The amount of soil-bound carbon released to atmosphere in the 2007 Anaktuvuk River fire was enough to impact the global climate, according to UF ecologist Michelle Mack and other scientists.
"The 2007 fire was the canary in the coal mine," Mack said. "In this wilderness, hundreds of miles away from the nearest city or source of pollution, we're seeing the effects of a warming atmosphere. It's a wakeup call that the Arctic carbon cycle could change rapidly, and we need to know what the consequences will be."
The fire covered more than 400 square miles on the North Slope of Alaska's Brooks Range and 2.1 million metric tons of carbon was released in the fire. It was twice the size the amount of greenhouse gases generated by Miami in one year.
The fire not only inserted greenhouse gases into the atmosphere but it also consumed 30 percent up of the insulating layer of the organic matter that protects moss covered landscape. Arctic tundra stores large amounts of carbon in cool, wet soils insulated by permafrost, a layer of permanently frozen ground.
"When the permafrost warms, microbes will begin to decompose that organic matter and could release even more carbon that's been stored in the permafrost for hundreds or thousands of years into the atmosphere," Mack said. "If that huge stock of carbon is released, it could increase atmospheric carbon dioxide drastically."
The study revealed how isolated fires can have massive impact, said University of Alaska biology professor Terry Chapin.
"When you think about the massive carbon stocks and massive area of tundra throughout the world, and its increasing vulnerability to fire as climate warms, it suggests that fire may become the dominant factor that governs the future carbon balance of this biome," Chapin said.
"The paper by Michelle and her colleagues raises this possibility for the first time. It presents a very different perspective on the way in which climate change may affect this biome in the future," he said.
Mack wishes her study will start a dialogue regarding how tundra fires are managed. Because the Anaktuvuk River fire was in a wilderness area, it was not suppressed nor contained. With better data on the long-term impact of tundra fire on global climate warming, Mack said, putting out these fires might become more of a priority.
"This fire was a big wakeup call, and it can happen again, not just in Alaska but in other parts of the Arctic, like Canada and Russia," Mack said.
"Suppressing a fire in the wilderness is costly, but what if the fire causes the permafrost to melt? We need to have that discussion."