Objectives

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Objectives
Discuss the major environmental problems and
their root causes.
Warm Up
What do you think are the largest environmental
problems today?
Climate change. Loss of biodiversity. Loss of our
ozone shield.
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• The two root causes of these problems are
• Overpopulation.
• Over consumption.

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POPULATION U.S. 305,457,863World 6,731,400,280
10.20.08
The Earths human population is increasing by
2.5 people / sec., 150 people/min, 9,000/hr.,
214,000 / day, 78 million/year. U.S. 4.6 of
the worlds population, we consume 40 of the
resources.
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Objectives
Discuss the effect of a growing human
population. Begin the histogram lab.
Warm Up
In which specific ways does a growing human
population have an impact on our planet?
Increase poverty, starvation, increase in crime,
increases extinction decreases biodiversity
forests, increases pollution, increases class
distinction.
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PROBLEMS OF OVERPOPULATION 1. Shortage of fuel
wood Can be a matter of life death. a. used
to cook food (some cant be eaten raw) b. used
to boil water (waterborne diseases common) 25
million people/yr, most of them children die of
diseases contracted from dirty water. (Lima Peru
1991 1st cholera epidemic in Western Hemisphere
in more than 75 years.) 2. The Urban Crisis. By
2020 almost 1/4 of the worlds city dwellers will
be homeless.
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3. Social Unrest Conflicts between groups for
scare resources. Water rights, food riots,
illegal immigration. 4. Environmental Refugees
Millions of people in search of food. Host
countries overwhelmed provide education, health
care jobs.
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• Soil infertility as a result of intensive farming
  decreasing the carrying capacity of the land
  which may take hundreds of years to recover if it
  can.
• The flood of environmental refugees is a good
  argument for helping other countries solve their
  environmental problems reduce their population
  growth.
•  Overall Resource depletion, environmental
  degradation threats to the ecological support
  systems that we all depend on.

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TO ACHIEVE A SUSTAINABLE FUTURE, THE PROBLEMS OF
OVERPOPULATION AND OVERCONSUMPTION MUST BE
SOLVED. Deep societal changes include 1.   
Improved social, educational economic status
for women (birth control womens rights are
often interdependent.) 2.    Improved status for
children. 3.    Acceptance of calculated choice
as a valid element in life in general fertility
in particular. 4.    Social security. 5.   
Knowledge, availability, use of effective
acceptable means of birth control.
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THEORY OF DEMOGRAPHIC TRANSITION Stage 1 Birth
Death rates are both high in pre-industrial
societies, population grows slowly if at
all.   Stage 2 When health care improves, the
population size increases. Birth rates continue
to be high, and people are living longer. The
population increases by about 3 percent each
year, which means that it doubles every 25 years
and is 30 times, its original size by the end of
100 years.   Stage 3 Birth rates fall until they
roughly equal death rates, and population growth
slows down and stops.
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1. For 99 of human history we were
hunter/gathers. Population was stable at
approximately 1 million people. (Detroit has 1
million people.)  2.The agricultural revolution
occurred 10,000 years ago. Due to increased
carrying capacity storage of food the
population grew slowly. It took from 10,000 years
until about A.D. 1804 for human population to
reach 1 billion people.  3. Population doubled
between 1800 and 1930 to 2 billion. (130
years) 4. 1975 to 4 billion (45 years) 5. 1987
to 5 billion (12 years) 6. October 12, 1999 6
billion (12 years ) 7 billion by 2008, 8
billion by 2019? 1/10th of all people are alive
today.
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Humans are living longer due to improvements in
nutrition, better sanitation. Declining
mortality, not rising fertility is the primary
cause of most population growth. Life expectancy
has risen from 40 to 65.5 yrs. This century.
There is a direct correlation between life
expectancy income.   The global intrinsic rate
of growth has decreased to 1.4. This means the
population will double again in about 50
years. U.S. 0.8 Legal immigration of 800,000
people/yr. even more people illegally is making
our total growth rate larger. Globally 38
million refugees.
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PROS FOR HAVING CHILDREN 1. Having children is
rewarding. (Pleasure, pride comfort.) 2. The
only source of income for the elderly in
countries without social security. Provides a
source of current income help with chores. 3.
Where infant mortality is high people need to
have more children to insure that at least a few
will survive. 4. Status. 5. Continuity a need
to replace those who die or are incapacitated. 6.
Birth control may be taboo in the culture or
religion. 7. Male pride. 8. People will provide
answers to our current problems extend the
global carrying capacity.
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NPP (Net primary productivity) total amount of
solar energy converted into biochemical energy
through photosynthesis minus the energy needed by
those plants for their own metabolic
requirements. (Measure of food resources
available on Earth.)
NPP without human influence 150 billions tons
of organic matter per year. Humans have caused a
12 decline in NPP through deforestation. Humans
utilize approx. 27 of the NPP for their own
purposes (food, building material, energy, etc.)
or by converting productive land to other
uses. Together this represents 40 of the NPP or
carrying capacity. Therefore 100 x 6 billion
(current population) 15 billion people
Theoretical maximum 40
(leaving
none for other consumers)
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Histograms graph of population distribution by
age. A Example of a stable population in a
MDC. B Example of a population with momentum
built in due to the enormous of children.
Typical of LCDs.