Arctic Wildfires Are Changing, With Big Implications for the Global Climate

Climate

Activists fight a peat fire in Siberia in September. ALEXANDER NEMENOV / AFP via Getty Images

The wildfires that ignited in the Arctic this year started earlier and emitted more carbon dioxide than ever before.


Now, a group of researchers is warning that the nature of Arctic fires may be changing, and it’s important to understand how in order to better predict the future of the global climate.

“It’s not just the amount of burned area that is alarming,” University of Colorado Boulder fire and permafrost ecologist Dr. Merritt Turetsky said in a press release published by Phys.org. “There are other trends we noticed in the satellite data that tell us how the Arctic fire regime is changing and what this spells for our climate future.”

Turetsky co-wrote a commentary in Nature Geoscience Monday with two other fire experts. The scientists pinpointed two important ways that Arctic wildfires are changing.

1. Zombie Fires

Zombie fires, also known as holdover fires, occur when fires from the previous season continue to burn beneath the ground during the winter. These blazes can then reemerge when the snow melts and the weather warms.

Satellite monitoring data from the Copernicus Atmosphere Monitoring Service confirmed that zombie fires helped drive 2020’s unprecedented wildfire season, which broke records both for the number of blazes and the amount of carbon released into the atmosphere, as Live Science reported. But the scientists writing in Nature Geoscience say they still need to learn more about these unusual fires and how they may contribute to climate feedback loops.

“We know little about the consequences of holdover fires in the Arctic,” Turetsky said in the press release, “except that they represent momentum in the climate system and can mean that severe fires in one year set the stage for more burning the next summer.”

Indeed, the 2020 wildfire season broke records that had been set just the year before, in 2019’s also unprecedented season.

2. Fires Where Fire Shouldn’t Be

The other troubling feature of the 2019 and 2020 Arctic wildfire seasons is that their blazes ignited in areas typically resistant to burning, the scientists pointed out. This included tundra vegetation such as dwarf shrubs, sedges, grasses and mosses and previously burn-free environments like bogs, fens and marshes.

Significantly, more than 50 percent of the 2020 fires burning above 65° North occurred on ice-rich permafrost, which contains the most carbon of any Arctic soil.

“Nearly all of this year’s fires inside the Arctic Circle have occurred on continuous permafrost, with over half of these burning on ancient carbon-rich peat soils,” commentary coauthor and London School of Economics and Political Science fire scientist Dr. Thomas Smith said in the press release. “The record high temperatures and associated fires have the potential to turn this important carbon sink into a carbon source, driving further global heating.”

The scientists called for more research into the dynamics of Arctic fires to better understand how they will contribute to the climate crisis. Part of this requires collaborating with local and Indigenous communities, who can provide on-the-ground observations to accompany satellite data.

“The burning Arctic is a global issue that requires a global solution,” the scientists concluded. “While the expertise of the Indigenous communities of the North and Arctic nations will be central to any success, we cannot expect them to shoulder the responsibility alone.”

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