of
Low – padi rice
High – greenhouses
land to move to and
natural ecosystems,
has a polyculture,
for salads and owers
time for forest to regrow
soil erosion, loss of
stocked with sh.
are heated and lit.
biodiversity
Also grow other
High
High
In dairying, grass
crops
is fer tilized, cows
produce waste
▲
Fige 5.2.10 Table of types of farming system
Farming’s energy budget
The
1.
efciency
Energy
We
harvested
2.
is
or
or
More
In
of
on
of
range
by
to
is
the
weight,
per
gram).
system
all
produce
to
soil,
package
to
factor
with
livestock
the
spatial
cereal
the
sow
now
food
for
market,
the
energy
farming
harvested
returns
the
we
from
lamb.
number
per
cereal
consider
the
live
of
ways.
unit
and
However
area.
root
this
biomass
marketable/edible
consider
meat)
a
product
calculation
the
do
or
in
portion
weight
of
of
the
deadweight?
systems
more
inputs,
a
to
do
deliver
is
it
a
the
crop,
dealing
to
the
that
is
of
is
You
market.
of
the
it
used
You
to
the
system
usually
sold
possible
(joules
farming
took
would
and
waste
the
at
operate
volume
energy
was
look
that
therefore
unit
prepare
with
end
that
balance
market.
energy
the
It
per
could
storage
the
etc.).
food
energy
transport
of
At
calculate
to
we
and
product
rice
in
the
and
harvest
cost
scales.
wheat,
calculate
then
honestly
outputs
marketable
contained
labour
seed,
measured
beef
temporal
of
need
and
fuel,
the
the
(maize,
to
of
only
perhaps
and
be
energy
terms
with
energy
order
you
in
and
crop
Does
(just
system
can
from
consider
agricultural
the
that
it
corn,
production
In
consider
the
it
dressed
a
eg
calculate
relative
and
scientically
–
a
the
problematic.
efciency
there
the
does
the
Efciency
system
within
wheat
harvest?
animal
farming
compare
from
calculation
the
a
contained
can
crops,
of
to
need
prepare
appropriately
would
products
also
have
associated
system.
255
5
S o i l
S yS t e m S
a n d
S o c i e t y
Data
exists
for
Shockingly,
there
is
efciency
for
more
all
but
input
of
agriculture
cereal
than
growing,
(see
gure
efciency
5.2.11).
is
less
than
one
–
output.
Eciec expee  eeg otpt:eeg ipt fo :
To o
Dairying
0.38
Cattle rearing – grain fed (beef)
0.59
Sheep (lamb)
0.25
Pigs (pork)
0.32
Cereal growing
1.9
Do you think that cattle fed
on grass only (pasture-fed)
would have a higher or lower
eciency of conversion?
What advantages or
disadvantages may there
be for pasture-fed instead of
Foo poct
grain-fed cattle?
White bread
0.525
Chicken
0.10
Battery eggs
0.14
Lettuce produced under glass
0.0017
▲
Fige 5.2.11
While
total
energy
considered,
●
Fats
out
remember
and
protein
is
less
that
than
the
contain
energy
quality
more
in
of
energy
when
the
all
factors
energy
content
per
is
are
different.
gram
than
carbohydrates.
●
You
need
amount
●
A
to
of
higher
eat
less
meat
and
sh
than
cereals
to
get
the
same
energy.
energy
content
food
costs
less
to
transport
as
it
has
a
lower
volume.
To
equate
wheat
measures,
grain
product)
is
that
the
would
sometimes
grain
have
equivalent
to
be
used
to
in
kilograms
produce
one
(the
quantity
kilogram
of
of
that
used.
Rice production in Borneo and California
Two
food
production
●
traditional,
●
intensive
Traditional
energy
Nearly
is
all
rather
energy
it
yield
is
energy
the
are
amounts
are
256
is
used.
high.
in
labour
the
form
fertilizer
As
a
is
production
result,
in
in
no
(no
is
the
of
high
is
form
Borneo
characterized
of
and
labour
efciency
or
products
(Kalimantan)
a
and
get
are
them
low
inputs
of
productivity.
seeds.
(dened
pesticides
and
by
low
as
The
used
to
rice
energy
yield
output/
(remember
market),
the
rice
pollution).
characterized
diesel
P)
Indonesian
intensity
fertilizer
intensity
(N,
in
here:
California.
energy
these
production
low
of
output
discussed
labour
the
As
make
are
production
high
added
to
only
rice
chemicals,
rice
However,
energy
rice
production
chemicals,
low.
Intensive
inputs
rice
input)
takes
extensive
extensive
and
systems
and
rice
and
or
a
petrol,
are
high
inputs
productivity.
not
pesticides
yields
by
high
in
the
form
(insecticides
obtained.
of
energy
The
of
and
and
energy
labour.
Large
herbicides)
However,
because
5 . 2
of
the
the
large
agricultural
energy
gure
production
The
compared
excess
inputs,
extensive
outputs.
outputs
of
energy
traditional
fertilizer
5.2.12:
T E r r E s T r I a l
to
energy
systems,
the
the
rice
were
not
energy
system:
Note
is
example.
inputs
production
extensive
pesticides.
P r O d u C T I O n
efciency
production
intensive
and
they
the
rice
F O O d
that
much
In
s y s T E m s
lower
some
are
system
pollution
in
these
not
are
than
F O O d
C h O I C E s
in
intensive
larger
also
a n d
than
has
the
the
extra
form
shown
in
measured.
1
Eeg (0 0 0 kc 
Boeo
)
Cifoi
Inputs
Direct energy:
Indirect energy:
labour
0.626
axe and hoe
0.016
–
machinery
–
0.360
diesel
–
3.264
petrol
–
0.910
gas
–
0.354
nitrogen
–
4.116
phosphorus
–
0.201
seeds
Outputs
0.008
0.392
1.140
irrigation
–
1.299
insecticides
–
0.191
herbicides
–
1.119
drying
–
1.217
electricity
–
0.380
transpor t
0.051
0.121
rice yield
7.318
22.3698
(protein yield)
(141 kg)
Eeg eciec
(462 kg)
7.08
1.55
5
▲
Fige 5.2.12 Rice production systems in Borneo and California
Other
typical
agricultural
differences
production
between
systems
traditional
extensive
and
intensive
are:
Titio ex teie gicte
Iteie gicte
Limited selective breeding
Strong selective breeding
No genetically engineered organisms
Genetically engineered organisms
Polyculture (many dierent crops)
Monoculture (single crop)
Small eect on biodiversity
Reduction in biodiversity
Little soil erosion
Strong soil erosion
5
K . Byrne, Environmental Science, 2nd Ed. Nelson Thornes, Cheltenham 2001, 180.
257
5
S o i l
S yS t e m S
a n d
S o c i e t y
To o
1.
Copy the table below and do your own research to ll it in.
2.
Repeat with another example of two named food production systems local to you.
3.
For each system, evaluate the environmental impacts.
Fcto
Inputs
Iteie beef
Ex teie beef
poctio i
poctio b mi
sot aeic
tibe of Et afic
Eg fer tilizer, water, pest control, labour,
seed (GM or not), breeding stock ,
livestock growth promoters
Outputs
Food quality, yield, pollutants,
transpor tation, processing, packaging
System characteristics
Diversity
Sustainability
Environmental
Pollution
impacts
Habitat loss
Biodiversity loss
Soil erosion/degradation
Deser tication
Disease epidemics
Socio-economic
Subsistence or for sale crop
factors
Traditional or commercial
For expor t or local consumption
For quality or quantity
Terrestrial versus aquatic food production systems
In
terrestrial
the
rst
(crops)
primary
Terrestrial
–
they
In
aquatic
often
each
at
the
in
of
have
in
to
food
levels.
is
like
are
do
have
level,
food
4
the
than
terrestrial
by
on
higher
have
energy
of
land.
Also
tend
food
energy
food
be
means
of
solar
comes
tied
up
to
in
comes
from
that
these
energy.
skeletal
their
of
of
the
of
losses
the
in
food
Note
tend
solar
and
energy
aquatic
systems.
of
from
carnivorous
chain
intake
because
it
originates
This
use
at
skeletons
land.
efciency
initial
when
energy
Because
the
harvested
usually
efcient
most
to
usually
(meat
terrestrial
along
the
on
is
chickens).
losses
more
systems,
sh
ecosystems
water.
and
rather
higher.
that
ecosystems,
than
or
conversions
a
food
level
pigs
themselves
production
lower
sunlight
trophic
making
support
level
systems
cows,
animals
Typical
trophic
aquatic
water
258
systems
energy
than
second
systems
trophic
systems
or
land-based
as
trophic
production
consumers
production
waste
food
to
energy
absorption
the
form
of
quite
‘losses’
at
production
that,
be
higher
are
although
more
is
less
and
heat
efcient
efcient
reection
are
higher
in
5 . 2
T E r r E s T r I a l
F O O d
P r O d u C T I O n
s y s T E m s
a n d
F O O d
C h O I C E s
Increasing sustainability of food supplies
Feeding
the
population
world’s
is
Not
only
and
malnourished
has
many
stated
and
this
Factors
new
needs
an
increase
contribute
●
salinization
●
desertication
●
urbanization.
improve
Maximize
problem
practices.
a.
is
of
Improve
Mixed
No
iii.
Plant
iv.
Biological
do
is
a
to
also
another
in
challenge,
agriculture
better
2
production
today’s
quality
billion
of
70%
agricultural
as
is
the
decreasing.
undernourished
food.
The
humans
of
current
land
FAO
to
feed
levels.
are:
also
irrigation
what
we
Genetically
from
the
on
Soil
Green
and
T
echniques
In
LEDCs,
eg
loss
storage
–
pests
less
and
the
habitat
foods
water
stubble
of
and
the
the
soil.
previous
soil.
and
how
that
conserves
agricultural
for
land
of
we
absorb
nutrient
pest
management
water.
grow
(GM).
allows
to
wildlife.
integrated
wasteful
and
it.
Inserting
them
to
x
fertilizers.
into
cereals
nitrogen
(See
box
the
would
on
GM
hydroponics.
food
through
more
having
too
where
nutrients
systems
breeding
as
bare
by
pest
no
and
with
strict
is
more
covered
energy
crops
mostly
in
refrigeration,
is
than
mostly
needed
standards
–
are
and
recycled
on
animals
balancing
adapted
and
drought,
increasing
no
in
and
weather,
canning
letting
apples,
it
factory
go
red
storage
lack
consumption
and
farms.
distribution.
production
severe
(round
to
drought-proong
storage
infestations,
waste
food
plants
soil
improving
waste
food
buying
(5.3).
outputs.
of
waste
such
measures
closed
keeping
MEDCs,
unsustainable
Revolution.
within
food
without
into
nitrogenous
conservation
shade,
In
and
Agroecology
Reduce
is
for
systems.
p262).
iii.
inputs
of
modied
Aquaculture
farms
water
legumes
ii.
new
seeds
around
grow
need
this
interplanting
provides
control
Trickle
crops
ii.
also
do
by:
agriculture.
drilling
zones
This
supplies
production
to
of
conserves
buffer
food
are:
and
losses.
save
i.
how
tillage,
of
food
this
reduce
Alter
A
of
cropping
plow
gene
b.
fed,
and
decrease
technology
ii.
i.
a.
be
be
food
the
course,
to
i.
v.
2.
yield
Ways
run-off.
c.
to
will
future
available
more
sustainability
the
crop
b.
in
the
erosion
could
A
need
there
to
in
area
need
2050,
that
the
mouths
people
by
soil
1.
and
that
●
We
population
growing
eg
off,
of
good
nearby.
consumers
supermarkets
strawberries)
so
259
5
S o i l
S yS t e m S
a n d
S o c i e t y
rejecting
much
preserve
be
3.
recycled
Monitoring
a.
By
By
c.
By
and
different
b.
Eat
less
c.
Improve
d.
Increase
more
of
meat
trend
is
in
reduce
food
supplier
NGO
that
could
may
otherwise
–
to
regulate
agricultural
corporations
to
raise
practices.
standards
farms.
pressure
towards
bodies
unsustainable
national
rapidly
more
food
groups.
and
our
diets.
average,
USA,
We
cannot
in
can
food
2000,
insects
lower
of
actually
big
the
protein
efciency
levels
available.
need,
so
the
people
human
–
source
that
numbers.
trophic
food
from
More
each
large
improve
from
taken
way.
food.
in
amount
they
by
other
the
diet
of
and
food
the
than
On
about
consumption
meat
the
and
education
increase
their
that
crops.
people’s
obtain
greatly
packaging
food
meat.
reproduces
Changing
food,
waste
intergovernmental
to
their
attitudes
Eat
we
on
individuals
a.
If
and
exports
practices
our
misshapen
livestock.
multinational
Change
if
contaminates
control.
governmental
and
4.
edible
but
for
and
imports
b.
foods
they
rst
in
food
People
could
trophic
LEDCs
consumed
of
in
of
will
eat
replace
However,
eating
kg
we
MEDCs
simply
level.
are
38
production.
(plants),
more
meat
some
the
meat.
per
year.
In
6
that
it
would
grain
than
to
we
some
was
all
122
eat
not
more
support
animals
need
kg,
which
to
countries.
UK
meat.
crops,
we
sustain
We
and
just
Brazil
Even
it
then
is
1,000
not
kg,
though
China
animals
energetically
eat.
ourselves.
do
77
In
seem
able
has
to
kg,
graze
inefcient
MEDCs,
Obesity
50
we
the
on
to
mostly
become
get
India
a
kg.
some
feed
eat
land
our
more
problem
balance
past
5
in
right.
projected
yad rep nosrep rep lacK/ekatni ecudorp lamina
900
800
700
600
500
400
300
200
100
0
1962
1970
1980
1990
2000
2015
industrialized countries
near East/Nor th Africa
transition countries
sub-Saharan Africa
2030
Latin America and the Caribbean
▲
Fige 5.2.13 Meat consumption past and projected in various regions
6
Myers N. and Kent J. 2005. The New Atlas of Planet Management. University of California Press.
260
2050
5 . 2
5.
Reduce
of
food
food
food
processing,
production
increasing
they
growing
country
such
them
the
in
as
cost
more
tomatoes
the
tropics
by
UK
and
in
may
While
in
a
transport,
more
them
foods
used
to
total
more
may
in
a n d
have
a
than
F O O d
C h O I C E s
aware
foodstuffs
produce
energy
the
be
of
greenhouse
into
s y s T E m s
and
labelling
local
energy
heated
use
ying
and
P r O d u C T I O n
improving
awareness.
may
F O O d
packaging
efciency
consumer
miles,
example,
T E r r E s T r I a l
and
lower
them.
For
temperate
growing
UK.
Predictions for future food supplies
The
FAO
has
predictions
1.
Human
in
reported
are
rate
The
human
calorie
3.
Numbers
of
More
people
5.
An
6.
LEDCs
7.
Most
will
will
people
eat
to
more
of
supply
for
2030
and
its
also
8
billion
1.7%
slow
but
in
by
2030,
2000.
not
in
a
slowdown
Demand
LEDCs
where
be
increasingly
will
to
3,000
decrease
this
well-fed
kcal
to
will
per
about
not
with
day
fall
440
as
per
from
capita
2,800
million
now.
but
in
much.
meat.
will
need
to
be
grown.
cereals.
will
be
from
higher
yields
and
more
land.
modied)
will
from
cereals
import
improved
Aquaculture
food
about
Africa)
production
more
(genetically
to
year
increasing
tonnes
have
not
measures,
9.
will
increased
irrigation
on
increase.
(sub-Saharan
billion
will
grow
per
products
will
hungry
4.
GM
will
population
areas
extra
predictions
1.1%
consumption
some
8.
to
agricultural
consumption
2.
its
follows:
population
growth
for
as
pest
crops,
control
no
tillage
will
all
planting,
increase
soil
conservation
productivity.
increase.
To o
Ogic  oc o gow i Ke  i-feigte?
to lower food miles and ar tisanal local producers. But
it is the large commercial farms and large supermarket
If all humans alive today adopted the diet of Europeans, we
chains that supply most of our food eciently and at the
would need 2.5 more planets like the Earth to support us.
lowest prices. We could not produce enough food if we all
If we all ate organic food, we could not produce enough.
ate organic, local produce.
Commercial intensive agriculture has done a remarkable
Food miles is a measure of how far food has moved from
job in managing to feed the rapidly increasing human
grower to your table. The premise is that more food miles
population. Bu t it may not in the future. What has to change?
means more bad environmental impact for a food. So
In MEDCs, there is an increasing supply of organically
shop for locally produced foods.
produced foodstus and these are sold at a premium.
But this is a fallacy as it is eciency of food production
The premise is that they are better for our health and
that we should be considering. Growing green beans in
free of pesticide residues. But there is little scientic
a heated glasshouse in Nor thern Europe uses far more
evidence to suppor t some claims for organic foods.
energy than growing them in Kenya even including
Locally grown foods are also marketed as ‘better ’ due
the carbon emissions of air-freighting them to Europe.
261
5
S o i l
S yS t e m S
a n d
S o c i e t y
In fact, Kenya’s bean industry is very environmentally
It costs more in carbon emissions to drive 6.5 miles to a
cost ecient. Beans are grown:
supermarket than ying a packet of beans from Kenya to
7
that supermarket.
●
using manual labour (no fossil fuels)
●
using organic fer tilizer from cows
●
with low-irrigation schemes.
Check out this ar ticle – http://shrinkthatfootprint.com/
food-miles. Do you agree with this argument? Will it
aect what foods you buy?
To tik bot
Opponents of GM crops say we do not know what we
Gm cop
are releasing into the environment. Could the GM plants
GM or geetic oie cop have DNA of one
cross-pollinate with other varieties so the introduced DNA
species inser ted into the crop species to form a
escapes into the wild populations? Could the DNA cross
tgeic pt. GM crops of soya bean, cotton and
the species barrier? If a GM crop can kill a pest species
maize are the most common but the issue of GM crops
that feeds on it, will that species die out? What will the
is surrounded by controversy in some countries over
eect on food chains be? Labeling of GM foods is now
ethics, food security and environmental conservation.
demanded and some countries have rejected them totally.
Proponents of GM crops say they are par t of the solution
to increasing food production. By making a crop disease
Te Eope uio’ (Eu) Coo agict
or pest resistant, fewer chemicals need to be used and
Poic (C aP)
less is lost in spoilage. We are only doing what selective
40% of the EU budget goes towards the CAP
, a system
breeding has done since farming began but on a molecular
of subsidies star ted in 1962 for agriculture in the EU. In
scale. Goe ice has been made to synthesize betathis farmers are guaranteed a price for their produce and
carotene, the precursor to vitamin A, so, as a humanitarian
a tari and quota are placed on impor ts of foodstus.
tool, it could stop vitamin A deciency suered by 124
The initial aims of the CAP were laudable: to ensure
million people. It has not yet been grown commercially.
productivity, give farmers a reasonable standard of
living, allow food stocks to be secured and provide food
in shops at aordable prices. However, it has cost a great
deal to implement and it is said that a cow in the EU gets
more money in subsidies than a poor person in Africa.
The CAP is being reformed with subsidies for individual
animals phasing out and a single farm payment being
given per hectare of cultivatable land.
One big issue with the CAP is that it is accused of being
protectionist – keeping products from other countries out
of the EU to the benet of the 5% of Europeans who work in
agriculture – ‘For tress Europe’. It has also been accused of
keeping food prices ar ticially high, causing massive food
stocks to build up as producers keep producing even if no
▲
Fige 5.2.14 Golden rice compared with white rice
consumers want to buy, as the EU will buy the products
7
See http://www.theguardian.com/environment/2008/mar/23/food.ethicalliving for more on food miles
262
5 . 2
T E r r E s T r I a l
F O O d
P r O d u C T I O n
s y s T E m s
(the wine lake, the butter mountain), and allowing farmers
Here
to pollute with high levels of chemicals to increase
Revolution.
production. All these issues are being addressed now.
or
are
has
the
it
two
a n d
very
Did
it
caused
1940s
to
F O O d
diff erent
sav e
more
the
C h O I C E s
the
ima ges
w orld
problems
196 0 s ,
plant
abou t
f rom
than
th e
m ass
it
Gr een
famine
s olv ed?
breeding
of
From
w heat
What do you think about protectionism in the trade of
and
rice
and
then
other
cereals
w as
u nder t ak en
to
food (stopping or adding taris to impor ts from other
produce
varieties
tha t
w ere
less
prone
to
dis ease,
countries so your own farmers can sell theirs)?
had
shor ter
stalks
(so
they
did
not
lodge
or
f all
over
Should small EU farmers have been allowed to go
in
rain)
and
gave
high er
y ields .
This
w as
d on e
by
bankrupt and give up?
ar tificial
plants
selection
that
had
of
the
the
tr a its
va rieties
w anted
a nd
and
indiv id ual
the
results
wer e
Te Gee reotio of te 20t cet
spectacular
we
knew
genetic
one
in
terms
about
the
to
crop
y ields.
pos s ibili ty
engineering
species
of
w hich
is
of
or
(It
w as
could
sw itching
b ef ore
carr y
genes
ou t
fr om
anoth er. )
In Mexico, wheat yields increased such that the
country became self-sucient in wheat and then
expor ted the surplus. In India, the IR8 variety of rice, a
HYV or high yielding variety, gave ve times the yield
of older varieties with no added fer tilizer and ten times
with. This led to a fall in the cost of rice and to India
expor ting the surplus. However, in Africa, there was
little dierence in crop yields.
Some have been critical of the Green Revolution varieties
as the result has been that more fer tilizer, irrigation and
pesticides have been used on them (if farmers can aord
them) and these cause eutrophication, salinization and
the accumulation of chemicals in food chains. They
have also reduced genetic diversity in the crops as most
▲
Fige 5.2.15 Green Revolution poster from Greenpeace
farmers use them. While some say that the poor have
become poorer because of this, there is little doubt that
the HYVs have allowed us to produce enough food for the
yield
population.
production
area har vested
1.
Explain the relationships between the four graphs in
seed
gure 5.2.16.
2.
Evaluate the impacts of the Green Revolution on
world food supply and the environment.
1960
▲
1970
1980
1990
2000
Fige 5.2.16 Coarse grain production 1961–2004
(coarse grain is wheat, maize, rice, barley)
263
5
S o i l
S yS t e m S
a n d
S o c i e t y
To o
Practical
Investigate
and/or
Work
food
consumption
production
Te FaO
patterns.
The Food and Agriculture Organization (FAO) is a UN agency. Find its website
Analyse
graphs
tables
that
dierences
outputs
and
in
inputs
associated
production
www.fao.org/worldfoodsituation from where the graph below is taken and
illustrate
the
answer the questions below.
and
with
food
2
150
systems.
utilization
Compare
and
contrast
the
2050
outputs
characteristics
food
and
for
production
Investigate
soil
system
two
sennot noillim
inputs,
named
systems.
proles
locally.
production
1950
1850
1
750
1997
1999
2001
2003
2005
2007
forecast
▲
Fige 5.2.17 World food supply and
use 1997–2007
1.
Describe the changes in the graph above.
2.
Read the 10 FAQs on the world food situation.
3.
Answer these questions in your own words:
4.
a.
Why are world food prices rising?
b.
What is the eect of biofuels on food prices?
c.
Who are the winner and losers?
Describe the current food situation in your own country and one other.
(Select an MEDC and an LEDC.)
264
5 . 3
s O I l
d E G r a d a T I O n
a n d
C O n s E r v a T I O n
5.3 s oi egtio  c oe tio
Sg s:
apps  sks:
Fer tile soils require signicant time to develop
➔
Expi the relationship between soil
➔
through the process of succession.
ecosystem succession and soil fer tility.
Human activities may reduce soil fer tility and
➔
dic the inuences of human activities on
➔
increase soil erosion.
soil fer tility and soil erosion.
Soil conser vation strategies exist and may be
➔
Ete soil management strategies in a
➔
used to preser ve soil fer tility and reduce soil
named commercial farming system and in a
erosion.
named subsistence farming system.
Kwg  ursg:
➔
Soil ecosystems change through cceio.
more than small-scale subsistence farming
Fer tile soil contains a community of organisms
methods.
that work to maintain functioning nutrient cycles
rece oi fe tiit may result in soil erosion,
➔
and that are resistant to soil erosion.
toxication, salination and deser tication.
h cti itie which can reduce soil fer tility
➔
soi coe tio measures exist such as: soil
➔
include deforestation, intensive grazing,
conditioners (for example, organic materials and
urbanization, and cer tain agricultural practices
lime), wind reduction techniques (wind breaks,
(irrigation, monoculture etc.).
➔
shelter belts), cultivation techniques (terracing,
Coeci itiize foo poctio
contour ploughing, strip cultivation) and avoiding
te generally tend to reduce soil fer tility
the use of marginal lands.
S gr
The
problems
lack
of
supplies
but
it
of
drinking
due
could
to
be
It
is
is
now
the
as
populations
greater
In
MEDCs
culture,
fertility
a
a
as
on
of
strives
land
change,
and
use.
the
All
degradation
equal
facing
and
to
of
as
social
made
has
the
of
is
loss
of
depletion
these
the
society
levels
size
biotic
biodiversity,
of
are
most
today,
and
a
scale)
cultural
larger
and
of
China
fuel
wood
signicant,
pressing
particularly
relatively
there
erosion.
changes
of
long
exists,
that
India
in
occur,
tradition
aims
the
for
even
agriculture
combined
ecosystem
soil
landscape
within
However
intensive
soil
and
(damaged
resulting
areas
management
soil
of
function
management
on
been
land
avoid
climate
unprecedented
to
land
industrial
when
of
impaired
poor
being
knowledge
and
area
there
an
rates
problem
having
are
climate
sanitation
poor.
an
result
where
that
social
expand,
occasions
about
that
demands
(agriculture
are
and
classied
structure)
include
poor
unsustainable
world’s
estimated
time
argued
environmental
affecting
our
water,
loss.
greater
and
of
and
soil.
agriculture
agricultural
sustained
in
As
MEDCs
conspire
to
soil
there
bring
erosion.
265
5
S o i l
S yS t e m S
a n d
S o c i e t y
very degraded soil
degraded soil
stable soil
without vegetation
▲
Fige 5.3.1 An estimate of soil degradation – 15% of ice-free land is aected. This is
2
11 million km
2
aected by water erosion and 5.5 million km
Two
●
types
of
the
soil
that
various
of
the
overgrazing
●
deforestation
●
unsustainable
occurs
Overgrazing
of
soil
the
bare
This
patches
happened
on
Sahara
desert)
wealth
of
levels
not
and
the
soil
activities
when
(erosion).
the
less
end
that
a
soil.
This
Wind
and
mainly
water
suitable
for
use .
and
In
up
in
the
soil
lead
to
soil
degradation
in
the
is
quality
is
bare
animals
patches
combined
scale
and
in
1970s
the
a
is
–
the
turn
area
In
occurs
can
then
these
the
soil
are:
this
in
leads
of
to
the
no
of
from
very
he
high
area .
and
hold
wind
area.
(just
African
cattle
same
longer
rain
the
Africa
many
number
in
roots
action
removed
Sahel
the
graze
where
with
1980s.
by
important)
becomes
soil
and
measured
is
overgrazing
many
bigger
huge
man
too
leaves
this
become
the
(quantity
soil
on
degradation:
run.
When
the
a
soil
away.
grasslands
together.
to
agriculture.
Overgrazing
the
rise
the
chemicals
long
●
away
make
human
give
vegetation
processes
Examples
south
of
countries
has
stocking
problem.
Fige 5.3.2
This
was
strongly
266
no
Processes
in
can
take
is
take
useless
▲
that
there
simply
●
processes
Processes
when
by wind erosion
then
exacerbated
reduced
the
in
growth
the
of
70s
the
and
80s
when
vegetation
a
which
long
was
dry
period
subsequently
5 . 3
eaten
and
the
cattle.
and,
process,
wet
The
blown
cattle
slow
In
by
were
later
it
climates
especially
and
surface
dry
it
often
is
the
rain
depletes
are
being
again
the
to
rain
soil
the
for
water
is
longer
the
that
and
erosion).
This
to
the
failure
can
American
soil.
to
If
Mid
to
soil
by
to
C O n s E r v a T I O n
roots
of
is
a n d
most
a
of
very
recover.
particles
away,
slopes.
the
crop
This
soil
soil
then
a
topsoil
major
as
the
especially
of
suffered
friable
fertility
fails
is
removal
West
place
death
formation
reduces
the
in
the
region
the
makes
erosion.
lead
soil
down
nutrients
in
Sahel
takes
owing
susceptible
As
d E G r a d a T I O n
kept
resulted
famine.
years
water
no
This
terrible
returned
crop
1930s,
a
were
wind.
many
wind
becomes
where
the
in
take
when
regions
During
on,
susceptible
nutrients
particles
by
will
Overcropping
(dry
soil
away
s O I l
no
soil
true
by
in
wind.
period
of
▲
wind
erosion
known
as
the
‘Dust
Bowl’.
Through
overuse
of
the
land
Fige 5.3.3 Deforestation for oil palm
an
plantation
area
to
about
Texas,
dust
twice
was
many
affected
ranging
removal
more
wet
of
the
a
the
of
drops.
This
root
while
The
also
by
the
be
trees
of
to
water
Of
will
Kingdom,
erosion.
forest.
mainly
This
some
the
be
from
The
Nebraska
winds
to
through
moved
slow
bind
the
quantities
eventually
forests
water.
in
down
soil
and
to
the
from
the
is
are
different
complete
removed,
in
of
give
soil
it
The
rain
particles.
and
the
can
regions.
progress
soil
the
relatively
Deforestation
together
water
returned
in
to
tropical
removing
soil
of
done
trees
vegetation
especially
and
be
the
most
explosively
to
can
of
more
As
due
erosion,
deect
help
of
erosion.
them
large
is
of
course,
to
soil
both
forests
wind
removal
prone
on
United
severe
removal
stop
absorbing
the
kilometres.
careful
effect
helps
absorbed
of
erosion
forest
systems
of
vegetation.
will
massive
leaves
is
from
all
soil
areas,
have
size
thousands
Deforestation
ways,
the
The
stability,
directly.
atmosphere
via
transpiration.
Unsustainable
be
or
applied
over
increased
(Total)
long
inputs
unsustainable
●
agricultural
a
of
of
chemicals
agricultural
removal
techniques
period
of
the
without
like
fertilizers
techniques
crops
are
time
after
result
techniques
decrease
or
in
harvest.
in
energy.
soil
This
that
cannot
productivity
Several
degradation:
leaves
the
soil
open
to
erosion.
●
Growing
erosion
the
●
crops
will
rows
Plowing
are
in
channels
●
toxic
●
for
In
irrigation
●
of
is
Monocultures.
This
the
means
soil
its
the
in
make
the
is
the
the
will
This
in
crops.
top
land
the
on
the
a
long
Again,
a
slope
and
of
unsuitable
the
same
soil
crop
are
is
with
make
called
part
of
minerals
the
ready-made
soil
run
is
major
The
leave
the
process
layer
nutrients
between.
grown
will
taking
This
(making
where
same
slope.
systems
the
in
are
slope.
down,
use.
soil
crops
the
This
salinization
This
that
loses
remain
the
of
irrigation
reaching
will
if
ow
agricultural
many
that
of
to
pesticides.
before
called
uncovered
direction
direction
water
crust
process
with
especially
rainwater
use
evaporates
rows
the
further
Irrigation.
salty
in
the
for
Excessive
in
occur,
soil
for
it.
the
the
too
water
dissolved
and
soil
toxication.
form
growing
in
a
the
hard,
crops.
This
salty).
grown
depleted
year
from
the
after
soil
year.
and
fertility.
267
5
S o i l
S yS t e m S
a n d
S o c i e t y
Urbanization.
in
cities
than
removing
may
it
erode
as
have
the
rural
a
soil
settlements
For
in
rst
source
of
expanded
were
into
in
Land
human
in
cities
agricultural
elsewhere.
that
time
areas.
Because
based
prime
on
land
our
history,
is
paved
and
major
agriculture,
agricultural
more
and
of
increasing
cities
many
us
built
the
so
run-off
expanded
of
live
upon
which
from
world’s
early
cities
land.
S rs
If
natural
vegetation
structure
soil
together
cover
soils
is
and
become
major
covers
largely
or
a
soil,
eliminated.
humus
removed
can
Three
▲
are
absorbs
even
prone
processes
when
to
of
processes
Leaves
large
it
is
that
deect
could
heavy
quantities
replaced
by
of
damage
rain,
water.
the
roots
If
agricultural
soil
hold
this
the
natural
vegetation
erosion.
soil
erosion
exist:
Fige 5.3.4 Gully erosion by water in
1.
Sheet
wash:
storm
periods
large
areas
of
surface
soil
are
washed
away
during
heavy
Virginia, USA.
2.
Gullying:
these
3.
and
channels
channels
Wind
erosion:
surface
in
mountainous
develop
become
on
drier
on
much
soils
areas
hillsides
moving
as
following
landslides.
rainfall.
Over
time
deeper.
high
winds
continually
remove
the
layer.
iprvg h s – s srv
A
variety
of
measures
can
be
taken
to
conserve
soil
and
soil
nutrients.
materials.
For
many
Addition of soil conditioners
Typical
soil
centuries
to
increase
benet
sand
raw
soil
●
of
conditioners
farmers
pH
clay
and
they
Acid
trap
soil
soil
more
stick
limestone
air,
helping
rain
acidic
or
chalk
has
that
more
a
they
the
the
soil
additional
act
more
draining
of
like
than
decomposition
number
means
to
the
free
improve
for
snow
so
are
to
or
Lime
together
created
become
Acid
organic
acidication.
particles
Soils
is
and
crushed
particles
larger
precipitation.
the
lime
by
reasons:
water
the
drains
acidic.
Fige 5.3.5 Dust storm of dry
●
soil blown by the wind
Some
■
soil
The
processes
breakdown
carbonic
■
The
removal
materials
into
nutrients
of
the
soil,
(after
make
organic
creating
Nitrication
slow
of
respiration.
■
back
also
through
Organic
▲
clay
The
are
added
counter
microorganisms.
through
▲
and
helping
particles.
have
This
of
more
releases
dissolves
basic
as
ions
straw,
improve
the
the
ions
to
Saskatchewan, Canada
268
and
better
carbon
into
through
or
green
texture
This
organic
of
is
nitrates
the
dioxide
soil
water
absorption
by
manure
the
soil
adds
crops
and
particularly
material
the
increases
leaching
means
Fige 5.3.6 Shelter belts in
nutrients
acidic:
acid.
decomposition).
of
soil
matter
then
ammonium
such
decomposition
the
plant.
to
act
slow
soil
that
good
acidity.
as
acidity.
are
a
plowed
supply
because
release
of
the
of
the
5 . 3
s O I l
d E G r a d a T I O n
a n d
C O n s E r v a T I O n
Wind reduction
The
effect
between
of
the
elds
adjacent
wind
can
(shelter
elds
(strip
be
reduced
belts)
or
by
cultivation).
by
planting
alternating
An
trees
low
alternative
is
or
and
to
bushes
high
build
crops
in
fences.
Soil conserving cultivation techniques
Growing
cover
the
of
rows
between
crops
main
harvest
(fast
crops
and
growing
(for
crops
example
sowing
can
to
cover
between
keep
the
the
rows
soil
of
soil)
corn
particles
in
between
plants)
or
place.
▲
Terracing
is
a
method
to
reduce
the
steepness
of
slopes
by
Fige 5.3.7 Terracing of rice
replacing
paddies
the
slope
wet
rice
with
elds
Plowing
autumn
and
sowing.
structure
seed
ie
are
in
trapping
be
instead
strongly
heavy
structure
is
is
slope.
up/down
water
reduced.
machinery
and
This
has
a
and
temporarily
that
the
to
walls.
Asian
to
make
plowing
along
and
the
to
a
is
drainage.
done
seed
bad
direct
and
contour
the
slope
ridges
downhill
over
is
in
bed
for
soil
drilling
of
biodiversity.
technical
tip
increases
tillage
parallel
ow
has
tendency
soil
furrows
water
method
by
plowing
soil
that
no
cultivating
plowing
hill
the
of
evidence
and
and
zones,
clods
improves
By
separated
way.
up
growing
plowing
the
of
and
breaks
and
terraces,
temperate
activity
erosion
to
this
Northern
there
soil
horizontal
further
farming
soil
soil
microbial
perpendicular
plowing)
up
the
But
and
of
constructed
frost
reduces
Contour
series
breaks
Traditionally,
for
a
act
and
used
as
small
thereby
problems
when
lines,
(contour
however:
parallel
terraces
erosion
to
can
modern
the
slope.
Improved irrigation techniques
By
careful
and
planning
thereby
canals
will
(There
reaches
systems
small
prevent
are
and
salinization
eld.)
consist
openings
known
Trickle
of
be
a
ow
next
irrigation
reduced.
before
where
network
of
greatly
evaporation
examples
the
construction
can
the
up
to
irrigation
of
pipes
to
the
plants
by
the
roots
water
50%
(also
reaches
of
the
called
covering
where
systems,
Covering
the
water
evaporation
irrigation
the
water
drip
eld.
comes
land.
never
even
irrigation)
The
out
pipes
have
drop-wise
▲
and
can
be
taken
in
before
it
evaporates.
It
is
this
Fige 5.3.8 Trickle ow
irrigation
irrigation system
system
that
made
it
possible
to
grow
roses
in
desert-like
areas
in
Israel.
Stop plowing marginal lands
Maybe
we
growing
of
need
crops
to
and
overgrazing).
accept
could
This
that
be
may
very
more
be
the
poor
land
suitable
case
in
for
land
is
simply
cattle
at
the
not
grazing
suitable
(but
boundaries
for
with
of
the
risk
deserts.
Crop rotation
TOK
Some
crops
as
are
the
more
the
soil
the
atmosphere.
‘hungry’
Rhizobium
than
bacteria
in
others.
their
Legumes
root
add
nodules
x
nitrogen
to
nitrogen
from
Our understanding of soil
Cereals
take
a
lot
out
of
the
soil.
The
earliest
farmers
conservation has progressed
recognized
that
growing
the
same
crop
on
the
same
land
year
after
year
in recent years. What
led
to
pest
and
disease
build-up
and
impoverished
the
soil.
Shifting
constitutes progress in
cultivators
in
tropical
rainforests
move
on
after
a
few
years
to
allow
the
dierent areas of knowledge?
soil
by
to
recover.
leaving
Ancient
ground
civilizations
fallow
(with
no
practiced
crops),
crop
rotation,
sometimes
by
sometimes
growing
several
269
5
S o i l
S yS t e m S
a n d
S o c i e t y
crops
Practical
Evaluate
Work
soil
strategies
in
commercial
and
in
a
farming
the
management
a
named
farming
named
system
subsistence
b etween
the
soil
succession
year
cash
growth
rotation
fallow
to
13th
of
of
maximize
centuries,
cropping
was
wheat
and
In
Islamic
rye
until
then
the
fertility
Golden
improvements
crops
civilizations.
introduced
soil
the
exporting
and
or
practised
revolution
continuous
yield.
agricultural
and
populations
winter
year
agricultural
system.
the
a
and
rotations,
be
Explain
in
8th
spring
ourished
In
oats
four-year
turnips
Europe,
or
of
clover
irrigation,
supported
three-year
then
the
so
between
as
and
a
barley
rotation
and
Age,
such
a
British
cropping
could
maintained.
relationship
ecosystem
and
soil
fertility.
Susb f ss
Saving soils
Human
and
on
quickly
activity
soil
lead
any
other
will
lead
of
the
to
in
turn
year).
a
soil
Soil
Soil
is
by
up
in
essential
Soil
soil
soil
a
water
eroded
producing
deep
to
24
ie
lack
a
Our
land
food
(90
that
of
requires
soil
shrinking
are
in
like
character
system
extra
will
Imbalances
inuence
production
million
tonnes
is
global
the
soils
soils
Soils,
state.
also
on
of
fertility.
thus
will
modern
resource
billion
and
This
a
of
dynamic
system
support
of
processes
the
soil
rate
of
estuaries
and
erosion
In
and
is
coastal
for
position
Eroded
soil
the
depends
system
mouths
that
per
informed
eroded
volume
upland
erosion
erosion
at
natural
nutrients
oodplain
and
conditions
prole.
geographical
fertile
the
in
impacts
exploitation
from
annually
rising).
set
another.
negative
and
population
natural
organics
one
within
be
under
the
loss
exist
important
natural
courses,
from
soil.
Croppable
may
within
minerals,
proles
the
of
and
ignorant
chemically.
fertility
an
soil
state
and
with
formation,
accumulation
end
the
burgeoning
However,
soil
in
annually.
by
and
system,
Approximately
formed
new
a
production
naturally.
global
therefore
landscape
is
and
positive
degradation,
the
associated
on
both
physically
supports
(though
have
Unmanaged
change
conservation.
the
soil
of
both
ecosystem
heavily
to
part
soil
can
fertility.
or
is
below
systems,
waters.
the
also
soils
will
occurs
offset
the
rate
eroded
Here
aquatic
may
also
often
it
of
soil
will
provides
ecosystems.
form
wash
the
basis
into
of
valleys
soils.
