A.P. Environmental
Science Introduction
Global
Environmental
Science Picture

Four global trends
Four Global Trends
Population growth and
increasing consumption
 Degradation of soils
 Global atmospheric changes
 Loss of biodiversity

1. Population growth
1. Population growth
reached 6 billion about October
12, 1999
 Will reach 7 billion October, 2011
 May reach 10 billion by 2050



World POPClock
Population Connection
?
Black Death—the Plague
Time
Hunting and
Gathering
Agricultural revolution
Industrial
Revolution
Fig. 1-1, p. 6
Fig. 1-12, p. 18
1. Population growth

The United States reached 300
million on October 17, 2006 at
3:46 AM.
http://www.census.gov/population/ww
w/popclockus.html

California now has 38
million, may have 50 million
by 2025
Population Growth
All people create demands
on the earth
 Demand tends to increase
with affluence “affluenza”

Question

“ How can Earth support a
near doubling of the
population and still
increase standards of
living”
2. Degradation of Soils
2. Degradation of Soils
Fertile soil is the foundation
for plant growth and food
production
 BUT-- soils are being
degraded by erosion ,
overgrazing, development

3. Global Atmospheric
Changes
3. Global Atmospheric
Changes
Burning fossil fuels ( oil,
natural gas , and coal) has
caused increases in global
carbon dioxide
CO2 blocks
infrared radiation
and therefore traps heat in
the atmospheric
resulting in displacement of
plants, rise in sea level,
changes in climate and
weather
4. Loss of Biodiversity
4. Loss of Biodiversity
Increasing population and
increasing consumption are
accelerating conversion of
forests, grasslands, and
wetlands, etc. to agriculture
and urban development
Destruction of
habitat
= destruction of
species
Biodiversity is important
Mainstay of crops and
medicine development
 Critical factor in maintaining
stability of natural systems
 For aesthetic and moral
reasons

Unifying Themes
of Environmental
Science
3 Unifying Themes
Sustainability
 Stewardship
 Sound science

Sustainability
Means that a system or process
can be continued indefinitely
without depleting resources to
keep it going
 Harvests cannot exceed
reproduction rates
 Lead to concept of sustainable
development

Stewardship
Stewards are responsible for
earth and its population
 Concept originated from
environmentalism movement

Sound Science
Environmental issues are
sometimes embroiled in
controversy
 One side is science
 One side are those who
mistrust scientists and their
interpretations and motives

Understanding science
People need to understand
how science is done
 Will lead to greater
understanding of the issues
 Sound science is essential to
helping guide us into the 21st
century
