Right now, methane emissions appear stable
Scientists believe that permafrost in the Arctic may hold as much as two and a half times the carbon that has been emitted since around the mid-1700s. And with the Arctic region warming at a very fast clip, those same scientists are concerned what will happen when this carbon is released into the atmosphere as the permafrost melts.
Permafrost, a thick layer of soil found mostly at polar regions that remains frozen throughout the year, stores a high level of carbon. And what is currently occurring with these carbon stores as the permafrost thaws remains subject of intense research. Carbon can take different forms when released, and some models predict that at least some of the carbon stored in permafrost could be released as methane. Methane is one of the most potent greenhouse gases, and is a major contributor to global warming.
One new study -- which included researchers from the National Oceanic and Atmospheric Administration (NOAA), NASA, the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder, and others -- analyzed nearly three decades of atmospheric methane measurements from the NOAA Barrow Atmospheric Baseline Observatory. The researchers found that, while spikes in methane due to short-term temperature changes have occurred, a long-term change in methane levels has not.
Lead author of the study Colm Sweeney said that thawing permafrost is indeed releasing carbon, but "it just isn’t showing up as methane."
— NOAA Communications (@NOAAComms) June 22, 2016
Billions of tons of carbon
One theory revolves around the concept that both methane-producing bacteria and methane-consuming bacteria can become more active as warmer temperatures prevail. A "balancing act" along these terms could help explain the lack of a long-term rise in methane despite the continuing thaw of permafrost.
Researchers are also moving on from methane to study carbon dioxide emissions from thawing permafrost, as a spike there could also go a long ways to explaining the endless warming cycle that has been observed in recent years.
With more than 1,000 gigatons (1,000 billion tons) of carbon estimated to be currently stored in Arctic permafrost, determining what form it takes when the permafrost melts is of utmost importance to those studying climate change. Because the permafrost is melting.