Climate change is causing more rain in the North. That’s bad news for permafrost New study shows wetter weather is thawing the frozen ground that covers a quarter of the northern hemisphere, threatening to release massive stores of carbon, The Narwhal, Julien Gignac, Local Journalism Initiative reporter . Aug 20, 2020
Longer, rainier summers are thawing permafrost at an accelerated rate in interior Alaska, according to a new study, begging the question: what does this mean for rainy summers in the Canadian North? “Thawing is happening even faster than we thought,” said Thomas Douglas, an environmental engineer with the U.S. Army Cold Regions Research and Engineering Laboratory and lead author of the study. “We’ve had these crazy wet summers. It’s gonna be bad for permafrost.” The study, published in Nature’s Climate and Atmospheric Science journal, found that between 0.6 and 0.8 centimetres of permafrost thawed for every centimetre of above-average rainfall in Alaska between 2013 and 2017……………… According to a 2015 report by Yukon University, annual precipitation in the territory has increased by six per cent over the past 50 years, with summers seeing the most rainfall compared to other seasons. “Rain water, especially in the summer, is pretty warm and it can move warm, thermal mass down through the soil a lot faster than just warm air temperatures can,” Douglas said. “If you lose three to four weeks of winter to summer, what used to be falling as snow is now falling as rain.”……… According to a 2015 report by Yukon University, annual precipitation in the territory has increased by six per cent over the past 50 years, with summers seeing the most rainfall compared to other seasons. “Rain water, especially in the summer, is pretty warm and it can move warm, thermal mass down through the soil a lot faster than just warm air temperatures can,” Douglas said. “If you lose three to four weeks of winter to summer, what used to be falling as snow is now falling as rain.”……….. it’s not only the North that is impacted by thawing permafrost. Arctic permafrost stores an estimated 1.4 million megatonnes of carbon in frozen organic matter. As it thaws, microorganisms that were dormant when frozen start to break down that matter, releasing carbon and methane into the atmosphere. “It has global ramifications,” Douglas said……………………. we could see all Arctic precipitation levels change in the coming years as sea ice continues to disappear, leaving more open water and more evaporation that eventually becomes precipitation. “As the Arctic Ocean becomes more ice-free in the summer, you would expect many of these areas to become eventually wetter,” Marsh said. https://thenarwhal.ca/climate-change-rain-arctic-permafrost-thaw/ |
|
|
Leave a Reply