Fresh concerns are being expressed about the carbon locked in the Arctic’s permafrost. New studies presented at the American Geophysical Union quantify the amount of soil carbon at about 1.9 trillion metric tons, indicating that previous estimates underestimated the climate risk if this carbon is released due to warming temperatures.
New laboratory experiments that are simulating the carbon released by thawing soil are bolstering concerns that continued carbon emission could lead to a carbon disaster. Disappearing Arctic ice is an anthropogenic cause of climate change. The melting of the permafrost can actually drive global warming. As it thaws, microbes devour the locked carbon, unleashing carbon dioxide and amplifying the warming power of carbon pollution in a feedback loop.
Scientists struggle to quantify this threat. Permafrost occurs on a quarter of the Northern Hemisphere landmass, from Alaska to Canada and all across Siberia, but far too few readings have been taken to make good estimates about this risk.
Logistical constraints limited researchers’ previous estimates. Now researchers believe that carbon down to a depth of at least 3 meters is susceptible to thawing and release. The new analysis concludes that there is 1,894 billion metric tons of carbon locked into the permafrost across the Arctic, 13% more than the previous estimate.
Scientists need to continue to research how much permafrost will thaw as the planet warms. A modeling study published earlier this year suggested 436 gigatons of carbon could thaw by 2100 and a new conservative estimate indicates that 20% of the available carbon could be released over 50 years.