Fire is an important and under-appreciated part of global climate change

http://www.eurekalert.org/pub_releases/2009-04/nsf-fia042309.php

Public release date: 23-Apr-2009
Contact: Lily Whiteman
National Science Foundation

Fire must be accounted for as an integral part of climate change, according to 22 authors of an article published in the April 24 issue of the journal Science. The authors determined that intentional deforestation fires alone contribute up to one-fifth of the human-caused increase in emissions of carbon dioxide, a heat-trapping gas that increases global temperature.
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Jennifer Balch, a member of the research team and a postdoctoral fellow at NCEAS, explains that there are bigger and more frequent fires from the western U.S. to the tropics. There are "fires where we don't normally see fires," she said, noting that it is in the humid tropics that a lot of deforestation fires are occurring, usually to expand agriculture or cattle ranching. "Wet rainforests have not historically experienced fires at the frequency that they are today. During extreme droughts, such as in 97-98, Amazon wildfires burned through 39,000 square kilometers of forest."