Tuesday, December 07, 2010

Alaskan Wildfires Could Trigger 'Runaway Climate Change'

Severe Alaskan wildfires have released much more carbon than was stored by the region's forests over the past 10 years, researchers report today. They warned that the pattern could lead to a "runaway climate change scenario" where larger, more intense fires release more greenhouse gases that, in turn, lead to more warming. The northern wildfires burn peatlands that consist of decaying plant litter, moss and organic matter in the soil, said Merritt Turetsky, an ecologist at the University of Guelph in Canada and lead author of a new study. Such fires have a huge impact given that the peatlands contain much of the world's soil carbon – about as much carbon as is found in the atmosphere or in the total of terrestrial biomass (plants and animals). "These findings are worrisome, because about half the world's soil carbon is locked in northern permafrost and peatland soils," Turetsky explained. "This is carbon that has accumulated in ecosystems a little bit at a time for thousands of years, but is being released very rapidly through increased burning." The fire-chasing researchers found that burned area has doubled in Alaska's interior over the last decade. They traveled to almost 200 forest and peatland burn sites so that they could measure how much biomass had gone up in smoke and flames, and also examined fire records dating back to the 1950s...more

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