Climate Change Tracker: The risks of a melting Arctic permafrost

According to the US National Oceanic and Atmospheric Administration, the world set a new temperature record last July—it was the hottest month since record-keeping began in 1880. It was almost 1 degree Celsius higher than the 20th century average. That month, the Arctic too recorded its highest summer temperature, with the Swedish village of Markusvinsa recording 34.8 degrees Celsius. In November, the North Pole recorded a temperature of 1.2 degrees Celsius, when it should have been about -20 degrees Celsius. The Arctic is warming twice as fast as the global average and this will lead to new risks.

With the Arctic permafrost thawing at an alarming rate, one big worry is about what might bubble to the surface, after being encased in ice for hundreds of thousands of years. Take, for example, buried carbon dioxide and methane. The current global carbon budget doesn’t account for Arctic GHG (greenhouse gas) emissions, and according to the Intergovernmental Panel on Climate Change (IPCC), the Arctic and boreal permafrost holds up to 1,600 gigatonnes of organic carbon, almost twice the amount in the earth’s atmosphere. And, depending on future emission scenarios, 24-69% of the Arctic permafrost could be gone by 2100.

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As global heating continues apace, the way the big thaw is proceeding is changing too. Researchers at US space agency Nasa have flagged millions of methane hot spots all over the Arctic. Arctic lakes, called thermokarsts, are releasing methane buried deep under the frozen soil, which is causing the surrounding permafrost to melt even further.

While methane, an even deadlier greenhouse gas than CO2, has a shorter atmospheric life than CO2, it is more efficient at trapping heat, thus precipitating even greater rates of global heating—84 times more over a 20-year period. A critical mass of methane in the atmosphere can cause a global heating spiral, and it’s starting to leak out of the Arctic.

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