How is our atmosphere different? Ecological Society of America 03.23.01 The Earth's atmosphere is a natural greenhouse that keeps the average global temperature around 60 degrees Fahrenheit. Water vapor, carbon dioxide, methane, nitrous oxide, and other trace gases in our atmosphere trap the sun's heat as it is reradiated from the Earth back into space. The natural composition of Earth's atmosphere is appropriate to maintain temperatures conducive to the development and maintenance of life. In the absence of atmospheric carbon dioxide, and other greenhouse gases that trap the incoming heat of the sun, the average global temperature would hover around freezing. Too much carbon dioxide would give us a much warmer atmosphere. For example, with its atmosphere of carbon dioxide, the temperature of the planet Venus is 885 degrees Fahrenheit, compared to 129 degrees Fahrenheit if its carbon dioxide atmosphere were to be removed. Prepared by the Ecology Society of America   1707 H St., NW   Suite 400   Washington, DC 20006 ©2001 The Aurora Collection, Inc. All Rights Reserved. Site Development by: Interactive Multimedia. Inc.