We’ve talked about permafrost before. It is the frozen soil, rock, or sediment piled up in the Arctic that has been there at least for two years but, for the most part, for millennia or even over a million years. Permafrost holds the carbon-filled remains of vegetation and animals that froze before they could start decomposing. Estimates are that there are nearly 2,000 billion tons of carbon trapped in Arctic permafrost. To put that in perspective, annual global carbon emissions are less than 40 billion tons.
Keeping all that carbon frozen plays a critical role in preventing the planet from rapidly heating. The ongoing warming of the Arctic is causing the subsurface ground to thaw and release long-held carbon to the atmosphere.
Scientists from Europe and the US are working together to better track permafrost carbon dynamics. They are trying to understand the mechanisms that lead to abrupt thaws in the permafrost that have taken place in some locations. These rapid thawing events are not well understood. Researchers are also studying the effects of the increasingly frequent wildfires in the Arctic on the permafrost.
Researchers are using satellites to better understand the effects climate change is having on the Arctic environment and how these changes, in turn, are adding to the climate crisis. Permafrost cannot be directly observed from space, so that its presence has to be inferred from measurements like land-surface temperature and soil moisture readings. Terrestrial observations are also necessary for understanding how greenhouse gases – both CO2 and methane – are being emitted from the Arctic.
Thawing permafrost is a ticking timebomb for the environment that demands the growing attention of the scientific community.
Photo, posted January 24, 2014, courtesy of Brandt Meixell / USGS via Flickr.