Under the ground across Canada and Siberia, permafrost is thawing and could release huge amounts of carbon dioxide and methane.
The release could be sudden, researchers have warned, releasing vast amounts of the greenhouse gases at once.
The resulting ‘feedback’ could pose serious challenges in the battle against climate change - and could be worse than previously thought, according to researchers.
Climate change has affected Arctic regions at roughly double the rate elsewhere, a report in Nature Geoscience suggested.
The study says that previous projections of how much carbon could be released may be wrong, and instead, icy terrain may crumble at speed.
Merritt Turetsky, head of the Institute of Arctic and Alpine Research in Boulder, Colorado told AFP, "Although abrupt permafrost thawing will occur in less than 20 percent of frozen land, it increases permafrost carbon release projections by about 50 per cent.”
"Under all future warming scenarios, abrupt thaw leads to net carbon losses into the atmosphere.”
The report concludes that “models considering only gradual permafrost thaw are substantially underestimating carbon emissions from thawing permafrost”.
Previous research suggested that thawing permafrost in the Arctic could create a dangerous ‘feedback’ in global warming by releasing greenhouse gases - adding £54 trillion to the cost of global warming.
The figure, revealed in a Nature Research study, is due to the release of carbon dioxide and methane frozen in Arctic permafrost, which will amplify Earth’s warming.
The feedback mechanism (combined with the loss of heat-reflecting white ice) could increase global warming by 5%, reports suggested.
That would push the cost of global warming up to $70 trillion (£54 trillion) between now and 2300, according to the research published in Nature.
Researchers assessed frozen organic matter buried up to 10ft below the ice across the Arctic, and ran supercomputer simulations to assess the amounts released by different levels of warming.
‘It’s disheartening that we have this in front of us,’ said Dmitry Yumashev of Lancaster University.
‘Even at 1.5C to 2C, there are impacts and costs due to thawing permafrost. But they are considerably lower for these scenarios compared to business as usual.
‘We have the technology and policy instruments to limit the warming but we are not moving fast enough.’