A NASA-funded study suggests winter carbon emissions in the Arctic may be adding more carbon into the atmosphere each year than is taken up by Arctic vegetation, marking a stark reversal for a region that has captured and stored carbon for tens of thousands of years.
The study, published Oct. 21 in Nature Climate Change, warns that winter carbon dioxide loss from the world’s permafrost regions could increase by 41% over the next century if human-caused greenhouse gas emissions continue at their current pace. Carbon emitted from thawing permafrost has not been included in the majority of models used to predict future climates.
Permafrost is the carbon-rich frozen soil that covers 24% of Northern Hemisphere land area, encompassing vast stretches of territory across Alaska, Canada, Siberia and Greenland. Permafrost holds more carbon than has ever been released by humans via fossil fuel combustion, and this permafrost has kept carbon safely locked away in an icy embrace for tens of thousands of years. But as global temperatures warm, permafrost is thawing and releasing greenhouse gases to the atmosphere.
“These findings indicate that winter carbon dioxide loss may already be offsetting growing season carbon uptake, and these losses will increase as the climate continues to warm,” said Woods Hole Research Center Arctic Program Director Sue Natali, lead author of the study. “Studies focused on individual sites have seen this transition, but until now we haven’t had a clear accounting of the winter carbon balance throughout the entire Arctic region.”
Read more at NASA/Goddard Space Flight Center
Image: The Active Sensing of Carbon Emissions over Nights, Days and Seasons (ASCENDS) campaign flew over Nome, Alaska, on August 5, 2017, as part of NASA's Arctic Boreal Vulnerability Experiment (ABoVE). (Credit: NASA)