Understanding what's happening in Earth's atmosphere in terms of heating, cooling, and the factors playing into that is a major part of tackling the climate crisis. Scientists have discovered a new source of nitrous oxide, a greenhouse gas that causes our planet to warm up.
The Yedoma type of permafrost is rich in organic material and stretches over a million square kilometers in the Northern Hemisphere.
The researchers found that the amount of nitrous oxide that would normally be expected from the thaw of the permafrost in northeast Siberia was between 10 and 100 times higher than it would normally be.
The high ice content of Yedoma makes it vulnerable for abrupt thaw and ground collapse, which can cause rapid mobilization of soil carbon and nitrogen stocks after thaw, according to the researchers.
The Yedoma exposure is high along the coastal zone of the Arctic Shelf because of the thaw of the Yedoma permafrost.
The soil has microbes that produce nitrous oxide. It's almost 300 times stronger than carbon dioxide as a warming agent over a 100 year period, and it's not as abundant as carbon dioxide and methane in the atmosphere.
The Yedoma's high N2O output is due to certain processes in the area that are drying and stabilizing after thaw. Over the course of less than a decade, nitrous oxide emissions from the melting permafrost increase.
As the soil thaws out, the N2O-Producing microbe population grows while the N2O-Consuming microbe population shrinks. More nitrous oxide is being pushed out because of that change in the nitrogen cycle.
"While it is important to remember that such high N2O emissions will occur in particular settings, these conditions are not limited to the retrogressive thaw slumps along rivers studied here," the researchers wrote.
Similar disturbed nitrogen-rich Yedoma with successional plant cover is widespread along thermokarst lake shores, coasts, slopes, and valleys across the Yedoma region.
The high ice content of the Yedoma exposed to the surface is likely to be found in a lot of other places.
Nitrogen trapped inside the permafrost isn't a particular worry for researchers because nitrogen cycling in the cold soil is very slow.
The study shows that more research is needed on how much nitrogen can be stored in the cold landscapes, how quickly it can be released, and what the effects could be on global warming.
The release of nitrogen from thawing permafrost can improve the availability of nitrogen in the environment, which in addition to the direct climatic feedback in the form of nitrous oxide, may have important consequences on carbon fixation by plants and water systems.
The research has been published.
