Thousands of acres of permafrost are burning in what appears to be Greenland’s biggest fire on record. And climate scientists are freaking out not just because the massive fires are unusual, but because they release large amounts of greenhouse gases and speed up the melt of the ice sheet and the carbon-rich permafrost.
Greenland is almost entirely covered in an enormous ice sheet, but grassy, carbon-rich peatlands along the coast are heating up and drying out. “These fires appear to be peatland fires,” wildfire expert Prof. Jessica L. McCarty told Wildfire Today. “They are likely occurring in areas of degraded permafrost, which are predicted to have high thaw rates between now and 2050.”
Peatlands, also known as bogs and moors, are the earliest stage in the formation of coal. A 2015 study noted, “Globally, the amount of carbon stored in peats exceeds that stored in vegetation and is similar in size to the current atmospheric carbon pool.”
Peat fires are difficult to stop, often burning until all the organic matter has turned to ash. A coauthor of the 2015 study noted, “Smouldering peat fires already are the largest fires on Earth in terms of their carbon footprint.”
“Fires in the High Northern Latitudes release significant CO2, CH4, N20, and black carbon,” said Dr. McCarty. “A fire this close to the Greenland Ice Shelf is likely to deposit additional black carbon on the ice, further speeding up the melt.”
And, no, this massive Greenland wildfire, which began at the end of July, is “not a typical wildfire,” as satellite data expert Prof. Stef Lhermitte told The Independent. “It’s a rare and unusual event. This one is the biggest one in the satellite record that we know of.”
Lhermite tweeted that, based on data from NASA’s Modis satellite, “wildfires have occurred in the past over Greenland but 2017 is exceptional in number of active fire detections by MODIS.”
Yet scientists have long predicted that global warming would lead to more wildfires in the defrosting Arctic. A 2008 study using paleoclimate data concluded, “greater fire activity will likely accompany temperature-related increases in shrub-dominated tundra predicted for the 21st century and beyond.” A 2013 study found that northern boreal forests are now burning at a rate not seen for at least 10,000 years–and double the rate seen hundreds of years ago.
A 2014 study found that the record-smashing ice-melt in July 2012, when 97 percent of Greenland’s surface was melting, was not just driven by rising temperatures. It was also exacerbated by black carbon (soot) from massive Siberian wildfires that darkened the great ice sheet, reducing its reflectivity and causing it to absorb more heat from the sun.
As the massive Greenland ice sheet shrinks–ice melt has sped up more than five-fold since the mid-1990s–more formerly ice-covered land will turn to grass- and shrub-covered peatland, leading to more wildfires, leading to more ice melt. No wonder scientists are freaking out.