To tik bot
irrigation water. This is the technocentrist ’s response.
Ecocetic o tecocetic iew of oi
But very quickly the farmers can nd themselves on
fe tiit geet?
a treadmill with spiralling costs as they attempt to
As agricultural systems, even those on the relatively
maintain or increase productivity per unit area while
small scale, become more and more intensive and more
at the same time maintaining soil health and thus
and more commercial, greater and greater demands are
guaranteeing long-term sustainability of the industry.
made on soil per unit area. The soil is required to ‘work
It costs relatively large amounts to buy synthetic
harder ’, produce greater volumes per unit area,
and
fer tilizers and the hardware for irrigation. Therefore
cope with greater demands from genetically modied,
the farmer must produce more to get the revenue to
nutrient-hungry plants. The soil in its natural state and
pay for this investment in chemicals and hardware. In
operating under ambient environmental conditions
producing more, more strain is put on the health of the
can no longer full the demands being made upon
soil system thus more external inputs are required.
it, therefore the soil environment must be modied
Potentially a vicious circle is set in motion. What would
ar ticially with the addition of fer tilizers and additional
the ecocentric farmer do?
270
s O I l
d E G r a d a T I O n
a n d
C O n s E r v a T I O n
E S A C
5 . 3
Y D U T S
du V, Sbh, ms
▲
Fige 5.3.9 Danum Valley rainforest
The
an
Danum
area
of
Valley
area
lowland
of
Sabah,
tropical
East
forest.
Malaysia
Annual
is
rainfall
The
of
Danum
channels,
catchment
most
of
is
covered
which
by
a
network
continually
ow
with
1
is
over
rain
pattern.
occur
are
2,500
mm
This
throughout
selectively
yr
with
means
the
felled
(only
of
the
forest
rather
the
entire
forest
area),
there
is
areas
with
loss
of
an
increase
full
in
canopy
transpiration
that
year.
out
little
forestry
Large
just
even
stream
cover.
where
the
are
cutting
This
returning
of
trees
ow
in
down
this
occurs
because
water
forest
taken
compared
is
the
operations
parts
certain
than
but
seasonality
back
to
of
to
the
water.
This
vehicles
the
to
banks
though
this
increase
is
much
to
areas,
drain
some
into
of
river
clear
felled
of
of
the
soil
bedrock.
large
ash
sensitive
vehicles
water
rather
This
tends
than
means
oods.
to
by
geology
to
This
ow
in
in
percolating
that
heavy
makes
disturbance,
used
terrain
forestry
keep
that
and
forestry
damaging
adding
companies
logging
roads
channels
carry
for
without
channels
drainage
gullies
difcult
clear
have
eroded
to
soil
have
of
tried
water,
developed
soil
into
the
the
less
major
factor
affecting
soil
erosion
in
than
is
the
logging
roads
that
have
been
put
in
areas.
impermeable
catchment,
or
very
systems.
place.
Because
the
where
these
wide
it
stream
Also
Danum
in
cross
of
erosion.
Another
atmosphere,
makes
the
the
down
rainfall
the
Danum
top
soils
especially
surfaces
into
can
create
angles
Many
up
lost
end
from
these
slopes.
movement
soils
of
of
up
The
soil
in
the
have
in
the
been
result
large
local
of
built
this
is
landslides.
streams
and
at
very
often
mass
These
rivers
steep
eroded
and
are
forest.
more
from
the
large
foresters.
271
5
S o i l
S yS t e m S
a n d
S o c i e t y
W E I VE R
To what ex tent are our solutions
To what ex tent can food
to soil degradation mostly aimed
production become more
at prevention, limitation or
sustainable?
restoration?
BiG QUeStionS
S sss 
s
In your opinion, discuss whether
inequitable food distribution
Evaluate the soil system model
may cause major conict in the
future?
Rv quss
➔
The soil system may be represented by a soil prole. Since a model is
strictly speaking not real, how can it lead to knowledge?
➔
Consumer behaviour plays an impor tant role in food production
systems. Are there general laws that can describe human behaviour?
➔
Our understanding of soil conser vation has progressed in recent
years. What constitutes progress in dierent areas of knowledge?
➔
Why are regional food production systems dierent?
➔
How are food choices inuenced by culture and religion?
➔
Many LEDCs produce cash crops that are sold to MEDCs; this reduces
food availability for the LEDC’s population.
272
■
Why does this happen?
■
What socio-political and factors inuence this?
■
What ecological and factors inuence this?
■
What are the international issues associated with this?
Quk rvw
All
questions
are
worth
1
mark
5.
Which
process
reduces
storages
of
soil
nutrients?
1.
Modern
tend
commercial
A.
lower
B.
reproduce
species
maximize
C.
agricultural
practices
to
create
diversity
early
net
stages
in
of
the
community.
succession
to
A.
Addition
of
well-composted
B.
Addition
of
lime
C.
Application
D.
Heavy
of
inorganic
organic
matter
fertilizers
productivity.
conditions
favourable
for
W E I VE R
R E V I E W
rainfall
r-selected
6.
Which
of
the
following
is
most
likely
to
lead
to
species.
desertication?
D.
2.
do
The
all
the
above.
downward
soil
prole
is
the
following?
leaching
primarily
A.
Transformation
B.
Transfer
of
of
of
an
nutrients
example
within
of
which
A.
Eutrophication
B.
Use
C.
Irrigation
D.
Ozone
the
of
energy
7.
energy
Which
of
3.
Transfer
D.
Transformation
Which
of
is
of
the
fertilizers
depletion
the
represents
C.
organic
of
following
most
characteristics
of
correctly
each
type
of
soil?
materials
best
of
s oi
C oi
Good water-inltration
Good water-inltration
capacity
capacity
Poor nutrient-holding
Good nutrient-holding
capacity
capacity
Good aeration
Good aeration
Good water-holding
Poor water-holding
capacity
capacity
materials
explanation
of
the
advantage
A.
contour-plowing?
A.
Plowing
across
efciency
of
the
contours
harvesting
improves
the
B.
techniques.
C.
B.
Plowing
drainage
across
of
the
the
contours
improves
soil.
D.
C.
Plowing
erosion
D.
of
Plowing
drainage
4.
Which
of
correctly
Human
.
.
.
II
.
.
parallel
the
the
the
contours
prevents
the
contours
improves
soil.
parallel
of
with
the
with
soil.
combinations
completes
activities
the
such
in
the
following
as
.
.
.
I
.
.
.
table
below
sentence?
can
cause
soil
.
I
II
A.
Overgrazing
Conservation
B.
Deforestation
Degradation
C.
Urbanization
Conservation
D.
Addition of organic material
Degradation
273
6
Atmospheric systems And society
6.1 Itodtio to th toh
sga a:
Ala a kll:
➔
The atmosphere is a dynamic system which is
➔
Di the role of the albedo eect
essential to life on Ear th.
from clouds in regulating global average
➔
The behaviour, structure and composition of
temperature.
the atmosphere inuence variations in all
➔
Oti the role of the greenhouse eect in
ecosystems.
regulating temperature on Ear th.
Kwlg a uag:
➔
➔
The toh i  dyi yt (with
➔
occur
undergone changes through geological time.
which
The atmosphere is predominantly a mixture of
carbon dioxide, argon, water vapour and other
➔
trace gases.
H ti viti it the atmospheric
in
the
are
connected
inner
the
Ear th)
and
above
Ear th).
layers
of
troposphere
the
to
living
the
atmosphere,
(0–10
stratosphere
systems
km
(10–50
above
km
Most clouds form in the troposphere and play an
impor tant role in the bdo eect for the planet.
➔
The ho t of the atmosphere is a
composition through altering inputs and outputs
natural and necessary phenomenon maintaining
of the system. Changes in the concentrations
suitable temperatures for living systems.
of atmospheric gases such as ozone, carbon
dioxide and water vapour have signicant eects
on ecosystems.
274
reactions
inputs, outputs, ows and storages), which has
nitrogen and oxygen, with smaller amounts of
➔
Most
6 . 1
I n T r O D u c T I O n
T O
T H e
a T m O s p H e r e
carbon dioxide, argon, water vapour,
t a 
ozone and others, 1%
The
atmosphere
ows.
the
Heat
and
is
a
dynamic
pollutants
system
are
with
carried
inputs,
across
the
outputs,
Earth
by
storages
air
and
currents
in
atmosphere.
oxygen, 2
1%
Over
geological
greatly
as
and
ozone,
the
time,
the
changes
carbon
composition
in
dioxide,
the
of
the
atmosphere
concentrations
methane
and
water
of
has
changed
atmospheric
vapour
have
gases
such
signicant
nitrogen, 78%
effects
on
ecosystems
(7.2).
atmosheight
constant rise (to 1500°C?)
pheric
(km)
pressure
▲
(mb)
Fi 6.1.1 Atmospheric
thermo-
100
composition
sphere
0.001
90
meso80
0.01
pause
70
meso0.1
sphere
60
50
1
strato-
pause
40
10
strato30
30
maximum
sphere
ozone
20
100
tropo-
pause
10
500
tropoMount Everest
sea
sphere
level
1013
100
90
80
70
60
50
40
30
20
10
0
10
20
30
temperature (°C)
▲
Fi 6.1.2 The ver tical structure of the atmosphere
Although
the
atmosphere
stratosphere
where
most
Human
(10–50
reactions
activities
is
km)
approximately
and
affecting
and
the
life
occur,
activities
1,100
km
troposphere
by
eg
ozone
other
in
(less
depth,
than
and
10
cloud
organisms
the
km)
are
formation.
impact
the
To do
atmospheric
composition
system.
the
And
through
atmospheric
altering
composition
inputs
affects
and
outputs
activities
of
of
the
humans
Draw a systems diagram of
and
other
organisms.
the atmosphere.
pa a ag
The
is
atmosphere
unstable
climate
Abiotic
●
Biotic
factors
factors
cannot
atmospheric
indirect
shells
from
Before
the
climate
of
uctuated
–
–
both
gas
mainly
plants
measure
temperature
and
and
has
Earth
greatly
have
in
always
the
past.
changed.
Factors
Climate
inuencing
are:
●
We
and
and
and
plants
evolved
atmosphere
on
but
to
are
it
is
in
the
in
by
bubbles
taken
hard
on
to
It
gradually
past
proxy.
trapped
how
there
increased
but
We
in
sediments
say
photosynthesize,
Earth.
precipitation.
distant
indirectly
concentration
period,
and
animals.
precipitation
directly
measurements
the
temperature
we
can
ice.
or
to
no
Various
they
free
about
measure
measure
fossilized
accurate
was
can
also
direct
animal
are.
oxygen
35%
at
in
the
275
6
At m o s p h e r i c
s ys t e m s
A n d
s o c i e t y
end
of
the
geological
Early
Carboniferous
timescale,
Carboniferous
Carboniferous,
was
20
°C,
probably
350ppm
400
590
505
carbon
1500
when
ppm
previous
the
the
carbon
600
438
period
slightly
about
350
million
per
the
360
°C
million)
286
248
the
years
was
cooled
today.
in
the
and
was
atmosphere
excepting
Earth
this
15
temperature
in
years
and
our
(million
on
concentration
(parts
average
MYA
MYA
than
dioxide
ppm
(300
temperature
lower
dioxide
408
period
average
12
in
12
°C
later
the
decreased
Today
in
the
was
to
there
less
the
the
temperature
atmosphere
(0.04%),
In
°C
When
this
°C.
to
ago)).
20
than
about
are
in
about
the
Carboniferous.
2
13
144
65
2
8000
y rait reT
suoecaterC
CENOZOIC
cissaruJ
cissairT
naimreP
nainoveD
MESOZOIC
suorefinobraC
6000
nairuliS
naicivodrO
7000
nairbmaC
PALEOZOIC
)mpp(
Quaternary
5000
2
ave. global temp.
3000
22°C
2000
1
7°C
1000
0
600
12°C
500
400
300
200
100
erutarepmet labolg egareva
OC cirehpsomta
2
atmospheric CO
4000
0
millions of years ago
▲
Fi 6.1.3 Global temperature and atmospheric CO
over geological time
2
1.
What
the
2.
is
the
relationship
between
carbon
dioxide
and
temperature
in
graph?
What
other
factors
besides
atmospheric
carbon
may
inuence
Earth
temperatures?
3.
Can
we
rely
on
the
data
collection
methods
used?
t gu 
The
greenhouse
maintaining
for
life
on
we
know
Earth.
it.
temperature
Earth’s
right
276
The
of
average
for
effect.
A
life
key
effect
suitable
is
Indeed,
nearest
−53
°C
33
°C
feature
natural
of
without
planets
and
surface
and
a
and
temperatures
it,
to
Venus
for
this
there
the
with
temperature
warmer
necessary
living
than
would
Earth
a
are
surface
is
a
it
would
temperature
phenomenon
systems
be
Mars
be
the
a
good
life
with
+15
without
fact
that
thing
on
a
°C,
the
Earth
as
surface
temperature
comfortable
is
–
no
of
so
+450
°C.
just
greenhouse
water
is
liquid.
6 . 1
The
effect
radiation
the
to
a
is
Earth’s
the
caused
back
surface
Earth.
glass
into
A
by
and
removes
reduces
loss
of
the
But
by
the
atmosphere
trap
it
heat
–
misnomer
more
than
that
trap
by
reducing
energy
some
is
greenhouses
heat
heat
in
They
reradiate
common
greenhouse.
which
gases
space.
back
this
I n T r O D u c T I O n
that
to
is
heat
by
radiation.
in
and
the
reducing
The
losses
reected
space
works
heat
T O
T H e
a T m O s p H e r e
by
Practical
from
some
same
back
way
as
convection
atmosphere
How
light
and
mostly
by
the
the
infrared
heat.
by
the
Earth.
Earth’s
the
4%
including
evaporation.
It
mostly
This
Nearly
is
55%
is
made
passes
the
and
of
of
this
clouds
incoming
reected
and
back
to
of
the
is
solar
light,
relevance
sustainability
longer
wavelength
to
it
radiation
the
the
that
This
ground
environment
is
scattered
reaches
absorbed.
of
infrared
and
is
Earth
human
absorbed
been
used
the
extent
activity
directed
limiting
the
in
seas,
several
causes,
infrared
energy
–
heat
energy.
(See
have
from
and
the
or
the
studying
on
at
environmental
or
surface
reaches
and
what
emerging
in
society
or
of
sustainable
the
solutions
the
preventing
impacts
extent
of
restoring
or
have
already
In
ways
might
of
causes
of
problems,
impact
systems
impacts
eect
atmosphere
from
in
these
which
occurred?
and
what
the
solutions
atmosphere
explored
as
addressed
systems
development?
ultraviolet
atmosphere
absorbed,
before
heating
the
visible
wavelength
51%
photosynthesis,
released
up
through
longer
50%
atmosphere
Of
surface,
processes
is
(although
atmosphere).
issues
radiation.
radiation
unaffected
reected
of
solar
the
atmospheric
To
Incoming
are
Work
gure
in
atmospheric
systems
and
6.1.4.)
society
the
alter
state
of
biosphere
incoming solar radiation is mostly
nearly 50% of this is absorbed, scattered
made up of visible light, ultraviolet
or reected by the atmosphere and clouds
light and infrared heat
before it reaches the surface of the Ear th
your
predictions
human
some
societies
decades
for
and
from
the
now?
4% is reected
51% absorbed;
this is used in several
processes including
photosynthesis, heating
the ground and seas,
evaporation
▲
If
Fi 6.1.4 Fate of solar radiation reaching Ear th
we
go
had
no
straight
drastically
There
the
Only
the
which
many
ones
our
re-emit
gases
atmosphere
molecules
re-emit
with
energy
atmosphere
that
but
to
two
in
as
heat
do
more
way.
not
heat
energy
this
–
is
heat
Earth
absorbed
back
to
greenhouse
carbon
warmer
or
this
this
on
would
would
by
Earth.
fall
gases
It’s
a
in
bit
the
like
Earth.
can
be
atmosphere,
temperature
of
vapour,
this
are
it
the
the
some
the
water
in
and
But
around
are
gases
space
night.
blanket
are
main
cause
and
a
into
every
atmosphere
having
greenhouse
back
than
bonds
Nitrogen
greenhouse
it
dioxide
would
joining
and
gases
and
be
the
(GHG)
without
atoms
oxygen
–
but
methane.
can
make
They
them.
up
absorb
most
of
gases.
277
6
At m o s p h e r i c
s ys t e m s
A n d
s o c i e t y
6.2 sttohi oo
sga a:
Ala a kll:
➔
Stratospheric ozone is a key component of the
evt the role of national and international
➔
atmospheric system because it protects living
organizations in reducing the emissions of
systems from the negative eects of ultraviolet
ozone-depleting substances.
radiation from the Sun.
➔
Human activities have disturbed the dynamic
equilibrium of stratospheric ozone formation.
➔
Pollution management strategies are being
employed to conser ve stratospheric ozone.
Kwlg a uag:
➔
Some ultraviolet radiation from the Sun is
➔
Pollution management may be achieved by reducing
absorbed by stratospheric ozone causing the
the manufacture and release of ozone-depleting
ozone molecule to break apar t. Under normal
substances. Methods for this reduction include:
conditions the ozone molecule will reform. This
●
recycling refrigerants,
●
developing alternatives to gas-blown
ozone destruction and reformation is an example
of a dynamic equilibrium.
plastics, halogenated pesticides, propellants
➔
Oo-dti bt (including
and aerosols, and
halogenated organic gases such as
●
developing non-propellant alternatives.
chlorouorocarbons – CFCs) are used in
➔
The uitd ntio eviot po
aerosols, gas-blown plastics, pesticides, ame
(UNEP) has had a key role in providing
retardants and refrigerants. Halogen atoms
information and creating and evaluating
(eg chlorine) from these pollutants increase
international agreements for the protection of
destruction of ozone in a repetitive cycle so
stratospheric ozone.
allowing more ultraviolet to reach the Ear th.
➔
➔
An i kt for ozone-depleting substances
utviot ditio reaching the surface of the
continues and requires consistent monitoring.
Ear th damages human living tissues, increasing
➔
The mot potoo (1987) and subsequent
the incidence of cataracts, mutation during cell
updates is an international agreement on the
division, skin cancer and other subsequent
reduction of use of ozone-depleting substances
eects on health.
signed under the direction of UNEP
. National
➔
The eects of increased ultraviolet radiation
governments complying with the agreement
on biological productivity include damage
made national laws and regulations to decrease
to photosynthetic organisms, especially
consumption and production of halogenated
phytoplankton which form the basis of aquatic
organic gases such as chlorouorocarbons (CFCs).
food webs.
278
6 . 2
s T r a T O s p H e r I c
O z O n e
iu  z
Ozone
it
is
is
found
‘good’
Ozone
is
a
and
in
two
the
layers
of
the
troposphere
molecule
made
up
atmosphere
(6.3)
of
where
three
it
oxygen
–
is
the
stratosphere
considered
atoms
–
O
.
to
be
where
‘bad’.
Oxygen
gas
ozone layer
is
3
stratosphere
diatomic,
O
.
The
stratospheric
and
protects
ozone
blocks
incoming
ultraviolet
radiation
2
troposphere
from
the
sun
life
from
damaging
ultraviolet
(UV)
radiation.
smog
Ozone
over
is
its
also
a
greenhouse
environmental
gas
(GHG)
(see
7.2),
so
do
not
get
confused
effects.
▲
t z la
Fi 6.2.1 Ozone in the
atmosphere
Ozone
lower
is
a
reactive
gas
stratosphere.
altitudes
is
between
But
it
The
ozone
ozone
a
is
very
an
to
of
is
In
split
also
and
of
an
poles
ppm
the
the
oxygen
oxygen
and
an
radiation
atom.
is
and
then
oxygen
in
20
the
seen
at
km).
ozone.
because
continuously
the
Oxygen
and
The
and
million)
of
oxygen
layer
usually
15
per
inuence
atoms.
with
are
equilibrium
atoms
formation
Under
UV
ozone
between
(parts
dynamic
combine
absorb
so-called
concentrations
the
oxygen
both
into
can
the
1–10
a
from
absorbed.
and
(at
about
made
in
ozone
km
example
are
can
molecule
40
oxygen.
reactive,
Ozone
oxygen
layer
radiation
molecules
extremely
ozone.
back
UV
oxygen
is
found
highest
and
continuously
converted
ozone,
layer
The
20
thin
mostly
destruction
UV
atoms
are
molecule
splits
atom
of
radiation,
into
can
to
form
an
react
with
energy
ox ygen atom
electron
another
ozone
molecule,
making
two
oxygen
molecules
(gure
6.2.2).
proton
The
adsorption
of
UV
radiation
by
the
ozone
layer
is
crucial,
for
without
it,
ox ygen
neutron
life
on
UV
-B
land
and
would
UV
-A
wavelength)
the
longer
The
be
impossible.
radiation.
and
is
wavelength
ozone
layer
UV
-C
therefore
(low
absorbs
UV
radiation
the
most
energy)
more
radiation
than
has
is
the
harmful
UV
-A
99%
usually
highest
type
radiation
of
the
divided
of
is
UV
-C
into
energy
UV
radiation
molecule
(shortest
radiation,
relatively
UV
-C,
while
harmless.
and
about
ozone
molecule
half
of
Hall,
the
UV
-B
Upper
radiation
Saddle
River,
(M.
B.
2003,
Bush,
p.
Ecology
of
a
Changing
Planet,
Prentice
▲
381).
Fi 6.2.2 Formation of ozone
e f ulavl aa
Damaging eects
Increased
exposure
to
UV
radiation
●
Genetic
●
Damage
to
●
Cataract
formation
●
Skin
●
Suppression
●
Damage
to
photosynthetic
●
Damage
to
consumers
mutation
living
and
will
subsequent
have
effects
a
variety
on
of
damaging
effects:
health.
tissues.
in
eyes.
cancers.
of
the
immune
of
system.
organisms,
especially
photosynthetic
phytoplankton.
organisms,
especially
zooplankton.
279
6
At m o s p h e r i c
s ys t e m s
A n d
s o c i e t y
Ultraviolet
radiation
This
especially
risk
number
People
is
of
protect
also
of
skin.
isolines
causes
denatures
In
Photosynthetic
New
in
the
food
–
and
humans
on
Zealand
cloudy
on
in
clothes
burn
organisms
effects
mutations
Australia
cancer
show
turns
in
wear
cataracts
and
disruptive
to
to
cause
high
skin
advised
their
includes
It
cases
are
can
the
the
has
daily
in
a
species’
Zealand
increased
beach
and
to
weather
where
DNA.
the
dramatically.
use
sun
report
in
blocks
to
summer
times.
lenses
of
eyes
instead
of
clear,
are
changes
New
sensitive
to
when
the
causing
UV
protein
of
blindness
radiation.
This
the
if
lens
untreated.
can
have
pyramids.
Benecial eects
●
In
animals,
our
bodies.
are
short
●
It
●
Use
can
a
radiation
Vitamin
of
also
as
water
●
UV
D
calcium
be
used
sterilizer
stimulates
deciency
and
to
as
too
treat
it
kills
soft
the
causes
to
production
rickets
support
psoriasis
and
pathogenic
vitamin
when
the
a
child’s
D
in
bones
body.
vitiligo,
bacteria
of
both
and
skin
as
an
diseases.
air
and
purier.
Industrial
uses
in
lasers,
viewing
old
scripts,
forensic
analysis,
lighting.
A llu a  z l
Since
in
be
the
the
1950s,
called
during
the
the
November.
that
scientists
stratosphere
the
ozone
spring
Apart
ozone
thickness
of
data.
Reductions
longer.
in
other
Environmental
have
the
this
was
amount
growing.
These
the
Science,
and
has
as
2nd
well,
ed.,
of
ozone
During
were
of
and
cycle,
the
later
what
years,
and
conrmed
the
ozone
arctic
Thornes,
ozone
again
scientists
30
of
later
would
signicantly
increased
the
last
stratospheric
1984
amount
decreased
drastically
including
Nelson
the
discovered
ozone
reduced
results
amount
measuring
They
October)
annual
layer
areas
been
Antarctica.
(September
ozone
taking
in
hole:
from
hole
the
been
observed
above
in
discovered
the
minimum
recovery
by
NASA
have
region
been
(K.
Cheltenham,
Byrne,
2001,
1997
strong long wave
weak long wave
total column ozone
low
▲
280
average
has
satellite
high
Fi 6.2.3 Ozone hole in Nor th America 1984 and 1997
p.
27).
6 . 2
s T r a T O s p H e r I c
O z O n e
oz-lg uba (ods)
Ozone
depletion
mostly
halogenated
there
is
the
human-made.
are
organic
others
result
The
of
most
gases,
for
air
pollution
important
example
by
chemicals
that
ozone-depleting
are
gases
chlorouorocarbons
or
are
CFCs,
but
too.
sbt
u/o
rk
Chlorouorocarbons
Propellants in spray cans,
Release chlorine
(CFCs or freons)
plastic foam expanders,
atoms
refrigerants
Hydrochlorouoro
As replacements for CFCs
Release chlorine
carbons (HCFCs)
atoms, but have a
shor ter lifetime in the
atmosphere. Stronger
greenhouse gases
Halons
Fire extinguishers
Release bromine
atoms
Methyl bromide
Pesticide
Releases bromine
atoms
,
Nitrogen oxides (NO, NO
Bacterial breakdown of
The nitrogen oxides are
nitrites and nitrates in the
conver ted to NO, which
soil (intensive farming)
reacts with ozone
2
O, often summarized
N
2
)
as NO
x
High-ying supersonic
aircraft
▲
Fi 6.2.4 The most impor tant ozone-depleting substances (ODS)
The action of ODS
When
chlorouorocarbons
1930s,
largely
They
they
seemed
because
were
they
used
●
propellants
●
expanders
●
pesticides,
●
ame
●
refrigerants.
Later
on,
plastic
time
to
of
CFCs
foam.
freons)
to
were
many
(non-reactive)
developed
technological
at
ground
during
the
problems,
level.
replaced
were
in
plastics,
and
refrigerants
was
radiation
inert
or
answer
aerosols,
CFCs
it
are
(CFCs
the
gas-blown
quickly
before
UV
in
used
be
as:
retardants,
Previously
therefore
to
also
are
were
by
the
the
used
as
extremely
discovered
very
toxic
non-toxic
and
and
propellants
stable
that
they
stratosphere.
UV
at
in
ammable,
non-ammable
spray
ground
were
and
not
radiation
cans
level
so
and
and
stable
releases
it
were
CFCs.
to
expand
took
when
a
long
exposed
chlorine
atoms
281
6
At m o s p h e r i c
s ys t e m s
A n d
s o c i e t y
from
Practical
Work
Investigate
changes
tropospheric
a
source
road)
of
and
solving
ozone
the
(eg
the
atoms
from
a
towards
of
when
ozone
chlorine
They
formation.
formed
One
chain
These
destruction.
are
atoms.
a
back
chlorine
reaction
and
atom
with
atoms
can
In
are
can
can
also
both
of
again
thus
positive
react
react
these
able
with
with
to
destroy
ozone,
oxygen
processes,
react
many
with
which
atoms,
the
results
thereby
chlorine
ozone
molecules
or
of
oxygen
ozone
in
feedback
problem.
While
Investigate
CFCs.
ozone
preventing
in
away
pollution
attitudes
in
two
examples
national
approaches
have
international
foam
impact
an
on
option
The
substances
toxic
and
of
to
atmosphere
is
the
nearly
their
the
used
as
good
less
as
blowing
difcult
before
the
to
agents
nd
a
introduction
properties.
The
refrigerants
HCFCs
effect.
also
Only
harmful
to
as
the
CFCs
and
plastic
CFCs
(HCFCs).
are
also
and
lifetime
layer
are
suitable
ozone
shorter
ozone
of
most
destroy
their
for
suitable
hydrochlorouorocarbons
as
However,
them
and
more
dangerous
greenhouse
makes
cans
much
so-called
inammable.
contribute
spray
it
refrigerants
are
are
in
easy,
because
replacements
environmental
discussions.
CFCs
relatively
refrigerant.
economic
an
replacing
is
than
not
CFC
These
non-
they
in
the
CFCs.
Sun
2. ozone and oxygen atoms
are continuously being
interconver ted as solar UV
breaks ozone and the oxygen
atoms reacts with another
1. oxygen molecules are
oxygen molecule (FAST)
photolysed, yielding 2
oxygen atoms (SLOW)
O
1
O
3
O
2
2
O
2
3. ozone is lost by a reaction
of the oxygen atom or the
3
ozone molecules with each
this interconversion process
other, or some other trace
conver ts UV radiation into thermal
gas such as chlorine (SLOW)
energy, heating the stratosphere
▲
Fi 6.2.5 The ozone cycle
CFCs
for
of
are
up
to
CFCs
thicker
282
extremely
100
into
years
the
ozone
stable,
after
and
their
atmosphere
layer.
will
therefore
release.
will
persist
Measures
therefore
take
in
taken
a
long
the
to
atmosphere
prevent
time
to
release
result
in
a
6 . 2
s T r a T O s p H e r I c
O z O n e
Reducing ODS
Using
the
strategy,
‘replace,
gure
regulate
6.2.6
and
shows
restore’
some
model
actions
for
of
pollution
reducing
management
ozone-depleting
substances.
stty fo di otio
ex of tio
Altering the human activity producing
Replace gas-blown plastics.
pollution
Replace CFCs with carbon dioxide, propane or air as a propellant.
Replace aerosols with pump action sprays.
Replace methyl bromide pesticides.
(But most of the gases that can be used to replace CFCs are greenhouse gases).
Regulating and reducing the pollutants
Recover and recycle CFCs from refrigerators and AC units.
at the point of emission
Legislate to have fridges returned to the manufacturer and coolants removed
and stored.
Capture CFCs from scrap car air conditioner units.
Clean up and restoration
Add ozone to or remove chlorine from stratosphere – not practical but it was
once suggested that ozone-lled balloons should be released.
▲
Fi 6.2.6 Table of replace, regulate and restore model of pollution management
for ozone depletion
t mal pl
TOK
The
discovery
international
organizations
started
aerosol
cans,
to
is
took
boycott
and
even
forges
●
studies
gives
One
of
Protocol
freeze
levels
of
a
by
1990
and
time
was
to
states,
an
CFCs
forbidden
in
and
many
(mainly
to
by
on
national
international
developed
spray
countries
cans).
ozone-friendly
law,
and
hardly
any
The
involved
in
The Montreal Protocol was
an international agreement
made by the UN. Can one
spray
group or organization know
CFC-
what is best for the rest of
the world?
anymore.
protecting
Programme),
the
environment
which:
a
organizations
the
series
the
of
reduce
Since
of
the
the
difculties
in
The
many
the
to
is
phase
CFCs
and
original
LEDCs.
Montreal
out
and
to
In
to
1986
production
Montreal
The
the
agreed
halons
amendments.
and
the
signatories
consumption
the
seven
MEDCs
public.
UNEP
agreement
1987,
of
and
direction
substances.
between
and
them
production
in
implement
agreements
international
2000.
made
public
changing
these
under
strongly
by
strengthened
distinction
of
enforcing
and
to
response
agreements
to
is
fast
governments
produced
ozone-depleting
substances
been
more
It
a
Environmental
signed
consumption
these
has
of
by
were
effectiveness
(1987).
production
before
organization
and
to
containing
were
Nations
treaties
led
general
quickly
CFCs
cans
information
the
the
products
international
the
hole
even
reacted
implementing
●
But
steps,
Nations
(United
●
ozone
before
spray
United
UNEP
the
levels.
industry
containing
The
of
the
Protocol
protocol
LEDCs
got
treaty.
283
6
At m o s p h e r i c
s ys t e m s
A n d
s o c i e t y
Some
197
world
Most
at
time,
countries
national
laws
were
still
need
for
of
countries
the
the
it
also
has
a
plan
The
reduction
substances
ventures
of
has
to
out
to
the
and
economic
phase
the
the
air
growth
ODS
do
the
huge
that
are
is
China
is
of
UN
before
the
and
made
however,
These
countries’
growing
But
in
agreement.
India
CFCs.
quickly
years
countries
Protocol
and
experiencing.
two
all
ratied
Montreal
amounts
production
because
China
has
schedule
now
and
India
so.
emissions
been
of
conditioners
they
–
universally
accordingly.
using
and
agreement
rst
rules
regulations
producing
to
was
followed
and
refrigerators
fast
agreed
ratied
so
one
of
of
CFCs
the
and
most
other
ozone-depleting
successful
international
cooperative
date.
Timeline in CFC reduction
1970s
Ozone-depleting
Sweden
banned
continue
1985
British
1987
Montreal
to
mount
Antarctic
1990
emissions
London
out
and
Industrialized
1992
and
Further
Nobel
and
2006
ever
2012
25th
to
Prize
and
by
for
NOAA
ozone
the
United
Over
strengthen
would
so
30
USA
and
Concerns
hole.
Nations
countries
Montreal
Montreal
eliminate
countries
by
accelerate
agree
to
cut
Protocol:
Protocol
CFC
phase-
amended.
production
by
2010.
phasing
out
of
ODS
and
chemicals.
awarded
work
record
1974
uses.
2000.
substitute
their
In
aerosol
the
(UNEP).
Chemistry
for
by
inadequate
to
recognized.
1980s.
reports
by
countries
measures
Crutzen
NASA
rates
developing
replacement
1995
half
CFCs
non-essential
organized
Amendment
dates
2000
through
Program
by
of
from
Survey
Protocol
Environmental
CFC
properties
them
on
the
to
Molina,
solving
the
Antarctic
Sherwood
ozone
ozone
Rowland
depletion
hole
as
the
issue.
largest
measured.
anniversary
of
signing
of
the
protocol.
Signicance of the Montreal Protocol
There
1
are
The
several
best
signicant
example
of
facts
about
international
it.
cooperation
on
an
environmental
issue.
2
An
example
of
the
precautionary
of
many
principle
in
science-based
decision
making.
3
An
to
4
example
research
The
rst
to
chemicals
5
284
The
rst
the
recognize
at
different
with
experts
problem
and
that
their
different
countries
depending
that
elds
coming
together
solutions.
different
times
regulations
in
nd
were
on
could
their
carefully
phase-out
economic
monitored.
ODS
status.
6 . 2
s T r a T O s p H e r I c
O z O n e
465,000
440,000
E1 : methyl bromide
415,000
C1−C2−C3 : HCFCs, HBFCs, bromochloromethane
390,000
B1−B2−B3 : other CFCs, CTCs, MCFs
A2 : halons
365,000
A1 : CFCs
340,000
total consumption
sennot ni SDO ni noitpmusnoc
315,000
290,000
265,000
240,000
2
15,000
190,000
165,000
140,000
115,000
90,000
65,000
40,000
15,000
1102
0102
9002
7002
8002
of
6002
life
5002
4002
2002
3002
1002
0002
9991
7991
8991
5991
6 991
4991
3991
2991
1991
0991
6891
▲
9891
10,000
Fi 6.2.7 EU consumption of ODS 1986–2011
However
the
this
is
not
atmosphere,
2005
still
nor
will
allowed
illegal
it
to
market
the
return
make
in
end
chlorine
to
and
ODS
of
did
the
not
story.
reach
pre-ODS
use
some
Due
its
levels
to
the
peak
much
HCFCs
in
long
the
before
until
2030.
CFCs
stratosphere
2050.
There
LEDCs
is
also
in
until
are
an
chemicals.
To do
To do
1.
What steps is your national
government taking to comply
USSR
11%
with these agreements?
N. America
2.
Name local or non-
33%
Asia 15%
governmental organizations
concerned with ODS
S. America 2%
reduction.
Africa 2%
Oceania 1%
3.
What actions are they taking
to persuade governments to
comply?
Europe
36%
4.
▲
5.
a.
Comment on the signicance of the data in relation to MEDCs and LEDCs.
b.
Discuss the success of UNEP and other international bodies in dealing with
What can you do to help
protect the ozone layer?
Fi 6.2.8 Percentage use of CFCs in 1986 by region
evt the role of
national and international
organizations in reducing the
the CFC problem.
emissions of ozone-depleting
c.
State one change in the data that the pie char t for the year 2015 might show.
substances.
285
6
At m o s p h e r i c
s ys t e m s
A n d
s o c i e t y
6.3 photohi o
sga a:
Ala a kll:
➔
The combustion of fossil fuels produces primary
evt pollution management strategies for
➔
pollutants which may generate secondary
reducing photochemical smog.
pollutants and lead to photochemical smog,
whose levels can vary by topography,
population density and climate.
➔
Photochemical smog has signicant impacts on
societies and living systems.
➔
Photochemical smog can be reduced by
decreasing human reliance on fossil fuels.
Kwlg a uag:
➔
➔
piy ott from the combustion of fossil
trapped beneath a layer of less dense, warm
fuels include carbon monoxide, carbon dioxide,
air. This causes concentrations of air pollutants
black carbon/soot, unburned hydrocarbons,
to build up near the ground instead of being
oxides of nitrogen, and oxides of sulfur.
dissipated by ‘normal’ air movements.
In the presence of sunlight, ody
➔
ott are formed when primary pollutants
undergo a variety of reactions with other
to smog.
➔
chemicals already present in the atmosphere.
➔
Toohi oo is an example of a secondary
Deforestation and burning may also contribute
Economic losses caused by urban air pollution
can be signicant.
➔
potio t tti include:
pollutant, formed when oxygen molecules
●
ati h tivity to consume less.
react with oxygen atoms that are released from
Example activities include the purchase of
nitrogen dioxide in the presence of sunlight.
energy ecient technologies, the use of public/
➔
Tropospheric ozone is highly reactive and
shared transit, and walking or cycling.
damages crops/forests/plants, irritates eyes,
●
rti d di ott t oit
creates respiratory illnesses and damages
of iio via government regulation/
fabrics and rubber materials. so is a complex
taxation.
mixture of primary and secondary pollutants, of
●
Using catalytic conver ters to clean exhaust
which tropospheric ozone is the main pollutant.
of primary pollutants from car exhaust.
➔
The frequency and severity of smog in an
●
Regulating fuel quality by governments.
●
Adopting -  such as
area depends on local topography, climate,
population density and fossil fuel use.
reforestation, re-greening, and conservation of
➔
Th ivio occur due to lack of air
areas to sequester carbon dioxide.
movement when a layer of dense, cool air is
286
6 . 3
p H O T O c H e m I c a l
s m O g
Uba a llu
UNEP
estimates
●
1
billion
●
1
million
●
2%
●
over
of
Air
is
of
is
be
may
air
eg
eg
by
pollution
in
in
air
to
pollution
air
year
pollution
MEDCs,
LEDCs
per
5%
in
comes
LEDCs
from
old
motor
maintained.
chemicals,
–
emitted
particulates
motor
directly
eruptions
vehicle
pollution
and
biological
is
from
or
exhausts.
from
the
a
process.
The
anthropogenic
A
major
combustion
process
(human-
source
of
of
fossil
fuels
and
produces:
●
carbon
monoxide
●
carbon
dioxide
●
unburned
●
nitrogen
also
oxides
nitrous
sulphur
●
particulates
ne
are
Other
–
from
incomplete
especially
oxide
dioxide
or
particles
taken
and
–
combustion
of
fossil
fuels
hydrocarbons
●
–
from
solid
the
nitrogen
nitric
coal
particulate
of
into
and
or
lungs
dioxide,
a
brown
gas,
but
oxide
with
matter
liquid
when
high
sulphur
(PM)
–
suspended
breathing
eg
content
black
in
air,
and
carbon
or
dangerous
cause
lung
soot
as
–
they
diseases
cancers.
sources
●
building
●
forest
variety
primary
pollutants
include:
res.
of
pollutants
reactions
atmosphere.
presence
of
sites
Secondary
a
due
pollution
volcanic
industry,
air
outdoor
be:
pollutants
anthropogenic
2.
air
poorly
caused
natural,
made),
this
are
to
prematurely
by
urban
These
Primary
exposed
die
lost
which
pollution
may
are
people
90%
materials.
1.
people
GDP
vehicles
that:
of
Examples
–
formed
with
Sometimes
other
this
is
a
when
primary
chemicals
pollutants
already
photochemical
present
undergo
in
reaction
the
in
the
sunlight.
of
secondary
●
tropospheric
●
particulates
●
peroxyacetyl
pollutants
are:
ozone
produced
nitrate
from
gaseous
primary
pollutants
(PAN).
t z
Only
it
is
gas
10%
in
of
atmospheric
concentrations
with
a
global
of
ozone
only
warming
is
in
the
0.02–0.3
potential
troposphere
ppm.
2,000
Ozone
times
is
that
(g
also
of
6.1.2).
a
Here
greenhouse
carbon
dioxide.
287
6
At m o s p h e r i c
s ys t e m s
A n d
s o c i e t y
Formation of tropospheric ozone
Among
the
pollutants
hydrocarbons
not
all
and
the
fuel
nitrogen
temperature
Nitrous
and
is
from
combustion
contributes
to
the
the
combustion
Hydrocarbons
Nitrogen
originating
during
during
oxides.
combusted.
