An unusually large North Slope wildfire released a massive amount of carbon into the atmosphere. That’s the conclusion of research published this week on the 2007 Anaktuvuk River fire, the largest wildfire ever recorded on the North Slope. The tundra blaze burned 256,000 acres, or about 400 square miles mostly in the month of September. University of Alaska Fairbanks ecologist Syndonia Bret Harte says the character of the lightning caused fire was also unusual for the normally wet tundra.
Bret Harte says sediment cores showed no previous evidence of wildfire in the area over the last 5,000 years. Analysis showed the wildfire burned and released carbon stored in dead plant matter accumulated over the previous 50 years. Fellow researcher Michelle Mack of the University of Florida says that’s substantial even when you consider the entire circumpolar arctic region.
That means one fire released enough carbon to offset the annual sequestration of the entire arctic. The individual event is not going to throw the world into climate change doomsday, but if it’s indicative of a new norm of warmer drier, more lightning prone conditions in the arctic, Brett Hart says that could trigger the release of vast stores of carbon from frozen soils.
Brett Harte says the massive release of long sequestered carbon would be a strong positive feedback to further warming. The Anaktuvuk wildfire research was published in the July 28 issue of Nature.
Dan Bross is a reporter at KUAC in Fairbanks.
