Growing Alaska Wildfires Threaten ‘Runaway’ Warming Scenario

Accelerated wildfires across wide swaths of the Alaskan interior caused by rising temperatures have released more carbon into the atmosphere over the last decade than was stored in the tundra and boreal forests, according to a new study. Over the last 10 years, the area burned by wildfires in interior Alaska has doubled to 18.5 million hectares — 71,000 square miles — largely because of an increased number of late-summer fires, which consume plant litter, moss, and organic matter in the soil that have accumulated over thousands of years, researchers say. It’s a trend that could portend “a runaway climate change scenario,” in which warming temperatures cause increasingly intense fires that release more and more carbon into the atmosphere, said Merritt Turetsky, a professor at the University of Guelph in Canada and lead author of the study, published in the journal Nature Geoscience. Researchers say the study supports a growing body of evidence that northern ecosystems are bearing the brunt of climate change, and that warming temperatures are turning these carbon sinks into large-scale sources of carbon.