(both
oxide
emitted
nitrogen
oxides
air)
are
react
as
are
of
fossil
emitted
formed
a
result
fuels
when
of
are
because
the
oxygen
high
reactions.
formation
of
tropospheric
ozone
(O
).
3
First
nitric
(NO
).
oxide
This
is
a
(NO)
reacts
brown
gas
with
that
oxygen
to
contributes
form
to
nitrogen
urban
haze.
dioxide
Other
2
pollutants
like
formation
of
into
oxide
nitric
react
with
hydrocarbons
nitrogen
and
oxygen
and
dioxide.
oxygen
carbon
When
atoms.
molecules,
monoxide
this
absorbs
These
forming
accelerate
sunlight,
oxygen
atoms
it
the
breaks
up
subsequently
ozone.
sunlight
nitric oxide
nitric oxide +
oxygen atom
+
oxygen molecule
ozone
▲
Fi 6.3.1
Under
back
very
normal
into
conditions,
nitrogen
slight
most
dioxide,
build-up
of
ozone
creating
ozone
near
a
molecules
virtual
ground
oxidize
cycle
that
nitric
leads
oxide
to
only
a
level.
Possible eects of ozone
●
Ozone
is
a
toxic
oxidation,
●
Damage
In
the
to
Damage
reduce
may
the
–
an
that
oxidizing
extra
O
tropospheric
ozone
are
degrades
so
agent
is
–
oxygen
causes
worse.
ozone
is
chlorophyll
absorbed
so
by
plant
photosynthesis
leaves.
and
reduced.
humans
actions
increase
throat
●
to
and
has
plants
leaves,
productivity
●
gas
ozone
–
of
at
low
the
concentrations,
lungs,
susceptibility
to
so
causing
infection.
It
photochemical
breathing
also
causes
smog
difculties,
eye,
nose
can
and
and
irritation.
Damage
to
materials
■
Ozone
■
It
reduces
■
It
also
attacks
the
and
products:
natural
lifetime
bleaches
rubber,
of
car
cellulose
and
some
plastics.
tyres.
fabrics.
Fa f aula
Burning
almost
particles
of
Poorly
288
any
carbon
maintained
organic
and
material
other
diesel
or
fossil
substances,
engines,
in
fuel
referred
particular,
releases
to
as
release
small
particulates.
large
amounts
of
6 . 3
particulates
or
(small
particulate
Dangers
1.
The
of
so
the
they
Many
3.
In
with
are
them
passages
enter
respiratory
2.
particles)
and
in
exhaust
smaller
fumes.
than
10
They
are
called
micrometres
in
s m O g
PM10
diameter.
particulates:
problem
lining
solid
materials
p H O T O c H e m I c a l
our
problems
close
developing
reduces
to
that
our
bronchi
and
and
are
respiratory
and
stay
even
crops
or
(nose
cannot
lter
asthma,
and
hairs
them
lung
out
cancer,
death.
(cancer-causing).
dense
urban
covered
because
lters
causing
premature
become
productivity
lungs)
there
carcinogenic
industrial
regions
their
the
bodies
particulates
areas
of
is
less
areas
with
and
especially
particulates,
sunlight
reaches
in
which
the
leaf.
t fa f al g
On
warm,
formed
fossil
In
sunny
over
fuels,
days
cities.
forest
Kalimantan,
with
lots
Although
burning
can
Indonesia,
of
trafc,
usually
also
forest
photochemical
associated
contribute
res
in
1997
with
to
the
smog
can
photochemical
caused
be
combustion
smog
of
smog.
over
much
of
▲
S
E
Asia.
The
res
burned
8
million
hectares,
cost
the
government
Fi 6.3.2 Indonesian forest res
nearly
in 1997 causing air pollution over a
US$
5
billion
and
released
a
huge
amount
of
carbon
dioxide
and
other
wide area
gases
into
the
atmosphere.
ultraviolet
nitric oxide : NO
rays
nitrogen oxides
nitrogen dioxide : NO
2
photochemical
reaction
photochemical smog
oxidants consisting mainly
of ozone (O
)
3
• PAN
• aldehyde
• acrolein
nitric oxide
oxygen
nitrogen dioxide
oil tank, paint
hydrocarbon
gas station
▲
Fi 6.3.3 Formation of photochemical smog
Photochemical
mixture
of
pollutants.
vehicle
smog
about
The
in
including
reactions
VOCs
nitrogen
different
contribution
cities.
hydrocarbons
Complex
mainly
hundred
biggest
exhausts
gaseous
is
one
It
from
create
(volatile
is
to
formed
vehicle
many
dioxide
ozone
and
ozone,
exhausts
smog
is
nitrogen
interact
in
but
with
PANs
a
complex
air
from
oxides
strong
photochemical
compounds),
is
secondary
photochemical
when
chemicals
organic
and
primary
motor
and
sunlight.
smog
(peroxyacyl
289
6
At m o s p h e r i c
s ys t e m s
A n d
s o c i e t y
nitrates),
reactive
ozone,
VOCs
breaking
up
of
Because
be
down
ozone
seen
Even
a
though
afternoon.
is
a
hue
main
a
hours,
This
is
and
an
and
in
and
city.
the
reaction,
fact
so
it
process.
these
things.
ability
that
the
reaches
This
Highly
without
leads
–
to
a
build-
at
higher
are
smog
can
strongly
concentrations,
oxides
during
its
peak
and
the
morning
maximum
important
its
smog,
concentrate.
nitrous
is
of
chemicals
At
to
concentration
smog
oxides.
dioxide
component
pollutants
photochemical
nitrous
formation.
All
living
and
nitrogen
the
smog
decreased
primary
to
into
important
the
maximum
due
photochemical
is
above
materials
reach
monoxide
oxide
molecules
level
dioxide
coughs
the
hydrocarbons
rush
ozone
affect
cause
carbon
nitrogen
ground
brown
and
can
evening
any
near
nitrogen
as
oxidizing
smog
aldehydes,
oxidize
in
the
smog-causing
in
the
afternoon
and
early
reaction
sun.
Photochemical smog forming conditions
peak smog
hydrocarbons
aldehydes
20
nitrogen oxides
time of day
mhpp/oitar gnixim
aerosols
– concentration of
15
ozone varies throughout
a 24 hr period
10
– maximum smog
production occurs
5
NO
NO
2
around midday.
ozone
8 am
▲
noon
4 pm
Fi 6.3.4 Concentrations of main components of photochemical
smog in a day
Because
often
from
called
this
Paulo,
The
Los
type
Beijing
smog
and
of
including
●
local
●
climate
●
population
●
fossil
smog
Angeles-type
of
occurrence
factors,
▲
photochemical
are
rst
caused
smog.
problems
Other
Santiago,
cities
Mexico
in
that
City,
Los
Angeles,
frequently
Rio
de
it
is
suffer
Janeiro,
Sao
Athens.
photochemical
smog
is
governed
by
a
large
number
of
the
topography
density
Fi 6.3.5 Beijing on a smoggy
day. A rainstorm would clear the air
fuel
use.
temporarily.
Smog
is
valleys.
of
Practical
the
most
The
wind
Thermal
changes
tropospheric
source
road)
of
and
solving
ozone
away
pollution
attitudes
the
in
problem
(eg
relatively
from
a
towards
even
on
formed
over
mountains
warm,
this
air
often
inversion
warm
warmer
large
cities
that
surrounding
calm
disappearance
makes
has
of
air
trapping
warm,
the
and
layer
rising,
in
disperse
290
and
or
days
severe
are
low-lying
these
cities
smog
can
take
and/or
away
in
most
occur.
Work
Investigate
a
often
hills
dry
of
worse.
tendency
on
the
top
of
rain
to
the
pollution
climates.
smog:
smog.
a
things
at
Weather
cleans
Normally,
rise.
air
an
of
warm
polluted
ground
plays
the
On
warm
air
level.
over
days
air
This
important
pollutants
cities
is
however,
can
occurs
role
while
an
prevent
in
most
the
winds
can
6 . 3
p H O T O c H e m I c a l
s m O g
To do
cooler air
lodo-ty o
cool air
This was the rst time the phrase
“smog” was coined. London-type
warm air
smog (smog = smoke + fog) is a
completely dierent type of smog.
It occurs at low temperatures.
The main primary pollutants are
also dierent: sulphur dioxide
and smoke particles produced by
normal pattern
burning coal. These smogs killed
many people until clean air acts in
cool air
1956 legislated to stop coal-burning
(unless smokeless fuels) in cities.
Explain why London smogs were
warm inversion layer
not photochemical smogs. (Hint –
cool air
what was being burned in homes?)
thermal inversion
▲
Under
the
harmful
city
where
above
or
itself.
damage
the
strategies
even
Often,
in
Complete
Fi 6.3.6 Thermal inversion trapping smog over a city
the
the
smog
was
table
the
levels.
is
concentration
Smog
blown
countryside,
smog
for
conditions
lethal
out
is
not
of
the
sometimes
up
of
only
city
to
pollutants
affecting
by
150
the
km
can
life
wind
away
in
reach
the
and
causes
from
the
city
formed.
below
reducing
to
evaluate
photochemical
the
pollution
management
smog.
stty fo di b i otio
ex of tio
Altering the human activity producing
Consume less, burn less fossil fuel – especially in the
pollution
internal combustion engine.
evtio
Act as informed consumers for purchase of energy
ecient technologies.
Use public/shared transit, walking and cycle paths.
Lobby governments to increase renewable energy use.
Regulating and reducing the pollutants at
Government regulation/taxation.
the point of emission
Catalytic conver ters to clean exhaust of primary pollutants
from car exhaust.
Fuel quality may be regulated by government.
Clean up and restoration
Aorestation to increase carbon sinks and lter air. But
remember this does not reduce emissions.
Re-greening of cities – more trees, more parks – absorb
carbon dioxide.
▲
Fi 6.3.7
291
6
At m o s p h e r i c
s ys t e m s
A n d
s o c i e t y
6.4 aid doitio
sga a:
Ala a kll:
➔
Acid deposition can impact living systems and
evt pollution management strategies for
➔
the built environment .
acid deposition.
➔
The pollution management of acid deposition
often involves cross-border issues.
Kwlg a uag:
➔
The obtio of foi f produces sulphur
potio t tti for acid
➔
dioxide and nitrous oxides as primary pollutants.
deposition could include the following measures:
These gases may be conver ted into secondary
Altering human activity eg through reducing
●
pollutants of dry deposition (eg ash and dry
use, or using alternatives to fossil fuels.
par ticles) or wet deposition (eg rain and snow).
➔
International agreements and national
The possible t of acid deposition on soil,
governments may work to reduce pollutant
water and living organisms include:
production through lobbying.
●
dit t, for example, acid on aquatic
Regulating and monitoring release of
●
organisms and coniferous forests
●
pollutants eg through the use of scrubbers
or catalytic conver ters that may remove
idit toxi t, for example, increased
sulphur dioxide and nitrous oxides from coal
solubility of metal (eg aluminium ions) on sh
burning power plants and cars.
●
idit tit t, for example,
Clean-up and restoration measures may
●
leaching of plant nutrients.
include spreading ground limestone in
➔
The impacts of acid deposition may be limited to
acidied lakes or recolonization of damaged
areas dowwid of major industrial regions but
systems but these are limited.
these areas may not be in the same country as
the source of emissions.
Acid
deposition
Often,
wet
or
the
acid
is
deposition
dry
the
comes
general
down
Dry
in
term
the
for
form
deposition
is
acid
of
coming
rain
when
the
(or
down
snow),
acid
comes
from
this
is
down
the
air.
called
as
ash
particles.
Acidity
+
Acids
The
a
are
acidity
pH
scale
times
292
of
value
solutions
pH
chemicals
of
solutions
7
is
not
more
a
is
values
linear
acidic
are
neutral
whereas
is
that
than
able
measured
(pure
above
scale,
a
to
it
give
using
water).
7
is
solution
a
hydrogen
the
Values
indicate
pH
3.
scale.
below
basic
logarithmic.
with
pH
ion
A
7
(H
On
)
away.
this
indicate
(alkaline)
solution
scale,
acidic
solutions.
with
pH
2
The
is
ten
6 . 4
Normal
This
is
unpolluted
caused
Precipitation
pollutants
lower
by
is
pH
is
slightly
presence
called
increase
than
rain
the
acidic
the
of
acidic
and
carbon
when
its
acidication
pH
of
has
dioxide
is
well
rain,
a
pH
in
of
the
below
which
about
D e p O s I T I O n
5.6.
atmosphere.
pH
can
a c I D
5.6.
Certain
sometimes
fall
2.
0
1
battery acid
2
lemon juice
3
vinegar
increasing
acid rain
acidity
adult sh die
4
sh reproduction aected
5
normal range of precipitation pH
6
milk
neutral
7
normal range of stream pH
8
baking soda
9
sea water
10
increasing
milk of magnesia
alkalinity
11
ammonia
12
13
lye
14
▲
Fi 6.4.1 The pH scale
ma a  llua a u
Pollutants
Air
pollutants
can
be
pollutants(6.3).
emitted
factory
directly,
or
the
for
pollutants
pollutants
leave
deposition
the
are
into
primary
pollutants
example
exhaust
secondary
acid
divided
Primary
pipe
(1.5).
those
of
a
So,
chimney.
sulphur
are
pollutants
car.
Primary
secondary
The
and
those
main
dioxide
(SO
secondary
pollutants
leaving
pollutants
primary
)
the
pollutants
and
react
made
pollutants
nitrogen
are
chimney
can
are
air
that
react
Carbon
with
dioxide
water
(CO
)
to
is
form
also
strong
oxides
(NO
acidic
the
to
).
x
acids
but
a
form
after
leading
2
They
of
to
–
sulphuric
forms
a
weak
and
acid
nitric
–
acids.
carbonic
acid.
2
Sources
Naturally,
nitrogen
sulphur
oxides
dioxide
by
is
produced
by
volcanic
eruptions
and
lightning.
▲
The
most
important
pollutants
thermal
steam
are
the
power
to
drive
human
activities
combustion
stations
the
which
of
that
fossil
use
fossil
lead
fuels
fuels
to
in
the
emission
motor
(coal,
oil,
cars,
gas)
of
industry
to
Fi 6.4.2 Industrial air pollution
these
and
produce
nitrogen dioxide +
turbines.
sulphur dioxide +
Sulphur
dioxide
is
formed
when
sulphur-containing
fuels
are
carbon dioxide +
combusted.
natural
gas.
Sulphur
is
common
in
coal
and
oil,
but
is
usually
absent
in
▲
Fi 6.4.3
293
6
At m o s p h e r i c
s ys t e m s
A n d
s o c i e t y
Nitrogen
air,
of
If
oxides
which
fossil
the
long
fuel.
The
primary
time,
dioxide
trioxide
are
readily
a
can
formed
takes
nitrogen
air
(SO
).
is
of
the
remain
oxygen
sulphur
of
high
part
secondary
with
Both
reaction
at
not
pollutants
variety
react
by
place
of
in
air
oxygen
the
the
the
dioxide
atmosphere
can
be
atmosphere
and
nitrogen
during
from
the
combustion
fuel.
pollutants
from
and
temperature
sulphur
for
a
sufciently
formed.
to
form
trioxide
Sulphur
sulphur
can
react
with
3
water
and
form
sulphurous
acid
(H
SO
2
respectively.
nitric
acid
The
(HNO
nitrogen
).
These
oxides
)
and
sulphuric
acid
(H
3
can
secondary
SO
2
also
react
pollutants
with
are
water
very
and
soluble
)
4
form
in
water,
3
and
are
removed
and
snow
(wet
from
the
air
by
precipitation
in
the
form
of
rain,
hail
deposition).
Acid rain
sulphur dioxide and
oxides
acid can
nitrogen oxides enter
conver ted
travel in
atmosphere
to sulphuric
clouds up
and nitric
to 1500 km
acids
from source
smog from
industries
and cars
dry deposition
local wet deposition
distant wet
on land
by rain, snow and fog
deposition
leaching
leaching
run-o
run-o
through to soil
to water body
▲
leaching
run-o
through to soil
through to soil
to water body
to water body
Fi 6.4.4 The eects of acid deposition on soil, water and living organisms
Acid
in
deposition
the
early
‘waldsterben’
showed
signs
Revolution
air
in
cities
damage
1970s
when
of
trees
of
term
all
focus
in
‘acid
both
But
1750),
rain’
of
Black
ages,
damage.
started
the
a
Germany’s
physical
(which
and
became
when
environmental
Forest
coniferous
before
people
was
showed
that,
in
noticed
rst
used
and
the
dieback
or
deciduous,
Industrial
acidic
in
attention
a
rain
and
acid
1872.
e f a 
Acid
deposition
can
have
direct
and
indirect
effects
on
soil,
plants
and
water:
●
direct
acid
effects,
falling
affecting
●
indirect
■
eg
on
aquatic
and
tree
ponds
growth
decreasing
in
the
■
coniferous
pH
of
the
forests,
water
organisms
toxic
effects,
eg
increased
which
is
toxic
solubility
to
sh
of
and
metal
plant
Fi 6.4.5 Forest death from
acid deposition
294
weakening
effects
aluminium
▲
by
lakes
nutrient
effects,
eg
leaching
of
nutrients.
ions
roots
such
as
and
6 . 4
a c I D
D e p O s I T I O n
Eect of acid deposition on coniferous forests
Acid
1.
deposition
Leaves
the
2.
and
form
These
buds
of
and
leached
affects
forests
show
lesions,
other
out
several
yellowing
thinning
changes
and
in
of
away
(loss
wax
reduce
washed
ways:
of
chlorophyll)
damage
in
cuticles.
growth,
and
and
and
allow
pathogens
and
nutrients
insects
to
to
be
gain
entry.
3.
Symbiotic
root
availability
4.
It
reduces
calcium,
5.
It
Trees
are
microbes
nutrients,
the
ability
of
magnesium
releases
damage
of
toxic
root
are
killed
further
soil
and
and
particles
potassium
aluminium
this
reducing
ions
to
hold
ions
from
greatly
tree
on
to
which
soil
reduces
the
growth.
nutrients,
are
particles
then
such
leached
which
as
out.
then
hairs.
weakened
and
may
die.
Toxic eects of acid deposition
Aluminium ions – eect on sh and other aquatic organisms
Aluminium
the
pH
of
released
are
is
the
a
common
soil,
from
the
particularly
soil
disturbs
water
body.
in
its
gasp
leading
shes’
other
for
to
gills,
This
breath
death.
toxic
the
At
leading
metals
to
the
higher
to
the
salt
soil.
more
ends
ability
inhibits
up
in
in
to
by
dissolve
Acid
normal
aluminium
streams
and
rivers.
a
of
low
the
their
suffocation.
because
At
intake
of
decreases
The
regulate
content
precipitation
soluble.
water.
concentrations,
death
can
the
aluminium
sh’s
and
in
aluminium
eventually
sensitive
aluminium
Fish
element
making
amount
of
oxygen
bodies
solid
is
Apart
is
of
salt
and
on
and
salt.
slowly
formed
from
increased
Fish
concentrations,
lost,
the
aluminium,
acidity.
Lichens
Lichens,
found
gaseous
of
which
growing
only
species
of
pollutants
lichen
a
symbiotic
trees
pollutants
pollution.
region
are
on
like
and
sulphur
Immediately
a
few
high
tolerant
levels
increases
indicator
of
species
species
are
more
used
to
an
and
of
are
a
alga
are
are
As
and
the
species
estimate
a
used
as
are
distance
able
pollution
are
to
measures
industrial
indicator
from
to
(2.1),
sensitive
indirect
polluting
These
are
fungus
particularly
heavily
found.
pollution.
and
of
They
dioxide
downwind
air
more
pairing
buildings.
the
survive.
source
Tables
of
of
levels.
Nutrient removal eect on soil fer tility
As
described
soil
particles
potassium
above
to
ions
nitrogen-xing
acid
hold
on
which
rain
to
are
bacteria
affects
the
nutrients,
then
and
leached
thus
soil
such
their
by
as
out.
reducing
calcium,
Acid
ability
to
rain
add
the
ability
magnesium
also
of
and
inhibits
nitrate
ions
to
the
soil.
Buildings
Acid
deposition
also
effects
human
constructions.
Limestone
buildings
▲
and
statues
(including
many
with
great
archaeological
and
Fi 6.4.6 Eect of acid deposition
historical
on a limestone sculpture – 1908 (top),
value)
react
with
acid
and
simply
dissolve.
1969 (bottom)
295
6
At m o s p h e r i c
s ys t e m s
A n d
s o c i e t y
Peat bogs
Recent
research
produce
bacteria
that
up
to
that
a
40%
use
produce
methane,
has
also
less
the
in
that
methane
sulphates
methane.
GHG,
found
This
the
as
peat
than
a
atmosphere
affected
before.
food
reduction
bogs
This
source
in
is
by
acid
because
outcompete
methane
rain
the
the
production
ones
reduces
(7.2).
Human health
Dry
deposition
and
these
lung
is
in
penetrate
disease
such
as
the
form
into
of
small
houses
asthma
and
and
particles
our
of
lungs.
bronchitis
can
sulphates
Premature
result
and
nitrates
deaths
from
from
this.
rgal  f a 
The
or
ozone
the
as
effects
acid
or
wet
thousand
Dry
can
nitrogen
the
It
is
that
were
It
usually
consists
deposition
nitric
therefore
are
all
long
The
the
in
contrast
Earth.
This
distances,
acids
mainly
occurs
of
occurs
seldom
quite
sulphur
at
pollutants.
is
they
to
climate
because,
return
to
travel
further
to
source
change
before
the
surface
than
a
few
close
dioxide,
the
sulphur
of
the
trioxide
acidic
and
the
slightly
It
longer
consists
of
distances
sulphurous
from
acid,
the
sources
sulphuric
mainly
the
downwind
affected.
affected
brought
by
over
For
acid
by
areas
example,
rain
of
originating
prevailing
major
industrial
Scandinavian
in
forests
Britain,
southwestern
regions
and
Poland
winds.
lakes
and
Industrial
N
ASIA
NORTH
EUROPE
AMERICA
Pacic
Ocean
Atlantic
Ocean
AFRICA
equator
SOUTH
AMERICA
Pacic
Ocean
Indian
Ocean
AUSTRALIA
the global problem of acid rain
0
2000
4000
mi
acid rain
polluted air emissions leading to acid rain
0
2000
4000 km
sensitive soils, potential problems
ANTARCTICA
▲
296
Fi 6.4.7 Regions of the world with most acid deposition impacts
of
acid
acid.
strongly
Germany
affect
over
regional
oxides.
primary
and
are
kilometres.
deposition
Wet
which
spread
precipitation.
substances.
●
deposition
depletion
pollutants
dry
●
of
6 . 4
pollution
from
the
USA
is
blown
by
prevailing
winds
towards
a c I D
D e p O s I T I O n
Canadian
To do
forests.
Industrialization
in
China
affects
S
E
Asia.
Research the eect of acid
Soils
or
bodies
of
water
are
most
often
affected
by
acid
rain.
However
deposition and intergovernmental
the
impact
of
acid
rain
will
depend
very
much
on
the
geology
of
the
area
agreements or legislation and
on
which
it
falls.
Acid
rain
does
little
harm
to
soils
derived
from
calcium
their eectiveness for one of:
carbonate
neutralize
produce
(or
soils
minerals
nearby
rocks,
ie
limestone
buffer)
that
from
the
are
these
acids.
very
soils.
and
chalk.
However
sensitive
This
These
to
reduces
acid
acid
are
alkaline
soils,
(non-alkaline)
rain.
Acid
biodiversity
rain
and
which
a)
rocks
leaches
run-off
Canada aected by acid
deposition from the USA
out
affects
b)
lakes.
Sweden and Norway aected
by acid deposition from
Poland, Germany, UK
pllu aag ag f a
c)
China.
Draw a poster to show the impact

and pollution management
Using
the
‘replace,
regulate
and
restore’
model
of
pollution
management
strategies.
strategy,
and
the
their
table
below
gives
some
actions
for
reducing
acid
deposition
evaluations.
stty fo di
ex of tio
evtio
otio
Altering the human
Replace fossil fuel use by using alternatives:
Also reduce CO
emissions but we live
2
in a fossil fuel reliant economy.
activity producing
•
Ethanol to run cars.
•
Renewable energy sources for electricity.
pollution
Demand for power is ever increasing,
par ticularly in India and China as they
Reduce overall demand for electricity – education
industrialize.
campaigns in the population to turn lights o,
insulate houses, etc.
Use less private transpor t – car pool, public
transpor t, walk , cycle.
Use low sulphur fuels, remove sulphur before
burning, or burn mixed with limestone.
Regulating and
Clean-up technologies at ‘end of pipe’ locations
Expensive and costs passed on to
reducing the pollutants
(points of emission), eg scrubbing in chimneys to
consumer.
at the point of emission
remove the sulphur dioxide.
Catalysers are cost eective if well
Catalytic conver ters conver t nitrous oxides back to
maintained but are expensive to buy.
nitrogen gas.
Clean up and
Liming acidied lakes and rivers (see below).
restoration
Eective in restoring pH but has to be
repeated regularly. Costly.
Recolonize damaged areas.
Aects biodiversity in other ways.
Liming forestry plantations. Trees acidify soils as
Treats symptoms and not the cause.
they remove nutrients.
International agreements
Agreements are dicult to establish
and to monitor.
▲
Fi 6.4.8 Table of replace, regulate and restore model of pollution
management for acid deposition
297
6
At m o s p h e r i c
s ys t e m s
A n d
s o c i e t y
t l f aal ag  ug
TOK
a 
Environmental problems
Acid
rain
is
an
international
issue
because
emission
of
a
particular
are often emotive. Under
pollutant
from
pollutant
in
one
country
does
not
equal
the
deposition
of
that
what circumstances should
the
same
country.
we maintain a detached
relationship with the subject
matter under investigation?
Timeline for political solutions
In Europe
1970s
Evidence
of
Practical
for
German
rain
accumulates
loss
of
lake
including
biodiversity
death
and
of
vast
tracts
accelerated
Work
weathering
Investigate
acid
a
of
selection
acid
forests,
deposition
of
buildings.
in
1979
UN
Convention
1983
Convention
on
Long
Range
Transboundary
Air
Pollution.
countries.
Canada
1985
modied
agreed
by
1993.
30
countries
Emissions,
(from
the
agreeing
1980
many
cut
levels)
of
that
and
the
to
by
reduce
1993.
that
European
emissions
Protocol
signed
those
fteen
sulphur
adopted
countries
and
to
did
the
sulphur
This
the
on
was
sign
countries,
30%
dioxide
also
USA
1980
of
30%
this
met
and
levels
Sulphur
emissions
the
achieved
have
of
Reduction
called
Protocol
not
by
by
club.
30%
All
of
reduction,
these
reductions.
1988
Soa
convention
levels
in
1994
motor
UN
27
1998.
for
reducing
Most
nitrogen
countries
missed
oxides
this
by
target
30%
due
of
to
1987
increase
vehicles.
Convention
1980
1999
by
levels
by
countries
further
modied
to
cut
emissions
by
80%
of
2003.
signed
Transboundary
Air
up
to
new
Pollution
protocol
to
reduce
on
Long
and
Range
prevent
air
pollution.
In Nor th America
1995
Clean
Air
below
in
Act
1980
Eastern
Allowance
allocated
These
target
levels.
states.
to
Also
trading
to
can
–
emit
be
sulphur
affected
target
scheme
allowances
allowances
reduce
Mostly
of
dioxide
reducing
producers
an
sold
power
nitrogen
of
amount
bought,
emissions
coal-burning
acid
of
and
to
stations
oxides.
deposition
sulphur
gases
dioxide.
traded.
Evaluation of success
In Europe
Average
of
developing
to
increase
countries
emissions
50%
rapidly
of
these
are
to
Europe
countries
technologies
Due
agreements
in
industrializing
developed
clean
gases.
achieved
rapidly
unless
‘leapfrog’
international
298
reductions
countries
to
the
and
regional
concerning
acid
by
2000.
and
can
However
emissions
help
lifestyles
character
deposition
are
set
developing
with
of
are
reduced
acid
more
deposition,
of
6 . 4
bilateral
Plants
or
regional
Directive.
installations
electricity
that
plants
character.
This
One
directive
have
and
a
thermal
large
example
regulates
the
capacity
industries.
of
is
the
EU
Large
emissions
more
Though
by
than
the
Combustion
D e p O s I T I O n
In USA
large
50
Kyoto
a c I D
MW
,
basically
protocol
Sulphate wet deposition
aimed
1983−85
at
reducing
CO
emissions
will
also
help
reduce
acid
deposition.
2
rug   f a 
Liming lakes to neutralize acidity
Starting
in
in
large
lake
the
1950s,
numbers
acidity.
By
of
the
loss
of
many
Scandinavian
1990,
over
400
sh
lakes
lakes
and
was
were
invertebrate
linked
to
virtually
high
species
levels
lifeless.
In
of
the
1992−94
1980s,
lakes
is
Sweden
and
rivers.
quickly
inow
of
raised
water;
Biodiversity
nutrient
experimented
was
balance
However
but
results
short-lived
liming
not
as
with
only
were
treats
the
powdered
mixed.
because
immediately
nutrients
adding
of
than
pH
acidic
symptoms
restored;
other
The
the
the
of
not
of
the
seemed
were
to
treated
nature
and
lime
calcium
limestone
their
lakes
the
cause.
to
affect
absent.
Reducing emissions
One
to
way
reducing
cars
and
wind
the
in
to
reduce
the
use
solar
of
the
emission
combustion
of
switching
and
loss
reduce
the
cars,
to
crops
sub-topic5.2)
and
of
of
fossil
sulphur
fuels.
developing
alternative
energy
food
1995−97
can
and
do
this.
increase
nuclear
more
energy
Also
the
power
dioxide
Reducing
efcient
sources
and
the
or
like
biofuels
for
is
electric-powered
this
reduce
and
may
problems
will
oxides
electricity,
waterpower
(though
malnutrition
generation
nitrogen
need
add
to
discussed
SO
and
NO
2
x
<5.0
12.0
19.0
26.0
33.0
>40.0
emissions.
2
kg SO
1
ha
1
yr
4
Precombustion techniques
Precombustion
techniques
aim
at
▲
reducing
SO
emissions
by
removing
Fi 6.4.9 Wet deposition in
USA 1983–1997
2
the
sulphur
the
fuel
which
used
can
can
in
from
be
be
the
obtained
used
in
construction,
production
of
fuel
in
the
or
sulphuric
before
combustion.
several
chemical
as
sulphur
acid,
one
useful
forms:
industry,
dioxide
of
the
The
as
as
the
can
used
removed
element
gypsum,
which
most
sulphur
which
be
used
from
sulphur
can
in
be
To do
the
chemicals.
Consider Figure 6.4.9 and
research the most recent
ndings on acid deposition.
End of pipe measures
End
of
from
pipe
the
plants
measures
waste
and
the
gases.
motor
remove
the
Examples
car
sulphur
include
catalytic
dioxide
waste
converter.
gas
and
nitrogen
scrubbers
Waste
gas
in
oxides
electricity
scrubbers
are
To do
intended
nitrogen
to
remove
oxides,
sulphur
together
dioxide.
with
other
The
catalytic
converter
removes
pollutants.
Evaluate the use of catalytic
conver ters in cars.
299
6
At m o s p h e r i c
s ys t e m s
A n d
s o c i e t y
W E I VE R
To what ex tent are our solutions
Human society depends on
to atmospheric pollution mostly
oil but this is not sustainable.
aimed at prevention, limitation
Discuss your predictions for the
or restoration?
state of a world without oil.
BiG QUestions
A 
a 
Discuss whether economic
development can ever be
sustainable development.
rv qu
➔
The Montreal Protocol was an international agreement made by the UN. Can
one group or organization know what is best for the rest of the world?
➔
Environmental problems are often emotive. Under what circumstances
should we maintain a detached relationship with the subject matter under
investigation?
➔
Explain why ozone depletion is a global issue.
➔
Explain why
➔
Explain why national economic decisions have an impact on international
acid deposition is a regional problem.
environmental discussions.
300
C.
Quk vw
Ozone
gas
is
atmosphere
All
questions
are
worth
1
Which
impact(s)
associated
with
on
the
ecosystems
release
of
may
be
sulphur
the
Increased
living
of
nitrogen
combustion
of
None
above
of
the
uptake
of
aluminium
ions
A
Which
A.
organisms.
decrease
the
of
these
The
in
certain
mineral
storages
B.
leaf
surface
area
in
the
oxides
produced
by
the
fuels.
statements
is
correct.
Ozone
C.
The
by
and
III
C.
I
is
correct?
of
of
ozone
involves
ultraviolet
the
radiation.
is
destroyed
by
by
burning
carbon
fossil
dioxide
fuels.
coniferous
forests.
II
in
in
soil.
III. Reduced
I,
fossil
statements
formation
released
A.
upper
increase
by
absorption
II.
the
atmosphere?
6.
I.
in
the
oxides
D.
into
of
mark
amount
1.
decreasing
because
W E I VE R
R E V I E W
type
the
of
ultraviolet
ozone
layer
radiation
does
not
absorbed
affect
living
only
organisms.
B.
I
and
III
only
D.
III
only
D.
2.
Which
of
the
deposition
A.
following
from
Leaching
of
is
burning
calcium
not
of
a
result
fossil
from
of
acid
are
fuels?
Death
of
coniferous
soils.
trees
in
rapidly
escape
7.
This
to
B.
Chlorouorocarbons
into
question
the
broken
graph,
the
in
the
down
outer
stratosphere
allowing
them
to
atmosphere.
refers
right.
forests.
IV
100
The
C.
Killing
of
sh
due
to
high
levels
in
concentration
of
of
aluminium
highest
ozone
is
in
the
lakes.
80
altitude
D.
Thermal
expansion
of
band:
oceans.
III
A.
0–10
altitude
km.
60
3.
Which
global
of
these
human
warming
and
activities
depletes
both
the
(km)
increases
ozone
B.
10–20
km.
C.
20–40
km.
D.
40–80
km.
layer?
40
A.
Emission
of
carbon
dioxide
from
vehicle
II
exhausts.
20
B.
Emission
of
sulphur
dioxide
from
power
8.
The
Vienna
and
Montreal
I
stations.
agreements
were
aimed
at
0
reducing
C.
Leakage
D.
Release
of
methane
from
gas
A.
of
CFCs
from
old
the
pipelines.
amount
released
4.
Which
statement
about
acid
rain
is
Acid
rain
is
countries
a
problem
because
it
is
of
developed
B.
Rain
industrial
always
with
pH
loss
of
above
7
is
considered
to
Lime
D.
Corrosion
A.
can
be
used
two
of
of
the
Ozone
of
to
restore
Ozone
buildings
the
main
following
gas
is
atmosphere
B.
in
tropical
release
of
all
greenhouse
burning
of
fossil
gases
through
amount
of
acid
fuels.
rain
affecting
Europe
and
rain.
C.
Which
particularly
be
acidied
gas
is
atmosphere
and
effects
rising
of
acid
statements
increasing
through
the
increasing
because
in
of
the
the
global
is
levels
The
is
concentration
greatest
in
of
ozone
in
the
atmosphere
the
rain.
A.
upper
stratosphere.
B.
lower
stratosphere.
C.
upper
troposphere.
D.
lower
correct?
upper
action
in
sea
America.
lakes.
9.
5.
biodiversity,
deposited
North
are
substances
atmosphere.
areas.
D.
acid
the
rainforests.
C.
onto
ozone-depleting
into
correct?
B.
A.
of
refrigerators.
of
CFCs.
troposphere.
upper
warming.
301
C l i m at e
C h a n g e
a n d
7
e n e r g y
p r o d u C t i o n
7
.1 Ene  e nd e 
Sc s:
acs  sks:
➔
There is a range of dierent energy sources
➔
Eve the advantages and disadvantages of
available to societies that vary in their
dierent energy e.
sustainability, availability, cost and
➔
D the factors that aect the choice of
socio-political implications.
energy sources adopted by dierent societies.
➔
The choice of energy source is controversial
➔
D the factors which aect energy security.
➔
Eve an energy strategy for a given society.
and complex. Energy security is an impor tant
factor in making energy choices.
Kw  s:
➔
F fe contribute to the majority of human
a degree of independence. An inequitable
energy supply and these vary widely in the
availability and uneven distributions of energy
impacts of their production and their emissions
sources may lead to conict.
and their use is expected to increase to meet
➔
global energy demand.
➔
scientic and technological developments,
emissions than fossil fuels include enewbe
cultural attitudes and political, economic and
ene  (solar, biomass, hydropower, wind, wave,
environmental factors. These in turn aect
tidal and geothermal) and their use is expected
energy security and independence.
low emission non-renewable resource but is
controversial due to radioactive waste and
potential scale of any accident.
Ene  e depends on adequate, reliable
and aordable supply of energy that provides
302
be inuenced by availability, sustainability,
Sources of energy with lower carbon dioxide
to increase. Ne pwe is a low-carbon
➔
The ene  e adopted by a society may
➔
Improvements in ene  eene and
ene  ne vn can limit growth in energy
demand and contribute to energy security.
7. 1
E N E r g y
1990
1995
20 01
so, this climate
climate change:
yep, we should really
c h o i c E s
a N D
s E c u r i t y
‘I have no doubt that we will
change thing could
denitely a
be getting on with sor ting
be a problem...
problem.
this out pretty soon...
be successful in harnessing
the sun's energy... If
sunbeams were weapons
of war, we would have had
solar energy centuries ago.’
Sir George Por ter
20 07
2013
2019
look, sorry to sound
we really have
is this thing on?
like a broken record
checked and we’re
here...
not making this up.
TAP
TAP
TAP
▲
Fe 7
.1.1
e sc
Imagine
having
yourself
can
re
to
cook
Could
a
you
no
collect.
on?
solar-powered
enterprising
of
What
Some
make
Ke pn
source
could
coal
you
may
What
for
be,
it
for
you
washed
electricity?
charger
energy
your
a
year
get?
up
Perhaps
on
a
would
smart
would
be
other
tough
Burn
work?
phone
and
and
what
rewood
beach?
not
than
your
Could
make
●
a
sources, non-renewable
have
and renewable.
However
lifestyle
would
●
change
enormously.
We
rely
on
energy
from
electricity,
gas
Society gets its energy
from a range of energy
furniture?
you
laptop?
your
to
you
and
oil
We demand more and
to
more energy to run the
function
in
our
daily
lives.
world economy.
Energy
they
to
be
security
can
them
make
to
is
the
produce
cheaper
to
buy
an
issue
right
that
choices
useful
energy
national
between
energy
from
and
governments
the
use
maintain
another
of
wrestle
resources
national
country
but
with
security.
what
so
●
available
It
happens
have advantages and
may
if
disadvantages.
you
●
fall
out
with
that
country?
If
fuel
prices
increase,
how
long
will
Dierent energy sources
Societies may choose
your
energy sources for
people
keep
paying
higher
prices
without
complaint?
dierent reasons:
Energy
price
uctuations
governments
so
using
energy
they
several
have
Energy
are
they
and
need
to
sources
political
spread
from
changes
the
risk.
several
can
This
places
be
risky
can
be
for
political, cultural,
achieved
including
their
by
own
economic, environmental
(if
and technological.
one).
sources
clumped
in
are
not
some
equally
areas
–
spread
there
over
are
the
large
world.
deposits
Fossil
of
coal
fuel
in
deposits
China,
oil
Ke e
in
the
from
work
Middle
others.
well
energy
if
East,
gas
in
Depending
there
security
is
Russia.
on
peace
risks
if
So
other
and
it
some
countries
countries
is
something
for
economic
goes
a
to
horribly
have
nation’s
do
so.
to
buy
fuels
energy
But
it
can
increases
wrong.
Ene e is the
ability to secure aordable,
reliable and sucient energy
supplies for the needs of a
The
energy
choices
made
by
a
society
depend
on
many
factors:
par ticular country.
●
Availability
●
Technological
developments
shale
harnessing
●
oils
Politics
more
also
–
of
and
can
supply
lead
expensive
impact
the
to
–
within
domestic
nding
wave
conict
decision
–
national
over
go
new
or
imported.
sources
of
energy,
eg
power.
supplies
to
borders
energy
for
nuclear
supplies
increased
or
or
choices
security,
this
to
use
may
not.
303
7
C L I M AT E
C H A N G E
A N D
E N E R G Y
●
P R O D U C T I O N
Economics
–
globalization
of
economies
can
make
it
uneconomic
to
toK
The choice of energy
●
source is controversial
produce
your
Cultural
attitudes
means
we
own
are
power
–
very
our
and
love
cheaper
of
reluctant
the
to
to
motor
give
import
car
them
it.
powered
up
or
by
change
fossil
to
fuels
electric
cars.
and complex. How can
●
Sustainability
–
only
renewable
energy
sources
are
sustainable
yet
we distinguish between
account
for
a
small
percentage
of
world
energy
supply.
a scientic claim and a
●
Environmental
pseudoscience claim when
generation
making choices?
too
–
considerations
being
dangerous
phased
after
the
–
out
backlash
in
against
Germany
Fukishima
nuclear
when
accident
people
power
felt
it
was
(1.1)
18
16
tnelaviuqe lio fo sennot noillib
other renewables
14
12
10
8
6
4
2
0
1980
1990
2000
2010
2020
2030
Source: IEA WEO 2007
▲
Fe 7
.1.2 Projected growth in global energy demand
The
need
keep
for
energy
these
to
power
non-renewable
efciencies,
the
the
global
fossil
economy
fuels.
inevitable
will
Even
is
with
happen
–
rising
and
we
improvements
we
will
run
out
in
of
resources.
