Billions of tons of frozen leaves and roots that have lain undisturbed for thousands of years in the permanently frozen ground of the northern hemisphere are thawing out, with potentially catastrophic implications for climate change, the researchers said.
A study into the speed at which the permafrost is melting suggests that the tipping point will occur between 2020 and 2030 and will mark the point at which the Arctic turns from being a net "sink" for carbon dioxide into an overall source that will accelerate global warming, they said.
The study is the first global investigation of what will happen in a warmer world to the huge amounts of frozen plant matter that has remained undegraded in the soil since it was incorporated into the permafrost about 30,000 years ago.
It also found that by 2200 about two-thirds of the Earth's permafrost will have melted, releasing an estimated 190 billion tons of carbon dioxide and methane into the air – about half of all the fossil fuel emissions of greenhouse gases since the start of the industrial revolution. More >>>
Location: Cayman Islands