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SCIENCE AND THE
ENVIRONMENT
HOW DO WE INTERACT WITH THE ENVIRONMENT?
ENVIRONMENTAL SCIENCE
• Environmental science seeks to understand
people and the environment influence
each other.
• There are two major areas of concern:
• How do we use resources in the environment?
• How are we altering the environment?
• Note that this question does not necessarily imply we
are knowingly changing our environment!
ENVIRONMENTAL SCIENCE
THE ENVIRONMENT AND US
• Humans have
always had a
substantial impact
on the environment.
HUNTER-GATHERERS
• For the majority of
human history, we
were huntergatherers.
• Groups were small
and often
migratory.
THE AGRICULTURAL REVOLUTION
• Over time, humans
learned to grow
crops and
domesticate various
animals.
• We call these
practices
agriculture.
THE AGRICULTURAL REVOLUTION
• This development led to several important
changes in human society.
• Human populations had enough resources to
grow into large groups.
• Humans began to concentrate their numbers in
smaller and smaller areas.
• Humans began to selectively breed both plants
and animals.
• Humans also began to convert substantial
patches of land into farmland.
THE INDUSTRIAL REVOLUTION
• Human society was powered by and
dependent on manual power for about 2.5
million years.
• This changed with the development of
alternate energy sources.
• Examples?
THE INDUSTRIAL REVOLUTION
• A large variety of
more efficient
energy sources –
such as water, coal
and oil – led to the
development of
industrial engines
and machines.
THE INDUSTRIAL REVOLUTION
• The Industrial Revolution has had a huge hand
in shaping modern human society.
• Humans began to develop factories and other centers
of mass production.
• Less land and labor was needed to maintain human
populations. The quality of transportation improved
greatly.
• Even more food was available to support larger
populations. Urban populations, in particular, began
to grow.
• Quality of life also improved considerably, and the
average human lifespan increased.
MODERN DEVELOPMENTS
• Both the agricultural
and Industrial
revolutions have
allowed the human
population to grow
incredibly fast.
MODERN DEVELOPMENTS
• Earth itself functions
as a closed system
– resources on Earth
are limited, and
there is no efficient
way to eliminate
waste products.
MODERN DEVELOPMENTS
• Together, these
developments
mean that we as a
species are placing
tremendous
pressure on the
environment!
MAJOR AREAS OF
CONCERN
WHAT DO WE WORRY ABOUT?
RESOURCE DEPLETION
• A natural resource is any material or energy
source we humans can use.
• Classified into two types:
• Renewable
• Non-renewable
• Depletion refers to using up a resource.
POLLUTION
• Like all other
organisms, humans
produce waste
products.
• However, since the
Industrial revolution,
we are beginning to
produce wastes
faster than they can
be disposed!
• Pollution is defined
as an undesirable
change to the air,
water or soil.
• This change must
adversely affect the
health, survival or
activity of one or
more organisms
(including humans!)
POLLUTION
Biodegradable wastes
• These are those that
can be broken down
via natural processes.
• Food waste
• Human sewage
Nondegradable wastes
• These are those that
cannot be broken
down via natural
processes.
• Lead
• Some plastics
LOSS OF BIODIVERSITY
• Biodiversity is defined as the number and
variety of species that dwell in a given area.
• Because the health of an ecosystem is
greatly dependent on the existence of
established species, extinction of multiple
species can prove critical to our
environment.
THE ENVIRONMENT
AND SOCIETY TODAY
WHAT INFLUENCES OUR DECISIONS?
TAKING CARE OF OUR RESOURCES
• Recall from our earlier studies that
resources on Earth are limited.
• We will consume these faster than they
can be replenished if we cannot or do
not take care of them!
“THE TRAGEDY OF THE COMMONS”
• In 1968, Garrett Hardin (an ecologist)
published his essay detailing what was, in his
opinion, the defining problem with solving
the environmental issues of his time.
• He believed that it was the tension between short
and long-term interests that was the fundamental
issue that prevented us from solving these issues.
• What do you think?
“THE TRAGEDY OF THE COMMONS”
• He chief example was the “commons”,
which were grazing fields that were owned
by a single village.
• Commons tended to rapidly fail, due to
overgrazing. Psychologically, the citizens
overgrazed, because there was no reason
to practice restraint. After all, if someone
didn’t graze the field, someone else would…
“THE TRAGEDY OF THE COMMONS”
• Eventually, commons were replaced with
individual fields. Now, each owner was
responsible for the well-being of a small
piece of land.
• In this instance, owners were much more
likely to practice restraint, because they only
had the small piece of land granted to
them. This kept the fields from being
overgrazed.
“THE TRAGEDY OF THE COMMONS”
• The tragedy of the
commons, then, is
the idea that we will
eventually deplete
resources by using
them up for shortterm gain…even if
we know we need
those resources in
the long run!
“THE TRAGEDY OF THE COMMONS”
ECONOMICS AND THE ENVIRONMENT
• The economy is a great influence into how
we use our resources.
• Recall the tragedy of the commons, where
overgrazing occurred because people took
the short-term gain of grazing as much
livestock as possible, while ignoring the longterm gain of maintaining the field as long as
possible.
ECONOMICS AND THE ENVIRONMENT
• The law of supply
and demand
dictate that:
• The greater the
demand for
something, the
more it is worth.
• The rarer
something is, the
more it is worth.
ECONOMICS AND THE ENVIRONMENT
• A cost-benefit is
used to evaluate
the costs of taking a
certain course of
action, and the
benefits that may
result.
• This is used to
determine the
optimum course of
action.
• Be aware, though,
that costs and
benefits can be
evaluated quite
differently,
depending on the
party doing the
analysis.
ECONOMICS AND THE ENVIRONMENT
• A huge part of costbenefit analysis is
anticipating and
predicting risk.
• One reason why
different people
can come to
different solutions is
the differences in
perception of risk.
POPULATION AND CONSUMPTION
• As discussed earlier, the pressure behind
most of our environmental problems is a
result of two issues:
• Human populations are growing beyond
levels that the local environment can
viably support.
• Humans, in general, are using resources
much faster than they can be replenished.
POPULATION AND CONSUMPTION
Developed Countries
• Developed countries
have higher average
incomes, slower human
population growth, and
stronger social support
overall.
• Resources are more
accessible, and are
consumed quickly,
leading to high levels of
waste and pollution.
Developing countries
• Developing countries
have lower average
incomes, greater human
population growth, and
may lack critical social
infrastructure.
• Rapid population growth
can lead to severe
population pressure.
POPULATION AND CONSUMPTION
• The ecological footprint is the amount of
land needed to support one given person.
• This includes land used for food, housing or
materials.
• It also includes land needed to absorb air
pollution at sustainable levels.
• The carbon footprint is the amount of
carbon dioxide generated over a
person’s lifetime.
POPULATION AND CONSUMPTION
• Ideally, the solution we are looking for is a
sustainable world.
• This means that human needs can be met
indefinitely, at a suitable standard of living.
• Creating a sustainable world requires great
cooperation to solve both local and global
issues threatening the environment.