Energy
conservation
contribute
at
energy
burning
the
to
energy
moment.
Our
can
limit
security
need
for
growth
but
it
only
more
and
in
energy
has
a
more
demand
small
impact
energy
is
and
on
total
use
insatiable.
Examples of energy security choices
1.
Ukraine–Russia
After
the
below
to
break-up
market
European
they
had
The
Explain
how
2.
oil
with
it
new
economic
to
Russia
80%
In
and
continued
in
affected
of
2006,
debts
changes
these
(gure
as
USSR,
Russian
were
gas
cut
using
2010
energy
the
the
exported
Russia
until
demonstrates
recent
shale
extracted
But
this
disputes
Some
their
dispute
Have
USA
Tight
304
paid
Europe.
Russia.
prices.
the
destinations.
not
Investigate
of
gas
to
ows
off
gas
when
security
relationship
gas
gas
Ukraine
through
supplies
to
intended
an
at
Ukraine
Ukraine
for
the
agreement
as
rest
was
of
signed.
issues.
between
Ukraine
and
supplies?
oil
7.1.4)
was
is
held
oil
technologies
extract.
that
tightly
Since
has
in
been
rocks
(fracking)
2008,
US
discovered
and
and
tight
not
high
oil
but
not
economic
oil
prices,
production
to
it
previously
extract.
has
has
become
increased
7. 1
E N E r g y
c h o i c E s
a N D
s E c u r i t y
to Shtokman eld
to Yamal elds
Barents
gas pipeline
Nadym
Sea
proposed gas pipeline
Teriberka
member states of the
European Union
Russia
0
500 kilometers
Ukhta
Punga
n
a
Y
FINL AND
Gulf of
NORWAY
s
t
h
g
i
L
500 miles
e
r
e
p
h
o
t
r
r
u
o
E
N
l
a
m
0
Finland
Vyborg
RUSSIA
Volkhow
taK
taget
North
Sea
SWEDEN
Gr ya
zove
ts-Vy
borg
Gryazovets
d
o
o
h
r
e
h
t
o
r
B
Bacton gas
Terminal
rd
No
m
ea
Str
B
B
L
NEL
e
p
o
r
u
E
l
a
Greifswald
Rehden
L
A
G
A
J
m
a
Y
JAMAL
L
A
P
O
GERMANY
Moscow
BEL ARUS
II
-l
a
m
a
Y
POL AND
Oibernhau
C
e
n
t
r
a
l
z
Soyu
Transgas
UKRAINE
rhood
Brothe
AUSTRIA
s
ia
z
u
y
o
S
Baumgar ten
gas hub
K AZAKHSTAN
A
G
A
T
HUNGARY
Subotica
Beregovaya
S
t
r
e
a
Sea
compressor station
m
a
e
rt
S
Adriatic
Stream
South
m
S
o
ITALY
h
u
t
ROMANIA
Pleven
Black Sea
Sea
e
u
lB
Varna
Caspian
BULGARIA
S
o
u
t
h
Durusu terminal
Ankara
S
t
r
e
a
m
GREECE
TURKEY
IRAN
Mediterranean Sea
IRAQ
▲
Fe 7
.1.3 Map of gas pipelines from Russia to Europe
The shale gale
barrels per day, m United States
forecast
from
600,000
to
3.5
million
barrels
a
day.
Shale
gas
and
oil
is
also
10
crude oil production
extracted
in
the
USA
now.
The
result
of
this
is
that
some
predict
the
USA
tight oil
8
may
change
exporter
think
by
this
from
2020
is
being
a
net
pumping
importer
11.6
of
million
oil
to
barrels
being
a
day
the
of
world’s
crude
largest
oil.
Others
6
overestimated.
4
The
result
is
that
now
fossil
fuel
security
for
the
USA
has
improved
2
dramatically.
0
Evaluate
the
production
of
shale
oil
in
the
USA.
1990
Discuss
the
Exporting
implications
Countries).
of
this
for
OPEC
(Organization
of
Petroleum
▲
1995
2000
2005
2010
2015
2020
2024
Fe 7
.1.4 USA production of
shale oil
305
7
C L I M AT E
C H A N G E
A N D
E N E R G Y
3.
P R O D U C T I O N
Wind
Wind
turbines
energy
energy
more
the
any
as
the
can
▲
be
the
its
In
the
a
energy
there
then
but
of
nuclear
to
for
the
wind
from
wind
is
that
plants
speeds
grid
Denmark
energy.
the
energy
wanted
offshore
national
mechanical
wind
Denmark’s
waters
to
electricity.
this
power
the
shallow
linked
the
government
Although
are
in
produce
reason
much
the
on
to
requirements
The
1970s,
ban
energy
turbine
country.
solution.
and
kinetic
wind
of
was
high,
sited
Denmark
stations
There
particularly
a
other
power
emissions.
seen
30%
change.
coal-red
was
drives
over
than
drove
converts
which
produces
in
to
in
was
reduce
and
wind
onshore.
is
from
carbon
power
Denmark
where
This
government
the
are
not
turbines
Denmark
is
Fe 7
.1.5 Wind turbines in
linked
to
the
electricity
grids
of
neighbouring
countries
and
can
buy
Denmark
electricity
is
less
from
than
them
that
if
the
wind
generated.
This
drops
is,
of
and
sell
course,
it
if
one
their
own
demand
disadvantage
of
wind
t d
power
–
you
turbines
kill
need
many
the
wind
birds
to
that
blow.
y
into
There
is
little
evidence
them.
Although
some
that
do,
wind
most
Evaluate the energy strategies
birds
y
over
or
round
the
turbines
and
adapt
their
migration
routes.
of your own country and one
Power
lines
kill
more
birds
than
do
wind
turbines.
other named country.
Evaluate
Denmark’s
wind
power
industry.
t d
e   scs
All
Using gures 7.1.6 and 7.1.7:
our
would
1.
energy
be
at
on
Earth
absolute
comes
zero,
from
which
our
is
Sun.
273
°C,
Without
and
it,
there
the
planet
would
be
no
Calculate the percentage
life
forms.
The
Sun’s
energy
drives
the
climate,
geochemical
cycles,
of global energy supply
photosynthesis,
animal
life
–
everything.
Humans
do
not
only
by
using
rely
on
from fossil fuels.
energy
2.
from
the
Sun
via
plants,
we
supplement
it
other
sources
Research the population
of
energy
to
power
our
civilization.
sizes of China and the
Fossil
fuels
are
simply
stored
solar
energy.
These
non-renewable
USA and suggest reasons
sources
of
energy
are
the
compressed,
decomposed
remains
of
organic
why they use similar
life
from
millions
of
years
ago.
Now
humans
extract
and
burn
them
amounts of energy.
to
3.
release
that
energy.
This
combustion
of
fossil
fuels
releases
carbon
Research the population
dioxide
that
was
locked
up
by
photosynthesis
when
they
were
formed.
size of India and suggest
This
emission
of
carbon
dioxide
is
having
a
large
effect
on
atmospheric
reasons why its use
carbon
dioxide
levels
(sub-topic
7.2).
of energy is so much
smaller than that of China.
other 0.5%
nuclear
tide 0.0004%
solar 0.039%
China
wind 0.064%
2
1%
hydro 2.2%
6.5%
gas
20.9%
rest of world
49%
renewables
combustible
13%
renewables
geothermal
and renewable
0.414%
United States
oil
20%
34.3%
waste 10.6%
coal
Russia
25.1%
6%
India 4%
non-renew. waste 0.2%
▲
306
Fe 7
.1.6 Energy sources worldwide (source IEA 2007)
▲
Fe 7
.1.7 World energy use
7. 1
E N E r g y
c h o i c E s
a N D
s E c u r i t y
‘Junkies nd veins in their
hw c  f fss fs?
toes when the veins in their
There
do
are
keep
gures
are
●
coal
●
gas
●
oil
Some
left
only
that
in
in
in
230
170
100
say
by
Two-thirds
are
in
oils
and
power
in
and
Humans
wealth
far
may
If
17
gas
is
run
But
out
we
of
shall
fossil
run
fuels
out.
and
Ball
we
park
arms collapse. Developing
tar sands is the equivalent.’
of:
The
and
we
be
oil
is
more
it
will
but
next
there
to
300
agreed
be
us
as
most
in
that
experts
10–20
years
the
and
will
think
we
can.
use
energy
be
of
We
years
30–40
as
be
Most
Canada
and
China’s
more
we
discovery
oil
East.
and
reserves
of
are
if
biomass.
as
will
none
of
the
(shale
fastest
need
for
coal.
richer
million
soon
USA
most
there
are
there
Middle
the
because
energy
the
increases,
the
in
burn
as
more
with
in
the
revolution,
then,
generally
are
with
it
lifetime?
mostly
countries
formed
use
found
energy
use
available
fuels
fuel
stations
Some
we
your
now
coal,
industrial
that
in
reserves
is
fossil
each
Since
more
which
to
more
power
the
the
at
known
more
think
sulphur
with
but
we
coal
left
to
the
future.
for
But
energy
it
150
a
is
dioxide,
carbon
burn
rate
We
amount
stations
gas.
the
left
enough
power
and
of
at
sooner.
the
oil
more
oil
or
which
source
left,
use
years
than
far
to
many
nd
out
shall
it.
of
we
and,
the
more
was
fuels,
using
as
use
not
than
from
we
the
our
is
energy
used
fossil
are
us
But
use
capital
ago.
exhausted
years’
that
shall
we
time
shall
have
in
–
50–100
in
your
not
looked
nd
in
years’
lifetimes.
more
most
areas
then.
after
is
rate
likely
and
sands).
after
LEDCs
in
run
consumption
it
some
reserves
by
the
fossil
Although
We
of
than
as
we
Al Gore, 2008
the
that
biomass.
more
time,
as
Is
use
when
extracting
years.
Before
–
stored
shall
distributed.
others.
of
and
years
increases,
evenly
wood
we
Russia
tar
increase
more
years
that
2075.
rest
estimates
nding
coal
We
think
of
the
coal’s
in
use
is
(CCS)
be
we
future
natural
that
–
80
coal
years.
is
the
tonnes
of
two
than
Since
There
energy
coal
of
oil
dioxide
power
making
oil’,
coal-red
that
carbon
build
technology.
the
more
faster
can
out
is
than
releasing
run
‘peak
building
growing
source,
will
reach
billion
was
it
to
There
say
1,000
2007,
States,
about
fewer
people
However,
should
United
are
decline.
are
in
energy
or
that
some
storage
this
will
there
burned.
and
anyway,
all
China,
and
of
reached
and
dirtiest
when
capture
use
mine
week
capita
produced
will
years.
the
per
have
we
coal
and
stations
are
a
going
clean
source.
e cs
We
an
of
are
in
an
increasing
well
know
We
over
we
shall
energy
rate.
US$145
use
more
have
to
crisis
Oil
per
and
use
yet
prices
barrel.
more
energy
continue
per
barrel
Are
they
energy
sources
to
use
reached
and
non-renewable
an
higher
that
other
or
all-time
lower
fossil
than
fuels
fossil
fuels
high
today?
will
fuels.
in
at
2008
We
run
out.
Renewable
307
7
C L I M AT E
C H A N G E
A N D
E N E R G Y
P R O D U C T I O N
sources
as
produces
a
well
less
proposal
In
the
from
only
to
for
waste
and
and
Nuclear
water
▲
cars
to
a
hydrogen
is
a
will
much
directly.
electrical
The
renewable
EU,
for
sources
example,
but
there
is
2020.
hydrogen
hydrogen
options.
humans
revert
energy
use
by
fuels,
where
the
from
have
Possibilities
is
the
fuel
generation.
as
their
highly
to
smaller
fuel,
gain
include
that
are
releasing
gas
energy
the
provides
There
ammable
their
population
energy
prototype
water
and
as
the
difcult
to
store.
fusion
and
20%
we
and
are
energy
to
fossil
solar
that
But
power
its
unless
industry
product.
transport
on
of
this
without
economy
transport,
engines
7%
sources
dependent
hydrogen
nuclear
increase
future,
other
as
than
fusing
involves
two
extracting
hydrogen
heavy
atoms
to
water
make
(deuterium)
helium.
In
from
theory
Fe 7
.1.8 The Airship
this
works,
but
in
practice
it
is
not
feasible
yet.
(Nuclear
ssion
uses
Hindenberg accident in 1937
uranium,
a
non-renewable
resource.)
when hydrogen that lled the
airship ignited
We
we
have
have
to
increase
the
our
technology
consumption
and
to
use
of
now,
increase
renewable
to
its
have
energy
absolute
efciency
of
sources
reductions
in
for
which
energy
use.
t d
Ene npn
Energy consumption is measured in tonnes of oil equivalent or TOE (the amount of energy released in burning one
tonne of crude oil).
0–0.25
0.25–0.5
0.5–1.0
1.0–1.5
>1.5
▲
308
Fe 7
.1.9 TOE equivalent energy consumption per capita in 2012 from BP statistical review 2013
7. 1
E N E r g y
c h o i c E s
a N D
s E c u r i t y
World consumption
13000
12000
11000
)EOM( tnelaviuqe lio sennot noillim
10000
9000
8000
7000
6000
5000
4000
3000
2000
1000
0
87
88
89
90
91
92
93
94
95
86
97
98
99
00
01
02
03
04
05
06
07
08
09
10
11
12
World primary energy consumption grew by a below-average 1.8
% in 2012. Growth was below average in all regions except Africa.
Oil remains the world’s leading fuel, accounting for 33.1% of global energy consumption, but this gure is the lowest share on record
and oil has lost market share for 13 years in a row. Hydroelectric output and other renewables in power generation both reached
record shares of global primary energy consumption (6.7% and 1.9%, respectively).
▲
Fe 7
.1.10 Consumption of fossil fuels by type from 1987 to 2012
Annual energy demand by region
Study the data in the three gures, 7.1.9, 7.1.10 and
600
7.1.11, on energy consumption.
1.
Describe the pattern of consumption per capita in
World
500
gure 7.1.9.
2.
Describe the lifestyle of someone with the highest
consumption and someone with the lowest. Name
400
the regions they live in.
J
01
21
3.
Suggest reasons for the sharp rise in energy
300
consumption in Asia and Oceania in gure 7.1.11.
4.
Suggest reasons for the drop in total energy
200
Asia & Oceania
consumption in 2008.
5.
Consider your own use of fossil fuels, list the
Nor th America
100
products you have and activities you do that rely on
Europe
Eurasia
fossil fuel consumption. (Remember, plastics are
Middle East
C. & S. America
1980
▲
derived from oil.)
Africa
0
1985
1990
1995
2000
2005
2010
Fe 7
.1.11 World energy demand by region
1980–2010
309
7
C L I M AT E
C H A N G E
A N D
E N E R G Y
P R O D U C T I O N
rwb  scs
Theoretically,
economy
practice,
when
could
our
energy
to
–
the
obtain
about
sources
in
produce
energy
requirements
we
resources
used
get
own
worldwide
renewable
Which
we
and
a
we
need
from
small
to
power
renewable
percentage
at
the
world
resources.
the
But,
moment
in
from
14%.
gure
7.1.12
energy?
oil 37%
Are
do
any
not
of
release
them
coal 25%
carbon
truly
dioxide
‘clean’?
gas 23%
nuclear 6%
biomass 4%
solar heat 0.5%
wind 0.3%
hydro 3%
geothermal 0.2%
biofuels 0.2%
solar photovoltaic 0.04%
▲
We
Fe 7
.1.12 Percentage of world energy sources
know
from
EU
plans
gains
that
to
in
That
20%
the
wave
TNCs
●
It
is
fuels
to
–
cheaper
from
most
Countries
trade
●
All
■
solar
■
wind
or
to
310
What
on
tidal
carbon
the
has
from
generated
power
power
or
Reasons
of
a
–
all
change
electricity
resources
at
is
from
the
being
from
cells,
for
corporations)
economy
energy
is
energy
or
scale
solar
our
and
renewables
renewable
gas.
of
been
is
and
may
fossil
US
But
efcient,
compared
with
be:
heavy
to
more
The
The
renewables.
small
machines
are
industry
made
to
are
run
imagine.
fuel
moment
2020.
sources
this
hard
by
produced
made.
burning
(ignoring
than
the
cost).
locked
or
into
tidal
are
power
resource
a
location
are
requires
has
the
they
currently
use
–
by
a
not
possible
sunny
range
of
dependent:
can
you
for
climate
wind
think
of?
land-locked
for
speeds
effectively.
reasons
that
convenience.
sources
power
other
oil
percentage
needs
making
produce
energy
operate
●
energy
renewable
are
the
progress
(transnational
and
renewable
wave
and
more
agreements
■
its
and
the
environmental
●
increase
domestically
nding
committed
fossil
of
of
research
in
into
must
resources
12%
example
research
●
get
about
investment
for
we
renewable
maximum
within
countries
efciency
which
it
can
on
7. 1
E N E r g y
c h o i c E s
a N D
s E c u r i t y
Cb sss f fss f b
Although
gures
about
amount
the
burning
fossil
to
in
parts
capita
on
from
Carbon
these
per
average
source
carbon
(enhanced)
reduce
much
of
fuels.
anthropogenic
going
vary
dioxide
source,
but
of
there
released
is
to
effect.
carbon
amount
to
general
Most
by
two-thirds
of
our
which
four
agreement
atmosphere
for
dioxide
over
is
the
responsible
greenhouse
emissions
million
to
dioxide
of
efforts
may
tonnes
not
per
the
are
look
year
per
worldwide.
Who produces what carbon emissions?
China
and
overtaken
in
China
But
per
the
the
and
US
US
produce
as
India
capita
the
most
biggest
reect
emissions
the
their
do
and
emitter.
rapid
not
China
The
may
rapid
now
growth
industrialization
relate
to
the
size
have
of
and
the
in
emissions
large
size.
country.
Ice-core data before 1958. Mauna Loa data after 1958.
400
)mpp( noitartnecnoc
350
OC
2
300
250
1
750
▲
1800
1850
1900
1950
2000
Fe 7
.1.13 Atmospheric carbon dioxide levels 1700–2012
CO
emissions per capita
2
20.0
18.6
18.0
18.0
atipac rep )sennot( snoissime
16.3
16.0
14.0
12.0
12.0
9.6
10.0
8.5
7
.4
8.0
5.9
5.5
6.0
OC
2
4.0
2.1
1.5
2.0
0.1
0.0
U
g
a
n
d
a
I
n
i
d
a
r
B
a
l
i
z
H
K
C
i
h
n
/
a
r
F
a
n
c
e
U
l
a
t
I
y
K
n
y
G
r
e
m
a
R
s
u
i
s
a
a
C
a
n
a
d
U
S
a
A
r
t
s
u
i
l
a
Source: World Bank EN.ATM.CO2E.PC
▲
Fe 7
.1.14 Carbon dioxide emissions per capita of selected countries in 2012
311
7
C L I M AT E
C H A N G E
A N D
E N E R G Y
P R O D U C T I O N
CO
emissions by country
2
China ǀ 23.33%
7
,031,916 kT
United States ǀ 18.11%
5,46
1,014 kT
European Union ǀ 14.04%
India ǀ 5.78%
4,1
77
,81
7 kT
1,742,698 kT
Russia ǀ 5.67%
Japan ǀ 4.01%
1,708,653 kT
1,208,163 kT
Germany ǀ 2.6
1%
786,660 kT
all other countries combined ǀ 26.45%
7
,77
1,200 kT
kT = kiloton (thousands of metric tons) of emissions
▲
Fe 7
.1.15 Carbon dioxide emissions by country or region in 2008
Singapore,
emissions,
China
The
is
Source: U.S. Depar tment of Energy
per
Gibraltar
followed
and
by
some
the
US
Gulf
with
states
have
emissions
the
highest
several
times
per
capita
that
of
capita.
United
Nations
responsible
for
calculates
more
CO
that
every
an
average
year
than
a
air-conditioner
person
in
in
Florida
Cambodia
is
in
2
a
lifetime,
much
as
and
three
that
also
this
to
due
dishwashing
machine
in
Europe
annually
emits
as
Ethiopians.
Deforestation
table
a
contributes
deforestation
to
carbon
and
peat
emissions
and
forest
and
Indonesia
tops
res.
ev f  scs   vs  svs
Ene e
F
ad vne
Dd vne
Nn-enewbe
c (f
Fossilized plants laid down in
fe)
the Carboniferous period.
•
Plentiful supply.
•
Non-renewable energy source.
•
Easy to transpor t as a
•
Cannot be replaced once used
solid.
Mined from seams of coal which
are in strata between other
•
Needs no processing.
(same for oil and gas).
•
types of rock . May be opencast
•
Burning releases carbon dioxide
which is a greenhouse gas.
Relatively cheap to mine
mined (large pits) or by tunnels
and conver t to energy by
•
Some coals contain up to 10%
underground.
burning.
Burned to provide heat directly
or electricity by burning to
•
Up to 250 years of coal
sulphur.
•
left.
Burning sulphur forms sulphur
dioxide which causes acid
create steam-driven turbines in
deposition.
power stations.
•
Particles of soot from burning coal
produce smog and lung disease.
•
Coal mines leave degraded land
and pollution.
•
Lower heat of combustion than
other fossil fuels, ie less energy
released per unit mass.
312
7. 1
o (f fe)
Fossilized plants and micro-
•
organisms that are compressed
to a liquid and found in porous
E N E r g y
c h o i c E s
High heat of combustion,
many uses.
•
rocks. Crude oil is rened by
•
•
Once found is relatively
cheap to mine and to
fractional distillation to give a
a N D
s E c u r i t y
Only a limited supply.
May run out in 20–50 years’
time.
•
conver t into energy.
Like coal, gives o carbon
dioxide when burned.
variety of products from lighter jet
•
Oil spill danger from tanker
fuels and petrol to heavier diesel
accidents.
and bitumen.
•
Risk of terrorism in attacking oil
Extracted by oil wells. Many oil
pipelines.
elds are under the oceans so
extraction is dangerous. Pipes
are drilled down to the oil-bearing
rocks to pump the oil out.
Most of the world economy runs
on oil either burned directly
in transport and industry or to
generate electricity.
N 
Methane gas and other
(f fe)
hydrocarbons trapped between
seams of rock . Extracted by
•
Highest heat of
•
combustion.
•
drilling like crude oil. Often
Lot of energy gained
Only limited supply of gas but
more than oil.
•
from it.
About 70 years’ wor th at current
usage rates.
found with crude oil.
•
Ready-made fuel.
•
Used directly in homes to
•
Also gives o carbon dioxide but
less than coal and oil.
Relatively cheap form of
produce domestic heating and
energy.
cooking.
•
Cleaner fuel than coal
and oil.
Ne n
Uranium is the raw material.
•
Raw materials are
This is radioactive and is split in
relatively cheap once
nuclear reactors by bombarding
the reactor is built and
•
•
it with neutrons. As it splits
can last quite a long
into other elements, massive
time.
Extraction costs high.
Nuclear reactors are expensive to
build and run.
•
Nuclear waste is radioactive
and highly toxic for a long time.
amounts of energy are also
•
released.
amounts. About 80 years’ wor th
left to mine at current rates but
it. Needs storage for thousands
of years. May be stored in
of energy.
has the most known reserves,
other countries have smaller
Big question of what to do with
produces a huge amount
Uranium is mined. Australia
Canada expor ts the most,
Small mass of
radioactive material
•
mine shafts or under the sea.
No carbon dioxide
Accidental leakage of radiation
or other pollutants
released (unless there
can be devastating.
•
are accidents).
Accidents rare but worst nuclear
reactor accident at Chernobyl,
could be extracted from sea
Ukraine in 1986.
water.
•
Risk of uranium and plutonium
being used to make nuclear
weapons.
•
Terrorist threat.
313
7
C L I M AT E
C H A N G E
A N D
E N E R G Y
P R O D U C T I O N
renewbe
hdee
Energy harnessed from the
pwe (hEP)
movement of water through
output compared with
rivers, lakes and dams to power
low quality energy input.
turbines to generate electricity.
•
•
Pumped-storage reservoirs
High quality energy
•
Reservoirs used for
•
Dams have major ecological
impacts on local hydrology.
•
recreation, amenity.
•
Can cause the ooding of
landscapes.
supplies.
•
Costly to build.
surrounding communities and
Creates water reserves
as well as energy
power turbines.
•
May cause problems with deltas
– no sediment means they are
Safety record good.
lost.
•
•
Silting of dams.
Downstream lack of water (eg
Nile) and risk of ooding if dam
bursts.
B
Decaying organic plant or
•
animal waste is used to produce
methane in biogas generators
Cheap and readily
•
available energy source.
•
or burned directly as dung/
lead to starvation.
If the crops are
replanted, biomass
plant material. More processing
•
can be a long-term,
can give oils (eg oilseed rape,
source.
When burned, it still gives
o atmospheric pollutants,
sustainable energy
oil palms, sugar cane) which
May be replacing food crops on
a nite amount of crop land and
including greenhouse gases.
•
If crops are not replanted,
can be used as fuel in vehicles
biomass is a non-renewable
instead of diesel fuel = biofuels
resource.
Wd
From felling or coppicing trees.
•
A cheap and readily
•
Low heat of combustion, not
Burned to generate heat and
available source of
much energy released for its
light.
energy.
mass.
•
If the trees are replaced,
•
When burned it gives o
wood can be a long-term,
atmospheric pollutants,
sustainable energy
including greenhouse gases.
source.
•
If trees are not replanted wood
is a non-renewable resource.
•
High cost of transpor tation as
high volume.
s –
Conversion of solar radiation
pv
into electricity via chemical
e
energy.
•
Potentially innite
•
energy supply.
•
can be costly.
Single dwellings can
have own electricity
•
supply.
•
•
Safe to use.
Manufacture and
implementation of solar panels
Need sunshine, do not work in
the dark .
•
Need maintenance – must be
cleaned regularly.
Low quality energy
conver ted to high.
cnened
Mirrors are arranged to focus
 pwe
solar energy on one point
(csP)
where heat energy generated
drives a steam turbine to make
electricity.
314
•
Solar energy renewable
•
source.
•
Cost of power stations
equivalent to fossil fuel
power stations.
Required area of high insolation
– so usually in tropics.
•
Relatively new technology but
improving all the time.
7. 1
s - pve
Using buildings or panels to
•
capture and store heat.
E N E r g y
c h o i c E s
Minimal cost if properly
a N D
•
designed.
s E c u r i t y
Requires architects who
can design for solar passive
technology.
Wnd
Wind turbines (modern
•
windmills) turn wind energy into
electricity.
Clean energy supply
once turbines made.
•
•
Little maintenance
required.
Can be found singularly, but
•
Need the wind to blow.
Often windy sites not near
highly populated areas.
•
usually many together in wind
Manufacture and
implementation of wind farms
farms.
can be costly.
•
Noise pollution though this
is decreasing with new
technologies.
•
Some local people object to on-
shore wind farms, arguing that
visual pollution spoils countryside.
•
Question of whether birds
are killed or migration routes
disturbed by turbines.
td
The movement of sea water in
•
and out drives turbines.
Should be ideal for an
the UK .
A tidal barrage (a kind of dam)
is built across estuaries, forcing
•
•
may be possible out at sea and
•
Only a few estuaries are
suitable.
•
Opposed by some
Tidal barrage can double
environmental groups as having
as bridge, and help
a negative impact on wildlife.
prevent ooding.
without dam.
Construction of barrage is very
costly.
Potential to generate a
lot of energy this way.
water through gaps.
In future underwater turbines
•
island country such as
•
May reduce tidal ow and
impede ow of sewage out to
sea.
Wve
The movement of sea water in
•
and out of a cavity on the shore
compresses trapped air, driving
Should be ideal for an
island country.
•
a turbine.
•
May disrupt shipping?
•
Construction can be costly.
•
These are more likely
to be small local
May be opposed by local or
environmental groups.
•
Storms may damage them.
•
Can be expensive to set up.
•
Only works in areas of volcanic
operations, rather than
done on a national scale.
gee
It is possible to use the heat
•
under the ear th in volcanic
regions.
Cold water is pumped into
ear th and comes out as steam.
Potentially innite
energy supply.
•
Is used successfully in
some countries, such as
activity.
•
New Zealand.
Geothermal activity might calm
down, leaving power station
Steam can be used for heating
redundant.
or to power turbines creating
•
Dangerous underground gases
electricity.
have to be disposed of carefully.
315
7
C L I M AT E
C H A N G E
A N D
E N E R G Y
P R O D U C T I O N
t d
Select an energy source from the table. Research for information on this
source.
Individually or in small groups, present a case to your class about that energy
source. Include in your presentation: what it is, where it is mostly used, how
much it is used, whether its use is sustainable, its relative cost, advantages
and disadvantages of the resource use, future prospects, reasons why some
countries may use this resource although it may not be the cheapest.
Peer evaluate the presentations based on:
Quality of spoken presentation – did they present in a clear, interesting way?
Did they not read it out? Did they look at the audience and engage them?
Quality of content – did you understand the content? Was it clear?
Quality of associated documentation (handout, slide presentation, data) – did
this enhance your understanding of the presentation?
▲
Fe 7
.1.16 CSP and
photovoltaic solar energy
t nk b
te ab  nd
NORTHWEST TERRITORIES
Wood Bualo
In Alber ta, Canada, there is a lot of oil in tar sands. It is
National Park
e
k
a
L
a very heavy crude oil, rich in bitumen which is used to
a
c
s
a
b
a
th
A
make roads. It takes so much energy to rene this oil
that it is only economic to do so if oil prices are high.
The cost of extracting a barrel of this oil is about US$30.
Prices for crude oil are high so it is being extracted –
Clearwater River
Provincial Park
by surface mining from the Athabasca Oil Sands in
Athabasca For t McMurray
Peace River
Alber ta. With some smaller deposits, these oil sands
Oil Sands
Oil Sands
SASK ATCHEWAN
cover 54,000 square miles of land. Growing on the land
Grande Prairie
is boreal forest and muskeg ecosystems. Muskeg is a
type of peat bog with acidic conditions so vegetation is
ALBERTA
Cold Lake
semi-decomposed. It can be up to 30m deep, is 1,000
Oil Sands
years old and is a habitat to beavers, pitcher plants and
Meadow Lake
Provincial Park
Edmonton
BRITISH
Lloydminster
mosses. Caribou deer (reindeer) also live there. Few
COLUMBIA
humans live there. The amount of oil in these tar sands
Jasper
National Park
is roughly equal to the rest of the world’s reserves put
Red Deer
together. It is mined by open-pit mining which destroys
Ban
National Park
the vegetation and changes the shape of the landscape
Calgary
as huge volumes of tar sands are removed. Mining
companies do restore the land to pasture or plant trees
CANADA
Medicine Hat
Lethbridge
but do not recreate the original boreal forest or muskeg.
United States
Not only does it cost to extract the oil, it also takes a lot of
NORTH
MONTANA
energy – one barrel of natural gas to extract two of crude
0
oil. It also takes a lot of water – two barrels of water for
50
100
Kilometres
each barrel of oil and the waste water has to be kept in
▲
large tailing (mining waste) ponds. Rather than reducing,
the carbon emissions of Canada are increasing, par tly
due to this mining of tar sands.
316
Fe 7
.1.17 Map of the Athabasca oil sands
200
7. 1
E N E r g y
c h o i c E s
a N D
s E c u r i t y
t nk b
a greenhouse gas than carbon dioxide. Some calculate
Bfe – e nwe  e pbe?
that maize ethanol requires 30% more energy to make
Biofuels are fuels made from crops.
than it contains.
W? In theory, they are greener as there are fewer carbon
The other problem is the land it takes to grow biofuels.
emissions as they are carbon neutral, meaning that all
It would take 40% of the EU cropland to meet the 10%
the emissions of carbon dioxide made from burning them
target. And this means less food is produced.
are xed by growing the plants to replace them. As 25% of
carbon emissions are from transpor t, it is a neat idea but
W e e neqene? Deforestation is
happening to plant crops for biofuels and this releases
things are not that neat in complex systems.
the carbon trapped in the trees. Wetlands are being
W p e ed? Sugar cane has been used for
drained and grassland being planted as well. Indonesia
decades in Brazil to make ethanol by fermentation. The
has planted so much oil palm on what was forest
ethanol (an alcohol) is sold alongside or mixed with petrol
land that it is now the third largest emitter of carbon
(gas) and 80% of cars sold in Brazil now have hybrid
in the world. US farmers are selling 20% of their maize
engines – they run on petrol, alcohol or a mixture of the two
for biofuel instead of food, so soya farmers there are
called gasoline. From 2000 to 2005, the world’s output of
switching to the more protable maize, so Brazilian
plant ethanol has doubled and biodiesel, made from oily
farmers grow more soya bean to expor t, so they plant it
plants like oil palm and soya bean, has increased.
on grazing land, so the cattle ranchers cut more forest in
In the USA, maize production for ethanol is heavily
the Amazon to turn into grassland.
subsidized; it has increased ve-fold and is set to increase
W d be dne?
more. In the EU, a regulation was passed that all fuels
must contain 2.5% biofuel, rising to 5% and 10% by 2020.
The calculations need to be checked and all costs
included for both fossil fuels and biofuels. Cellulosic
W’ e pbe?
ethanol, from wood chips, switchgrass or straw may be
Amazingly, in calculating the carbon balance of biofuels,
no-one considered the additional carbon costs in
the answer as its production will reduce far more carbon
emissions than maize or soya bean growing.
extracting the ethanol, transpor ting the crop to the
There is iner tia in the systems so once subsidies and
extraction plant and transpor ting the processed fuel.
legislation are in place, it will take time to change
Some of those costs also apply to conventional fossil
them if we need to. If biofuels are leading to increased
fuel extraction, of course, but there is also the cost
greenhouse gas emissions, not reduced ones, and taking
of (oil-based) fer tilizer applied to the crop. Fer tilizers
up land needed to grow food, what are we doing?
release nitrous oxide which is 310 times more powerful
Practical
Investigate
Work
people's
Evaluate
the
Evaluate
an
Investigate
attitude
advantages
energy
the
to
and
strategy
relationship
global
climate
disadvantages
for
a
named
b etween
change.
of
dierent
energy
sources.
society.
carbon
footprint
and
wealth
/
education
level.
317
7
C L I M AT E
C H A N G E
A N D
E N E R G Y
P R O D U C T I O N
7
.2 ce ne – e nd p
Sc s:
acs  sks:
➔
Climate change has been a normal feature of
D the feedback mechanisms that would
➔
the Ear th’s history, but human activity has
be associated with a change in mean global
contributed to recent changes.
temperature.
➔
There has been signicant debate about the
Eve contrasting viewpoints on the issue
➔
causes of climate change.
of climate change.
➔
Climate change causes widespread and
signicant impacts.
Kw  s:
➔
➔
ce describes how the atmosphere behaves
➔
The potential p f e ne may
over relatively long periods of time whereas
vary from one location to another and may
wee describes the conditions in the
be perceived as either adverse or benecial.
atmosphere over a shor t period of time.
These impacts may include changes in
water availability, distribution of biomes and
Weather and climate are aected by en nd
crop growing areas, loss of biodiversity and
pe  e.
ecosystem ser vices, coastal inundation, ocean
➔
hn  ve are increasing levels of
acidication and damage to human health.
greenhouse gases (eg carbon dioxide, methane
➔
and water vapour) in the atmosphere, which
Both ne ve nd p ve feedbk
en are associated with climate change
leads to:
and may involve very long time lags.
●
an increase in the mean global temperature
●
increased frequency and intensity of
➔
There has been nn debe due to
conicting EVSs surrounding the issue of climate
extreme weather events
change.
●
the potential for long-term change in climate
➔
gb e de are complex and there is
and weather patterns
a degree of uncer tainty regarding the accuracy
●
rise in sea level.
of their predictions.
‘ The famous quote from
C  w
a century ago, attributed
It
to Mark Twain and Charles
is
important
with
respect
to
to
understand
climate
the
different
between
climate
and
weather
change.
Dudley Warner “everybody
Weather
is
the
daily
result
of
changes
of
temperature,
pressure
and
talks about the weather
precipitation
but nobody seems to do
anything about it” may have
been true once. But it isn’t
in
sometimes
over
only
do
too
really
many
uctuate
our
very
so
short
with
variables
wildly
atmosphere.
–
a
distances.
some
that
very
Weather
accuracy
interact
hot
day
in
Peter Gleick
318
temperatures
are
changing.
a
try
about
such
or
true anymore.’
average
We
varies
a
very
to
from
predict
ve
days
complex
cold
place
one
to
place,
weather
ahead.
way.
does
but
There
Weather
not
can
are
can
mean
that
7. 2
Climate
on
is
Earth.
kept
The
for
the
long
The
are
similarity
away
again
–
Human
which
later
in
both
may
–
–
in
–
we
change
is
change
to
gases
sub-topic).
changes
If
of
dioxide,
the
the
ocean
years
Earth.
For
burn
fossil
a
a
if
timescale
and
location
records
are
on
which
atmospheric
them
GHG,
but
of
ash
example,
global
fuels
on
or
in
a
if
of
a
gases
or
reect
sunlight
regrowth
which
Mt
traps
keep
circulate
Pinatubo
temperatures
and
heat
are
show
is
the
for
in
a
livestock,
inputs
decreases
it
in
the
few
both
years.
of
from
(gure
and
or
the
7.2.1)
increasing
is
if
the
gases,
the
less
may
by
have
(see
organisms.
to
climate
atmosphere
passed
that
released
outputs
both
which
although
happened
change:
temperature.
greenhouse
point
always
climate
atmosphere
equilibrium
tipping
has
affecting
in
loss
more
and
inuence
scale,
output
dynamic
Earth
that
global
heat
a
change
(see
heat
change,
warms
later
is
stabilize
in
lost.
or
eg
up.
The
reach
(1.3).
global
there
are
average
surface
uctuations
from
year.
Dierences in temperature
Estimated actual
from 196
1–1990
global mean
Mean value, °C
temperature, °C
0.6
14.6
0.4
14.4
0.2
14.2
0.0
14.0
−0.2
13.8
−0.4
13.6
−0.6
1880
for
changes
by:
quantities
lowering
insolation
reduce
records
temperature
to
solar
there
equilibrium
Long-term
year
in
increases
Greenhouse
new
is
underneath
huge
Factors
climate
input
by
affected
heat
long-term
sub-topic).
proportions
a
and
i m P a c t s
GHGs.
Changing
system
many
a N D
them.
1990
●
this
climate
affected
release
Fluctuations
heat
and
also
carbon
cooling
erupted
activities
this
trap
●
For
over
trends
c a u s E s
stores.
eruptions
release
are
are
above
release
atmosphere,
Climate
pattern
long-term
weather
Both
Earth
carbon
Philippines
●
that
clouds
res
in
Volcanic
the
is
from
Forest
●
between
systems.
Clouds
●
weather
show
–
measured.
circulatory
●
may
c h a N g E
enough.
difference
they
average
Climate
c l i m a t E
13.4
1900
1920
1940
1960
1980
2000
Source: land commodities research
▲
Fe 7
.2.1 Global average temperature 1860–2008
319
7
C L I M AT E
C H A N G E
A N D
E N E R G Y
P R O D U C T I O N
t nk b
sn f epee nee?
Since 2000, average global temperature has shown
Cherry-picking data is a characteristic of pseudoscience
no increase and some climate sceptics (who do not
and gure 7.2.2 shows a shor t period in which average
believe humans are causing climate change) use this as
global temperature fell.
1
evidence to suppor t their hypothesis. But
we know that
In gure 7.2.2:
there are variations in climate and it is very complex.
1.
Which was cooler 2011 or 2010?
2.
Which was warmer 2011 or 2008?
3.
Which was cooler 2011 or 2007?
Volcanic eruptions, ENSOs, cloud cover and ocean
variability aect it so this stalling may be only a ‘pause’.
But how do we know?
Taking such snapshots does not give long-term trends as
they are minor variations.
Global
temperature anomalies from 20th century average 20 07–2011 (
°C)
0.70
0.65
0.60
0.55
0.50
C° erutarepmet
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0.00
0.05
2007
2008
2009
2010
2011
0.10
year
0.15
▲
Fe 7
.2.2 Global temperature anomalies from 20th century average 2007–2011
4.
Compare gure 7.2.3 and gure 7.2.4.
5.
What are the trends (blue lines) in these graphs?
Global
6.
