Download - A.P. Environmental Science Introduction
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
Fig. 1-1, p. 6
IndustrialRevolution
?
Agricultural revolutionHunting andGathering
Billio
ns o
f peo
ple
Time
Black Death—the Plague
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/www/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 BiodiversityIncreasing 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