Population and Society
4 Major Causes of
Environmental Change
1.
2.
3.
4.
Population change
Institutions
Attitudes, values, belief systems
Technological change
Carrying Capacity

The maximum number
of organisms an
environment can
support.

But highly dependent on
technology, there is no set
carrying capacity, technology
increases production
Thomas Malthus (17661834)
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An Essay on Population (1798).
Wrote at beginning of the 19th century,
when population growth and industry
were raising demands for food faster
than English agriculture could respond.
Human population would always
increase exponentially (the larger it gets
the faster it grows) while the supply of
food and land would only increase
“arithmetically” (additively)

Scarce farmland

Overuse of resources

Poverty and human misery

Each increase in food
supply only meant that more
people could live in poverty
Cultural Carrying Capacity

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“There should be no more people in a country
than could enjoy a daily glass of wine and a
piece of beef for dinner.” --Thomas Malthus
Cultural carrying capacity is smaller
than simple carrying capacity.
World Population Growth Rates
Population growth rates measured by annual increase in a country’s population are highest in
Africa and Middle East. Growth rates are flat in U.S., Europe, and former Soviet Union
World Population Growth Doubling
Time
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1800-1850
1930
1960 (30 years)
1974 (14 years)
1986 (12 years)
1999 (13 years)
1 billion
2 billion
3 billion
4 billion
5 billion
6 billion
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The current increase of the Earth’s human population
in either absolute or relative terms, vastly exceeds the
average increases over most of human history.
Nobody saw this coming.
In 1936 demographers predicted that the world
population 2.645 billion people by the end of the 21st
century (we hit that by 1955).
1950 estimate 3.3 billion by 2000 (off by 50%.)
World Population Growth

Growth rate was at all time peak of 2.1%
between 1965-1970 (The Population Bomb by Paul
Ehrlich, 1968).

Predicted "in the 1970s and 1980s and 1980
hundreds of millions of people will starve to
death", that nothing can be done to avoid mass
famine greater than any in the history, and
radical action is needed to limit the
overpopulation. ( a neo-Malthusian position)

The growth rate has since declined to about 1.2%
per year.
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Global fertility rates are falling: from 5 children per
woman per lifetime in 1950-55 to 2.7 children in
2000-2005
Absolute annual increase in population peaked
around 1990 at 86 million and has fallen to 77
million.
In 1960, five countries had total fertility rates at or
below the required level required to replace the
population in the long run.
By 2000 there were 64 such countries with 44% of
world population
The Demographic Transition Model

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Beginning-High Birth
rates, high death rates
Transition-High birth
rates, low death rates
(By 1900, life
expectancy at birth was
40-50 years, today it is
78 years for women
and 71 for men and
rising rapidly).
Third Stage-low death
rates, low birth rates
Why has the world’s population
increased by so much?
The Demographic Transition Model
People didn’t start having more babies, more
people began to survive.
Demographic Transition Continued
What makes the death rate
decrease?
1)
2)
Increased productivity: agriculture can
support larger populations than before
Advances in the control of epidemic diseases
and improvement in public health, death
control: antibiotics, biocide DDT to control
insect vectors of infection, vaccines against
smallpox, measles, whooping cough, and
drugs that cured tuberculosis and malaria
Demographic Transition Continued
What makes the birth rate decrease?
1)
2)
3)
As people become urbanized children go
from being an economic asset, to becoming
an economic burden
Cultural norms that encouraged a women to
have large numbers of children weakened.
Increasing opportunities for women: low
status of women=economic dependence and
higher birthrates.
The Six Commandments of
Population Control

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1. Promote Contraceptives.
2. Develop Economies
3. Save Children
4. Empower and Educate Women
5. Educate Men
6. Do all of the above
The Population Debate

Neo-Malthusian: our capacity to
produce food cannot keep up
with our reproductive capacity.

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Population growth is a severe
threat
There are limits to the physical
capacity of the planet to sustain
growth
Population growth is also a major
cause of environmental
degradation
Explaining World Hunger

Agricultural modernization perspective argues that
the world hunger problem is caused by not enough
food produced by traditional agriculture

Another major factor lies not in the quantity of food,
but the distribution of food.
Where is most population growth in the
US from?

According to the census
bureau, post-1970
immigrants and their
descendents will account
for over 80% of US
population growth
between now and mid
21st century.
Migration: Population Growth in
the US

1994: US Commission on
Immigration Reform declared: “We
disagree with those who would
label efforts to control immigration
as being inherently anti-immigrant.
Rather it is both a right and a
responsibility of a democratic
society to manage immigration so it
serves national interest.”
Population growth in the US

According to surveys by the Wall Street
Journal and the Latino National Political
Survey: Clear majorities of African Americans
and Latinos favor reductions in legal and
illegal immigration.
The Politics of Population

1974: The First UN Conference on Population

Developing countries rejected the NeoMalthusian position, that poor countries are
poor because of overpopulation.

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Instead, poverty causes overpopulation.
Redistribution of wealth is needed.
Birth control vs. wealth control

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Today, many developing countries are actively
trying to limit population.
China’s one child policy
Today’s World Population

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World POPClock Projection
According to the International Programs
Center, U.S. Bureau of the Census,
http://opr.princeton.edu/popclock/
Will Malthus always be wrong? Current
Declines in World Population Growth
Rate
How Big will the Population Get?
Trends
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The global total fertility rate fell from 5 children per
woman per lifetime in 1950-55 to 2.7 children in
2000-2005.
Absolute annual increase in population peaked
around 1990 at 86 million, and more recently is at 77
million
64 countries with 44% of total population now have
fertility rates below those needed to replace
population
More Trends

More than half of the annual increase currently
occurs in six countries: India, China, Pakistan,
Bangladesh, Nigeria, and the US (but US only
4%).
Population Growth Scenarios

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Fertility at current
levels= 12.8 billion by
2050.
Medium projection-8.9
billion by 2050 assumes
family planning efforts
will continue and
suceed, fertility
continues to drop..
Most optimistic
prediction7.066 billion

More than half of annual increase in six
countries: India, China, Pakistan, Bangladesh,
Nigeria, and the US (mostly from
immigration)
Will Food Production Keep Up?
Will Malthus always be Wrong?