Renewable Energy Success Stories

Acid Rain

Scientists have determined that sulfur dioxide (SO₂) and nitrogen oxides (NO_x) are the primary causes of acid rain. In the U.S., about 2/3 of all SO₂ and 1/4 of all NO_x comes from electric power plants burning fossil fuels like coal.¹⁶ Half of the nitrogen oxides come from cars and trucks burning gasoline.¹⁷ Acid rain occurs when these gases react in the atmosphere with water, oxygen, and other chemicals to form various acidic materials. The result is a mild solution of sulfuric acid and nitric acid rain or snow. This acid is then washed into lakes, rivers, and land by rainfall and snow. Acid rain has a variety of effects, including damage to forests and soils, materials, fish and other living organisms including human health.

This photo of dying trees in Maine shows the effects acid rain can have on forests.¹⁸ Acid rain may harm or kill individual fish in a lake, or completely eliminate fish and other living organisms from a body of water, decreasing biodiversity. The Canadian government has estimated that 14,000 lakes in eastern Canada are acidic.¹⁹ In a national survey of the problem in the U.S., acid rain caused acidity in 75 percent of the acidic lakes and about 50 percent of the acidic streams.²⁰

16 U.S. Environmental Protection Agency (EPA) website.

17 U.S. Environmental Protection Agency (EPA) websitehttp://www.epa.gov/air/nitrogenoxides/, (8-Feb-2003).

18 Paul Donahue, Tree Death and Forest Decline, Forest Ecology Network.

19 U.S. Environmental Protection Agency (EPA) website.

20 U.S. Environmental Protection Agency (EPA) website.