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Greenhouse Gases
Greenhouse GasesGreenhouse gases are trace gases in the atmosphere that absorb outgoing infrared radiation from Earth and thereby, like a greenhouse, warm the planet. Naturally occurring greenhouse gases (primarily water vapor and carbon dioxide) make the planet habitable for life as we know it. Anthropogenic greenhouse gases contribute to further warming, referred to as global warming. Carbon dioxide (CO2) is both a natural and anthropogenic greenhouse gas. Anthropogenic inputs of CO2 mainly from the burning of fossil fuels and deforestation continue to rise, making it the number-one contributor to global warming. Other anthropogenic greenhouse gases include methane (CH4), nitrous oxide (N2O), sulfur hexafluoride (SF6), chlorofluorocarbons (CFCs), and hydrofluorocarbons (HFCs). The last three compounds are synthetic greenhouse gases, which did not exist in the atmosphere before the twentieth century. Molecule for molecule, these gases trap more energy than CO2, but are less abundant in the atmosphere. One molecule of CH4, for example, traps as much heat as twenty-three molecules of CO2. SF6 traps as much heat as 22,200 molecules of CO2. In 1997 the Kyoto Protocol proposed legally binding restrictions on greenhouse gas emissions, targeting a 5-percent reduction over 1990 levels by 2012. As of December 2001, 186 countries had ratified the protocol. The United States, however, is not one of them. see also Carbon Dioxide; CFCs (Chlorofluorocarbons); Global Warming; Methane; MontrÉal Protocol; NOx; Treaties and Conferences. Bibliographyturco, richard p. (1997). earth under siege: from air pollution to global change. new york: oxford university press. internet resourcesu.s. environmental protection agency. "global warming." available from http://www.epa.gov/globalwarming. united nations framework convention on climate change. "greenhouse gas emissions." available from http://unfccc.int/resource. Marin Sands Robinson |
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Cite this article
Robinson, Marin Sands. "Greenhouse Gases." Pollution A to Z. 2004. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. Robinson, Marin Sands. "Greenhouse Gases." Pollution A to Z. 2004. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1G2-3408100111.html Robinson, Marin Sands. "Greenhouse Gases." Pollution A to Z. 2004. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1G2-3408100111.html |
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greenhouse gas
greenhouse gas A gas composed of molecules that absorb and reradiate infrared electromagnetic radiation. When present in the atmosphere, therefore, the gas contributes to the greenhouse effect. On Earth, the principal greenhouse gases are water vapour, carbon dioxide, methane, nitrous oxide, ozone, and certain halocarbon compounds. See GLOBAL WARMING POTENTIAL.
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Cite this article
AILSA ALLABY and MICHAEL ALLABY. "greenhouse gas." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. AILSA ALLABY and MICHAEL ALLABY. "greenhouse gas." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O13-greenhousegas.html AILSA ALLABY and MICHAEL ALLABY. "greenhouse gas." A Dictionary of Earth Sciences. 1999. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O13-greenhousegas.html |
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greenhouse gas
greenhouse gas A gas that absorbs long-wave radiation and therefore contributes to greenhouse-effect warming when present in the atmosphere. The principal greenhouse gases are water vapour, carbon dioxide, methane, nitrous oxide, halocarbons, and ozone. See also global warming.
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MICHAEL ALLABY. "greenhouse gas." A Dictionary of Ecology. 2004. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "greenhouse gas." A Dictionary of Ecology. 2004. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O14-greenhousegas.html MICHAEL ALLABY. "greenhouse gas." A Dictionary of Ecology. 2004. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O14-greenhousegas.html |
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greenhouse gas
green·house gas • n. a gas that contributes to the greenhouse effect by absorbing infrared radiation, e.g.. carbon dioxide and chlorofluorocarbons. |
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Cite this article
"greenhouse gas." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. "greenhouse gas." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O999-greenhousegas.html "greenhouse gas." The Oxford Pocket Dictionary of Current English. 2009. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O999-greenhousegas.html |
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