A.P. Environmental Science Introduction

Global Environmental Science Picture n Four global trends

Four Global Trends n Population growth and increasing consumption n Degradation of soils n Global atmospheric changes n Loss of biodiversity

1. Population growth

n reached 6 billion about October 12, 1999 n Will reach 7 billion October, 2011 n May reach 10 billion by 2050 n World POPClock World POPClock n Population Connection Population Connection

Fig. 1-1, p. 6 Industrial Revolution ? Agricultural revolution Hunting and Gathering Billions of people Time Black Death—the Plague

Fig. 1-12, p. 18

1. Population growth n The United States reached 300 million on October 17, 2006 at 3:46 AM.

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n California now has 38 million, may have 50 million by 2025

Population Growth n All people create demands on the earth n Demand tends to increase with affluence “affluenza”

Question n “ How can Earth support a near doubling of the population and still increase standards of living ”

2. Degradation of Soils

n Fertile soil is the foundation for plant growth and food production n BUT-- soils are being degraded by erosion, overgrazing, development

3. Global Atmospheric Changes

u Burning fossil fuels ( oil, natural gas, and coal) has caused increases in global carbon dioxide

u CO 2 blocks infrared radiation and therefore traps heat in the atmospheric u resulting in displacement of plants, rise in sea level, changes in climate and weather

4. Loss of Biodiversity

u 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 n Mainstay of crops and medicine development n Critical factor in maintaining stability of natural systems n For aesthetic and moral reasons

Unifying Themes of Environmental Science

3 Unifying Themes n Sustainability n Stewardship n Sound science

Sustainability n Means that a system or process can be continued indefinitely without depleting resources to keep it going n Harvests cannot exceed reproduction rates n Lead to concept of sustainable development

Stewardship n Stewards are responsible for earth and its population n Concept originated from environmentalism movement

Sound Science n Environmental issues are sometimes embroiled in controversy n One side is science n One side are those who mistrust scientists and their interpretations and motives

Understanding science n People need to understand how science is done n Will lead to greater understanding of the issues n Sound science is essential to helping guide us into the 21st century