Carbon-rich Arctic soils are thawing, and that has the potential to undermine global climate policies, The Washington Post reports.
Permafrost is basically soil that stays frozen all year long. Because it never melts, it holds thousands of years’ worth of dead plants and their carbon. About 24 percent of land in the Northern Hemisphere is covered with the stuff.
Northern permafrost—ground frozen year-round—may contain more than twice as much carbon as there is in the atmosphere. And at least some of it could already be escaping to the atmosphere—as carbon dioxide or methane—as the Arctic warms.
According to the National Academy of Sciences
, the amount of carbon stored in northern permafrost (1,800 billion tons) is more than double the amount that’s currently in the atmosphere (800 billion tons).
Its unclear how much of that carbon will ever emerge, but delaying agreements to cut global emissions could accelerate the problem, scientists say. Once the ground thaws, they point out, it’ll be impossible to refreeze it.
Kevin Schaefer, a scientist with the National Snow and Ice Data Center at the University of Colorado in Boulder, said that the latest IPCC climate projections didn’t account for thawing permafrost because this area of research is relatively new.
Still, early estimates show that permafrost could be emitting an average of 160 billion tons of carbon per year by the end of the century. Which would be bad since, according to the National Academy of Sciences, we need to keep atmospheric carbon below 1,100 billion tons if we want to limit warming to 2 degrees Celsius.
After shrinking 35 per cent over several decades, the low point reached in Arctic ice cover each year appears to have stabilized. This is despite a record low maximum ice extent this winter and new research that shows the annual melt was beginning days earlier each decade.
A survey of threatened Arctic mammals highlights melting sea ice as a prime threat to eleven keystone species, meaning that efforts to conserve them may be doomed to failure unless we also tackle the causes of climate change.