TORONTO: Vast amounts of carbon, about twice as much as contained in the atmosphere, is stored in the Arctic, according to a new study. The amount of carbon in frozen soils, sediments and river deltas raises new concerns over the role of the northern regions as future sources of greenhouse gases.
Carbon in permafrost is found largely in northern regions including Canada, Greenland, Mongolia, Russia, Scandinavia and the US.
"We now estimate the deposits contain over 1.5 trillion tonnes of frozen carbon, about twice as much carbon as contained in the atmosphere," said Charles Tarnocai, of Agriculture and Agri-Food, Canada and lead study author.
Pep Canadell, executive director of the Global Carbon Project at Australian Commonwealth Scientific and Research Organization (CSIRO), Australia, and study co-author says that the existence of these super-sized deposits of frozen carbon means that any thawing of permafrost due to global warming may lead to significant emissions of the greenhouse gases.
"Radioactive carbon dating shows that most of the carbon dioxide currently emitted by thawing soils in Alaska was formed and frozen thousands of years ago. The carbon dating demonstrates how easily carbon decomposes when soils thaw under warmer conditions," said Ted Schuur, professor at the University of Florida and co-author of the paper.
The authors point out the large uncertainties surrounding the extent to which permafrost carbon thawing could further accelerate climate change.
"Permafrost carbon is a bit of a wild card in the efforts to predict future climate change," said Canadell, according to a CSIRO release.
The results were published this week in the journal of Global Biogeochemical Cycles of the American Geophysical Union.
