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What is global warming?
Natural gases such as water vapor and carbon dioxide form a shield around the earth capturing some of the sun's energy, which otherwise would radiate back into space. Without this "greenhouse effect" Earth's temperatures would be inhospitably cool.
Human activity in the last century, however, has concentrated this blanket of gases, trapping additional heat. The earth's surface temperature is now about one degree Fahrenheit warmer than it was 100 years ago, according the National Academy of Sciences. Researchers believe the burning of fossil fuel is primarily responsible for the buildup of three important greenhouse gases: carbon dioxide, methane and nitrous oxide.
Fossil fuel is used to run cars and trucks, generate electricity, heat buildings and power factories.
Fossil fuel-burning activities account for 98 percent of U.S. carbon dioxide emissions, 24 percent of methane emissions and 18 percent of nitrous oxide emissions, according to the U.S. Environmental Protection Agency. Agriculture, deforestation, landfills, industrial production and mining also contribute to the problem.
Unless emissions are reduced, scientists predict the earth's atmosphere will continue to warm, resulting in flooding in some areas and drought in others. According to the EPA, in 1997, the United States emitted about one-fifth of total global greenhouse gases.
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These pages are produced by the WSU Extension Energy Program Library staff with financial support provided by the Washington Department of Community Trade and Economic Development from the US Department of Energy State Energy Program funds.
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Contact
WSU Extension Energy Program
905 Plum Street SE
Olympia, WA 98504-3165
Phone: (360) 956-2000
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