Transcript ENVIRONMENTAL SCIENCE - Clinton Community College

Chapter 7
Applying Population Ecology:
The Human Population
Is the World Overpopulated?
Let’s see what the RAND Corporation has to say:
http://www.rand.org/pubs/monograph_reports/MR1114/MR1114.chap4.html
http://www.goalsforamericans.org/gallery/d/281-6/Overpopulation.jpg
History of Human Population
US Population Growth
www.cnn.com/.../01/pip.overpopulation/index.html
Human Population History
• Humans developed and moved into other species
habitat
• Modern agriculture has provided more food per
area of land to be produced
• Manage to put off reaching the limits of disease,
food, water and energy at this time
The question is - “How long can we put it off?”
Population Change
Population change depends on
– Birth
– Death
– Migration
http://pinkdome.com/archives/overpopulation1.jpg
Population change = (Birth + Immigration) – (Death Emigration)
Annual Birth Rate
Annual Birth Rate of natural pop. % =
Birth rate – Death rate x 100%
1,000 people
or more simply stated:
Annual B.R. % = (B.R. – D.R.)/10
Fertility Rate
• Replacement-level fertility = # of children a
couple must bear to replace themselves (2.1-2.5)
• Total fertility rate (TFR) = average # of children a
woman will have during her reproductive years
– This has dropped in the last 50 years from 2.5-6.5 to
1.6-3.0
• US – 76 million in 1900 to 296 million in 2005
– Projected US Census Bureau as 457 million in 2050 &
571 million in 2100.
Affecting Birth/Fertility Rates
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Cost of raising children
Cost of educating children
Infant mortality
Contraceptives and abortion
Urbanization
Educational & employment opportunities for
women
• Religious beliefs
Affecting Death Rates
• Death rate has declined because
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Increased food supply
Better nutrition
Advances in medicine
Improved sanitation
• Life expectancy = average # of years a baby is
expected to live (see fig 7-5 on pg 132)
• Infant mortality rate = #babies die before their first
birthday/1000 babies born
Quality of Life
• Infant mortality is the best single measure
of a society’s quality of life & is caused by:
• Inadequate health care
• Malnutrition
– Insufficient quality of food
• Under nutrition
– Insufficient quantity of food
• High incidence of infectious disease
• Poor water quality
Hunger and Poverty
www.getf.org/millennium/atlas.html
In some areas of our world,
each day offers only a
struggle of life and despair.
Today, over 1.3 billion people
worldwide live in the lowest
poverty level existing on less
than one dollar a day.
Another 3 billion live on less
than two dollars a day. More
than 1.5 billion people in
developing countries have no
access to clean water. In
these regions, there is often
intense demand on natural
resources which often
translates into hunger,
famine and even death. How
can those that have so much
contribute to the solution?
"Hunger and Poverty"
oil & acrylic on canvas
44"x 60"
Some Statistics
• Average lifespan of the world is 65
• Afghanistan has the highest population
growth 4.92%
• United States population growth 0.92%
• Immigration new arrival in 2003 358,411
• There are more than 293 million people in
the United States
Some Statistics
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Average lifespan in the world is 65
Average lifespan in Japan is 81.5
Average lifespan in the United States is 77
Population Density in the United States is
60 million people 250,000 square
kilometers
Influencing Population Size
• Migration
• Reduce birth rate
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Define optimum sustainable population
Define the Earth’s carrying capacity
Influence of economic development on B.R.
Family planning influences & improvements
• Economic rewards & penalties
Overpopulation
The earth's carrying capacity
is under increasing stress
from its sheer number of
inhabitants. Nearly eighty
million people are added to the
world population every year,
putting additional stresses on
our planet. By 2025, the world
population, at current rates,
will elevate to 8.6 billion with
the largest impact felt in the
urban centers of developing
countries. The combined
pressures of population
growth and massive poverty
will weigh heavily on our
stewardship potential.
www.getf.org/millennium/atlas.html
"Overpopulation"
oil on canvas
74"x 57"
Reducing Global Population Growth
• Health care improvements & services
• Reproductive health care & involve males
in family planning
• Implement national population policies
• Provide educational & economic
opportunities particularly to females
• Eradicate poverty & establish sustainable
patterns of life
Bioinformatics
• The storing of important biological data and
the interpretation of that information
• Celera (Human Genome Project):
www.celera.com
• Human genome project
Urban & Rural Growth
• Urbanization patterns
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Increase urban population
Migration from rural to urban areas
Growth of megacities/megalopolis
More urbanization, more poverty
• Urban growth problems
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Poverty
Pollution
Aging infrastructure
Urban sprawl
Heat Islands
asusmart.com/urbanclimate.php
design.asu.edu/apa/proceedings99/ESTES/ESTES.HTM
Urban Areas & Environmental Problems
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Use many resources in a concentrated area
Produce large amounts of waste
Urban sprawl causes habitat destruction
Compromised water supplies
Very little “greenspace”
Infectious diseases
Concentrated pollution
Heat islands – crowded populations
Urbanization: Riyadh, Saudi Arabia (ASTER)
www.satimagingcorp.com/svc/urban_and_land_dev...
Sustainable Development
www.answers.com/topic/sustainable-development