What conclusions can you draw?
temperature anomalies from 20th century average past decade (
°C)
0.70
0.65
0.60
0.55
0.50
C° erutarepmet
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0.00
0.05
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
0.10
year
0.15
▲
Fe 7
.2.3 Global temperature anomalies from 20th century average 2002–2011
1
Char ts from Peter Gleick’s ar ticle 'Global Warming Has Stopped'? How to Fool People Using 'Cherry-Picked' Climate Data. Forbes 2012.
http://www.forbes.com/sites/petergleick/2012/02/05/global-warming-has-stopped-how-to-fool-people-using-cherry-picked-climate-data/
320
7. 2
Global
c l i m a t E
c h a N g E
–
c a u s E s
a N D
i m P a c t s
temperature anomalies from 20th century average. Last 15 years (
°C)
0.70
0.65
0.60
0.55
0.50
C° erutarepmet
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0.00
0.05
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
0.10
year
▲
Fe 7
.2.4 Global temperature anomalies from 20th century average 1997–2011
We know that the decade of 2000–9 was the warmest on
7.
record since records star ted in 1850 and that the past 15
If you take records for the last 130 years, gure 7.2.5
years are amongst the warmest since 1850.
Global
What does that say about gure 7.2.3?
shows the data.
surface temperature changes from the 20th century average (
°C)
0.70
0.65
0.60
0.55
0.50
0.45
0.40
0.35
0.30
C° erutarepmet
0.25
0.20
0.15
0.10
0.05
0.00
0.05
0.10
0.15
0.20
0.25
standard polynomial
0.30
trend lines added
0.35
0.40
0.45
1880
1890
1900
1910
1920
1930
1940
1950
1960
1970
1980
1990
2000
2010
year
▲
8.
Fe 7
.2.5 Global surface temperature changes from 20th century average 1880–2011
What does this tell you?
But remember, these are only average global
temperatures. They do not record variation across the
shows that since 1970 far more heat has gone into the
oceans than is absorbed by land.
9.
So do you now think the Ear th is warming up?
planet. We know that more extra heat is warming the
10. And what do you think is causing this?
Arctic and melting Greenland and Arctic ice. Figure 7.2.6
321
7
C L I M AT E
C H A N G E
A N D
E N E R G Y
P R O D U C T I O N
Change in Ear th’s total heat content
250
ocean heating
)seluoJ
land + atmosphere + ice heating
200
01( 1
6 91 ecnis tnetnoc taeh latot ni egnahc
1
2
150
100
50
0
1960
1970
1980
1990
2000
2010
year
▲
Fe 7
.2.6 Change in Ear th’s total heat content
T
aken from Church et al. Sept 2011. Revisiting the Ear th's sea-level and energy budgets from 196
1 to 2008. Geophysical research
letters. Ar ticle rst published online: 16 Sep 2011
gb c s
Modelling
climate
computing
been
developed
greenhouse
to
gases.
approximations.
included
oceans,
The
rain
land
latest
predict
The
not
a
complex
models
changes
models
have
solve
Now
the
with
a
range
over
they
requiring
climate
complex
improved
clouds.
business
of
have
emissions
equations
30
have
of
huge
system
years.
but
The
interactive
of
have
early
to
use
ones
clouds,
rain,
aerosols.
climate
models
changes
increases
is
Simple
They
but
and
temperature
with
change
resources.
to
ranging
predict
those
from
similar
predicted
1.6
to
possible
by
4.3°C.
global
models
(See
1.2
5
or
on
average
10
years
ago,
models.)
gs ss
There
gases)
is
very
but
activities
The
list
of
methane
oxide
and
three
dioxide
GHGs
of
greenhouse
nitrous
reviewing
carbon
other
(activities
and
are
little
and
vapour
There
322
it
are
in
the
atmosphere
increasing
through
(0.04%
of
the
total
anthropogenic
humans).
gases
but
not
also
only
includes
carbon
chlorouorocarbons
dioxide,
(CFCs
and
water
HCFCs),
ozone.
points
statistics
on
that
may
climate
be
confusing
change.
when
reading
about
or
7. 2
1.
The
role
of
ozone
2.
The
role
of
water
3.
Whether
gures
(anthropogenic)
and
c l i m a t E
c h a N g E
–
c a u s E s
a N D
i m P a c t s
CFCs.
vapour.
refer
to
total
greenhouse
GHG
effects
or
the
enhanced
effect.
t c s c
As
humans
increase
greenhouse
effect
believe
this
that
is
is
emissions
of
exaggerated
causing
global
some
or
greenhouse
enhanced.
warming
and
gases
Most
(GHGs),
climate
climate
the
scientists
change.
reected radiation
by atmosphere
infrared radiation
infrared radiation
re-emitted back to Ear th
emitted by Ear th
▲
absorbed
reected radiation
radiation
by Ear th’s surface
Fe 7
.2.7 The greenhouse eect
6% scattered from
atmosphere
20%
scattered
and
reected
19% absorbed by
by clouds
atmosphere and clouds
4% reected
by surface
51% absorbed
by Ear th
▲
Fe 7
.2.8 The greenhouse eect showing percentages absorbed,
reected or scattered
323
7
C L I M AT E
C H A N G E
A N D
Ke e
E N E R G Y
gb w  (gWp)
The
gWP is a relative measure of
P R O D U C T I O N
gas
greenhouse
it
effect
of
a
molecule
of
a
GHG
varies
depending
which
is.
how much heat a known mass
Carbon
dioxide
has
a
GWP
of
1.
Methane
has
a
GWP
of
21
so
traps
of a GHG traps over a number
21
times
as
much
heat
as
the
same
mass
of
carbon
dioxide.
of years compared to the
same mass of carbon dioxide.
Ozone
occurs
troposphere
absorbs
a
coolant.
to
are
ozone
of
no
the
reach
troposphere.
atmosphere
the
and
a
layers
the
made
are
is
so
surface
and
is
of
as
but
not
humans
well
as
the
global
sun
In
a
and
there
more
in
to
act
chemicals
processes.
as
so
Although
ozone
in
than
1%
of
warming.
down
the
present
many
their
links.
ultraviolet
break
not
are
as
indirect
less
GHGs
are
There
that
acts
causing
coincidentally
but
so
and
are
amounts
the
layer
warming
allowing
this
that
HCFCs.
forms
signicant
stratosphere
natural
it
complex,
certainly
human-made
result
CFC-12
by
is
atmosphere.
from
between
layer
the
the
radiation
link
Earth
of
stratosphere
climate
Earth’s
reach
CFCs
as
the
reaching
they
in
direct
ozone
chemicals
when
CFC-11
is
two
but
ultraviolet
because
radiation
CFCs
lower
GHG
the
There
thinning
solar
a
of
but,
radiation
the
is
much
depletion
The
in
it
in
types
the
eg
concentration
in
9
the
atmosphere
contribution
has
be
a
high
is
than
up
a
When
data
is
due
the
Clouds
its
Also
the
The
IPCC
scientists,
on
that
in
the
up
to
a
the
snow
much
and
water
of
25%
a
of
the
cause
the
rest,
of
on
stops
gas
with
it
Panel
the
may
of
the
30
last
million
(400
carbon
is
in
the
which
radiation
water
but
on
by
type
it
and
acting
their
carbon
concentration
years
added
not
but
dioxide
atmosphere
are
is
as
a
effect
is
Climate
calculations
water
of
vapour.
cloud
dioxide
–
to
seem
this
the
each
year
be
recent
and
to
is
higher
rapid
due
when
an
over
to
and
having
year
last
25
of
in
is
is
than
of
at
any
increase
of
activities.
due
parts
3.2–4.1
years
it
that
of
human
each
through
and
now
rate
measured
increase
the
there
activities
atmosphere
much
equates
may
the
are
human-made)
anthropogenic
unprecedented
may
ppm)
to
160,000
carbon
activities
GHGs
CFCs
due
dioxide
years
of
most
(except
a
effect
greenhouse
contribution
(depending
molecule
molecule
largest
from
large
GWPs
concentration
that
a
1.
greenhouse
vapour
50%
of
the
(Intergovernmental
omit
a
contribution
in
ice
36–66%
each
long-wave
GWP
has
have
Their
means
trapping
has
potent
so
because
That
vapour
most
of
gure
GHGs
these
Carbon
amount
of
water,
at
whether
varies
they
effect.
human
form
the
it
),
atmosphere.
dioxide.
which
(10
effect
the
Water
region
The
other
processes
in
to
the
contribute
during
30ppm
in
most
and
consider
is
trillion
effective
dioxide
so
in
carbon
more
because
per
greenhouse
excluded.
energy
work
increase
time
324
and
may
concern.
or
listed
remember
natural
times
parts
lifetime
of
carbon
vapour.
IPCC
largest
that
condensing
altitude)
the
heat
water
Change),
but
of
Somewhere
to
long
presented,
usually
constantly
GHG.
10,000
is
a
times
included
trapping
not
of
in
enhanced
and
molecule
vapour
on
to
measured
the
GWP
thousands
CFC
is
to
is
Gt
to
per
C
according
in
to
the
7. 2
c l i m a t E
c h a N g E
–
c a u s E s
a N D
i m P a c t s
9
the
to
IPCC.
A
Gt
is
a
4,100,000,000
include
half
of
carbon
this
gigatonne
tonnes
in
above
methane.
carbon
each
geene 
or
one
the
natural
Natural
year
(see
billion
sinks
Carbon
tonnes
carbon
(10
(oceans,
cycle
)
cycle
so
that
and
plants)
is
does
absorb
up
not
about
2.3).
Pe-nd
Peen
nenn
nenn
gWP
% cnbn
ape fe
 enned
e/e
eene
(pp)
(pp)
ee
Carbon dioxide, CO
270
400
1
50–60
50–200
0.7
1.774
21
20
12
0.27
0.31
206
4–6
140
0
0.00025
3500
14 (all CFCs)
45
not known
variable
2000
variable
not known
2
Methane, CH
4
Nitrous oxide, N
O
2
CFC-11
Ozone
▲
Fe 7
.2.9 Major GHGs information
se: adapted from 'Recent Greenhouse Gas Concentrations' by T. J. Blasing, from
http://cdiac.ornl.gov
t d
What does this graph suggest about the changes in the relative impor tance of
the GHGs?
450
pre-industrial
concentation
400
present
concentation
350
300
250
PWG
200
150
100
50
0
carbon
methane
dioxide, CO
2
CH
nitrous
oxide N
4
O
2
GHG (excluding ozone)
▲
Fe 7
.2.10 GWP (global warming potential) of the three major GHGs
325
7
C L I M AT E
C H A N G E
A N D
E N E R G Y
P R O D U C T I O N
t nk b
heating. But much is not captured and is released into
mene   eene 
the atmosphere.
Methane is a simple hydrocarbon, CH
. Since about
4
1950, the concentration of methane in the atmosphere
has increased by about 1% per year due to human
activities. About 60% of the methane in the air is from
human activity and 15% of this from cattle. We also
use methane as a fuel. Natural gas is methane, biogas
digesters produce methane which is used for cooking or
heating.
se f ene:
ce
There are 1.3 billion cattle in the world and they are
ruminants with bacteria in their stomachs that break
▲
Fe 7
.2.12 Scavenging on a waste tip
down the cellulose in the grass that they eat. These
2
bacteria live in anaerobic conditions and release
re pdd ed cover 1.5 million km
methane as a waste product. It comes out of both ends of
a staple crop. The elds release up to 100 million tonnes
of land and rice is
the cattle and amounts to 100 million tonnes of methane
of methane per year due to anaerobic respiration by
per year. Each methane molecule is 21 times more
bacteria in the soil. But they only release methane when
eective than one of carbon dioxide at absorbing and
ooded which is about one third of the year and the rest
radiating heat energy and methane contributes about
of the time may act as a sink for methane, absorbing it.
20% of the anthropogenic greenhouse gases. If we could
capture this methane, we could use it as a fuel. Some
scientists are trying to reduce the amount that cows
produce by feeding them special diets higher in sugar
N e f ene
2
swp nd b – 5 million km
of bogs and marshes
release methane.
levels or taking the bacteria in kangaroo stomachs and
tee may produce 5% of atmospheric methane
putting them in cow stomachs.
as bacteria in their guts release it as they break down
cellulose.
te nd – the bogs and swamps of the tundra
contain much methane produced by decomposition
in waterlogged soils. But this methane is locked up as
it is frozen in the permafrost. There is evidence that
the permafrost is melting and that some methane is
being released. In some par ts of Siberia or Nor thern
Canada, you can dig a hole and set re to the methane.
As the permafrost melts, it releases more methane
which causes more warming – an example of positive
feedback . In Arctic seas is another source of methane,
locked up as methyl hydrates in clathrates which are
▲
Fe 7
.2.11 Cows produce methane
molecular cages of water that trap methane molecules
within them. These are only stable when frozen and
We p
under high pressure at the bottom of the seas. There may
Waste tips in richer countries give o methane as waste
10
be up to 1 × 10
tons of methane in these structures and
food decomposes in the tip in anaerobic conditions.
companies are already trying to mine them. But it is very
There can be so much methane that it is tapped and
dangerous work as the methyl hydrates can bubble up to
piped away to be used to generate electricity or for
the surface and sink any ships in the area.
326
7. 2
c l i m a t E
c h a N g E
–
c a u s E s
t c c b
The
only
environmental
discussion
But
we
to
that
are,
use
as
is,
climate
in
some
more
more
Climate
or
change
ways,
less,
and
resources
change
issue
and
from
global
and
fate
national
economies
of
whether
if
of
complex
We
climate
issue
talked
(topic
2).
about
on
we
are
There
are
all
will
a
be
and
can
count
more
growth.
how
people
many
wanting
How should we react when we
have evidence that does not
t with an existing theory?
stock.
have
bound
become
global
up
Added
suffer,
new
will
of
debate
population
We
effect
politics,
effect.
much
human
with.
direct
nite
as
with
to
this
whether
equilibrium
affected;
emotive
scientic
are
the
there
and
you
very
economics
issues
the
debate
about
questions
will
be
whether
can
and
begin
to
of
losers
the
see
and
power
what
a
is.
environmental
change
what
we
viewpoints
certainly
as
near
inuences
technocentrists
should
do
or
can
do
the
how
and
to
start
you
of
this
book
interpret
ecocentrists
mitigate
the
the
clash
effects
on
that
seeing.
are
●
there
●
GHG
facts
is
a
that
there
are
not
greenhouse
emissions
probably
●
to
viewpoint
of
a
deal
warming
billions
shifts
climate
question
a
and
nations
this
Your
evidence
the
or
different
see
to
i m P a c t s
toK
caused
probably
international
cause
millions
winners
bases
and
was
can
national
evidence
have
clearer
where
the
to
a N D
are
been
a
debate:
effect
increasing
increasing
has
in
the
due
to
greenhouse
recent
pattern
of
human
activities
and
are
effect
increased
average
global
temperature.
There
nor
is
not
over
The
vast
total
what
majority
correlation
there
citing
is
the
But
a
are
all
agree
Adding
the
action
how
Here,
we
Climate
●
as
not
the
change,
actions
take
the
‘Warming
of
of
the
of
wobble,
this
eld
and
rise
in
temperature
not
accept
weather
and
effect,
activity
the
the
increased
different
cause
sunspot
can
of
mechanisms
and
the
what
the
our
or
other
that
way
patterns.
some
increased
round.
And
to
be
IPCC
in
see
we
done
system
–
and
why
think
very
complex
though
prevention
nation
there
we
is
states
is
are
in
such
much
so
fth
or
cure
have
much
to
or
in
discuss
know.
(Intergovernmental
their
changes
are
models,
climate.
individuals
begin
climate
that
should
that
www.ipcc.ch
the
and
GHG,
model
what
observed
in
the
the
deniers.
behind
view
of
it.
emissions
change
Earth
inertia
you
GHG
question
feedback
the
cause
working
increased
exactly
lag
Change)
many
the
question
and
managing
and
may
who
change
that
the
about
climate
causing
system
about
doing
increased
rotational
climate
improved,
no
is
be
scientists
minority
earth’s
complex
of
causing
a
temperature
there
should
between
temperature,
But
agreement
we
assessment
unequivocal,
and
unprecedented
Panel
on
report
in
since
the
over
2014:
1950s,
decades
to
millennia.
327
7
C L I M AT E
C H A N G E
A N D
E N E R G Y
●
P R O D U C T I O N
Atmospheric
oxide
have
800,000
●
warming
Limiting
emissions
and
of
of
of
greenhouse
in
change
all
dioxide,
unprecedented
on
the
probability)
global
require
gas
methane,
in
at
least
and
the
nitrous
last
warming
will
of
cause
the
further
climate
substantial
and
[global]
system.
sustained
emissions.
climate
that
gases
components
will
greenhouse
inuence
(95–100%
cause
carbon
levels
changes
climate
reductions
Human
of
to
years.
Continued
●
concentrations
increased
system
human
between
is
clear.
inuence
It
is
was
extremely
the
likely
dominant
1951–2010.’
t d
anpen e f eene e
Copy and complete the table with sources due to human activities.
geene 
se de  n ve
cbn dxde
mene
ozne
N xde
cFc
What is climate change and what will happen?
Changes
in
changed
temperatures
sheet
thinning
process
and
average
are
change
1.
and
warming
There
There
may
3.
There
was
temperature
global
be
a
in
a
since
which
gas
change
(Figure
7.2.13b).
It
respond
may
reach
until
a
but
new,
a
not
slowly
in
at
rises.
the
These
It
may
severe
It
may
1970s
could
pollution
can
higher
–
proportion
action
but
not
and
be
be
storms,
due
the
be
no
in
ice
a
steady
rise
to
in
sunspot
general
trend
is
change
over
time
due
to
a
rst
in
but
in
a
more
forcing
(Figure
which
linear
then
(changes
in
solar
7.2.13a).
forcing
way.
It
increases
is
accelerate
but
insensitive
until
it
to
reaches
a
7.2.13c).
point
reaches
much
to
in
climate
follow
(Figure
tipping
then
2000.
due
the
buffering
equilibrium
level
relationship
change
may
sea
ways.
more
levels.
does
It
different
century.
direct
more
be
last
in
patterns,
recorded
dimming
the
ways
seen
and
cooling
change
changes
328
be
rainfall
climate
new
4.
may
can
or
thickening
greenhouse
radiation),
2.
or
over
ve
in
climate
there
global
variations
for
the
a
–
that
is
the
threshold,
equilibrium
at
is
climate
which
makes
point
reached.
it
no
response
changes
(Figure
to
rapidly
7.2.13d).
7. 2
5.
In
addition
new
over
a
occur
Figure
know
to
the
threshold
equilibrium
new
in
threshold
just
7.2.13
which
even
a
few
shows
one
and
falls
decades
these
we
are
change,
when
the
rapidly.
scenarios.
in.
get
stuck
decreases
These
until
threshold
problem
how
(a)
then
c h a N g E
–
c a u s E s
at
it
a N D
i m P a c t s
the
then
changes
tips
could
7.2.13e).
Our
So
may
forcing
(Figure
living
it
c l i m a t E
do
we
is
that
decide
we
do
what
not
to
do?
(b)
egnahc metsys
forcing
response
(c)
(d)
egnahc metsys
threshold
time
time
(e)
egnahc metsys
time
▲
A
Fe 7
.2.13 Possible climate change system responses to a forcing mechanism
way
of
forcing
In
(b)
you
slowly
a
visualizing
mechanism)
–
it
push
has
shallower
steeper
then
falls
with
more
gradient
again.
over
this
are
In
it.
(d)
is
to
imagine
pushing
the
same
force
resistance.
and
you
Can
the
push
you
In
car
the
uphill.
but
(c)
explain
the
(e)
climate
(a)
the
you
moves
until
In
car
reach
more
car
in
as
you
car
moves
a
part
easily
reaches
this
a
push
that
much
of
the
before
the
you
steadily
more
hill
the
edge
(the
uphill.
of
with
hill
a
gets
cliff
and
analogy?
329
7
C L I M AT E
C H A N G E
A N D
E N E R G Y
P R O D U C T I O N
t d
what the climate was like at the time the ice froze.
Wee  e evdene?
The propor tions of dierent isotopes of hydrogen and
See 6.1 for past climate changes.
oxygen give an indication of the climate then and levels
of gases can be measured. The age of the ice can be
me een e ne
calculated by ice rings in the top layers (rather like tree
Ice cores have been taken from the Antarctic and
rings showing summer and winter) and by the dust from
Greenland ice caps. The Vostok core in the Antarctic went
volcanic eruptions lower down. It gets less accurate the
down as far as ice laid down 420,000 years ago. A more
deeper you go. From the ice cores, a picture of CO
and
2
recent one reached 720,000-year-old ice. The bubbles
temperature over time can be built up. See gure 7.2.14.
of air trapped in the ice can be analysed to tell us
interglacial
300
period
glaciation
glaciation
)mpp(
2
OC cirehpsomta
250
200
200
150
100
50
0
present
thousands of
years ago
)Cº( erutarepmet cirehpsomta ni egnahc
2
0
–2
–4
–6
200
150
100
50
0
present
thousands of
▲
Fe 7
.2.14 CO
years ago
and temperature levels of the last 240,000 years
2
1.
What conclusion can you draw from the two graphs?
In Hawaii in the Pacic, atmospheric CO
has been
2
measured since 1958. See gure 7.2.15.
Since we star ted burning large amounts of fossil fuels,
humans have added CO
to the atmosphere in addition to
2.
Describe and explain this trend.
2
the natural amounts in the carbon cycle. Ice core records
3.
What is the percentage increase in CO
levels
2
show CO
levels have risen from about 270 ppm before
between 1960 and 2008?
2
1750 to 400 ppm by volume today. Although CO
levels
2
4.
Why is there an annual cycle? (Hint: think about
were far higher than this (see 6.1) in geologic time,
which hemisphere has the most land mass and then
the recent increase has been due to human activities
when plants photosynthesize.)
and adds 27 billion tonnes a year of carbon to the
atmosphere.
330
7. 2
c l i m a t E
c h a N g E
–
c a u s E s
a N D
i m P a c t s
390
380
360
350
annual cycle
340
)mpp( noitartnecnoc edixoid nobrac
370
330
320
Jan
Apr
Jul
Oct
Jan
310
1960
1970
1980
1990
2000
year
▲
Fe 7
.2.15 Atmospheric CO
in ppm 1958–2007
2
5.
The temperature of the Ear th since 1850 is shown in
6.
What would you have said in 1910 or 1950?
gure 7.2.16. Although this has uctuated, there is a
trend. What is it?
0.6
annual average
ve year average
0.4
0.2
)C°( ylamona erutarepmet
0
0.2
0.4
0.6
0.8
1860
1880
1900
1920
1940
1960
1980
2000
year
▲
Fe 7
.2.16 Average annual temperature 1880–2010
331
7
C L I M AT E
C H A N G E
A N D
E N E R G Y
P R O D U C T I O N
More recently, over the last 100 years, sea level changes
7.
Sea temperature has also been recorded. Figure 7.2.17
have been recorded as well. But these are dicult to
shows average surface sea temperature since 1980.
measure as the land is not static but also moves up and
What is the trend?
down slowly. What measurements do show, however, is
8.
What happened to temperature when Pinatubo (a
that sea levels have risen and sea ice thickness at the
volcano in the Philippines) erupted? Explain this.
poles has decreased.
What happens in El Niño years? Explain this.
monthly average
0.7
annual average
0.6
ve year average
0.5
)c°( ylamona erutarepmet
0.4
0.3
0.2
0.1
0
0.1
Pinatubo volcano
0.2
0.3
El Nino / La Nina
1980
1985
1990
1995
2000
2005
year
▲
Fe 7
.2.17 Sea surface temperature 1980–2007
What is the consensus view?
toK
There
is
evidence
There has been considerable
increased
debate about the causes of
caused
climate change. Does our
climatic
interpretation of knowledge
atmospheric
from the past allow us to
very
reliably predict the future?
others
The
set
since
this.
variation
react
IPCC
is
by
the
and
up
swans
are
Australia.
in
the
as
of
332
being
further
deep
an
correct’,
the
a
assessment
report
the
climate
system
the
dominant
went
in
2014
with
cause’.
could
‘very
as
to
from
far
was
The
as
eg
have
activity
be
due
earth),
to
the
has
natural
some
patterns
Climate
into
due
are
to
very,
atmosphere,
this
the
rst
a
until
more
as
major
while
see
–
a
in
about
probability
‘9
of
human
stating
swan
time
10
case.
‘unequivocal
that
of
likely’,
out
is
example,
over
their
It
research
used
wary
for
certain
stating
issue.
who
black
‘extremely
was
World
reports
are
theory
you
the
world
four
condence’,
clear
Change
and
scientists
falsify
possible
very
95–100%
on
look
such
high
as
the
weather
around
became
terms
of
may
Programme)
hypothesis
used
that
quickly,
change.
language
they
human
oceans.
statements
experiment
as
of
Panel
1988
climate
outcome’,
so
in
scientists
some
works
report
of
respond
the
and
and
Environment
of
on
However,
condence
eg
concentrations
wobble
climate
parts
UN
qualied
white’
fourth
activity,
the
Organization
report
that
certainty,
(the
hundreds
regularly
language
some
slowly,
Some
Intergovernmental
UNEP
of
But
gases
Revolution
changing.
(sunspot
and
Meteorological
made
is
forcings.
very
greenhouse
Industrial
Climate
complex
up
that
the
‘all
in
and
‘ >95%
chance
The
fth
warming
inuence
of
was
7. 2
c l i m a t E
c h a N g E
–
c a u s E s
a N D
i m P a c t s
ics f c c
Global
most
average
of
that
temperature
since
1980
has
and
increased
this
has
had
by
a
about
number
0.85
of
°C
since
1880,
impacts.
1. On oceans and sea levels
Sea
levels
melting
sea
water.
thinning.
levels
into
This
the
eg
rise
and
The
the
eg
If
there
the
are
carbon
is
a
not
of
by
and
the
this
heats
are
will
is
more
and
on
are
°C
Netherlands
that
sea
would
sea
entered
mean
a
proportional
levels
Low
of
are
becoming
could
a
ice
and
variables
4.5
affected.
and
volume
land
mean
assuming
exceeded,
be
up
the
lying
lose
could
states,
land
area
–
completely.
dioxide
and
0.1
this
pH
anthropogenic
corals.
is
seas
1.5
that
will
it
predictions
with
between
But
as
increasing
sheets
the
but
improves
nations
by
sea
ice
of
clear
data).
and
acidic
particularly
is
disappear
carbon
more
the
Antarctic
increase
40
expands
into
expansion
(IPCC
Maldives
absorb
the
modelling
to
water
and
threshold
Up
produced
organisms,
and
An
would
slightly
land
much
15–95cm
metres.
because
thermal
how
climate
Tuvalu,
oceans
They
the
By
as
of
many
is
the
Greenland
Bangladesh,
some,
off
programmes.
relationship.
by
This
slips
more.
accurate
level
rise
rising.
land
The
rise
more
sea
are
on
But
as
as
makes
they
activities.
they
them
have
warm,
slightly
absorbed
This
may
they
acidic.
about
affect
absorb
half
marine
less
CO
.
2
2. On polar ice caps
Melting
to
rise
the
of
as
land
it
Arctic
will
displacement
these
melt
by
will
would
slow
be
Melting
region
the
in
the
release
of
slow
the
water.
or
stop
North
down,
of
glaciers
of
down
If
shut
volume
But
volume
water.
Arctic
could
allow
Methane
traps
the
Greenland
Melting
the
of
will
the
water
are
The
the
cause
oating
as
ice
melting
North
climate
of
the
of
the
same
into
the
seas
ice
Atlantic
Drift
levels
cap
has
Greenland
Atlantic
sea
ice
sheet
Drift
current
UK
and
and
could
current
and
the
Gulf
Scandinavia
colder.
and
reserves.
that
and
and
oceans.
water.
the
even
much
easier
the
increase
salt
or
Antarctica
liquid
completely
Stream
oor
not
as
in
into
increase
diluting
fuel
ice
ows
clathrate
methane.
methane
open
up
trade
exploitation
may
If
this
trigger
is
of
a
form
were
a
to
rapid
routes,
undersea
of
ice
melt
make
under
and
increase
travel
minerals
the
reach
in
in
and
Arctic
the
the
fossil
Ocean
surface,
the
temperature.
3. On glaciers
In
the
size.
Little
They
dimming
decrease
to
many
to
drought
over
size.
and
landslides.
80%
of
its
fed
in
by
the
Tanzania
and
the
the
1850,
period
warming)
Glacier
(River
1550
for
melted
below
rivers
are
problems
global
have
living
about
(except
masked
Asian
which
between
Some
people
major
Yangtze)
Age
decreased
possibly
in
ooding
supply
Ice
then
and
completely.
summer
glacier
Ganges,
Loss
glacier
provides
this
the
has
glaciers.
It
increased
when
continued
of
is
Kilimanjaro
a
to
fresh
Indus,
causing
glacier
in
global
ice
provided
Brahamaputra,
Himalayan
where
have
melt
and
glaciers
1950–90
leads
water
water
to
Yellow,
signicant
has
lost
volume.
333
7
C L I M AT E
C H A N G E
A N D
E N E R G Y
P R O D U C T I O N
4. On weather patterns
More
heat
more
violent
Global
soil
means
and
salinization.
violent
(eg
more
more
may
lack
There
of
extreme
than
in
with
more
rainfall
or
used
climate
bigger
by
will
storms
up
to
mean
There
is
droughts
and
so
and
more
15%.
more
hurricanes
Katrina).
they
the
increase
water
were
Hurricane
often
energy
sporadic
precipitation
erosion
and
and
more
in
This
2007
weather
severe
will
irrigation
evidence
are
the
and
some
that
occurring.
be
droughts.
cause
and
will
more
consequent
were
severe
more
weather
Monsoon
rains
fail
to.
5. On food production
Warmer
so
temperatures
photosynthesis
there
has
may
no
expanded.
winners
well.
If
earth
soils
There
that
and
to
by
the
too
crop
cold
seas,
NPP
.
In
shift
much
with
its
away
many
variables
will
spread
to
to
biochemical
less
of
be
the
fertile
certain.
growing
fertility
with
soils,
latitudes
NPP
is
they
be
soils
rich
will
so
will
the
70%
what
as
too
season
there
of
its
from
But
reactions
increase
equator,
Ukraine
changes
higher
will
crop
the
on
from
ranges
of
the
from
depends
thinner
huge
rate
respiration
Europe,
northwards
state
the
But
as
black
fall.
to
+11%.
certain
will
not
is
be
winters.
a
small
marine
Heatwaves
very
shifts
pests
in
biomes
It
Siberia
just
some
many
if
predictions
are
killed
But
losers.
increase
increase.
increase
production
Various
In
be
should
should
food
and
increase
in
temperature
can
kill
plankton,
the
basis
of
webs.
drought
kill
livestock.
6. On biodiversity and ecosystems
Melting
of
the
tundra
trapped
in
the
frozen
melting
and
Animals
of
year
can
and
tundra
higher
and
Plants
Loss
are
of
ocean
droughts
Increase
in
continually
cooler
they
too
and
least
to
to
shifting
but
as
them
species
it
could
dormancy
of
cannot.
The
germinate
at
is
is
distribution
and
about
1
extinct.
neither
become
their
which
permafrost
thaws.
slowly
go,
methane
Russia,
becoming
to
shifted
salinity
and
which
happens
stop
release
plants
seeds
nowhere
already
also
Canada
to
up
in
in
nor
the
higher
in
per
Species
higher
extinct
ranges
grow
km
wild.
latitudes.
earlier.
marine
waters
and
changes
to
habitats.
then
and
wildres
for
of
are
more
likely
to
wipe
out
other
animals.
fresh
reserves
and
salt
could
water
nd
may
their
kill
sensitive
animals
dying
species
and
the
static.
forest
signicantly
this
winter
habitats
parks
But
Polar
have
temperature
for
disperse
decreased
alter
are
regions
have
their
would
Alaska,
it
slowly
regions
latitudes.
boundaries
Indonesian
334
as
In
on
habitats.
increase,
at
national
park
to
breaking
glaciers
or
built
butteries
currents
species
and
shift
perhaps
or
towards
Birds
move
favourable
alpine
If
can
plants
more
houses
permafrost
soils.
res
years.
have
The
carbon
in
set
re
amount
the
to
of
the
peat
carbon
atmosphere.
bogs
which
released
by
have
these
burned
adds
7. 2
Pine
forests
which
are
is
very
degree
in
the
many
in
not
British
being
sensitive
can
cause
corals
food
are
Columbia
killed
to
off
increased
coral
If
are
the
and
sea
the
as
they
the
dies.
by
pine
too
–
c a u s E s
increase
are
the
a N D
i m P a c t s
beetle
mild.
of
Corals
one
zooxanthellae
Corals
ecosystem
c h a N g E
are
An
mutualistic
coral
die,
devastated
winters
temperature.
as
the
corals
being
cold
bleaching
expelled
webs.
by
c l i m a t E
basis
algae
for
dies.
7
. On water supplies
Increased
Without
says
and
that
water
2.4
their
glaciers
evaporation
a
billion
water
are
rates
supply,
people
supply
also
in
may
cause
populations
is
live
in
the
reducing.
some
would
river
In
rivers
have
basins
Europe
and
to
fed
and
lakes
move
by
the
North
to
dry
away.
up.
The
UN
Himalayas
America,
retreat.
8. On human health
Heatwaves
disease
they
will
spread
and
to
Warmer
off.
latitudes.
and
some
fungal
asthma
households.
on
killed
warm
dying
the
in
spread
and
from
And
Europe
to
Algal
are
in
fewer
2006.
regions
Malaria,
chest
yellow
blooms
toxic
will
These
may
as
less
fever
may
(red
the
be
tides)
increase;
in
and
drier
fever
common
can
kill
areas,
Insect
winters
dengue
more
and
increase.
cold
as
means
could
seas
humans.
dust
In
a
increases
infections.
higher
the
in
more
disease
temperatures
people
tolls
be
higher
to
many
will
climate,
leading
of
not
lakes
wetter
killed
vectors
cold
latitudes
each
snow
year
storms
would
and
and
reduce
reduce
icy
roads
the
number
heating
means
bills
lower
for
death
roads.
t d
9. On human migration
Copy and complete the table
If
people
cannot
grow
food
or
nd
water,
they
will
move
to
regions
below using the data in this
where
they
can.
Global
migration
of
millions
of
environmental
section.
refugees
states,
is
quite
services
150million
possible
and
and
this
economic
refugees
from
would
and
climate
have
security
change
implications
policies.
by
The
for
IPCC
nation
estimates
2050.
ad vne
Dd vne
f e
f e
ne
ne
The
Africa will
Nor thwest
lose food
Passage
production
10. On national economies
Some
would
would
gain
Canada
suffer
if
and
it
if
water
became
Siberia)
supplies
easier
that
to
would
decrease
exploit
have
or
drought
mineral
been
occurs.
reserves
frozen
in
the
(tar
Others
sands
permafrost
of
or
will improve
under
ice
sheets.
If
rivers
do
not
freeze,
hydroelectric
power
generation
shipping
is
possible
The
to
higher
Northwest
the
Pacic
explorers
stopped
in
at
by
sea
recorded
Overall,
tropics.
Darfur
has
of
to
nd
ice.
is
seas
In
a
sea
of
this
route
the
the
for
Arctic
route
2007,
will
be
gains
production
Africa
millions
the
in
shipping
Ocean
the
northern
passage
was
from
north
of
the
Atlantic
Canada.
summers
navigable
for
but
the
Many
were
rst
time
history.
there
Agricultural
Passage
via
tried
latitudes.
will
seen
and
may
probably
lose
desertication
hectares
become
losses
rise
in
food
on
a
for
national
higher
economies.
latitudes
production
massive
scale
but
and
fall
in
rainfall.
already
and
the
Northern
many
desert.
335
7
C L I M AT E
C H A N G E
A N D
E N E R G Y
To
put
the
1%
P R O D U C T I O N
a
monetary
former
of
global
change
How
to
fast
more
chief
GDP
save
up
could
changes
all
in
value
on
economist
should
to
of
go
difcult
World
to
global
happen?
your
is
the
now
20%
this
this
of
It
the
mitigating
GDP
is
but
Bank)
in
a
Stern
the
in
effects
recession
happening
Report
suggested
now
of
(from
2006
that
climate
later.
and
there
will
be
lifetime.
Fbck css  c c
Feedback
to
affect
There
is
are
two
Negative
return
example,
increased
kinds
any
of
of
of
the
output
from
a
system
as
input,
so
as
feedback:
is
feedback
deviation
increased
snowfall
part
outputs.
feedback
counteract
For
the
succeeding
on
from
that
an
evaporation
the
polar
tends
to
dampen
equilibrium,
ice
in
and
tropical
caps,
down,
promotes
latitudes
which
reduces
reduce
leads
the
or
stability.
to
mean
global
temperature.
Positive
leads
to
feedback
exponential
increased
levels,
While
thawing
which
that
feedback
deviation
of
we
that
away
permafrost
increases
modelling
complex
is
the
climate
cannot
from
leading
mean
keeps
be
amplies
global
an
to
of
the
increases
an
increase
in
change;
For
it
example,
methane
temperature.
improving,
sure
or
equilibrium.
some
feedbacks
are
so
results.
t d
Figure 7.2.18 lists changes that may have positive and negative feedbacks.
Draw feedback cycles for three of the boxes in gure 7.2.18.
Also look at sub-topic 1.3 to see some of these feedbacks.
Pve feedbk  ped ne
Oceans
Neve feedbk  dpened dwn ne
in warmer water
Oceans are a carbon sink containing 50 times
Oceans absorb more CO
the amount of carbon as the atmosphere. They
as phytoplankton photosynthesize faster,
release more carbon dioxide to the atmosphere
producing more phytoplankton that absorb
as they warm up as warm liquids hold less gas.
more CO
2
so dampening global warming.
2
Stalling of the Nor th Atlantic Drift could reduce
transfer of heat to the nor th and increase
temperatures dramatically.
Huge amounts of methane are frozen in
methane clathrates in the ocean sediments. If
these are released, the volume of methane in
the atmosphere will increase dramatically.
Clouds
More evaporation leads to more clouds which
More evaporation leads to more clouds which
trap more heat.
reect more heat.
It could be either. In the dark , clouds keep heat in, in the light they reect it. But it depends what type of cloud as
well. Cirrus (high, thin) clouds have a warming eect, low, thick ones a cooling one.
336
7. 2
Pollution
c l i m a t E
c h a N g E
–
c a u s E s
a N D
i m P a c t s
At night, cloud formation increased by aerosols
Aerosols from pollution, par ticularly sulphates,
acts as insulation, trapping heat. More clouds,
form condensation nuclei and more clouds
more heat trapped.
form. These reect heat and increase albedo,
reducing warming in the day.
Black soot falling on ice decreases albedo,
increasing heat absorption, increasing
temperature and melting.
Polar ice
Forests
Ice has a high albedo – reects heat and light.
Warmer air carries more water vapour so more
When it melts, the sea or land have a lower
rainfall, some of which will be snow so more
albedo and absorb more heat and more ice
snow, more reection, lower temperatures,
melts.
more snow and ice. Possibly the next ice age.
CO
Forests are cut down and burned. Less carbon
absorbed – forests act as a carbon
2
is absorbed. More CO
in the atmosphere so
sink , removing CO
2
from the atmosphere, so
2
higher temperatures. Forests die due to high
temperature rise decreases.
temperature and may catch re, more CO
2
released, temperature rises.
Tundra
As temperatures rise, permafrost melts, releasing
CO
which is trapped in the frozen soil.
2
Methane is also released.
▲
Fe 7
.2.18 Possible feedback mechanisms in climate change
t d
Look at the eects of climate change again and put them in diagrammatic
form or pictorial form to include the eects, positive and negative changes and
feedback mechanisms.
t nk b
gb dn
Global dimming is a reduction in solar radiation reaching
the surface of the Ear th. It was rst noticed in the 1950s
when scientists in Israel and Australia measured pan
evaporation rates (evaporation of water from a salt pan).
In the 1980s, more research in Switzerland, Germany
and the USSR also found that the incoming radiation
was less than it was. At the time, most were sceptical
of the results which showed a reduction in the rates
because of a reduction in sunlight and so a cooler Ear th
at a time when it conicted with evidence that the Ear th
was getting warmer. When aircraft were grounded for a
few days in the US after 9/11, the absence of contrails
(vapour trails from aircraft) produced a sharp rise in the
▲
Fe 7
.2.19 Contrails
range of the Ear th’s surface temperature.
337
7
C L I M AT E
C H A N G E
A N D
E N E R G Y
P R O D U C T I O N
Other experiments measuring sunlight levels over the
hemisphere and may be masking the full increase of
Maldives showed that par ticulates in the atmosphere
global warming. There is some evidence that, as we
were causing global dimming. The small pollutant
clean up our atmospheric pollutants, global dimming
par ticles of mostly sulphate aerosols in the clouds both
decreases and we see the full eect of global warming.
block sunlight from reaching the Ear th’s surface and
While global warming would increase temperature and
reect it back into space. These act as nuclei around
give more energy to the water cycle, decreased energy
which water droplets form and the clouds then reect
input would slow it down and make it more humid with
more sunlight back into space. Other par ticles come from
less rain.
volcanic eruptions, dust storms and incomplete burning
It has been suggested that we could control global
of fossil fuels which produce black carbon or soot. It
dimming and so mitigate the eects of global warming.
appears that global dimming aects weather patterns to
Putting sulphur in jet fuel would cause it to produce
the extent of shifting the monsoon rains and the longsulphates in ight and so cool the ear th. But the danger
term drought in the 1970s and 80s in sub-Saharan Africa.
in this is that we would be creating more pollution, not
The drop in temperature caused by global dimming was
less, and may nd ourselves in a cycle of increased
about 2–3% from 1960 to 1990 but no drop has been
warming and increased pollution to counteract it.
