Pg. 75
How does this affect Natural Disasters?
ADD
1.) Consider Katrina 1,000 years ago??
2.) Consider economic losses over time
ND pg. 11 fig. 1.6 and table 1.6
NDs increasing?
Cost/losses ARE increasing!
WHY???
Is it, itself, a potential disaster for the future?
HOW????
Pg. 75
Populations grow exponentially link for general discussion
a) The J-curve and more?
ND pg. 16 fig. 1.11
b) Very slow growth for thousands of years then a sharp upward shift.
ADD But what about later? More complete picture
c) birth rate does not have to change - death
rate falls dramatically. What could cause
this?
Related to 1.) tools (1 million ya) 2.) agriculture (8,000
ya) and 3.) medicine (1700s)
Pg. 75
d) 1810 pop. 1 billion - doubled by 1925 at
2 billion (115 years). 1925-1974 doubled to
4 billion (49 years). by 2000 reached 6 billion
The future?? The bigger it gets the bigger it gets
FASTER.
e) think of it in terms of doubling time - it will
take CHANGE THIS 44 years for the world’s
population to double at present growth rate of
1.6% per year.
ADD Doubling Time=70DIVIDED BY (% growth
rate/year)
Pg. 75
In general, there are TWO views on human population
1) Too many people
2) Not enough people
Hmmmm - let’s investigate these viewpoints.
Pg. 76
1) Too Many
a) The J curve points out that earth’s population
will double every 50 years (or less!).
With current birth/death rates
b) That puts 8 billion on earth in early 2000s
and 16 billion by mid to later 2000.
***The issue of too many people is: RESOURCES
More people strain resources - especially as standard of
living raises worldwide.
What if everyone lived “high on the hog” like us?
Like…CHINA??
This is termed carrying capacity in biological terms.
What might happen if we exceed carrying capacity?
Pg. 76 Too many continued
Resources & Facts
1) Food
a.) 3/4 of a billion already suffer malnutrition
largely due to unequal food distribution
ADD
b.) only 11% of Earth’s surface is arable land
this diminished due to….
1) erosion can’t farm the dirt if it ain’t there
2) expansion are ya going to live on it or grow on it?
3) salinization irrigation water has salts. Arid areas
H2O evaps. leaves behind salts=dead crops
From 1945-1990 3 billion acres (China and India combined)
have been degraded.
Pg. 76 Too many continued
Resources & Facts
2) Water
a) At present 31 countries (8% world pop.) have
chronic water shortages.
b) Due to improper management (sewage), unequal
distribution (high pop. Vs. low pop.),
contamination (keeping clean and cleaning up).
c) Estimates suggest by 2025 35% world pop.
affected
WHY?? Many of those countries cannot pay the cost
for water (desalinization). Global financial inequity.
Pg. 76-77
3) Clean air-more people=more production=more pollution.
OK…potentially could we do things differently
4) Trash – More people= more trash…where to put
the piles!
5) Deforestation-more people=more demand for
lumber/agriculture=less forest
Consider link to greenhouse effect?
6) Energy Resources-more people=more demand for energy
fossil fuels are being used faster than they are
being created
Pg. 77
7) Resources used in technology and consumer
products - including homes, hospitals, schools, etc.
(sort of a composite of the above)
8) Species extinctions as habitat is removed or altered
SO, what’s the problem if a few species go extinct?
9) Unequal distribution of resources is cited as an
issue - can that affect political stability worldwide?
Global jealousy?
Political history?
10) Jobs and money - will there be enough for everyone?
Sure. The question is at what level/standard of living.
**Could Earth sustain a global population ALL living
like we do?
Pg. 77
U.S. population is expected to peak in 2028 and then
decline - So we don’t have a problem - or do we.
Does the U.S. add to world population issues/concern?
**A LOOK at the Economic burden on the world ecological
system**
3 things dictate the economic burden
1) Population size
2) Consumption
3) Technology used to provide goods
and services-medicine, transportation.
Pg. 78
THE U.S. IS THE LARGEST CONSUMER IN THE WORLD
3 million Americans = 90 million people from
India (resources/year) a factor of 30!!!
As standard of living is raised in other nations resource
use per person will rise.
Developed and developing nations want more STUFF
Such as… coffee/tea and soda, meat, wood, fruit.
POSSIBLE SCENARIO (can you think of others?)
This leads to deforestation generally of rainforest.
POSITIVE FEEDBACK (positive???)
Poor soils - land used up in short time - new areas turned
to crop land-poor soils-land used up…..
Pg. 78
ONE RESULT
Poor nations trade products for money.
Is that a DEAL?
NOConsumers do not pay for the environmental damage to
the ecosystems.
Sustainability - consumers need to use less and pay more.
WHY???
