Saturday, December 11, 2010

Climate change, wildfires in vicious cycle

Fire Engineering via CBC News (Canada): Northern wildfires and climate change are fuelling each other, a new study shows. "Increasing temperatures â?¦ [are] going to result in increasing fire in both Alaska and Canada," says Merritt Turetsky, lead author of the study published this week in Nature Geoscience. "This results then, according to our data, in more greenhouse gas emissions, which then feeds back to climate warming through the greenhouse effect."

Turetsky, an ecology professor at the University of Guelph, and her collaborators found that the area of interior Alaska that burns each year has doubled and the amount of carbon dioxide released by wildfires has tripled over the past decade relative to the previous 50 years.

…In 2004 alone, Alaskan wildfires released 52 million tonnes of carbon dioxide over a season of three to four months. "That's equivalent to the amount of carbon released by all domestic airline flights in the United States for the entire year," Turetsky told CBC's Quirks & Quarks. While her study focused on Alaska, she said "very similar patterns are held across Canada."

A warmer climate causes ecosystems to dry out, leaving them more vulnerable to fires. Turetsky said the fires are burning more deeply into the forest floor, releasing stores of carbon from thick layers of moss and peat. A key uncertainty is whether, in the future, peatlands and muskeg, which hold tremendous amounts of organic matter, may also become vulnerable to burning, Turetsky said. Currently, they are protected because their soil is extremely wet and much of it is locked up in permafrost….

August 2009 fire in Flintridge, California outside Los Angeles, also known as the Station Fire -- a little too far south for a northern forest. Shot by mbtrama, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license

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