2
recorded since then.
The amount varies around the
Perhaps not the best idea?
Ear th with more in the temperate zones of the Nor thern
t d
Select and summarize two opposing views of global climate changes and
present your own viewpoint.
t d
Climate modelling
Watch the lm ‘An
We
all
want
to
know
what
the
weather
will
be
and
we
base
our
Inconvenient Truth’.
predictions
Watch ‘ The great global
and
warming swindle’.
are
on
authority
general
climate
past
(the
experience
experts
circulation
with
these
who
models
since
(what
the
tell
and
rst
it
was
like
last
June,
us
their
informed
we
have
been
computers.
The
for
instance)
predictions).
trying
early
to
model
ones
had
GCMs
the
few
Watch ‘Global Dimming’, a
inputs
and
were
not
very
accurate
predictors
but
we
now
have
AOGCMs
BBC Horizon documentary
(atmosphere–ocean
GCMs)
which
split
the
Earth
into
sub-regions
and
or the NOVA programme
consider
the
inputs
of
the
atmosphere,
oceans,
ice
sheets,
land
and
‘Dimming the Sun’.
biosphere.
This
includes
the
effect
that
humans
are
having
on
forests
Read peer-reviewed ar ticles
(deforestation).
The
latest
AOGCM
models
quite
accurately
reect
past
and books on the issue of
climate
change
and
have
predicted
changes
with
various
concentrations
climate change. (There is a
of
greenhouse
gases.
These
are
reported
by
the
IPCC.
lot of propaganda out there.
Make sure you are reading a
reliable source.)
Form an opinion based on
evidence and decide what
actions you will take.
W x  c c?
Humans
species
and
you
making
are
resourceful
extinct.
should
on
But
it
and
will
understand
these
climate
alter
your
the
change
will
lifestyle
science
and
not
choices
the
make
and
politics
the
human
possibilities
behind
decision-
issues.
2
Hegerl, G. C., Zwiers, F. W., Braconnot, P
., Gillett, N.P
., Luo, Y., Marengo Orsini, J.A., Nicholls, N., Penner, J.E., et al. (2007), ‘Chapter 9, Understanding and
Attributing Climate Change – Section 9.2.2 Spatial and Temporal Patterns of the Response to Dierent Forcings and their Uncer tainties’,in Solomon, S.,
Qin, D. & Manning, M. et al., Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the
Intergovernmental Panel on Climate Change, Intergovernmental Panel on Climate Change, Cambridge, United Kingdom and New York, NY, USA: Cambridge
University Press, http://www.ipcc.ch/pdf/assessment-repor t/ar4/wg1/ar4-wg1-chapter9.pdf.
338
7. 2
Your
parents’
about
the
human
than
to
the
grandparents’
War,
population
the
Earth
ignore,
for
or
Cold
of
growth.
could
climate
rest
nuclear
Until
provide
change
your
generations
proliferation
as
an
lifetimes,
the
and
issue
the
were
and
1980s,
were
c l i m a t E
not
affecting
climate
probably
deterrent,
we
all
c h a N g E
were
really
all
change
not
life
on
c a u s E s
a N D
i m P a c t s
concerned
World
War
utilizing
aware
debate
–
of,
or
Earth.
will
II
more
chose
Now
not
or
go
and
Practical
Evaluate
as
it
is
a
moral
as
well
as
an
economic
and
environmental
issue
that
two
your
lifestyle
and
moral
not,
as
an
to
these
all
ethical
have
a
dilemmas
drive
or
not,
have
an
high
involve
what
for
standard
your
type
effect
question
on
climate
change
choices.
and
The
dierent
will
viewpoints
affect
Work
away,
on
of
personal
car,
your
living
and
of
choices
live
personal
governments
of
to
in
a
carbon
MEDCs
why
should
(whether
city
or
the
to
they
to
it.
or
There
peoples
deny
reaction
countryside)
emissions.
whose
y
our
this
is
mostly
to
those
in
toK
LEDCs
the
by
asking
economic
them
model
to
we
decrease
have,
their
LEDCs
economic
aiming
to
development
increase
their
rate.
GDP
In
(gross
There is a degree of
domestic
product)
and
so
improve
the
lives
of
their
people
and
would
be
uncer tainty in the extent
unwilling
to
reduce
growth
rates.
and eect of climate
The
the
cost
alleviating
world’s
towards
the
of
GDP
this
and
technology
have
fuels.
the
–
we
should
so
to
not
will
because
do
not
change
cleaner
to
put
for
been
all
something
energy
efforts
democratic
plan
has
governments
towards
make
collective
Perhaps
elections
so
climate
50
vote
else?
to
into
100
this
is
as
a
value
give
We
production
politics
or
given
2%
have
as
we
short-termist
years
but
for
less
of
and
systems
long
of
–
2%
their
can
but
we
can
change. How can we be
GDP
condent of the ethical
develop
do
burn
until
than
of
the
not
fossil
next
responsibilities that may
arise from knowledge when
that knowledge is often
provisional or incomplete?
ve.
339
7
C L I M AT E
C H A N G E
A N D
E N E R G Y
P R O D U C T I O N
7
.3 ce ne – n nd dpn
Sc s:
acs  sks:
➔
Mitigation attempts to reduce the causes of
➔
D mitigation and adaptation strategies to
climate change.
deal with impacts of climate change.
➔
Adaptation attempts to manage the impacts of
➔
Eve the eectiveness of international
climate change.
climate change talks.
Kw  s:
➔
➔
mn involves reduction and/or stabilization
with N/P/Fe to encourage the biological
of greenhouse gas (GHG) emissions and their
pump, or increasing upwellings to release
removal from the atmosphere.
nutrients to the surface.
mn ee  ede ghg in general
➔
should include:
●
reduction of energy consumption
●
reduction of emissions of oxides of nitrogen
Even if mitigation strategies drastically reduce
future emissions of GHGs, past emissions will
continue to have an eect for some time.
➔
adpn ee can be used to reduce
adverse eects and maximize any positive
and methane from agriculture
eects. Examples of adaptations include
●
use of alternatives to fossil fuels
●
geo-engineering.
ood defences, vaccination programmes,
desalinization plants and planting of crops in
➔
mn ee f bn dxde ev
previously unsuitable climates.
(CDR techniques) include:
➔
●
adp ve p varies from place to place and
protecting and enhancing carbon sinks
can be dependent on nancial and technological
through land management eg United Nations
resources. MEDCs can provide economical and
reduction of emissions from deforestation and
technological suppor t to LEDCs.
forest degradation in developing countries (UN
➔
There are nenn e  and conferences
REDD) programme
to address mitigation and adaptation strategies
●
using biomass as fuel source
●
using carbon capture and storage (CCS)
●
enhancing carbon dioxide absorption by the
for climate change (eg Intergovernmental Panel
oceans through either fer tilization of oceans
on Climate Change (IPCC), National Adaptation
Programmes of Action (NAPAs), United Nations
Framework Convention on Climate Change
(UNFCCC), etc.
340
7. 3
c l i m a t E
c h a N g E
–
m i t i g a t i o N
a N D
a D a P t a t i o N
Ss  v c c
Ke e
We
do
can
either
try
to
reduce
the
impact
of
climate
change
or
adapt
to
it
or
mn involves reduction
both.
and/or stabilization of
There
are
three
routes
we
can
take
on
this
issue:
do
nothing,
wait
and
greenhouse gas (GHG)
see,
take
precautions
now.
Science
cannot
give
us
100%
certainty
on
emissions and their removal
the
issue
of
global
warming
nor
predict
with
total
accuracy
what
will
from the atmosphere. It is
happen.
What
it
can
do
is
collect
data
and
provide
evidence.
How
that
anthropogenic intervention
evidence
is
interpreted
and
extrapolated
will
depend
on
individual
to reduce the anthropogenic
viewpoints,
scientic
consensus,
economics
and
politics.
forcing of the climate system;
There
is
global
a
minority
warming
development
as
usual
and
so
and
on
Alternatively,
scientists
climate
Earth.
approach,
progress
of
out
they
of
say
may
that
we
poverty
that
others
change
They
saying
and
is
a
who
problem
take
the
may
forfeit
for
many
warming
is
do
‘do
by
a
not
for
accept
human
nothing’
and
economic
reacting
good
to
thing,
that
it includes strategies to
activity
and
business
sources and emissions and
development
a
non-threat.
brings
benets
reduce greenhouse gas
enhancing greenhouse gas
sinks.
and
IPCC, 2007. http://www.ipcc.
technology
can
manage
the
effects.
ch/publications_and_data/ar4/
The
danger
actions
fuel
to
base
will
effect
is
a
in
than
results.
the
sorry,
and
To
slow
may
feedback
could
strategy
move
tipping
which
see’
process
process
the
positive
equilibrium
‘wait
long,
reach
as
the
have
economies
we
in
the
and
not
point
8
°C
that
global
the
be
it
possible
our
than
But
the
it
a
long
away
is
it
is
will
of
a
climate
So
to
for
fossil
wg2/en/annexessglossary-
e-o.html
national
possible
have
now.
time
from
disruption
actions
change
warmer
takes
economy
necessary.
when
mechanisms
be
is
that
little
a
Ke e
new
better
safe
perhaps?
adpn is the adjustment
in natural or human systems
in response to actual or
The
precautionary
strategy
is
the
majority
choice.
Act
now
in
case.
expected climatic stimuli
Even
if
we
nd
out
that
burning
fossil
fuels
is
not
causing
global
or their eects, which
warming,
we
know
they
will
run
out
and
it
makes
sense
to
clean
up
the
moderates harm or exploits
pollution
caused
by
burning
fossil
fuels
and
nd
alternative
fuel
sources
benecial oppor tunities.
now,
before
we
international
offset
and
run
out.
targets
lifestyle
What
are
we
are
precautions
changes
–
against
seeing
–
in
carbon
national
emission
increased
climate
policies
and
reduction,
carbon
IPCC, 2007. http://www.ipcc.
ch/publications_and_data/ar4/
change.
wg2/en/annexessglossaryThese
precautions
can
be
divided
into
three
categories:
a-d.html.
●
international
●
national
●
personal
commitments,
actions,
lifestyle
and
changes.
m ss
A.
Stabilize
or
reduce
GHG
a.
reduction
of
energy
b.
reduction
of
emissions
emissions
consumption
of
nitrogen
oxides
and
methane
from
agriculture
c.
use
of
alternatives
B.
Remove
C.
Geo-engineering
In
carbon
mitigation,
stabilize
GHG
we
use
to
fossil
dioxide
from
technology
emissions
and
fuels
the
and
remove
atmosphere
substitutions
GHGs
from
that
the
reduce
or
atmosphere.
With
341
7
C L I M AT E
C H A N G E
A N D
E N E R G Y
P R O D U C T I O N
respect
reduce
But
climate
even
GHGs,
the
to
GHG
mitigation
past
gases
There
if
is
emissions
are
a
difference
GHG
atmosphere
are
adding
remove
of
to
strategies
will
the
between
stabilizing
the
emissions
at
today’s
GHGs
to
(see
the
an
GHG
atmosphere.
to
levels,
rise.
This
atmosphere
carbon
reduce
have
future
effect
for
cycle
If
as
emissions
and
we
their
is
faster
stabilizing
could
concentrations
because
than
our
natural
in
human
the
activities
processes
can
edixoid nobrac fo snoitartnecnoc
to
of
time
2.3).
edixoid nobrac fo noissime
To
to
emissions
some
tomorrow
time
▲
policies
sinks.
atmosphere.
in
continue
to
implementing
carbon
drastically
continue
in
means
enhance
GHGs
would
them
mitigation
and
circulating
concentrations
stabilize
change,
emissions
time
Fe 7
.3.1
stabilize
reduce
unlikely
GHG
concentrations
emissions
to
by
80%
of
in
the
peak
next
100
emission
years,
levels.
we
This
would
is
need
extremely
happen.
A. Stabilize or reduce GHGs
●
Reduction
■
of
Reduce
fuel
energy
economy
insulate
energy
■
and
Reduce
practices,
driving,
■
Adopt
■
Set
■
Personal
national
Change
change
342
taxes
limits
reduce
development
low
Improve
eg
in
remove
a
fossil
fuel
production
can
toll
for
be
and
by
and
less
schools,
or
being
more
business
walking
often
not
(7.1).
subsidy.
a
traded
and
and
carbon
and
credit
system.
encourage
socio-economic
educate
charge
for
trucks.
energy
in
footprint.
pathways
has
of
electricity
lifestyles
cycling
zones
efciency
and
y
government
London
emission
vehicles,
education
transport,
carbon
improving
appliances.
changing
which
eg
electric
economy,
GHG
their
efciently,
energy
by
or
private
and
on
and
efciently,
hybrid
circular
credits
priorities
attitudes,
and
less
meat,
more
more
for
–
it
engines,
bulbs
less
using
carbon
to
light
demand
less
using
car
buildings
using
carbon
people
■
eg
eat
by
motor
cool
overall
and
consumption.
waste
in
efcient
efcient
■
energy
production.
cars
to
choices
change
driving
–
social
into
the
city
7. 3
●
Reduction
of
emissions
of
nitrous
c l i m a t E
oxides
c h a N g E
and
–
m i t i g a t i o N
methane
a N D
a D a P t a t i o N
from
agriculture.
■
●
Reduce
methane
reduced
by
■
Capture
more
■
Sustainable
Use
■
of
nuclear
eg
methane
from
cows
can
be
diets.
produced
from
landll
sites.
agriculture.
high
emission
their
methane
alternatives
Replace
production,
changing
to
fossil
GHG
ones,
eg
power
fuels.
emission
energy
hydroelectric
generation
sources
and
instead
other
of
with
low
GHG
renewables
burning
fossil
and
fuels.
B. Remove carbon dioxide from the atmosphere
This
1.
is
termed
Increase
which
carbon
amount
carbon
sink
restore
grasslands.
a
(2.3)
For
Emissions
is
member
Carbon
capturing
industries
increase
have
It
is
to
be
energy
CCS
3.
Use
in
metal
there
then
by
b.
Indirectly
biogas
scale
in
power
rate
so
–
map
do
not
( UN
GHG
Removal
of
rates,
get
Reducing
in
LEDCs.
aiming
reducing
at
biomass
Degradation)
road
and
rocks
a
mineral
using
to
This
allow
emissions
source
the
fuel
carbon
from
of
pilot
power
If
of
the
and
But
stays
reacting
plants
there.
there.
An
carbon
Limestone
limestone
will
rocks
transported
and
other
this
suitable
is
means
but
have
is
the
carried
out
stations.
the
same
carbon
captured
for
it,
dioxide
making
fuel.
then
next
by
crop
is
dioxide
planted
to
that
photosynthesis
year’s
harvest.
This
fuel.
generate
biofuels
animal
store
by
dioxide
This
reneries
dioxide.
pressure
few
CCS
ready
to
A
oil
temperatures.
amount
neutral
it
produce
is
To
carbonates
like
carbon
atmosphere.
carbon
carbon
high
be
equal
of
under
amount.
an
the
products.
large-scale
as
to
stations,
amounts
would
huge
no
from
in
in
burning
to
Bali
the
a
deforestation
programme
(CCS)
captured
the
replanted
a
into
emissions
forest
the
released
from
the
it
year,
is
be
Directly
ii.
a
is
oxides
burning
a.
i.
is
are
biomass
should
it
large
it
so
biomass
by
storage
into
store
following
released
when
to
and
increasing
decreasing
UN-REDD
of
so
converted
reduce
resources
energy
and
carbonate
more
the
is
needed
but
of
found
with
calcium
and
emit
cost
and
not
out
pool
before
pumped
alternative
to
is
degradation.
emissions
which
the
then
dioxide
and
in
the
coming
done
it
does
Deforestation
capture
easily
dioxide
reforesting
This
countries
deforestation
(CDR).
photosynthesis
example,
from
removal
carbon
by
collaboration
more
of
atmospheric
confused.
2.
dioxide
waste
heat
(7.1)
in
or
electricity
eg
Indian
villages
or
on
a
larger
fermenters
biodiesel
and
vegetable
oils
ethanol
or
from
from
waste
planting
organic
crops
such
matter
as
or
sugar
waste
cane.
343
7
C L I M AT E
C H A N G E
A N D
E N E R G Y
P R O D U C T I O N
C. Geo-engineering
Geo-engineering
projects.
because
been
1.
This
so
tried
is
far
they
and
Scatter
or
iron,
have
2.
Release
sulphur
3.
Send
mirrors
take
ethical
or
up
or
space
large-scale
the
questions
on
oceans
the
to
act
them.
to
as
a
and
For
increase
global
the
strategies
they
carbon
increase
Earth
intervention
mitigation
models,
around
and
airplanes
between
other
computer
carbon
from
–
from
phosphates
more
dioxide
into
engineering
different
hypothetical
nitrates
which
4.
are
they
blooms
solar
climate
somewhat
have
not
example:
algal
sink.
dimming
Sun
to
(7.2).
deect
radiation.
Build
with
light-coloured
roofs
to
increase
albedo
and
reect
more
sunlight.
a ss
Adaptation
effects.
aims
to
Examples
programmes,
unsuitable
adverse
adaptations
desalinization
effects
include
plants
and
and
ood
maximize
defences,
planting
of
any
positive
vaccination
crops
in
previously
climates.
Adaptation
natural
reduce
of
initiatives
and
human
and
measures
systems
against
aim
to
actual
reduce
or
the
expected
vulnerability
climate
of
change
effect.
But
who
pays?
resources
individual.
Having
This
available
This
is
adaptive
implementation
outcomes
support
1.
a.
Do
UK
▲
land
not
in
is
effective
from
on
the
the
capacity
of
LEDC
Change
on
called
resulting
to
depends
and
the
will
technological
of
adaptive
a
a
and
economic
industry,
company
necessary
condition
strategies
change.
MEDC
for
to
the
design
reduce
nations
the
can
and
damaging
provide
nations.
use
through
planning
allow
building
on
2014,
see
ood
legislation.
plains
–
localized
ooding
in
4.2.
Fe 7
.3.2 Mirrors in space to deect
2.
Build
to
resist
ooding.
sunlight from the Ear th. Could this really
work?
a.
Plan
b.
Build
water
catchment
houses
on
stilts
and
or
run-off
with
to
garages
minimize
which
underneath.
Ke e
3.
Change
agricultural
production.
adpve p is
the ability or potential
a.
Irrigate
b.
Store
c.
Breed
d.
Grow
more
effectively
in
drought
areas.
of a system to respond
rainwater
for
times
of
water
shortage.
successfully to climate
drought
tolerant
crops.
variability and change,
and includes adjustments
different
crops.
in both behaviour and in
4.
Manage
the
weather.
resources and technologies.
From IPCC repor t 2007
344
a.
Seed
b.
Plant
or
capacity.
adaptation
climate
country,
clouds
trees
to
to
encourage
encourage
rainfall.
more
rainfall.
ooding.
can
be
ooded
the
7. 3
5.
Migrate
to
6.
Vaccinate
7.
Manage
other
c h a N g E
–
m i t i g a t i o N
a N D
a D a P t a t i o N
areas.
against
water
c l i m a t E
waterborne
diseases
eg
typhoid.
supplies.
a.
Desalination
b.
Increase
c.
Harvest
d.
Use
plants.
reservoirs.
run-off
water
more
effectively.
harvesting
from
clouds
in
higher
areas.
i c:   f s
 cs f c
1979
First
World
recognized
response
Climate
as
a
when
Conference.
serious
problem
evidence
of
Climate
change
needing
increasing
an
ofcially
international
carbon
dioxide
levels
established.
1988
Intergovernmental
established
by
Panel
United
on
Nations
Climate
Change
Environment
(IPCC)
Programme
(UNEP)
t nk b
and
the
World
collaborative
Meteorological
body
comprising
Organization.
over
2,000
The
IPCC
climate
is
a
scientists
Research and discuss
worldwide.
Its
main
activity
is
to
provide
at
regular
intervals
an
the strategies adopted to
assessment
of
the
state
of
knowledge
on
climate
change.
alleviate climate change by:
1990
First
that
1992
Rio
Earth
and
on
IPCC
climate
Report
change
Summit
of
concentrations.
nations
were
strategies
by
the
for
year
NAPA
(a
reporting
reality
the
The
Change.
and
(UNFCCC)
reducing
to
of
by
on
by
154
stabilize
to
gas
conrmed
scientic
or
emissions
You
●
Your school
●
Your town
●
Your country.
Convention
governments.
developing
●
data
Environment
greenhouse
developed
committed
greenhouse
Report
Framework
signed
is
governments
The
supported
Conference
Nations
Convention
voluntarily
was
Nations
United
Change
objective
Climate
a
(United
Development).
Climate
The
on
was
gas
annexI
national
to
1990
levels
2000.
National
proposed
Programme
by
the
of
UNFCCC
Action )
for
is
LEDCs
one
to
form
decide
of
how
to
Practical
meet
their
most
urgent
needs
to
adapt
to
climate
Evaluate
1995
First
UNFCCC
conference.
Governments
Work
change.
recognized
the
international
voluntary
commitments
were
inadequate
and
eectiveness
of
that
work
started
climate
change
to
talks.
draft
a
protocol
for
adoption
at
the
third
Conference
of
Parties
in
Discuss
1997.
Second
IPCC
report
concludes
that
the
balance
of
two
suggests
a
discernible
human
inuence
on
the
global
The
Kyoto
Protocol
signed
by
some
160
mitigation
adaptation
and
strategies
to
climate.
deal
1997
two
evidence
nations
at
with
impacts
of
climate
third
change.
UNFCCC
binding
conference.
commitments
greenhouse
2012.
2001
The
Third
global
The
gas
US
IPCC
mean
to
reduce
emissions
signed
Report
but
Protocol
to
has
states
temperature
by
carbon
5.2%
not
that
5.8
°C
calls
for
the
dioxide
below
ratied
1990
the
and
ever
ve
levels
legally
other
before
protocol.
anthropogenic
by
rst
emissions
will
raise
2050.
345
7
C L I M AT E
C H A N G E
A N D
E N E R G Y
P R O D U C T I O N
2004
The
Kyoto
Protocol
adopt
to
the
protocol
be
than
However
2005
Kyoto
Fourth
have
less
55%
the
US.
Western
2007
Work
the
by
Global
2009
but
China
2013
2014
must
I
signed
by
that
they
will
on
to
major
serious
cause.
a
Bali
the
is
levels.
37.5%.
in
2007
map
nations
Japan,
corporations.
effects
road
for
1990
industrial
and
(fully
annexI
only
of
emissions
Dec
ratify
enough
accelerates
reducing
Kyoto
to
accountable
governments
of
the
have
countries
emissions
cost
be
are
according
annex
warns
agreed
crisis
carbon
fall
gas
the
–
reduction
emissions
results
overtook
climate
warming
would
UN
to
be
far
climate
have
a
global
in
USA
lower
as
emissions.
in
international
reductions
the
192
GHG
as
national
emissions
country
with
governments
from
the
at
will
to
economies
industry.
largest
the
Copenhagen
summit.
of
400
pause
ppm
in
carbon
warming
dioxide
in
explained
atmosphere
as
oceans
reached.
have
continued
warm.
Fifth
IPCC
warming
through
in
damage
on
this
Apparent
there
regional
report
Bali
of
For
countries
together
emissions
retard
US
55
end.
Milestone
to
to
and
effect,
evident;
in
greenhouse
UN
into
economic
negotiate
fall
goes
IPCC
than
the
ineffective.
least
which
percentage
become
treaty
of
Europe,
conference
2008
countries
treaty
except
still
at
commitments)
(developed)
more
is
effective
the
is
report
was
happening,
burning
fossil
the
strongest
human
fuels
warning
activities
and
are
increasing
yet
that
mostly
carbon
global
causing
dioxide
atmosphere.
C c  ss
Management
strategies
management
model
Use
the
section
research
se f edn
to
Expe f n
Altering the human activity
producing pollution
Regulating and reducing
the pollutants at the point
of emission
Clean up and restoration
346
Fe 7
.3.3 Clean up actions on climate change
be
gure
mitigation
complete
b en
▲
on
in
can
the
looked
at
using
the
pollution
1.5.6.
and
table
adaptive
strategies
below.
Evn
and
your
it
levels
own
7. 3
c l i m a t E
c h a N g E
–
m i t i g a t i o N
a N D
a D a P t a t i o N
t ee
1.
a.
Find out what major climate change meetings there
Calculate your carbon footprint. (This measures
your carbon use in tons of CO
have been since 2007 and what the outcomes are.
not hectares as in
2
ecological footprints.)
2.
Find out:
b.
a.
List as many ways as you can of reducing your
What your own government policy is on climate
own carbon footprint size.
change and carbon emissions.
c.
b.
How many of these will you do?
What alternative energy sources the country in
which you live is developing.
5.
Which of the strategies you have listed would be the
most eective in reducing CO
c.
What are the advantages and disadvantages of
emissions and why?
2
Consider whether they need people to cooperate, if
these?
they reduce your quality of life, if the technology is
3.
List the possible ways that countries could reduce
available, how easy they are to do. Are the strategies
their carbon emissions.
ecocentric or technocentric?
4.
Research your own carbon footprint. www.
6.
What do you think are the ethical issues surrounding
carbonfootprint.com is a good place to star t.
the geo-engineering strategies?
t d
cbn e nd bn en dn
ticket now and you will be asked by many airlines if
you want to pay to oset the carbon emissions that you
As par t of the Kyoto Protocol in which 163 countries
are causing by ying on a plane. If you agree to this,
agreed to aim to limit their GHG production, the concept
the money should go to a company that invests it in a
of bn en dn evolved. In this scheme,
scheme that reduces carbon emissions. This is usually
countries that go over their quota (set by international
in a renewable energy scheme such as wind turbines,
agencies) on carbon dioxide emissions can buy carbon
tree planting or hydroelectric power generation. Although
credits from countries which do not meet their quotas.
small the market is increasing as environmentally aware
In this way they still produce carbon dioxide but globally
individuals invest. But some schemes have minimal
the limits are still met. You can imagine how complex this
impact on global carbon emissions as they must invest in
system is to operate. Monitoring carbon emissions for an
a scheme that would otherwise not have happened. Just
industry is hard enough but for a country is very dicult.
taking the money and planting trees which would still have
1.
Which country owns the emissions from an
been planted is not recapturing any more carbon dioxide.
international ight or container ship – where it star ted
Pen bn wne (PCAs) are talked about. In
or ends up or the country where the airline is based?
this idea, we are all issued with an allowance for carbon
2.
Who sets the quotas?
While a market has grown up for trading carbon emission
permits, it is a volatile one. The EU emissions trading
scheme, for example, has seen the value of carbon credits
fall due to an overestimate of the allocation required when
it started. The scheme does not encourage industries or
countries to reduce their emissions either if they can buy
permission to continue emitting. Carbon emissions trading
is an alternative to a Carbon Tax where organizations
are taxed for polluting – for releasing carbon dioxide.
emissions. If we travel a lot or live in energy inecient
homes, we would either have to change our lifestyles
or buy more PCAs on the open market from people who
produce less carbon dioxide.
To become bn ne is a goal that some talk about.
Being carbon neutral means that you have no net carbon
emissions – all carbon you release is balanced by an
equivalent amount that is taken up or oset. This could
be by planting trees, buying carbon credits or through
projects that reduce future GHG emissions.
Also many TNC (transnational corporations) locate their
5.
Do you think this is possible for an individual? What
production in LEDCs.
would you do? You may want to make a list of all the
3.
To which country do the carbon emissions belong?
4.
Which do you think is the better option?
There are voluntary schemes now to e bn
en for individuals and companies. Book a plane
things that you do that aect your carbon emissions –
researching your carbon footprint may help.
6.
How do you think dierent societies would react to
becoming carbon neutral?
347
7
C L I M AT E
C H A N G E
A N D
E N E R G Y
P R O D U C T I O N
W E I VE R
Comment on the ways
To what ex tent can
in which your EVS
society mitigate the
inuences your attitude
eects of climate
towards your lifestyle
change?
choice with respect to
Evaluate climate models
in predicting climate
change.
climate change.
Big QueStionS
C c 
 c
Carbon dioxide levels
To what ex tent
can
Examine the factors
are now 400ppm in the
nations achieve
that may make your
sustainable
own EVS dier from that
development and
of others with respect to
energy security?
climate change.
atmosphere. Discuss
whether you think we
have reached a tipping
point on climate change.
rcv qss
➔
How should we react when we have evidence that does not t with an existing theory?
➔
The choice of energy source is controversial and complex. How can we distinguish
between a scientic claim and a pseudoscience claim when making choices?
➔
There has been considerable debate about the causes of climate change. Does our
interpretation of knowledge from the past allow us to reliably predict the future?
➔
There is a degree of uncer tainty in the extent and eect of climate change. How can we
be condent of the ethical responsibilities that may arise from knowledge when that
knowledge is often provisional or incomplete?
➔
Why does a country's choice of energy source impact another country?
➔
What factors determine energy choices for a country?
➔
The impacts of climate change are global. Who decides what action is necessary
for mitigation?
348
Qck vw
All
1.
questions
The
are
major
worth
1
greenhouse
A.
nitrous
B.
water
oxide
and
vapour,
6.
mark
gases
are
chlorouorocarbons.
carbon
dioxide,
ozone
Methane
is
produced
I.
bacterial
II.
decomposition
by
activity.
in
landll
sites.
and
III. digestive
systems
of
cattle.
methane.
C.
carbon
D.
ozone,
dioxide,
water
nitrogen
vapour
and
and
The
rise
in
the
Earth’s
mean
I
and
C.
II
considered
between
to
be
1860
caused
only
B.
I
and
III
only
and
III
only
D.
I,
II
and
III
chlorine.
Which
of
these
human
activities
both
increases
surface
global
temperature
II
ozone.
7.
2.
A.
W E I VE R
R E V I E W
and
the
present
warming
and
depletes
the
ozone
layer?
is
A.
by
Emission
of
carbon
dioxide
of
sulphur
from
vehicle
exhausts.
I.
release
of
methane
II.
deforestation.
from
wetlands.
B.
Emission
dioxide
from
power
stations.
III. burning
of
A.
I,
II
III
C.
II
and
and
III
fossil
fuels.
B.
only
I
D.
and
I
II
and
III
Which
column
in
the
table
correctly
Leakage
D.
Release
of
methane
from
gas
pipelines.
of
CFCs
from
old
refrigerators.
only
8.
3.
C.
only
shows
What
might
be
a
consequence
of
a
signicant
the
decrease
in
the
amount
of
the
CO
in
the
2
effects
of
the
pollutant
gas?
atmosphere?
a.
B.
c.
sp
hened
dxde
e
D.
mene
A.
The
Earth
becoming
B.
A
decrease
C.
A
rise
D.
The
warmer.
cbn
in
CFC
levels
in
the
atmosphere.
dxde
in
sea
levels.
nee e
eene
Yes
No
Yes
Earth
becoming
cooler.
Yes
ee
9.
Which
effect
pair
is
of
statements
about
the
greenhouse
correct?
depee
pe
Yes
Yes
No
Yes
A.
It is caused by carbon
It increases acid rain.
zne
dioxide and methane.
nee
B.
Yes
No
No
Yes
It occurs in the
It may cause a rise in
troposphere.
sea levels.
It accelerates ozone
It is caused by CFCs.
d f n
C.
4.
If
part
of
the
cost
to
the
environment
of
fossil
depletion.
fuel
use
most
were
likely
added
effect
to
the
would
price
be
of
the
fuel,
the
D.
that
It blocks UV light.
It occurs in the
asthenosphere.
A.
global
warming
B.
use
renewable
C.
more
D.
consumption
of
would
increase.
energy
would
decrease.
10.
5.
Which
of
produced
fossil
the
Methane
B.
Carbon
C.
CFCs
D.
Methane
of
would
fossil
following
only
A.
fuels
by
and
fuels
would
water
list
contains
only
greenhouse
gases?
A.
Carbon
dioxide,
B.
Methane,
C.
Carbon
D.
Nitrogen,
water
and
methane
decrease.
gases
CFCs
and
sulphur
dioxide
are
dioxide,
lead
and
methane
activities?
chlorouorocarbons
and
Which
produced.
greenhouse
human
dioxide
and
be
water
water
and
CFCs
(CFCs)
vapour
vapour
349
H u m a n
s y s t e m s
a n d
8
r e s o u r c e
u s e
8.1 Hman atin dnamic
sigi i:
applii  kill:
➔
A variety of models and indicators are
➔
Cacate values of CBR, CDR, TFR, DT and NIR.
➔
Exain the relative values of CBR, CDR, TFR, DT
employed to quantify human population
dynamics.
and NIR.
➔
Human population growth rates are impacted
➔
Anae age/sex pyramids and diagrams
by a complex range of changing factors.
showing demographic transition models.
➔
Dic the use of models in predicting the
growth of human populations.
➔
Exain the nature and implications of
exponential growth in human populations.
➔
Anae the impact that national and
international development policies can have on
human population dynamics and growth.
➔
Dic the cultural, historical, religious, social,
political and economic factors that inuence
human population dynamics.
Kwlg  ig:
➔
➔
Demographic tools for quantifying human
human population growth. The DTM is a model
population include crde bir th rate (CBR), crde
which shows how a population transitions from
death rate (CDR), tta fer tiit rate (TFR),
a pre-industrial stage with high CBR and CDR
dbing time (DT) and natra increae rate (NIR).
to an economically advanced stage with low or
declining CBR and low CDR.
Gba hman atin has followed a rapid
growth cur ve but there is uncer tainty as to how
➔
this may be changing.
➔
➔
Age/ex ramid and demgrahic tranitin
mde (DTM) can be useful in the prediction of
350
include cultural, historical, religious, social,
political and economic factors.
As the human population grows, increased
stress is placed on all of Ear th’s systems.
Inence n hman atin dnamic
➔
Natina and internatina devement
icie may also have an impact on human
population dynamics.
8 . 1
H u M A N
p o p u l A T I o N
D y N A M I C s
H ppli ii
Are
the
there
crash?
that
The
grow
are
capacity
enough
‘World
number
on
Earth.
humans
difculty
of
the
we
able
for
–
At
live
the
the
in
the
of
of
into
give
an
is
it
to
the
the
Earth
we
trying
large
writing
What
the
Are
answer
and
live
use
search
estimate
this,
when
Have
for
a
these
environment.
the
of
and
that
cannot
we
look
change.
will
nd
population
bureau
reading
is
increase
Here
you
human
census
are
can
population
the
exceeded
questions
We
regions
engine
of
US
you
in
we
population
technology.
dynamics
a
today?
heading
cities,
population
clock’
that
7,150,229,812.
in
study
websites
time
on
manipulate
population
of
alive
Earth?
have
to
locally,
food
demographics
Type
a
many
capacity
humans
carrying
at
too
carrying
gure
is
this?
World bir th and death rates
Estimated 2011
Bir th rate
Death rate
19 bir ths/1,000 population
8 deaths/1,000 population
131.4 million bir ths per year
55.3 million people die each year
360,000 bir ths per day
151,600 people die each day
15,000 bir ths each hour
6,316 people die each hour
250 bir ths each minute
105 people die each minute
Four bir ths each second of every day
Nearly two people die each second
Average life expectancy at bir th is approximately 67 years. Sources: Population
Reference Bureau & the World Factbook (Central Intelligence Agency)
▲
Figre 8.1.1 World bir th and death rates 2011
Global
human
exponential
rate
a
of
growth
population
Our
90
current
million
growth
population
curve.
which
This
is
increases
people
rates,
it
are
will
when
rate
each
born.
to
the
generation
growth
double
has,
rate
is
now,
an
population
from
are
within
followed
follows
2
to
phenomenal
Predictions
again
until
population
proportional
in
population
growth
is
that,
4,
–
100
to
each
even
another
size.
4
an
accelerating
with
For
8,
8
example,
to
year
16
etc.
about
slowing
years.
Population of the Ear th
number of people living worldwide since 1
700 in billions
2048
9
snoillib ni noitalupop dlrow
2024
8
2012
7
1999
6
1987
5
1974
4
1960
3
1804
2
1
1927
0
1
700
1800
1900
2000
year
Source: United Nations world population prospects, Deutsche Stiftung Weltbevölkerung
▲
Figre 8.1.2 World human population growth since 1700
351
8
H u m a n
s ys t e m s
a n d
r e s o u r c e
u s e
T d
From gure 8.1.2, calculate the doubling time in years for the human
population to increase:
a.
1 to 2 billion
b.
2 to 4 billion
c.
4 to 8 billion
Then complete the table below.
Of
year
patin
Dbing time
1804–1927
1–2 billion
123 years
the
We
7.1
know
future
we
are
human
number
(see
billion
the
gure
humans
living
alive
today,
about
unsustainably
population
exponential
growth
curve
but
rate
will
we
will
start
half
can
be,
to
of
live
only
and
level
us
poverty.
estimate
when
out
in
and
and
at
even
what
what
decrease
8.1.3).
16000
15000
estimated
14000
U.N. high
U.N. medium
13000
U.N. low
12000
actual
11000
elpoep fo snoillim
10000
9000
8000
7000
6000
5000
4000
3000
2000
1000
0
001
2
0602
0802
0202
0402
0891
0002
0491
06 91
0091
0291
0881
0481
0681
0081
0281
T d
▲
Figre 8.1.3 Global human population growth rate over time
and three predictions for the future
Now watch the 1-hour long
documentary from Hans Rosling
If
you
look
at
any
statistics
or
any
graph
of
projected
human
population
titled ‘Don’t panic–the facts about
growth
estimates
vary
enormously.
This
is
because
they
are
based
on
population’,
past
and
current
trends.
We
can
apply
mathematical
formulas
to
current
http://www.gapminder.org/videos/
gures
but
they
assume
human
behaviour
is
predictable.
It
is
also
dont-panic-the-facts-aboutvery
hard
to
build
in
the
impact
of
the
demographic
structure
of
the
population/
population.
Summarize the conclusions of
the documentary in 200 words.
CBR
But
of
if
352
a
10/1000
you
bearing
In
have
years
population
with
will
signicant
an
the
have
ageing
impact
a
a
high
population
will
be
far
proportion
impact
with
less.
on
fewer
of
young
population
people
in
people
a
growth.
the
child-
8 . 1
In
●
gure
The
8.1.3,
high
that
the
there
variant
CBR
are
–
will
three
H u M A N
p o p u l A T I o N
D y N A M I C s
estimates:
assumes
that
continue
to
CDR
fall
will
continue
to
fall
rapidly
but
slowly.
Ke term
●
The
medium
projection
of
variant
the
is
the
middle
ground
and
a
straightforward
curve.
Measures of total human
●
The
the
low
variant
other
big
assumes
killers
and
we
will
that
the
not
nd
CBR
a
will
cure
to
AIDS
or
any
of
population change are:
fall.
•
Crde bir th rate (CBR) is
the number of bir ths per
thousand individuals in a
mig ppli hg
population per year.
The
four
rate,
main
death
factors
rate,
that
affect
immigration
population
and
size
of
organisms
are
birth
•
emigration.
Crde death rate (CDR) is
the number of deaths per
Fertility
rates
higher
than
2.0
result
in
population
increase,
while
lower
thousand individuals in a
than
2.0
results
in
population
decrease,
because
the
two
parents
should
population per year.
be
replaced
Migration
by
is
two
not
children
taken
into
in
order
to
maintain
a
stable
population.
Crude bir th and death rates
consideration.
are calculated by dividing
Fertility
rate
is
the
number
of
births
per
thousand
women
of
child-
the number of bir ths or
bearing
age.
In
reality,
replacement
fertility
is
from
2.03
in
MEDCs
deaths by the population
and
2.16
in
LEDCs
because
of
infant
and
childhood
mortality.
size and multiplying by
Fertility
there
is
is
a
sometimes
difference
percentage:
births
considered
in
per
a
expression.
1000,
or
synonym
Birth
hundred
to
rate
(%)
is
birth
rate.
expressed
of
1000. Write these out as a
However,
as
formula.
a
the
total
population,
birth
rate
(CBR)
not
•
of
each
woman.
However,
in
practice,
crude
is
Natra increae rate
used,
(NIR) is the rate of human
which
is
per
thousand
individuals,
male
and
female,
young
and
old.
growth expressed as a
percentage change per
T d
year.
1.
Calculate the population density, crude bir th rate, crude death rate, and
Natra increae rate =
(Crude bir th rate
natural increase rate from the data provided. Put the data in a table.
crude
death rate) / 10 (migration is
2.
patin denit is the number of people per unit area of land. Calculate
ignored)
2
the population density in number per km
•
Regin
pn
land
Bir th
area
10
Death
Crde
Crde
Natra
pn
bir th
death
increae
denit
rate
rate
rate
Dbing time (DT) is the
time in years that it takes
6
6
10
6
10
for a population to double
2
km
in size.
