Over millennia, cold, wet conditions have slowed the breakdown of plant material in the Arctic, and large quantities of carbon and nitrogen have built up in permanently frozen ground — termed permafrost. The depths of permafrost can be astonishing – up to six and seven thousand feet. much of the Arctic is underlain by between 500 and a thousand feet of permafrost. Climate change threatens to thaw these frozen soils and release large quantities of methane and carbon dioxide to the atmosphere. Nitrous oxide — another potent greenhouse gas — can also be emitted from permafrost soils. It was originally through that nitrous oxide did not play a large part in greenhouse gas emissions from thawing permafrost -and it does not – at least upon the initial thawing. But a complex set of biogeochemical circumstances release a tremendous amount of nitrous oxide when the thawed permafrost is rewetted and allowed to decompose in an oxygen deprived environment: Like under water. These circumstances happen a lot more often that one might think. In fact, they happen as a rule rather than not. Thawing permafrost tends to create what are called thermokarst lakes – or thawed permafrost lakes. The organic matter in the permafrost, which has been from stored in the deep freeze for millennia to hundreds of millennia, can and readily does decompose underwater – in an oxygen deprived environment. Methane (35 times more potent that CO2, not 21 to 25 times more potent like we once understood) is the primary decomposition product, but nitrogen oxide production is twenty times greater than was initially understood. This change in magnitude is something that the authors say should be taken into consideration in climate modeling, because it can make a difference.