The largest wildfire in Greenlandic history flashed brightly last summer, a potential warning sign for a future shaken by catastrophic climate change.
Scientists are concerned that Greenland's massive ice sheet could absorb the carbon-black smog produced by the fires, as well as any fires that occur in the future.
A third of the ice sheet has been affected by soot from the forest fire, which accelerates the absorption of heat and the melting of glaciers.
"I think it's a warning sign that something like this can happen in permafrost that was supposed to be melting at the turn of the century," rather than the present, Andreas Stohl, Senior Scientist at the Norwegian Institute for Air Research (NILU) he told Live Science.
There was no lightning activity - a leading cause of wildfires - prior to the blaze, which was about 90 miles (150 kilometers) northeast of Sisimiut, Greenland's second-largest city. The fire is suspected of being man-made, although Stohl noted that peat, in oxygen-rich environments, can self-ignite, even at relatively low temperatures.
Researchers estimated that the fire burned around 9 square miles (2,345 hectares) of land. The NILU-led team also studied how much of the soot from the fire settled on the ice.
"If you consider that Greenland has the largest ice sheet outside of Antarctica, you immediately get to thinking: what if some smoke falls on this ice sheet?" said Nikolaos Evangeliou, another scientist at NILU.
Using a computer model to simulate how soot could have been produced in the atmosphere, the researchers calculated that about 7 tons of an aerosol called black carbon - 30 percent of the total emissions from that fire - landed on the ice sheet. .
This amount of carbon didn't have much of an impact on the overall albedo or reflectivity of the ice sheet, Stohl and Evangeliou said. The wildfire, while unprecedented in size for Greenland, was small compared to the wildfires that hit the Americas last year. (The record wildfires in British Columbia in 2017 burned more than 4,600 square miles, or 12,000 square kilometers, according to the Canadian news magazine Maclean’s.) By sending gigantic plumes of smoke into the atmosphere, the North American fires deposited much more carbon in Greenland. the ice sheet than the Greenland forest fire, Evangeliou said. However, the Greenland fire was much more effective in dropping carbon onto the ice sheet, he explained.
"If the larger fires were to burn, they would actually have a substantial impact on the meltdown," Stohl said. And, there are more chances of such fires, if more of the Greenland permafrost melts and exposes the peat, which is actually the early stage material used in the formation of coal, and therefore burns easily.
Perhaps more worryingly, these peat fires can burn underground and go unnoticed for a long time. Stohl pointed out that peat fires in Indonesia can burn for years before they erupt again on the surface.
"We can't be sure that the fires (in Greenland) are out there," Stohl said.
Original article in English, Live Science.