6
× 10
A NIR of 1% will make a
Wrd
6,000
131
121.0
55.8
population double in size
Aia
3,500
31
88.2
29.4
India
1,000
3
29.0
10.0
730
29
30.7
10.0
in 70 years. This is wor th
remembering.
•
Africa
The doubling time for a
population is 70 / NIR.
Tanzania
30
0.9
1.3
0.4
730
22.7
8.5
8.2
7
0.04
0.09
0.07
Another way to measure
Ere
switzerand
bir ths is the:
•
N America
460
21.8
9.3
3.6
us A
270
9.6
4.3
2.4
Tta fer tiit rate (TFR)
is the average number of
children each woman has
over her lifetime.
3.
Describe and explain the dierences in the data for the three regions Asia,
India and Africa.
353
8
H u m a n
s ys t e m s
a n d
r e s o u r c e
u s e
T think abt
1.
Research, sketch and describe the shape of the exponential growth curve
in the human population over the last 500 years.
2.
Exponential growth is characterized by increasingly short doubling times.
Doubling time is the number of years it would take to double the size of a
population at a particular rate (%) of growth. For example with a 2% growth rate
or natra increae rate, the population doubling time would be about 35 years,
with 4% natural increase rate a population will double in about 17 years. How
long would it take for a population to double if the natural increase rate was 1%?
3.
Using gure 8.1.2, copy and complete the table with doubling times for the
global population (in billions).
Date
patin
Dbing
Date
patin
time (r)
4.
Dbing
time (r)
1500
0.5
1,500
5.0
1800
1.0
300
6.0
1927
2.0
7.0
3.0
8.0
4.0
9.0
What do you notice about the changing doubling times?
T d
Ineqaitie f ife
5 would control 32% of the entire world’s wealth; all
5 would be US citizens
If we could reduce the world’s population to a village
33 would be receiving –and attempting to live on– only
of precisely 100 people, with all existing human ratios
3% of the income of ‘the village’.
remaining the same, the demographics would look
something like this:
The village would have 60 Asians, 14 Africans, 12
Europeans, 8 Latin Americans, 5 from the USA and
Canada, and 1 from the South Pacic
How would you illustrate this information?
The State of The Village Repor t by Donella H. Meadows
was published in 1990 as Who lives in the Global
Village? and updated in 2005. It is controversial as some
people think she was biased in the use of statistics and
51 would be male; 49 would be female
some of these are inaccurate. Examples of this are:
82 would be non-white; 18 white
Male:female ratio is 1.05:1
67 would be non-Christian; 33 would be Christian
Almost 80% of the world’s population is now literate
80 would live in substandard housing
There is less than 1/6th of the world’s population
67 would be unable to read
malnourished
50 would be malnourished and 1 dying of starvation
About 3% of the world’s population will have a college
33 would be without access to a safe water supply
education
39 would lack access to improved sanitation
About 9% will now own a computer
24 would not have any electricity (and of the 76 that do
The US controls no more than 30% of the world’s wealth.
have electricity, most would only use it for light at night)
However, it is a stark demonstration of the haves and
7 people would have access to the internet
have-nots.
1 would have a college education
Do you think this is an example of propaganda in favour
1 would have HIV
2 would be near bir th; 1 near death
of a par ticular viewpoint or does it make valid points
about the unequal distribution of wealth and goods on
ear th – or is it both?
354
8 . 1
H u M A N
p o p u l A T I o N
Ledc  medc
The
UN
Human
It
domestic
used
top
to
of
product
this
Countries
based
on
are
in
(GDP)
recent
also
their
as
measures
countries.
list
Index
Programme
combines
rank
ToK
Development
Development
country.
per
a
of
(HDI)
has
measure
health
capita)
Iceland,
and
Norway
of
(life
been
the
by
‘well-being’
expectancy),
education
and
adopted
into
Canada
the
of
one
have
(gross
value.
been
A variety of models and
a
wealth
at
It
is
the
grouped
indicators are employed to
quantify human population
dynamics. How can we know
which indicators to use?
years.
industrial
D y N A M I C s
into
more
and
development
less
and
economically
developed,
the most accurate models?
GDP
.
Mre ecnmica deveed
le ecnmica deveed
cntrie (MEDC)
cntrie (lEDC)
Most countries in Europe and Nor th
Most of the countries in sub-Saharan
America, and South Africa, Israel and
Africa, large areas of Asia and South
Japan
America
Industrialized nations with high GDPs
How can we judge which are
Less industrialized or have hardly any
industry at all
Population is relatively rich
May have raw materials (natural
capital) but this tends to be expor ted
and processed in MEDCs.
Individuals are unlikely to starve
Population has a lower GDP and higher
through pover ty
pover ty rates
Relatively high level of resource use
More people are poor with low
per capita (per person)
standards of living
Relatively low population growth rates
High population growth rates largely
largely due to low CBR but rising CDRs
due to rapidly falling CDRs
Have very high carbon and ecological
Have lower carbon and ecological
footprints
footprints
▲
It
Figre
is
in
easy
8.1.4 Comparison of MEDCs and LEDCs
to
reality
countries
Various
put
this
these
being
other
very
terms
industrialization
have
been
LEDCs
are
used
in
characteristics
division
are
countries.
The
First,
Soviet
bloc,
nations
accompanied
the
At
cities
the
to
by
provide
moment,
the
table
the
of
the
extremes
continuum
LEDC
and
and
has
are
replaced
called
Fourth
with
but
many
industrialized
workforce,
following
used
countries
and
trade
countries
are
to
and
to
the
stateless
have
GDP
,
population
least
within
(NICs)
often
migration
increased
considered
some
or
refer
states
increased
and
developing
as
states
countries
investment,
free
failed
World
in
and
these
Communist
development
foreign
differences
Developed
underdeveloped
Newly
a
describe
democracies,
industrial
massive
a
countries.
and
Third
economically
their
to
of
decline
Second,
into
changing
categorize.
used
advanced
respectively.
accelerated
to
MEDC
developed
terms
gradually
wealth
economic
technologically
a
hard
and
but
is
to
civil
be
to
rights.
NICs:
355
8
H u m a n
s ys t e m s
a n d
r e s o u r c e
China,
u s e
India,
South
Africa,
Malaysia,
Thailand,
Philippines,
Turkey,
T think abt
Mexico
or
and
Brazil.
And
it
would
be
very
hard
to
dene
them
as
LEDC
MEDC.
Perhaps it would be possible
to apply population ecology
models to human populations.
H ppli gwh  
There is a range of models
Human
population
causing
environmental
impact
appears
to
be
available that explore
underpinned
by
a
set
of
simple
facts:
population dynamics and the
●
more
people
require
●
more
people
produce
●
people
●
so
interrelationship between
more
resources;
a species’ population size
more
waste;
and other environmental
usually
want
to
improve
their
standard
of
living;
parameters, resources and
internal controls.
the
more
people
there
are,
the
greater
the
impact
they
have.
How do J and S curves
If
we
can
control
population
increase
and
control
resource
demand,
(2.1) apply to human
levels
of
sustainability
should
increase.
populations?
Demography
populations,
time
with
and
There
are
remain
so
there
examples
Size
on
we
of
We
and
similar
impact
with
in
the
birth
stable
is
no
the
and
sex
the
in
of
death
the
indirect
and
of
human
changes
over
rates.
rate
population
population.
and
characteristics
composition,
death
gain
examples
direct
statistical
and
when
net
human
alone
base
need
to
resource
on
the
size)
is
and
also
population
examples of resource
time
(or
assumption
have
exploiting
Select one of these
not
our
impact
of
and
the
birth
rate
are
size.
of
Modern
impact
the
a
that
resource
history
famines
is
the
is
failure
littered
and
all
on
responsible
environment
wealth
Many
of
a
and
the
with
droughts
needs
resource
(or
and
use
principle.
in
impact
all
our
and
impact
which
resource
models
populations
thus
individual
dynamic
for
population,
population
individuals
However,
a
factor
on
resource
(based
use)
only
the
use).
same
resource).
resource
the
impact
consider
need
environmentally
and
of
age
Earth.
resource
function
T d
on
population
live.
desire
a
of
the
our
study
size,
numerous
consequences
across
the
total
variations
Populations
equal
is
eg
have
waste
the
of
same
associated
resource
use
(and
Resource
use
varies
in
space.
failure or choose your own
●
MEDCs
●
Urban
and
LEDCs
demonstrate
contrasting
resource
use
per
capita.
and research the reasons
for it happening and the
and
rural
populations
demonstrate
varying
resource
use
proles.
consequences, what
happened afterwards.
●
●
Young
●
Amazonian
people
have
different
resource
needs
to
the
elderly.
Sahel long drought
Indians
have
different
resource
needs
than
Parisians.
1968–72
Yet
●
all
these
groups
may
have
an
impact,
though
the
impact
will
vary
scale,
type
and
severity.
And
the
impact
may
not
necessarily
be
linearly
1959–61
related
●
Irish potato famine 1845
●
Biafran famine 1967–70.
About
to
population
20%
MEDCs
is
negative
356
in
Great Chinese famine
of
us
falling
in
some
live
as
size.
in
MEDCs,
birth
MEDC
rates
80%
are
countries
in
higher
(eg
LEDCs.
in
Italy,
The
LEDCs
proportion
and
Germany).
in
sometimes
8 . 1
H u M A N
p o p u l A T I o N
D y N A M I C s
T d
World population growth, 1750–2150
12
economically developing countries
10
snoillib ni noitalupop
industrialized countries
8
1999
6
4
2
0
1
750
▲
1800
1850
1900
1950
2000
2050
2
100
2
150
Figre 8.1.5 Human world population growth 1750–2150 for MEDCs and LEDCs
People’s Republic of China
India
Indonesia
other Asia
Africa
Europe
USA
other Nor th America
(incl. Caribbean)
South America
Middle East
Oceania
▲
Figre 8.1.6 Distribution of world population in 2005
1.
With reference to gure 8.1.5:
Calculate the percentage of the world’s population living in LEDCs and
MEDCs in 1950 and predicted in 2150.
2.
Estimates of human population size vary greatly.
List three reasons why estimates might be greater or smaller than the
true gure.
3.
What are the limiting factors on human population growth?
4.
Estimate the percentage of the world population living in Asia in 2005 from
gure 8.1.6.
Ppli gwh  f hg
There
are
supply,
two
from
main
theories
Malthus
and
relating
to
population
growth
and
food
Boserup.
Malthusian theory
Thomas
from
Malthus
and
Malthus
1766
to
was
1834.
expressed
claimed
that
an
In
a
English
his
text
pessimistic
food
supply
clergyman
An
essay
view
was
the
on
and
the
over
the
main
economist
principle
of
dangers
limit
to
who
lived
population ,
of
1798,
overpopulation
population
growth.
357
8
H u m a n
s ys t e m s
a n d
r e s o u r c e
Malthus
u s e
believed
that
the
human
population
increases
geometrically
(ie
food required
2,
4,
(ie
8,
2,
16,
4,
6,
32,
8,
etc.)
10,
whereas
12,
etc.),
food
being
supplies
limited
can
by
grow
only
arithmetically
available
new
land.
Malthus
Malthusian trap
added
that
the
‘laws
of
nature’
dictate
that
a
population
can
never
doof fo ytitnauq
food
T
increase
beyond
the
food
supplies
necessary
to
support
it.
produced
According
These
to
population,
fertile
Malthus,
prevent
land
enough
which
is
population
numbers
the
to
feed
a
people
available
available,
food
of
resources
Malthus
growing
increase
is
increasing
believed
limited
cannot
that
population.
by
beyond
certain
the
support.
there
would
However,
as
‘checks’.
optimum
As
long
as
be
more
than
population
and
t
1
the
demands
for
food
increase,
there
is
a
greater
pressure
to
farm
more
time
intensively
▲
and
cultivate
poorer,
more
marginal
land.
According
to
Malthus,
Figre 8.1.7
though,
the
food
production
productive
Beyond
the
cultivation
capacity
ceiling
and,
decline
in
returns
where,
increase
serve
food
in
as
a
increases
eventually
only
the
where
even
to
food
but
is
soil
still
place
levels
occur.
be
so
limit
a
certain
its
levels
fullest
occurs,
known
as
of
of
determined
extent,
law
of
over-
with
limited
to
a
general
diminishing
only
marginal
did
a
small
returns
ultimately
acknowledge
new
food
by
technology.
technology,
Malthus
that
level
contributing
the
These
possible
maintained
and
to
growth.
would
to
existing
used
is
higher
eventually
output
and
erosion
This
population
he
take
with
will
increase
land
land
production.
check
production,
of
ultimately,
yield
in
can
methods
supply
in
that
food
would
population.
pop
BR
growth
falling
higher demand
early marriage
for food
pop decline
lower prices
late marriage
higher prices
lower
demand
pover ty
▲
Figre 8.1.8 Feedback cycle showing population changes and demand for food
Neo-Malthusians
are
now
seeing
slowing.
The
agree
the
Club
with
limits
of
of
Rome,
Malthus’
growth
an
arguments
as
NGO,
increase
is
in
and
believe
food
that
production
we
is
neo-Malthusian.
Limitations of Malthusian theory
Anti-Malthusians
of
food
is
ignores
the
Poverty
results
on
is
‘closed’
not
the
one
reality
limits
food
that
people
so
Even
it
the
for
food
a
is
actually
poor
does
so,
theory
not
year,
ie
a
only
global
enjoy
an
simplistic.
the
of
poor
resources,
scale,
the
fair
and
not
possibly
is
technology
the
size
enough
of
land
This
physical
community
distribution
feed
of
foreseen
mean
football
to
shortage
hungry.
not
have
which
a
go
world’s
even
A
reasoning.
who
a
area
there
too
Malthus’
could
farming
from
being
for
distribution
on
Malthus
in
as
explanation
Except
changes
enough
the
possible
from
and
spectacular
1,000
criticize
production.
supplies.
produce
358
just
we
pitch
the
can
to
supply
whole
8 . 1
human
the
population.
Malthusian
Rather
than
increases.
there
are
theory.
there
food
–
could
1992,
There
60
food
were
not
have
food
that
7
is
this
trend
have
exist
and
centuries
only
Britain
million
when
model
is
is
production
tonnes
to
living
in
and
Malthusian
Malthus
of
repeated
Globalization
D y N A M I C s
contradicts
contrary
standard
p o p u l A T I o N
arithmetically.
agricultural
26
continue,
high
This
world.
two
reached
in
a
last
increasing
will
people
most
the
the
surpluses
imported.
across
of
supply
surpluses
million
and
some
from
food
European
million
though
evidence
of
starvation,
In
indications
are
import
Thus
notion
H u M A N
lived.
and
MEDCs
something
Now
enough
which
Malthus
expected.
Boserup’s theory
In
1965,
in
population
(the
Esther
optimistic
population
to
change
and
will
theory
Boserup’s
ideas
systems,
rainforests
Her
theory
higher
new
that
to
technology
by
the
more
stages
of
that,
on
as
intensity
methods.
population
and
growth
into
to
act
food.
various
as
in
in
that
can
of
sum
up
use
food supply
total population
tropical
South
the
from
rise
incentive
invention’.
land
the
any
an
East
agriculture
and
increase
production
as
We
mother
increases,
arising
leads
so
cultivation
innovation
conclusion
naturally
the
cropping,
population
through
The
research
shifting
an
food
suggested
and
more
is
that
increase
food
produce
multiple
asserted
to
Boserup
for
‘necessity
her
extensive
intensive
view).
demand
sentence
based
from
suggests
farming
the
economist,
technologists
technocentric
were
ranging
Danish
increase
agrarian
Boserup’s
a
stimulate
doof fo ytitnauq
in
Boserup,
would
introduction
Boserup’s
time
Asia.
moves
into
of
theory
▲
Figre 8.1.9 Food supply and
population curves
is
development.
Limitations of Boserup’s theory
Like
Malthus,
community.
‘closed’
has
Boserup’s
In
reality,
because
therefore
migration
been
Sahel.
can
this
it
excessive
not
in-
based
at
a
and
difcult
occurs
in
on
global
the
assumption
scale,
test
of
are
Boserup’s
to
a
ideas.
Boserup’s
to
‘closed’
are
common
over-population
according
of
communities
out-migration
to
areas
which,
lead
population
From
support
does
so
is
This
is
It
because
relieve
theory,
not
features.
the
then
leads
to
innovation.
Overpopulation
land
very
pressure,
technological
the
constant
usually
population
idea
except
always
is
to
clear
that
numbers
lead
unsuitable
pressure
to
of
may
farming
be
certain
people.
technological
practices
responsible
types
In
of
such
for
fragile
cases,
innovation
that
may
environment
population
and
degrade
desertication
in
the
cannot
pressure
development.
Application of theories of Malthus and Boserup
There
may
is
be
evidence
suffering
ideas.
been
so
Both
to
On
and
the
other
by
growing
Malthus
the
suggest
at
famine
motivated
meet
to
appropriate
in
some
hand,
at
a
increasing
the
ideas
scales.
LEDCs
On
of
a
today
national
both
may
scale,
population
to
Boserup
global
level
the
reinforce
some
and
Malthus
growing
Malthusian
governments
develop
their
have
resources
and
demands.
and
Boserup
environmental
technological
that
different
limits
can
be
while
right
because
Boserup
Malthus
refers
to
refers
cultural
and
issues.
359
8
H u m a n
s ys t e m s
a n d
r e s o u r c e
u s e
T d
1.
Read the description of the theories of Malthus and Boserup and
summarize their models in a table like the one below.
Math
Ber
Mde diagram
Main idea
limitatin
Aicatin
2.
Look at the graph of food supply in India (gure 8.1.10).
i.
According to the Indian National Commission on Population, the
population of India was about 846 million in 1991, 1,012 million in
2001 and estimated to be 1,179 million in 2009. As the population of
India has increased what happens to the per capita food supply?
ii.
Add a third line to show increase in human population.
iii.
Whose theory is represented by this data? Explain your reasoning.
Index of total and per capita food production,
India. 19 61–1998
140
)001=9891( xedni
120
100
per capita
80
60
total
40
20
0
1960
▲
1970
1980
1990
2000
Figre 8.1.10 Total and per capita food production
in India 1961–1998
3.
Gba atin grwth
The pattern of human growth is not uniform with most growth currently taking
place in LEDCs. Use the following data to construct population growth curves
for MEDCs and LEDCs of the world from 1800 until 2100 AD. Plot the LEDCs
9
above the MEDCs (units = 10
Date
MEDC
lEDC
).
Date
MEDC
lEDC
1800
0.3
0.7
1980
1.1
3.3
1850
0.4
0.8
1990
1.2
4.1
1900
0.6
1.1
2000
1.3
5.0
1950
0.8
1.7
2025
1.4
7.2
1960
0.9
2.1
2050
1.4
8.0
1970
1.0
2.8
2100
1.4
8.0
4.
The values for the next century are only estimates. What will be the most
impor tant social factor that will determine human population size?
360
8 . 1
H u M A N
p o p u l A T I o N
D y N A M I C s
What will be the future world population?
What
do
fertility
Fer tiit rate
A
have
will
predicted wrd atin (biin) in 210 0
3.6
2.0
10.1
2.5
15.8
to
what
rate
the
it
is
rise
of
now
to
to
2.0
to
15.8
only
population
about
3.0,
has
1.7
in
is
will
at
by
2.6
in
2100.
to
3.6
and
estimates
If
a
every
however,
of
billion.
themselves,
population
a
Total
3.4
rate
(but
do
not
from
woman
decides
population
the
second
up
and
increase
2.5,
fertility
world
size
population
of
every
two,
population
will
second
fertility
averaging
for
2.1
If,
replace
the
instead
although
(high),
couple
children,
2100.
sink
a
scenario
child
MEDCs,
calculated
stabilizing
two
one
falling
that
this
billion
than
billion
have
rate
In
10.1
rather
world
Fertility
means
population.
three
decides
UN
mean?
1.5
fertility
add
rates
woman
rate
of
fertility
to
6.0)
continues
to
is
in
to
1.5,
the
now
LEDCs.
increase.
change
based
on
fertility
(medium/replacement
level)
and
1.6
The
rates
(low).
Wh i   vppl?
If
the
optimum
economic
return
countries
UK
and
population
may
per
have
capita,
a
Netherlands
is
using
higher
have
when
the
all
available
optimum
high
population
resources,
population
population
produces
then
density
densities
but
the
some
than
can
highest
others.
support
The
this
2
population
the
north
the
richer
with
is
a
high
living
overpopulated
countries
have
standard.
as
to
resources
import
Brazil
are
goods
with
much
and
two
people
scarcer.
services
The
from
per
km
snag
is
in
that
elsewhere.
Wh  ppl hv lg fili?
It
of
1.
appears
a
High
child
and
that
2.
that
country
some
parents,
welfare
3.
in
of
an
them
old
the
on
more
help
are
the
but
contribute
of
on
to
insurance
an
the
the
The
more
(26,500
to
have
soon
look
as
not
correlated
may
day)
more
due
than
with
GNP
be:
according
per
for
asset
each
need
family
to
UNICEF
to
you
is
the
child.
their
in
are
during
the
children
after
they
children
parents
in
more
burden
economic
their
is
reasons
mortality:
tradition
children
as
children
Some
one
malnutrition
may
need
so
adulthood.
parents.
less
land
have
seconds
reach
age:
their
and
work
are
is
to
wealth.
childhood
three
network,
Children
Status
It
of
dependent
4.
and
every
disease.
care
decision
personal
infant
dies
Security
take
the
nor
If
More
feeding.
their
children
secure
there
is
no
will
the
social
parents.
agricultural
able.
that
more
In
societies.
children
MEDCs,
education
They
mean
children
and
take
are
longer
to
society.
women:
subordinate
to
the
men.
traditional
In
many
position
countries,
of
women
they
are
is
that
they
deprived
of
361
8
H u m a n
s ys t e m s
a n d
r e s o u r c e
u s e
many
an
rights,
considered
depends
outside
more
the
girls
the
than
The
but
ways
to
2.
Improve
simple
and
by
health
Enhance
seed
some
size
the
tools.
(at
for
seedlings
by
through
soil
or
roads
force
grow
the
of
small
by
projects
buy
cost
an
not
LEDC
population
into
of
We
which
cash
is
a
are
status
boys.
religious),
status
contributed
is
in
MEDCs.
the
like
prime
to
cannot
diseases
way
have
get
them.
the
adults.
nutrition,
vaccines.
available.
a
on
the
practice
auto
that
to
to
family
that
buy
buy
pans
mechanic
will
has
some
feed
through
to
to
get
the
whole
credit
community.
people
may
projects,
have
realized
in
(eg
grow
tree
prevent
projects
then
cropping
and
through
improving
woman
an
Major
is
children
peasant
start
Local
work.
to
guaranteed
reforestation
measures.
do
is
a
for
may
loan
management.
often
this
focusing
for
for
yarn,
members
in
and
Bank,
given
enterprises
the
or
rate
they
by
counselling
Gramin
are
of
water),
medication
the
or
social
gaining
would
literacy
spread
tomatoes,
of
them
getting
and
particularly
of
fertility
MEDCs
work
their
probably
women
basic
the
family
to
career,
(social
capable
has
low
for
(boiling
the
and
produce,
be
in
own
to:
form
loans
conservation
for
HEP
in
transplanting
LEDCs
and
very
small-scale
as
to
formed
in
are
and
Return
projects
they
discrimination
pay
simple
Small
resource
for
to
their
agricultural
children,
many
preventing
weaver
Thus,
least).
associations
Improve
a
the
hygiene
some
fertilizer
bread,
family
and
poor
the
children
LEDCs,
in
Microlending,
and
bake
In
by
success.
of
education
contraceptives
high
making
children
toward
too
income
of
of
contraceptives:
of
providing
4.
for
having
most
bearing
family
measures
Make
had
an
education
3.
level.
are
reduce
Provide
of
do
barriers
of
fertility.
they
1.
get
anything
reducing
them
5.
to
context
Unavailability
of
only
such
property,
they
number
down
allowing
owning
Instead
worthy
on
Breaking
5.
like
education.
debt
that
like
large
building
(Third
tobacco,
erosion
oil
dams
World
debt)
palm).
T think abt
The tat f wmen
According to the UN, women’s rights are the key to reducing the population
growth rate. Fer tility rates remain high where women’s status is low. Less than
20% of the world’s countries will account for nearly all of the world’s population
growth this century. Not coincidentally, those countries — the least developed
nations in sub-Saharan Africa, south Asia, and elsewhere — are also where
girls are less likely to attend school, where child marriage is common, and
where women often lack basic rights.
362
a.
Make a list of issues which may maintain the low status of women.
b.
Suggest proposals which might lead to a lowering of fer tility rate.
c.
List four reasons why educating women will reduce fer tility/bir th rate.
8 . 1
H u M A N
p o p u l A T I o N
D y N A M I C s
T d
patin ramid
All pyramids are taken from the US census website at http://www.census.gov/population/international/data/idb/
informationGateway.php. Have a look at this site as it has dynamic pyramids which change over time.
Population or age/sex pyramids show the distribution of individuals in a population, by sex and age. They contain a lot
of information.
1.
List the pieces of information that you can nd in the population pyramid of Afghanistan in 2000.
male
Afghanistan: 20 0 0
female
80+
75–79
70–74
65–69
60–64
55–59
50–54
45–49
40–44
35–39
30–34
25–29
20–24
15–19
10–14
5–9
0–4
5
4
3
2
1
0
0
1
2
3
4
5
population (in millions)
▲
2.
Figre 8.1.11 Population pyramid of Afghanistan in 2000
What changes are there in this predicted pyramid of 2025?
male
Afghanistan: 2025
female
80+
75–79
70–74
65–69
60–64
55–59
50–54
45–49
40–44
35–39
30–34
25–29
20–24
15–19
10–14
5–9
0–4
5
4
3
2
1
0
0
1
2
3
4
5
population (in millions)
▲
3.
Figre 8.1.12 Population pyramid of Afghanistan in 2050
Draw two horizontal bands (at 15 and 65 years). What do these bands represent?
Population pyramids can indicate political and social changes too. China used the concept of optimum population to
try to stabilize its population at 1.2 billion by the year 2000 and reduce the population to a government-set level of
700 million by the end of the century.
363
8
H u m a n
4.
s ys t e m s
a n d
r e s o u r c e
u s e
Explain the decrease in population younger than 35–45 in China in 2007. Think of at least two reasons.
male
China: 20 07
female
100+
95–99
90–94
85–89
80–84
75–79
70–74
65–69
60–64
55–59
50–54
45–49
40–44
35–39
30–34
25–29
20–24
15–19
10–14
5–9
0–4
70
60
50
40
30
20
10
0
0
10
20
30
40
50
60
70
population (in millions)
▲
Figre 8.1.13 Population pyramid of China in 2007
dgphi ii l
The
in
demographic
mortality
and
economic
development.
ve-stage
population
sigmoid
The
1.
growth
stages
Stage
to
no
poor
2.
1:
and
is
due
3.
2:
food
Stage
more
and
so
Late
to
4:
Stage
5:
fertility
As
a
model,
China
and
Saharan
model.
transition
can
be
a
pattern
result
can
linked
to
be
of
of
decline
social
described
the
stages
of
and
as
a
the
Low
the
is
(LEDC’s)
is
–
rates,
rates
Death
reduced
expands
so
–
High
cultural
due
rate
lifespan
rapidly
low.
(Wealthier
also
desire
have
stationary
for
and
(MEDC’s)
passed
those
–
of
to
birth
due
factors
disease,
drops
as
famine,
sanitation
increases.
child
as
to
–
As
access
emancipation
Birth
mortality
rate
falls
–
Low
ageing
by
in
country
to
women.
and
becomes
contraception,
low
Population
infant
death
birth
or
extrapolating
may
death
not
countries
stages
war
and
rates,
sizes.
be
replaced
as
workforce.
some
the
a
families.
Population
changes
of
goods
population
through
affected
criticized
due
material
(MEDC’s)
Problems
LEDC’s)
fall
smaller
Stable
explains
have
been
death
education,
and
countries.
or
High
rates
people
DTM
Brazil
has
birth
Declining
rate
societies)
mortality
medicine.
off
that
countries
It
the
as
medicine.
disease
healthcare,
industrialized
5.
families.
little
expanding
level
mean
Stage
is
country
(Pre-industrial
infant
population
improved
3:
high
expanding
developed,
begins
4.
large
improve,
improved
rates
stationary
Early
high
to
which
(DTM)
a
Demographic
model,
control,
hygiene
still
of
curve.
High
birth
Stage
model
(natality)
are:
encouraging
364
transition
fertility
very
civil
the
but
not
quickly.
unrest
do
European
others.
Some
not
sub-
follow
model
the
worldwide.
8 . 1
H u M A N
p o p u l A T I o N
D y N A M I C s
1
bir th rate
40
25
30
15
death rate
20
10
noitalupop 0001 rep etar ht rib
noitalupop 0001 rep etar htaed
20
10
5
total population
0
0
time
▲
Figre 8.1.14 The demographic transition model
Population
DTM
pyramids
take
one
of
basic
four
shapes
which
reect
the
stages:
Stage 1 – Expanding
Stage 2 – Expanding
Stage 3 – Stationary
Stage 4 – Contracting
Age
65
15
males (%)
▲
females
(%)
males (%)
females
(%)
males (%)
females
(%)
males (%)
females
(%)
High bir th rate; rapid fall in
High bir th rate; fall in death
Declining bir th rate; low
Low bir th rate; low death
each upward age group due
rate as more living to middle
death rate; more people
rate; higher dependency
to high death rates; shor t
age; slightly longer life
living to old age.
ratio; longer life expectancy.
life expectancy.
expectancy.
Figre 8.1.15 The four shapes of population pyramids
T d
1.
Copy and complete the table with the characteristics of each pyramid
stage
1. Exanding
2. Exanding
3. statinar
4. Cntracting
Bir th rate
Death rate
life exectanc
patin grwth rate
stage f DTM
Exame
365
8
H u m a n
2.
s ys t e m s
a n d
r e s o u r c e
u s e
For each pyramid below, identify the stage. You might like to look up your own country, if not included, and do the
same. Comment on the bir th rate, death rate, life expectancy, gender dierences and stage of development of
the country.
male
India: 20 07
female
male
Thailand: 20 07
female
80+
100+
95–99
75–79
90–94
70–74
85–89
65–69
80–84
60–64
75–79
70–74
55–59
65–69
50–54
60–64
45–49
55–59
40–44
50–54
45–49
35–39
40–44
30–34
35–39
25–29
30–34
20–24
25–29
20–24
15–19
15–19
10–14
10–14
5–9
5–9
0–4
0–4
70
60
50
40
30
20
10
0
0
10
20
30
40
50
60
70
3.5
3.0
2.5
2.0
1.5
1.0
population (in millions)
male
0.5
0.0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
population (in millions)
Italy: 20 07
female
male
Brazil: 20 07
100+
female
80+
95–99
75–79
90–94
70–74
85–89
65–69
80–84
75–79
60–64
70–74
55–59
65–69
50–54
60–64
45–49
55–59
50–54
40–44
45–49
35–39
40–44
30–34
35–39
25–29
30–34
25–29
20–24
20–24
15–19
15–19
10–14
10–14
5–9
5–9
0–4
3.0
2.5
2.0
1.5
1.0
0.5
0.0
0–4
0.0
0.5
1.0
1.5
2.0
2.5
3.0
10
8
6
4
2
population (in millions)
male
0
0
2
4
6
8
10
population (in millions)
United States: 20 07
female
85+
80–84
75–79
70–74
65–69
60–64
55–59
50–54
45–49
40–44
35–39
30–34
25–29
20–24
15–19
10–14
5–9
0–4
16
14
12
10
8
6
4
2
0
0
2
4
6
8
10
12
14
16
population (in millions)
▲
Figre 8.1.16 Population pyramids for ve countries in 2007
The
in
controversial
several
through
●
●
The
these
initial
model
in
have
fallen
as
recent
fall
in
the
areas
death
Deaths
●
The
from
fall
in
always
the
death
the
the
of
was
all
rate
have
birth
practices
and
case.
it
models,
it
has
the
fth
countries
has
not
or
and
based
all
limitations.
stage
such
always
no
which
as
on
change
countries
These
has
Germany
only
and
go
are:
become
Sweden
assumes
allow
to
been
cities
as
has
sanitation
steep
as
created
and
this
large
consequent
suggests
urban
high
inrm.
diseases
increased
is
that
decline.
poor
rate
that
suggests
countryside
young
is
it
when
the
model
yet
without
AIDS-related
religious
education
Like
from
of
this
countries
population
which
rates
●
that
about
years
into
movement
slum
366
stages.
clear
The
thing
industrialized
for
may
also
affect
availability
this.
literacy
It
also
rates
for
of
this.
contraception
assumes
women.
and
increasing
This
is
not
8 . 1
●
Some
countries
Asian
‘Tiger
example,
this
●
have
sequence
This
is
a
become
states’,
have
compressed
economies’
leapt
in
the
eurocentric
to
the
Malaysia,
time
model
This
and
timescale
Singapore
industrialized
same
industrialized.
for
of
status
period
as
assumes
may
not
be
of
H u M A N
these
and
without
p o p u l A T I o N
changes.
Hong
going
Kong,
D y N A M I C s
The
for
through
others.
that
the
all
case
countries
in
some
will
‘failed
example.
T d
T think abt
uing cmter mde t redict atin change
Models may be very
generalized and simple
Go to the UN Economic and Social Aairs oce website http://esa.un.org/unpd/
to use or so complex that
wpp/unpp/panel_population.htm
they are dicult to use.
1.
Using the basic data and median variant, nd the data for the following:
They should present the
a.
World population in 2050
b.
More developed regions population in 2050
c.
Less developed regions population in 2050
d.
Calculate the percentage of total world population that each region
signicant factors without
extra detail that may
confuse us. They should be
useful in helping us to make
predictions and make sense
makes in 2050
of the real world. How far
e.
Repeat these steps for the year 2015
f.
What does this tell you?
does the DTM help us or does
it hinder our understanding
of population change which
2.
Now go to the detailed indicators in the left-hand column
is far more complex than this
a.
Look up and make a note of fer tility rates for the same regions and
model suggests?
same years.
b.
Which region has the highest fer tility rate and why?
c.
What has happened to bir th rates of these regions over time and what
does this mean?
d.
What has happened to death rates of these regions over time and what
does this mean?
e.
3.
What has happened to life expectancy in these regions?
Using the same website, pick two variables that you think are impor tant
when trying to explain population growth, justify why they are impor tant
and explain what they show over the period 1950–2050.
4.
What are the problems with using computer models to predict population
expansion? How valid are they and what are they useful for?
5.
For the country in which you live or where you hold nationality, examine
the change in population between 1950 and 2050.
367
8
H u m a n
s ys t e m s
a n d
r e s o u r c e
u s e
T think abt
The AIDs eidemic – Africa, an rhaned cntinent
aord anti-retroviral drug treatments. Although the
multinational drug companies have agreed to reduce the
Information taken from UNAIDS, a joint UN agency on
prices of these drugs in Africa, they are still out of the
AIDS research and relief.
reach of all but a few. The eect is to leave a generation
Worldwide, 35 million people live with the HIV virus.
of orphan children, looked after by their grandparents.
10% of these are aged 15 or under. In 2010, 1.8 million
1.
Describe the population pyramid for South Africa
people died from AIDS related illnesses. About 2/3rds
in 2000.
of these were in sub-Saharan Africa which is the worst
aected region.
2.
What type of pyramid is this?
South Africa is the worst aected country with more
3.
Explain why it changes for 2025.
than 15% of the people infected.
4.
Most people who die from AIDS related illnesses are the
Explain the factors that inuence the pyramid in 2050.
(Remember economic factors as well.)
wage-earners of a family and those who are poor cannot
male
South Africa: 20 0 0
female
80+
75–79
70–74
65–69
60–64
55–59
50–54
45–49
40–44
35–39
30–34
25–29
20–24
15–19
10–14
5–9
0–4
▲
Figre 8.1.17 The
3.0
2.5
2.0
1.5
1.0
0.5
0.0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
population (in millions)
World Aids Day ribbon
male
South Africa: 2025
female
80+
75–79
70–74
65–69
60–64
55–59
50–54
45–49
40–44
35–39
30–34
25–29
20–24
15–19
10–14
5–9
0–4
3.0
2.5
2.0
1.5
1.0
0.5
0.0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
population (in millions)
male
South Africa: 2050
female
80+
75–79
70–74
65–69
60–64
55–59
50–54
45–49
40–44
35–39
30–34
25–29
20–24
15–19
10–14
5–9
0–4
3.0
2.5
2.0
1.5
1.0
0.5
0.0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
population (in millions)
▲
368
Figre 8.1.18 Population pyramid for South Africa 2000, 2025 and 2050
8 . 1
H u M A N
p o p u l A T I o N
D y N A M I C s
Iig h ppli gwh
picie that ma redce atin
picie that ma increae atin
grwth rate
grwth rate
Parents in subsistence communities
Agricultural development, improved
may be dependent on their children
public health and sanitation, etc. may
for suppor t in their later years and
lower death rates and stimulate rapid
this may create an incentive to have
population growth without signicantly
many children. So if the government
aecting fer tility.
introduces pension schemes the CBR
comes down.
If you pay more tax to have more
Lowering income tax or giving
children or even lose your job, you may
incentives and free education and
decide to have a smaller family.
health care may increase bir th rates,
eg Australia baby bonus.
Policies that stimulate economic
Encouraging immigration, par ticularly
growth may reduce bir th rates as a
of workers – for example Russia allows
result of increased access to education
migrants to work who do not have
about methods of bir th control.
qualications to ll the gap in manual
labour.
Urbanization may also be a factor in
reducing crude bir th rates as fewer
people can live in the smaller urban
accommodation.
Policies directed toward the education
of women, and enabling women to
have greater personal and economic
independence may be the most
eective in reducing fer tility and
therefore population pressures.
▲
Figre 8.1.19 National and international policies inuence human
population growth
While
they
do
we
are
not
really
support.
Earth’s
live
may
and
All
be
know
our
to
they
how
evidence
resources
within
able
where
count
live,
many
we
have
or
nd
many
even
people
at
unsustainably
means
how
and
the
but
ways
people
predict
and
other
moment
are
to
we
are
is
in
species
that
inventive
increase
alive,
changes
we
what
the
the
Earth
are
using
enough
age
future,
to
we
can
the
either
productivity?
369
8
H u m a n
s ys t e m s
a n d
r e s o u r c e
u s e
T think abt
The greing f Ere
some countries, fer tility rates are lower than in others.
Italy has a fer tility rate of 1.2 children per woman. This
Europe’s population growth rate is falling and its
is not enough to replace the population yet some see
population is ageing (going grey). Who will be the
immigration as bringing major social problems as well.
workers who suppor t the older population? Immigration
may help but immigrants also grow old and need state
Ser vices
suppor t.
social
such
as
suppor t
Immigration
education,
are
is
not
across
medical
increasing
the
EU,
to
care
meet
mostly
and
demand.
from
east
to
So the combination of decreased replacement rate and
west
but
also
into
the
EU
from
LEDCs.
Debate
about
fewer workers means it is not looking good for Europe.
immigration
soon
becomes
political
with
terms
like
Within the geographical boundaries of Europe are some
‘illegal
immigrant ’,
‘economic
migrant ’
and
‘bogus
731 million people (with 499 million of these in the 28
asylum
seeker ’
being
used,
yet
migration
has
always
EU member states). In 1900, Europeans made up 25% of
occurred
for
a
host
of
economic,
social
and
political
the world population; by 2050, they will be 7% according
reasons.
It
is
inevitable.
The
skill
for
politicians
will
to UN projections. This is because the growth rate in other
be
to
inter vene
to
change
retirement
age
and
countries is far higher than that of Europe. By 2050,
pension
systems,
improve
productivity
and
the median age of Europeans will be 52 years. The total
stimulate
worker
mobility.
fer tility rate across the EU is about 1.59 children but, in
Some
Practical
To
what
extent
country's
on
its
Work
does
control
a
development
economy
demographics
and
that
European
alleviate
depend
large
the
over
countries
problems
their
of
own
are
an
trying
ageing
fertility
to
increase
population
they
rarely
their
but
wish
to
birth
once
go
rates
women
back
to
to
have
having
families.
its
inuence
T d
its
development
Explain
the
nature
implications
growth
in
Discuss
of
the
social,
inuence
populations.
cultural,
economic
Research population policies in one of India, China, Iran, Colombia, Brazil,
and
exponential
human
religious,
and
policies?
historical,
political
factors
human
that
population
dynamics.
Discuss
in
human
A
the
variety
quantify
of
models
growth
models
are
of
To
methods
sciences
and
employed
human
dynamics.
the
of
the
populations.
indicators
370
use
predicting
what
of
to
population
extent
the
are
human
`scientic'?
Singapore or your own country. Write a shor t case study on this and exchange
it with your classmates.
