Permafrost is soil that has remained frozen for at least two years, but some of it is ancient — frozen for tens of thousands of years or more. Since massive amounts of organic material is trapped in permafrost worldwide, scientists fear that as it thaws it will release all of that stored carbon in the form of greenhouse gases.
This sort of process is known as a feedback loop. As global warming thaws permafrost, more greenhouse gases get released, which speeds up global warming, which thaws even more permafrost... and so on. It's bad news, and figuring out how quickly this process is occurring is important for making accurate climate change projections.
A 2019 study from University of Guelph researchers in Ontario found that permafrost is melting much more quickly than previously thought, which means more greenhouse gases are being released into the air. That also means more changes to the landscape since permafrost covers about a quarter of the land in the Northern Hemisphere.
“We are watching this sleeping giant wake up right in front of our eyes,” said lead researcher, university ecologist Merrit Turetsky in a statement.