Pg. 78
THE SECOND IDEA OF HUMAN POPULATION IS THAT
THERE ARE TOO FEW PEOPLE.
TOO FEW PEOPLE
Information provided by the Population Research Institute
1) This group believes the population in NOT expanding as
fast as predicted.
2) They cite shrinking family size.
Census Bureau world fertility rate is 2.9 children per
woman. This is lowest level ever. In 1985 it was 4.9.
Mmmm…?
3) Developed nations have lowest fertility rate. Europe
especially low at 1.3 children per woman.
Germany and Japan offer financial incentives for more
children.
ADD
Another way to look at it. If you calculate
a.) 6 billion people (todays pop.)
b.) Each get 3 x1 foot space
c.) the entire world population fits in 26mi2?
So the world is mostly uninhabited. Right?
AGREE
DISAGREE
STRONGLY DISAGREE
STRONGLY AGREE
Pg. 79
WHY??
Economies based on growth.
Countries with low growth rates fear:
a) labor shortages reducing production of goods
b) housing market will stagnate/real estate sales slow
c) above affect whole economy
Pg. 79
4) Believe world population will peak at 2030 and then
continually decline. But….
ADD POPULATION DENSITY RELATED ISSUES
A) Intraspecies Competition: members of the same species
compete for resources
reindeer example and gypsy moth example
Food resource issue
B) Interspecies Competition: two species compete for
resources
Paramecia species cultivation (alone vs. together)
better competitior?
Which better represents concerns for human populations?
WHY?
Pg. 79
Another Issue - Population “control” can lead to loss of
freedom - genocide in some cases.
a) freedom to choose family size
example: China
b) enforced sterilization of specific groups
example: Peru (target is poor rural women
which generally are Native Indians)
POINT: Opens the door to ethically/morally “dicey” policy?
CASE HISTORY
Rapa Nui (Easter Island)
Volcanic island west of Chile
Not the greatest to begin with
Source: http://www.unmuseum.org/easteri.htm
high temp and humidty
no permanent rivers
poorly drained, marginal soils
Early 5th century seafaring Polynesians settled here.
Brought with them
1) chickens
2) rats
3) food plants (only yams could survive harsh climate)
CASE HISTORY
Rapa Nui (Easter Island)
Developed a complex
social system
Customs include competitions Source: http://www.unmuseum.org/easteri.htm
building huge statues (moai)
up to 20 ft. high
Pop. peaked at about 7,000, moai 600 with about 300
more being built in quarries.
Civilization began to decline rapidly and savagely
CASE HISTORY
Rapa Nui (Easter Island)
Easter Sunday, 5 April 1722 first European contact, Dutch
Found 2,000 people living in caves in a primitive state
These remnants were engaged in nearly constant warfare
Practicing cannibalism
WHAT HAPPENED????
Source: http://www.unmuseum.org/easteri.htm
CASE HISTORY
Rapa Nui (Easter Island)
Transporting the moai used up trees and resources.
With no trees…
a) Soil erosion increased and farming became more difficult
b) Homes could not be built
c) No fuel
d) No transportation (canoes) to leave or to use for fishing.
RESULTS: statue based religion disintegrated, clans
were reduced to warfare and cannibalism to survive
HOW IS THIS LIKE EARTH?
QUIZ
1.) Which of the following best describes how populations
increase exponentially?
+
B
A
POP.
-
+
POP.
-
TIME
+
+
TIME
C
POP.
-
-
TIME
+
+
QUIZ
2.) Which part of the curve represents carrying capacity?
C
B
A
QUIZ
3.) What evidence is used to support the view that there
are not enough people on the planet?
a) exponential growth
b) that the current population only takes up about 26 mi2
c) first part of human history saw little population growth
d) family size is increasing
4.) What evidence is NOT used to support the view that
there are too many people?
a) Shrinking family size
b) Only 11% of the Earth’s surface is arable (farmable)
c) Resources are also part of the equation
d) There already exists a significant water shortage
QUIZ
5.) Which BEST describes what the Reindeer case history
implies might happen to human populations?
a) Populations reach carrying capacity and then crash
b) Populations reach carrying capacity and then increase
c) Populations reach carrying capacity and then fluctuate
d) Populations reach carrying capacity and then remain
constant
6) The people/island/moai/Dutch in the Rapa Nui
(Easter Island) case history each represent what?
QUIZ
7.) The idea of sustainability suggests that consumers
should pay…
a) More to fix increasing environmental problems caused by
production
b) The same to fix the constant environmental problems
caused by production
c) Less to fix the decreasing environmental problems caused
by production
QUIZ
8.) In the graph below what could best explain the portion
labeled C?
a) Increase in fertility
b) Decreae in mortality
c) Introduction of predator species
d) disease