8 . 2
R E s o u R C E
u s E
I N
s o C I E T y
8.2 Rerce e in ciet
sigi i:
applii  kill:
➔
The renewability of natural capital has
➔
otine an example of how renewable and
implications for its sustainable use.
non-renewable natural capital has been
➔
The status and economic value of natural
mismanaged.
capital is dynamic.
➔
Exain the dynamic nature of the concept of
natural capital.
Kwlg  ig:
➔
Renewabe natra caita can be generated
cause damage making this natural capital
and/or replaced as fast as it is being used. It
unsustainable.
includes living species and ecosystems that
➔
use solar energy and photosynthesis. It also
products) and er vice (eg climate regulation)
includes non-living items, such as groundwater
that have value. This value may be aesthetic,
and the ozone layer.
➔
cultural, economic, environmental, ethical,
intrinsic, social, spiritual or technological.
Nn-renewabe natra caita is either
irreplaceable or only replaced over geological
➔
timescales, eg fossil fuels, soil and minerals.
➔
➔
Natra caita rvide gd (eg tangible
The concept of a natural capital is dnamic.
Whether or not something has the status of a
Renewable natural capital can be utilized
‘natural capital’, and the marketable value of
sustainably or unsustainably. If renewable
that capital, varies regionally and over time.
natural capital is used beyond its natural income
This is inuenced by cultural, social, economic,
this use becomes unsustainable.
environmental, technological and political
factors, eg cork , uranium, lithium.
The impacts of extraction, transpor t and
processing of a renewable natural capital may
nl pil  l i
Natural
are
capital
goods
or
is
a
resource
services
that
which
we
has
some
value
Ke term
to
humans.
Resources
Renewabe natra caita
use.
can be generated and/or
Natural
income
is
the
rate
of
replacement
of
a
particular
resource
or
replaced as fast as it is being
natural
capital
(see
1.4).
used.
In
the
past,
economists
spoke
of
capital
as
the
products
of
Nn-renewabe natra caita
manufacturing,
human-made
goods,
and
separated
these
from
land
and
is either irreplaceable or only
labour.
But
we
now
recognize
that
capital
includes:
replaced over geological
●
natural
resources
organisms
●
and
that
ores
natural
resources
erosion
protection
have
bearing
that
value
provide
provided
to
us,
eg
trees,
soil,
water,
living
services
by
forests,
timescales, eg fossil fuels,
soil and minerals.
minerals,
that
support
life,
eg
ood
and
and
371
8
H u m a n
s ys t e m s
a n d
r e s o u r c e
●
u s e
processes,
respire,
eg
the
photosynthesis
water
cycle
or
that
other
provides
processes
oxygen
that
for
life
maintain
forms
to
healthy
ecosystems.
So
the
term
services
can
be
natural
that
are
improved
monetary
values
add
to
value
they
are
still
capital
not
is
now
or
degraded
to
ecosystems.
them,
used
manufactured
eg
natural
mine
and
tin
but
given
We
or
capital.
The
income
in
to
describe
have
a
may
value
be
–
able
uranium,
terms
value
goods
humans.
we
to
turn
resource
these
to
can
begin
process
trees
and
or
They
to
these
into
give
to
timber,
natural
but
capital
are
interchangeable.
Just
as
yields
capital
objects,
with
cherry
fresh
include
it
has.
goods
its
In
trees
water.
rate
of
it
extraction
this,
including
Renewable
living
LEDCs
now
of
species
and
of
the
how
add
may
have
true
to
water
wealth
mineral
natural
of
–
cycle
a
of
country
by
the
country
ecological
produce
provides
resources,
income
a
capital
factories
unprocessed
wealth
and
natural
services)
the
greater
the
dioxide
or
and
resources
capital
economics,
many
value
calculates
carbon
of
harvest
cherries,
eg
natural
natural
terms
or
measure
capital,
MEDCs
and
Bank
(yield
produce
The
natural
from
World
●
income
general
The
by
yields
natural
us
must
forests,
rivers
manufacturing
natural
by
capital.
including
damage
the
caused
emissions.
includes:
ecosystems
that
use
solar
energy
and
photosynthesis
●
It
non-living
can
be
used
Ecosystem
used
Renewable
is
The
to
by
between
transport
▲
372
its
natural
natural
is
the
depletion
conserve
damage
sustainably
there)
replaced
such
Assessment,
beyond
much
items,
political
and
capital
can
parties
this
1.4.)
this
run
are
and
of
If
use
out
rate.
is
if
a
natural
at
ozone
the
the
ie
it
Millennium
natural
standing
more
will
source
The
renewable
layer.
capital
is
unsustainable.
is
of
levels
(how
than
of
capital
run
and
conict
impacts
natural
stock
taken
eventually
unsustainable
countries.
capital
(See
the
Then,
often
the
renewable
unsustainably,
resources
resources
and
unsustainably
growth
processing
making
or
income,
natural
these
groundwater
sub-topic
harvested
natural
of
as
can
be
out.
efforts
within
and
extraction,
may
cause
unsustainable.
Figre 8.2.1 A non-renewable resource – coal and a renewable resource – a forest
8 . 2
Non-renewable
amounts
used
or
and
Depending
or
(or
fossil
depleted.
(high
and
only
on
rainfall
regions
rell
rates
resources
or
resource
or
longer
used,
water,
is
soil,
need
where
collected
an
in
you
be
average
s o C I E T y
been
in
used
or
stocks
found.
live
where
I N
geological
and
natural
and
regions
have
capital
to
u s E
nite
they
water
natural
renewable
(drier
than
exist
after
normally
alternatives
rain
capital
–
minerals,
is
considered
most
that
replaced
timescale
include
drinking
be
where
at
long
stock
of
may
natural
slowly
a
the
of
source
water
non-renewable
aquifers
As
are
renewed
over
sources
your
rainfall,
not
resources
fuels.
New
capital
are
Non-renewable
aquifers
annual
natural
Earth
depleted
scales).
are
on
R E s o u R C E
the
capital
for
drinking)
underground
human
lifetime).
Recyclable resources
Iron
ore
is
processed
produce
is
iron
signicant
made
iron
can
parts
non-renewable
is
can
which
iron
resource.
can
or
recycled.
be
used
remanufactured
renewable
replaced
commodity
from
be
not
but
The
to
the
our
cast
within
Old
or
new
iron
is
parts
for
in
cars
other
objects.
from
ore
has
–
cars
be
or
ore
mined
iron
their
90%
becomes
of
ore
a
a
steel
down.
parts
iron
ore
and
we
represents
However,
broken
Therefore
the
and
About
steel.
can
been
from
forms
societies.
products
damaged
metal
the
However
numerous
modern
extracted
true
Once
lifetime.
into
iron-derived
replace
into
same
be
resource.
in
and
Their
can
is
car
be
non-
renewable
aluminium.
T think abt
Exiting the e
The Arctic and Antarctic are perhaps the last
wildernesses on Ear th and are beautiful. Their
Kuril
Island
ecosystems are fragile and contain much biodiversity
Kamchatka
found nowhere else. Any disturbance has a long
Okhotsk
Peninsula
recovery time as growth is slow because temperature is
E
a
i
t
u
e
l
A
9
0
S
limiting. On land, water is also limiting as it is frozen for
Bering
much of the year and so unavailable to plants.
St. Lawrence
Sea
Island
The Arctic
Sea
Sea
Novosibirskiye
Nor ton
Bering
Until recently humans could not exploit the resources
Sound
Novaya
Strait
Alaska
Sea
of the Arctic on a large scale as the seas are frozen for
Zemlya
Beaufor t
Barents
all but a few months of the year and conditions are
Sea
Ellesmere
Franz Joseph
Sea
Island
harsh. But there are mineral riches locked under the
Land
Svalbard
Arctic Ocean and surrounding land masses, especially
(Spitsbergen)
hydrocarbons.
Greenland
Devon
Island
Sea
Greenland
Sea
Ban
The world's oil supply comes from many countries.
Bay
To have a national source of oil is a desire for many
Hudson
Da
vis
Iceland
Bay
countries which would then not be dependent on
Str
ait
0
a
a
it
E
impor ting oil. Some 40% of oil comes from and is
expor ted by OPEC (Organization of the Petroleum
Labrador
Expor ting Countries – 12 countries whose economies
N
°
0
5
Sea
rely on oil expor ts) and they control oil prices and
supply. The USA produces about 10%, Russia about
▲
Figre 8.2.2 Map of the Arctic
373
8
H u m a n
s ys t e m s
a n d
r e s o u r c e
u s e
13% with the remaining dispersed across a number of
0
60
S
other countries. The price of a barrel of crude oil varies
Maud Rise
ATLANTIC OCEAN
45
greatly. It reached over US$100 in 2008 and 2011 while
W
45
E
South Orkney
Princess Ragnhild
Islands
Coast
it hovered around $30 a barrel for much of the 1990s
WEDDELL SEA
INDIAN OCEAN
Drake
Ruser Larsen Ice Shelf
Passage
and in 2009.
Queen Maud Land
Caird
Enderby
Coast
Larsen
Mawson
Land
Ice Shelf
Coast
With climate change causing the Arctic to warm up,
Antarctic
Amery
Filchner
Peninsula
there are more ice-free days. High oil prices means
Ronne
Ice Shelf
Ice Shelf
Ice
Pensacola
Prydz Bay
Ronne Entrance
Shelf
EAST
Mountains
West Ice
that reser ves that were once uneconomic to extract
WEST
BELLINGSHAUSEN
ANTARCTICA
Shelf
ANTARCTICA
SEA
90
South Pole
W
90
are no longer so and the Arctic could be the next
E
Pine Island
Glacier
T
r
a
goldmine or environmental disaster, depending on your
Scott Glacier
n
AMUNDSEN
s
M
A
Getz Ice
n
u
t
a
n
Ross
t
a
Land
i
n
Ice Shelf
s
r
c
t
i
c
ec
I
o
Marie Byrd
SEA
environmental worldview. At 2008 prices, the estimated
fle
hS
no
te
lk
ca
hS
Denman Glacier
Shelf
Wilkesland
value of the Arctic’s minerals is US$1.5–2 trillion. There
Rupper t
Coast
WESTERN
Ross island
PACIFIC
are crude oil reser ves under Nor thwestern Siberia and
PACIFIC OCEAN
Victoria Land
ROSS SEA
Clarie
OCEAN
Coast
Alber ta, Canada. There is also oil right under the Nor th
Cape
Adelie Coast
Adare
Pole. Humans have the technology to extract this oil.
135
135
W
E
Balleny
Islands
Why would we not?
500
180
0
500
1000
Kilometers
Wh wn the Arctic?
▲
Figre 8.2.3 The Antarctic
There is no land at the Nor th Pole, it is ice oating
this is increasing. No one country owns Antarctica but
on water. Under the international United Nations
seven have staked territorial claims via ‘ The Antarctic
Convention on the Law of the Sea (UNCLOS), a state
Treaty’ which was perhaps the rst step in recognition
can claim a 200 nautical mile (370 km) zone and
of international responsibility for the environment. It
beyond that up to 150 nautical miles (278 km) of rights
was signed in 1959 by 12 countries including the US,
on the seabed. So it may sh or exploit the minerals
UK and USSR who signed it in the middle of the Cold War.
exclusively in this zone and other countries may not.
The treaty was strengthened in 1991 and covers all land
This distance is not measured from the border or edge
south of latitude 60 °S. The agreement is that:
of a country but from the edge of the continental shelf,
●
which may be some distance away from the border of
The area will be
the country under the sea.
In August 2007, a Russian submarine expedition
■
free of nuclear tests and nuclear waste
■
for peaceful purposes
■
a preserved environment
■
undisputed as a territory.
planted a Russian ag on the seabed at the Nor th Pole,
two miles under the Arctic ice cap. They claimed that
the seabed under the pole, called the Lomonosov Ridge,
●
There will be
is an extension of Russia’s continental shelf and thus
Russian territory.
■
prevention of marine pollution
■
clean up sites
■
no commercial mineral extraction.
Six countries — Canada, Denmark , Iceland, Norway,
Russia and the United States — have Arctic Ocean
coastlines and Denmark has sent its own scientic
●
Sealing has annual limits.
●
Commercial whaling is now tightly regulated.
expeditions to study the opposite end of the Lomonosov
Ridge to see if they can prove it is par t of Greenland
which is a Danish territory.
Fishing is less of a success story with overshing of
many species which is hard to regulate in the seas
The Antarctic
around Antarctica. And this is causing the crash of many
penguin and seal populations.
Antarctica is a continent of which 98% is covered in ice
and snow. In Antarctica, no large mineral or oil reserves
have been found. But humans exploit the continent
There is so much ice on Antarctica, that it is approximately
61 percent of all freshwater on Ear th. If all this melted,
1
through tourism, shing, sealing and whaling. About
10,000 tourists visit the Antarctica each year and
1
Kusky, TM (2009), ncyclopedia of Ear th.
374
it would add 70 m in height to the world's oceans.
It
appears that the ice is melting and some large ice sheets
8 . 2
are ‘calving’ or breaking up and slipping away from the
R E s o u R C E
u s E
I N
s o C I E T y
Questions
land. Over three weeks in 2002, a huge ice shelf, over
Why is there no Arctic Treaty?
3,000 square km and 220 m deep, Larsen B, broke
Who should own the oceans?
up and oated out to sea. But in other areas, the ice is
Who should regulate human exploitation of the oceans?
getting thicker.
di  f l pil
The
importance
available
the
it
past
today
may
previously
economic,
of
types
may
not
be
had.
not
a
of
natural
be
a
resource
resource
Our
use
of
environmental,
capital
today,
natural
in
or
varies
the
it
future.
may
capital
technological
T d
over
not
A
on
political
A
resource
resource
have
depends
and
time.
the
available
resource
cultural,
factors.
For
Find out about uranium
in
as an example of natural
value
capital.
social,
example:
What are its uses?
●
Technocentrists
believe
solutions
problems;
to
old
that
new
for
discoveries
example,
will
provide
hydrogen
fuel
new
cells
Where is it mined?
replacing
Evaluate its use as natural
hydrocarbon-based
fuel,
or
harvesting
algae
as
a
food
source.
capital.
●
Arrowheads
●
Uranium
is
made
in
but
may
not
the
hydrogen
from
demand
be
if
we
int
as
rocks
raw
could
are
no
material
harness
longer
for
the
in
nuclear
energy
of
demand.
power
by
nuclear
ssion
fusion
–
economy.
Examples of changing value of natural capital
1. Cork forests
Cork
to
from
seal
lids
are
And
are
forests
are
cut
is
good
a
Cork
continues
to
it
in
live
Many
is
of
and
their
oak
tree
plastic
of
fossil
land
the
that
cork
now
from
the
but
forests
to
the
But
losing
and
thing
only
of
cork.
made
are
down
oak
second
bark
bottles.
replacing
they
Cork
the
wine
has
corks,
these
are
been
essential
screw-top
not
for
bottles
biodegradable
centuries
and
like
plastic
cork.
fuels!
value
used
as
for
natural
other
capital
purposes.
to
humans
You
might
so
they
think
that
not.
Mediterranean
the
Amazon
only
the
bark
region
rainforest.
is
have
In
harvested
high
biodiversity,
harvesting
by
hand
cork,
every
9
the
tree
▲
Figre 8.2.4 A cork oak forest
years.
2. Lithium
We
use
electric
ores
Now
lithium
car.
were
we
More
carbonate
Thirty
in
the
cannot
world
get
half
the
desert
salt
plain
in
China
has
found
not
than
years
nearly
petrol
world’s
Bolivia.
to
we
because
enough
some
enough
batteries
ago,
in
of
we
we
have
little
did
a
idea
not
mobile
where
use
much
phone,
tablet
or
lithium-containing
of
it
as
a
resource.
them.
known
More
Tibet.
power
if
had
is
reserves
under
But
electric
the
of
the
lithium
Chilean
annual
cars
if
they
are
underneath
Atacama
production
were
to
of
lithium
replace
a
desert.
cars
is
with
engines.
375
8
H u m a n
s ys t e m s
a n d
r e s o u r c e
u s e
MINING FOR LITHIUM AT S AL AR DE UYUNI
Lake Titicaca
3
PERU
La Paz
BOLIVIA
Crust
2
SAL AR DE UYUNI
Uyuni
100 miles
CHILE
Liquid brine
1. The lithium is found beneath the salt crust
1
and above a halite body (a solid bed of rock salt)
at Salar De Uyuni, Bolivia.
2. Lithium is either sucked up using industrial
Permeable
pumps bored into the ground in low–lying
halite body
salt deser ts, or deep channels are cut into
high in lithium
the ground and the brine seeps into them.
4
3. The brine-a mix ture of water,
light metal lithium, salt and
magnesium-is then stored in
football-pitch-sized pools so
much of the water can evaporate.
4. The resulting slush – a mix ture
of lithium chloride and magnesium
chloride – is shipped to a processing
plant in tanks.
5
5. The lithium is separated out and
turned into ne powder and moulded into
small bricks. It is then transpor ted as
vacuum-packed packages-if lithium is
oxidised it becomes unstable and
impossible to transpor t.
▲
Figre 8.2.5 Mining for lithium in Bolivia
Valuing natural capital
We
●
●
can
Use
divide
the
valuation
–
Economic
price
■
Ecological
functions,
■
Recreational
Non-use
a
■
If
it
■
If
there
has
on,
are
If
it
has
that
marketable
eg
–
water
eg
capital
we
can
two
put
a
main
price
categories:
on,
eg:
goods.
storage
tourism,
natural
into
capital
or
gas
leisure
that
it
exchange
in
forests.
activities.
is
almost
impossible
to
eg:
value
future
uses
potential
value
(Amazon
natural
capital
functions,
intrinsic
medicines,
■
of
valuation
price
of
natural
■
put
376
valuation
by
(the
that
gene
existing
rainforest).
right
we
to
do
exist).
not
yet
know
(science,
pool).
for
future
generations
–
existence
value
8 . 2
Many
people
feel
that
the
only
way
to
make
people
realize
R E s o u R C E
u s E
I N
s o C I E T y
the
T d
importance
a
price
tag
of
on
these
them
non-use
so
valuation
people
realize
things
what
is
they
to
nd
are
some
worth.
way
Others
to
put
feel
Review the resources of a
this
may
just
encourage
exploitation
of
them.
tropical rainforest using the
Whether
We
may
then
more
3.3
Slash
are
and
and
virgin
time
to
human
to
are
that
can
be
planted,
is
sustainably
agriculture
but
maintained
biodiversity
(See
in
resource
think
structure
If
a
lost
due
it
and
to
is
is
used
is
sustainable
only
the
what
as
crops
sustainable
environment
agriculture,
can
it
we
if
is
be
are
the
not
need
to
eaten
soil
know.
and
fertility
degraded
and
overall.
burn
recover.
both
(shifting
sustainable
Adequate
population
provided by a rainforest for
humans by making a table
and services.
agriculture
are
Identify goods and services
with two columns – goods
sustainable?
5.2.)
forest
valuation list in the text.
time
densities.
to
Are
cultivation)
as
long
recover
we
as
is
or
the
sporadic
dependent
currently
logging
environment
giving
it
on
has
low
enough
time
recover?
T d
1.
Make a list of resources that you are using. (You can do this by rst
writing down what objects you are using and subsequently stating
which resources are required to manufacture these objects.) Don’t forget
transpor t.
2.
Do all humans use the same types and amounts of resources? Explain
using examples.
3.
If wood became so scarce that we cannot use it for construction of houses
anymore, how could we solve this problem?
4.
We all use oil and oil products (fuel oil, diesel oil, chemicals, plastics).
Sweden however, does not have its own oil reserves. What would happen to
the carrying capacity of Sweden, if it could not impor t oil?
T think abt
ptting a vae n the envirnment
In groups, put these in an order of increasing
Consider the systems in this list:
(1)
use value
(2)
and then non-use value.
Your school
The Sahara Deser t
Your city
Lake Superior
Your home
San Francisco
Your local park or protected area
Tundra in Siberia
Tigers
Antarctica
Mosquitoes
Great Barrier Reef
Polio virus
Shanghai
The Amazon rainforest
Tokyo
Write down the criteria that your group used. Compare
your list with other groups and be ready to justify your
decision. If you change your mind, reorder the images to
your personal preference and amend your list of criteria.
What are the diculties in assessing the impor tance of
dierent types of environment and what characteristics
need to be taken into consideration when trying to do
this? Do you think that environments can have their own
intrinsic value?
377
8
H u m a n
s ys t e m s
a n d
r e s o u r c e
u s e
T think abt
urbanizatin
100
90
The drift from the countryside to urban life star ted
80
long ago and has continued. According to the UN DESA
3400
3314
50% of us in cities. China is 50% urbanized. Some 60% of
us will be city dwellers by 2030 and 70% in 2050.
% noitalupop
of urban to rural population worldwide is now more than
2860
70
(Depar tment of Economic and Social Aairs), the balance
1906
60
50
40
30
3819
3150
1983
20
850
10
0
1955
2005
1985
2015
(predicted)
year
▲
Figre 8.2.7 Ratios of urban: rural populations
Cities are not necessarily unsustainable. There are
eciencies in living in high density populations where
transpor t costs are reduced for commuters and moving
resources around, people tend to live in smaller spaces
so they use less energy to heat or cool and services
are nearby. But cities have to remove their waste and
process it, they need a large land area to supply them
with food and they create pollution. Inevitably they
encroach on or degrade natural habitats.
1.
Do you live in a city? (If not, select a city near to
your home.)
▲
Figre 8.2.6
Which cities are these?*
nodnoL ,ytiC ocixeM ,iahgnahS
378
*
2.
What is its population and land area?
3.
How much has it grown since 1955?
4.
Where does the food sold in the city come from?
5.
Where do the wastes (sewage, garbage) go?
8 . 2
Since
the
using
a
early
system
1980s,
of
socio-economic
environment
the
cost
national
to
of
UNEP
integrated
(UN
environmental
and
track
degrading
product),
assessment
resource
their
the
Environmental
environmental
cost
–
depletion.
natural
real
and
resources
and
health
Programme)
economic
SEEA)
If
to
try
countries
within
of
the
R E s o u R C E
to
value
their
GNP
I N
s o C I E T y
been
accounting
would
nation
has
u s E
(or
the
include
(gross
would
be
clearer
see.
From
(see
the
1.1).
their
own
UN
An
Earth
undertaking
plan,
community.
Summit
a
local
What
in
was
Agenda
does
your
Rio
de
given
21
local
Janeiro
that
in
local
involving
Agenda
1992
came
councils
consulting
21
Agenda
would
with
21
produce
the
local
say?
T d
Fair trade www.fair trade.net
Fair trade is an NGO charity.
1.
What is the vision of Fair trade?
2.
What does it do?
3.
Name three products that have the Fair trade logo.
4.
Evaluate the impact of Fair trade on (a) the producer
and (b) the consumer.
▲
Figre 8.2.8 Fair trade logo
T think abt
Gbaizatin
Globalization has been facilitated by new technologies,
air travel and the communication revolution. The World
Did you know?
Trade Organization (WTO) controls the rules of this global
●
51 of the world’s top 100 economies are corporations.
●
Transnational corporations:
trade. Information is one email, website, phone call away.
Everyone can access the global market – if they are
connected. Ebay, for example, allows someone in Europe
■
control two-thirds of world trade,
■
control 80% of foreign investment, and
to purchase goods from another individual in the USA.
Global trade is not new. The Ancient Greeks and Romans
■
employ just 3% of the world’s labour force of
traded across their world. The Han dynasty in China
2.5 billion.
traded across the Pacic Basin and India. European
empires and the Islamic world traded via trade routes
●
Wal-mar t may be bringing 38,000 people out of
around the world. What is new is the speed and scale
pover ty per month in China.
of the trade and the communication. Since the end of
Globalization is the concept that every society on Ear th
is connected and unied into a single functioning entity.
The connections are mostly economic but also allow
the easy exchange of services as well as goods and
information and knowledge.
the Second World War, protectionism of markets has
decreased and free trade has increased. The World Bank
and the International Monetary Fund (IMF) were set up
in 1944 and have inuenced development and world
nance, including third world debt, since then. Some
379
8
H u m a n
s ys t e m s
a n d
r e s o u r c e
u s e
think that globalization only leads to higher prots for the
system not recognizing these dierences. Globalization
transnational corporations (TNCs) but there is evidence
is making the individual more aware of the global
that pover ty has decreased in countries with increased
community, its similarities and its dierences. Such
global contacts and economies, eg China. Ecologically,
globalization is both a positive and negative force. In one
international agreements on global issues such as
instance it can make us aware of the plight of others on
climate change or ozone depletion have tended to be
the other side of the globe and in another instance make
easier to conclude with increased globalization. There is
us aware of what one society has and we do not have.
a tendency for it to westernize some countries.
Many, if not most, products are now traded on a global
Globalization is not internationalism. The latter
scale. They are par t of what is referred to as the ‘global
recognizes and celebrates dierent cultures, languages,
market’ and minerals mined in South Africa or Australia
societies and traditions. It promotes the unit as the
are traded and shipped globally.
nation state. The former sees the world as a single unit or
What do you think about globalization?
Practical
Are
there
cultural
dierences
the
Work
in
capital?
causes
If
so,
resources
we
have
about
to
what
b ecome
make
extent
to
use
them.
should
limit
knowledge?
scarce,
decisions
damage
environment
380
in
natural
explain
whether
what
potential
of
of
these.
As
To
attitudes
management
to
the
our
pursuit
8 . 3
s o l I D
D o M E s T I C
W A s T E
8.3 s id dmetic wate
sigi i:
applii  kill:
➔
Solid domestic waste (SDW) is increasing as
➔
Evaate SDW disposal options.
➔
Cmare and cntrat pollution management
a result of growing human population and
consumption.
strategies for SDW.
➔
Both the production and management of SDW
Evaate, with reference to gure 8.3.15,
➔
can have signicant inuence on sustainability.
pollution management strategies for SDW by
considering recycling, incineration, composting
and landll.
Kwlg  ig:
➔
There are dierent types of sDW of which the
Controlling release of pollutant: governments
●
volume and composition changes over time.
➔
create legislation to encourage recycling
and reuse initiatives and impose tax for
The abundance and prevalence of nn-
SDW collection, impose taxes on disposable
bidegradabe (eg plastic, batteries, e-waste)
items.
pollution in par ticular has become a major
environmental issue.
➔
Clean-up and restoration: reclaiming
●
land-lls, use of SDW for ‘trash to energy’
Wate dia options include landll,
programmes, implementing initiatives
incineration, recycling and composting.
to remove plastics from the Great Pacic
➔
There are a variety of trategie that can be
Garbage Patch (clean-up and restoration).
used to manage SDW inuenced by cultural,
economic, technological and political barriers.
These strategies include
Altering human activity: includes reduction of
●
consumption and composting of food waste.
Wh i sdW?
Solid
domestic
trash,
of
garbage,
paper,
plastic,
(see
packaging,
gures
only
agricultural
1.4
in
and
in
the
MEDCs.
per
up
is
municipal
materials
It
is
about
waste,
capita
People
or
residential
batteries,
8.3.2).
industrial
EU.
Why
and
old
makes
production
kg
from
organic
paint,
8.3.1
it
(SDW)
rubbish
textiles,
although
SDW
waste
in
per
(waste
collected
day
LEDCs
is
is
of
about
to
waste
3.5
we
kg
produce
It
glass,
is
is
a
and
which
can
in
metals,
etc.
shops
and,
includes
control.
the
less
our
mixture
dust,
(e-waste)
homes
waste,
that
(MSW)
areas.
food),
from
total
waste
tend
waste
urban
electronic
5%
it
solid
and
USA
SDW
and
than
those
this?
▲
Figre 8.3.1 Solid domestic waste
381
8
H u m a n
s ys t e m s
a n d
r e s o u r c e
u s e
Te f sDW
Exame
Biodegradable
Food waste, paper, green
rubber,
leather &
food waste
tex tiles
14.1%
waste
8.3%
Recyclable
Paper, glass, metals, some
wood
6.5%
plastics, clothes, batteries
Waste electrical
TVs, computers, phones,
and electronic
fridges
paper
28.2%
metals 8.6%
equipment – WEEE
Medical
Needles, syringes, drugs
5
Pesticides, herbicides
o
t
8
.4
Toxic
%
c
i
t
s
a
l
p
h
e
r
%
3
.
2
1
Paints, chemicals, light bulbs
3
.
Hazardous
s
s
a
lg
yard waste
13.7%
Iner t
Concrete, construction waste
Mixed
Tetrapaks, plastic toys
Source: Municipal solid waste in the United States: 2009 facts and gures, EPA
▲
Figre 8.3.2
▲
Figre 8.3.3 SDW propor tions in the USA in 2009
When is something waste?
T d
A
resource
List (or collect) the waste
human’s
that you produce in 24 hours.
LEDCs
Do the same for waste from
round
your household in a week.
‘useful’
Put the waste into categories:
just
Recyclable
Biodegradable
there
are
so
stuff.
they
is
most
In
can
of
a
to
It
areas
many
trawl
(8.2).
on
how
industries
going
has
processes
the
no
to
carry
it.
to
on
its
–
bins
energy
of.
and
If
We
another
in
People
it
is
production,
out
landlls
the
city.
not
create
many
travel
taking
the
from
producer.
is
why
around
arrives
disposed
is
SDW
.
and
that
waste
That
collect
communal
live
be
out
human’s
value
to
waste
value
needs
we
up
families
through
and
set
One
we
through
LEDCs
which
problem
the
humans
depends
whole
material
becomes
in
value
residential
Waste
it
has
resource.
recycled
waste
transport,
Hazardous/toxic
industrial
WEEE
domestic
processes,
construction,
selling
of
goods
and
services,
and
activities.
How much do you recycle?
Who does this? Where does
th il 
it go?
Most
We
goods
nd
produce
down
Our
and
is
our
in
materials
(make).
model
a
or
linear
Often
has
model
natural
these
been
to
–
capital
goods
discard
‘take,
(take)
become
and
then
make,
and
dump’.
use
energy
redundant
replace
or
them
to
break
with
(dump).
global
its
no
produced
raw
goods
and
others
are
the
economy
resources
away.
obtaining
available
Even
been
nite
reducing
resources
to
has
are
only
so
built
we
fossil
delay
on
this
cannot
fuel
the
use
unsustainable
really
and
inevitable
throw
premise.
things
becoming
dwindling
away.
more
of
Earth
There
efcient
natural
at
capital
humans.
1
The
It
circular
aims
●
be
●
use
economy
is
a
model
that
is
sustainable.
to:
restorative
of
renewable
the
environment
energy
sources
1
http://www.ellenmacar thurfoundation.org/circular-economy/circular-economy/the-circular-model-
an-overview
382
8 . 3
●
eliminate
●
eradicate
or
reduce
toxic
s o l I D
D o M E s T I C
W A s T E
wastes
ToK
waste
through
careful
design.
The circular economy is
To
do
these
things,
the
model
relies
on
manufacturers
and
producers
a paradigm shift. Does
retaining
ownership
recycling
them
of
their
products
and
so
being
responsible
for
knowledge develop through
or
disposing
of
them
when
the
consumer
has
nished
paradigm shifts in all areas
using
them.
The
producers
act
as
service
providers,
selling
use
of
their
of knowledge?
products,
products
and
not
when
return
This
the
husbandry
they
them
model
has
and
products
to
are
the
no
longer
This
needed,
means
that
disassemble
they
or
take
back
refurbish
them
market.
similarities
soil
themselves.
to
agricultural
conservation
lead
to
practices
in
sustainable
which
growth
good
of
foodstuffs.
http://www.ellenmacarthurfoundation.org/
s
e
d
/manufa
gn
ct
u
re
g
n
il
cy
cer
a
li
re
e
r
o
t
c
e
s
circular
e
economy
s
/
r
L
/
A
r
p
a
e
i
r
/
d
l
r
e
c
h
y
c
li
n
g
c o ns
▲
um
e
/
o
h
u
Figre 8.3.4 The circular economy
Linear economy
Circular economy
technical
biological
nutrients
nutrients
take > make > dump
waste
technical & biological
nutrients all mixed up
living systems
something useful
After W McDonough and M Braungar t
▲
Figre 8.3.5 Diagram of the circular economy and linear economy
383
8
H u m a n
s ys t e m s
a n d
r e s o u r c e
u s e
princie
Agrictra tainabe ractice
Circar ecnm ractice
Design out waste
Reduce or eliminate food waste
Recycle plastics, metals
Build resilience through
Manage for complex ecosystems
Build for connections and reuse of
diversity
components
Use renewable energy
Use more solar energy, human labour, fewer
Shift taxation from labour to non-
sources
chemicals and fossil fuels
renewable energy
Think in systems
Systems are non-linear, feedback-rich and
Increase eectiveness and
interdependent, emphasize storages and ows
interconnectedness in manufacturing
Use all stages of a process. Decomposition
Do not produce waste. Use it to
recycles all nutrients. Burning wood shor tcuts
produce more products
Think in cascades
this and breaks down nutrients
▲
Figre 8.3.6 Applying principles of the circular economy
ToK
T think abt
To what extent is emotion
involved in environmental
knowledge claims?
To what extent is language
neutral in reference to
environmental knowledge
claims?
▲
Figre 8.3.7 Shell adver t
The caption on the adver t reads: If only we had a magic bin that we could throw
stu in and make it disappear forever, what we can do is nd creative ways to
recycle. We use our waste CO
to grow owers and our waste sulphur to make
2
super-strong concrete.
Shell, a multinational oil company, was criticized by Friends of the Ear th (FoE),
an NGO, and others when the adver t in gure 8.3.7 was produced in 2007.
To show chimneys emitting owers, according to FoE, misrepresents Shell’s
impact on the environment.
According to FoE, the adver t implied that a signicant propor tion of Shell’s
emissions were recycled to grow owers or reduce sulphur emissions. (Growing
owers is theoretically possible if carbon dioxide is captured and it can raise the
rate of photosynthesis.) But the reality is that these are small research projects.
1.
What do you think about the ethics of this adver t?
2.
Were FoE right to complain or should we take advertising with a ‘pinch of salt’?
3.
Find another adver t about the environment and society that you think may
be misleading.
384
8 . 3
s o l I D
D o M E s T I C
W A s T E
mgig sdW
We
have
a
choice.
somewhere
but
We
we
can
can
minimize
not
throw
it
waste
or
we
can
dispose
of
it
away.
1. Strategies to minimize waste
These
best
can
be
action
summarized
we
can
take
is
in
three
words:
producing
less
reduce,
waste
reuse,
in
the
recycle.
rst
place.
The
See
http://www.nrdc.org/thisgreenlife/0802.asp
Reduce
This
is
the
resources.
best
We
place
do
to
not
start
have
with
to
the
stop
3R’s
our
and
it
lifestyles,
requires
we
just
us
to
need
use
to
fewer
cut
back.
●
Make
last
●
sure
you
know
how
to
maintain
your
possessions
so
that
they
longer.
Change
shopping
■
buy
■
look
■
buy
■
choose
■
avoid
■
be
things
for
that
items
products
will
with
that
products
things
aware
water,
habits:
of
last,
less
are
that
that
are
how
made
are
from
energy
recycled
materials
eg
paper
efcient
imported
many
electricity
packaging,
resources
you
are
using
in
the
home
–
etc.
Reuse
This
is
where
original
the
purpose
products
or
they
are
are
used
for
returned
something
to
the
other
than
manufacturer
their
and
used
repeatedly.
●
Returnable
to
the
bottles
–
take
the
bottle
back
to
the
shop
to
be
returned
manufacturer.
●
Compost
●
Use
●
Hire
●
Read
old
food
waste.
clothes
DVDs
–
as
cleaning
don’t
buy
rags.
them.
E-books.
Recycle
This
is
probably
kerbside
for
recycling
In
Germany,
●
In
the
UK,
best
This
before
●
they
the
recycling.
it
for
there
produce
known
is
the
leaves
the
example,
is
more
R.
each
the
of
towns
waste
and
into
cities
now
separate
have
containers
home.
discussion
than
Many
sorting
household
about
has
charging
standard
four
bins
for
households
amount
of
this.
more
if
waste.
385
8
H u m a n
s ys t e m s
a n d
r e s o u r c e
●
In
u s e
India
thrown
●
In
MEDCs,
Recycling
stream
is
of
is
to
fo r
The
or
materials
production
no t
or
very
fed
50%
to
of
little
r e us e.
a nd
waste
a nd
(I f
cost
from
thi s
of
the
is
worthw hi l e
food
food
waste
as
this
is
either
not
of
can
waste.
s ep a ra tin g
are
wi th out
se p ar a t ed
the
in
so
fro m
the
so m e
c os t
ha ve
r ec yc l in g
Al u m i n iu m
a nd
a
of
cans
of
it
is
the
hi gh
t h es e
a re
w as t e
wa y,
wh e t h e r
ma rk et
m a t e ri a ls
a nd
co mmer cia ll y.
m a t e ri a ls
d et e r m i n e
wi t h
S om e
mate ri al
wa st e
pr oc e s si n g
re c yc l in g
v ar y
r e cy cl ing.
ra w
is
ma teri a ls
r e us ed
e co nomi cs
a nd
waste
animals.
co l l e cti ng
washe d
reuse.)
particularly
▲
or
up
them
and
commercial
raw
China,
involve s
processing
this
and
away
c os t
is
p ro b abl y
Figre 8.3.8 Recycling bins in
the
best
example
of
thi s.
Orchard Road, Singapore
T think abt
German: what beng where?
Adapted from www.howtogermany.com/pages/recycling.html
Many, but not all, German households are allocated three waste bins of
dierent colours and what goes in which is carefully controlled.
Brown bin (biological waste)
Kitchen waste: old bread, egg shells, coee powder and lters, food leftovers,
tea leaves and tea lters.
Fruit and vegetables: peels, apple cores, leaves, nutshells, fruit stones and
pips, lettuce leaves.
Garden waste: soil, hedge trimmings, leaves, grass clippings, weeds, dead
T d
owers, and twigs.
Wate eectrica and
Other: feathers, hair, kitchen towels, tissues, sawdust, and straw.
eectrnic eqiment
Blue
bin (paper)
(WEEE)
Envelopes, books, catalogues, illustrations, car tons, writing pads, brochures,
The Wate Eectrica and
writing paper, school books, washing detergent car tons without plastic,
Eectrnic Eqiment
newspapers, paper boxes.
Directive (WEEE Directive)
Yellow bin or yellow plastic bags (plastic, etc.)
is a term from the European
Community. It had a target
Aluminum foil, plastic wrap, inside packaging materials.
of minimum recycling rate of
Tins, cans, liquids rell sachets/bags, yogur t cups, body lotion bottles.
4 kg per capita of electrical
Plastic bags, margarine tubs, milk sachets, plastic packaging trays for fruit
goods recycled by 2009. It
and vegetables, screw-top bottle tops, detergent bottles, carry bags, vacuum
failed to meet this target but
packaging, dishwashing liquid bottles.
awareness was increased
and more recycling of WEEE
Grey bin (household waste)
goods did happen.
Ash, wire, carbon paper, electrical appliances, bicycle tubes, photos, broken
386
Find out the fate of unwanted
glass, bulbs, chewing gum, personal hygiene ar ticles, nails, porcelain,
or broken electrical and
rubber, plastic ties, broken mirrors, vacuum cleaner bags, street sweeping
electronic goods in your
dir t, carpeting pieces, diapers, cigarette butts, miscellaneous waste. Those
country.
households that do not have a brown bin put their biological waste in a grey bin.
8 . 3
s o l I D
D o M E s T I C
W A s T E
T think abt
Reccing atic
drinks bottles to make one eece garment. Sadly, most
plastic is used once and then put in holes in the ground.
Plastics are made from oil and the world's annual
consumption of plastic materials has increased from
Many LEDCs have an informal recycling sector – see
around 5 million tonnes in the 1950s to nearly 100
earlier in this sub-topic.
million tonnes today. As much as 8% of the world’s oil
PET
production may be used to make plastics and we throw
1
pethene terehthaate – Fizzy
drink bottles and oven-ready meal
away most of this as it is used mainly in packaging.
trays.
Plastic is a dicult material to recycle as there are many
HDPE
High-denit ethene – Bottles
dierent types of plastic and it is bulky and light. Some
2
for milk and washing-up liquids.
types of plastic are wor th more than others to recyclers
but these have to be sor ted from the rest. However,
PVC
3
plastic recycling is carried out to some extent.
pvin chride – Food trays,
cling lm, bottles for squash, mineral
water and shampoo.
A repor t on the production of carrier bags made from
recycled rather than virgin polythene concluded that
LDPE
4
the use of recycled plastic resulted in the following
lw denit ethene – Carrier
bags and bin liners.
environmental benets:
PP
●
reduction of energy consumption by two-thirds,
●
production of only a third of the sulphur dioxide and
5
●
reduction of water usage by nearly 90%,
●
reduction of carbon dioxide generation by two-and-a-
microwaveable meal trays.
PS
6
half of the nitrous oxide,
prene – Margarine tubs,
ptrene – Yoghur t pots, foam
meat or sh trays, hamburger boxes
and egg car tons, vending cups,
plastic cutlery, protective packaging
fo