Chapter Essay
Essay:
“The Lessons of Easter Island”
By Jared Diamond, Ph.D.
Rapid Human
Population Growth
Today’s Objective:
• 26.4 How Is the Human Population
Changing?
– The Human Population Continues to Grow Rapidly.
– Technological Advances Have Increased Earth’s
Carrying Capacity to Support People.
– The Demographic Transition Helps Stabilize
Populations.
Rapid Human
Population Growth
A Quiz Question for You:
Q: Which of the nations listed below has the
lowest annual rate of increase (as a %)?
A. New Zealand
B. Australia
C. China
D. United States
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Rapid Human
Population Growth
• In the last few
centuries, the
human population
has grown at nearly
an exponential rate.
– follows a “J-shaped” growth curve associated
with exponential population growth.
Population
Doubling Times
Rapid Human
Population Growth
World Population of Humans: 6,629,952,311
Net Growth/year (2004) . . . . 77,401,492
Growth/month . . . . . . . . . . . . .6,450,124
Growth/day . . . . . . . . . . . . . . . .212,059
Growth/hour . . . . . . . . . . . . . . . . . 8,836
Growth/minute . . . . . . . . . . . . . . . .147
Growth/second . . . . . . . . . . . . . . . . ~2.5
Sources:
http://www.census.gov/ipc/www/worldpop.html
http://www.census.gov/cgi-bin/ipc/popclockw
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Rapid Human
Population Growth
United States:
303,322,309
One birth every.................................. 8 seconds
One death every................................ 12 seconds
One migrant (net) every....……........ 26 seconds
Net gain of one person every............ 11 seconds
Sources:
http://www.census.gov/ipc/www/worldpop.html
http://www.census.gov/cgi-bin/ipc/popclockw
Rapid Human
Population Growth
• Most species must "make
due" with the resources in an
area.
• Humans have manipulated
the environment to increase
the Earth’s carrying capacity
for humans.
– Global Population Growth Is
Unevenly Distributed
– Fertility in Europe Is Below
Replacement Level
– The United States Populations Is
Growing Rapidly
Technological
Advances
• Technical and cultural revolution
– Primitive humans tools and weapons increased
hunting effectiveness.
– Fire, shelter, & clothing increased habitable area.
• Agricultural revolution (c. 8,000 B.C.)
– Domesticated plants/animals – more food (stable).
• Industrial-medical revolution (mid-18th Century)
– Allowed fewer people to produce more food and
decreased the death rate from infectious diseases.
3
Demographic
Transition
• In "developed" countries, the
industrial-medical revolution
resulted in an initial rise in
population, which then
stabilized.
– Caused by a decrease in
death rates, followed later by
a decrease in birth rates.
– This change in population
size is called a demographic
transition.
Demographic
Transition
• Declining birth rates
associated with from:
– Increased access to
contraceptives.
– Education.
– Demographic shift to
cities.
– Women working outside
the home.
Replacement-level
Fertility (RLF)
•
•
•
•
In most developed nations.
When adults have enough children to replace themselves.
RLF is slightly higher than 2.00 .
Even if countries drop to RLF or below (like China), growth will
continue for some time as “excess" people in younger age groups
reach reproductive age.
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RLF in Europe
• Average fertility rate is 1.4, substantially < RLF.
• Concerns about availability of future workers and
taxpayers have prompted several countries to offer
incentives for couples to have children at an earlier
age.
RLF in the
United States
• U.S. population is fastest
growing of all industrial
nations.
– U.S. fertility rate is only
~2.0, actually below RLF
– However, immigration is
adding people rapidly.
Uneven Distribution
• “Developing" nations have rapidly growing populations (birth
rates vastly exceed death rates)
– Low incomes and the need for many children to raise
family income or produce food.
– Knowledge of and access to contraception is limited.
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Uneven Distribution
• Despite the population
reduction of some
developing countries,
zero population growth
will not be achieved globally.
– The U.N. predicts a
global human population
of 8.9 billion in the year
2050
Population Age
Structure
• If developing nations were
to achieve RLF
immediately, their
population increases
would continue for
decades.
– A large population of
children today create a
momentum or “inertia”
for future growth as
they enter their
reproductive years.
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Rapid Human
Population Growth
• Rapid population growth in the U.S. may
have serious implications for the
environment of the U.S. and the Earth.
– Americans consume far more resources and
produce far more pollution than the global average
– The "ecological footprint," is more than four times
greater for U.S. residents than the global average.
Rapid Human
Population Growth
A Quiz Question for You:
Q: Which of the nations listed below has the
lowest annual rate of increase (as a %)?
0.7%
A. New Zealand
B. Australia
0.6%
C. China
0.5%
0.6%
D. United States
In Summary . . . . . .
1. ?
2. ?
3. ?
4. ?
5. ?
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Next Week’s Quiz
Next Friday
Chapter #26
http://www.vcld.org/pages/newsletters/01_02_fall/testtaking.htm
Next Week . .
Communities
http://www.vcld.org/pages/newsletters/01_02_fall/testtaking.htm
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