Every dark cloud has a silver lining and the silver lining for a thawing permafrost is...still a dark cloud.

The climate is warming in the Arctic at twice the rate of the rest of the globe. That has led to a longer growing season and increased plant growth, which captures atmospheric carbon - that is good - but it is thawing the permafrost, which releases carbon into the atmosphere. Permafrost contains three to seven times the amount of carbon sequestered in tropical forests. A thawing permafrost which will result in the release of carbon dioxide and methane into the atmosphere creating feedbacks to climate change – more warming and greater permafrost thaw.  

Woods Hole Research Center (WHRC) Assistant Scientist Sue Natali and colleagues engineered first-of-a-kind warming experiments in the field to determine net gains or losses in carbon emissions and found that growing season gains do not offset carbon emissions from permafrost thaw.  

 A photo from the winter warming experiment. Credit: WHRC


Prior to this study, "the understanding of permafrost feedbacks to climate change had been limited by a lack of data examining warming effects on both vegetation and permafrost carbon simultaneously," said Dr. Natali.


The three year long Carbon in Permafrost Experimental Heating Research (CiPEHR) project warmed air and soil and thawed permafrost using two warming experiments. The "winter warming" treatment consisted of snow packs, which functioned like down comforters insulating the ground during the winter until the snow was removed at the start of the growing season. The "summer warming" treatment consisted of open-topped greenhouses that warmed the air during the summer. The team measured warming effects on CO2 uptake by plants and release by plants and microbes.



Article: "Permafrost degradation stimulates carbon loss from experimentally warmed tundra" in Ecology.
Source: Woods Hole Research Center