As the ice melts, fire is taking over in the north. Wildfires in the Alaskan interior have increased in number and intensity over the last 10 years, according to research led by Merritt Turetsky at the University of Guelph in Ontario, Canada. The increasing number and intensity of fires in the northern boreal forest, peatlands and tundra could add to a climate change feedback loop, the researchers warn.
More wildfires means more greenhouse gases, especially carbon dioxide. More greenhouse gases means more warming in the arctic and hence more fires. The cycle then repeats.
The burning wilderness is now releasing more carbon than the living plants there are absorbing, the researchers said in a University of Guelph news release.
"These findings are worrisome because about half the world's soil carbon is locked in northern permafrost and peatland soils. 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," said Turetsky.
To determine how much carbon was being released by the fires, the researchers examined the sites of nearly 200 forest and peatland wildfires over several years. The researchers also looked at records kept since 1950 to determine fire's historical frequency and size.