September 22, 2015
Climate change could cost trillions more in damages, because of thawing Arctic permafrost. As global warming thaws perpetually frozen Arctic land called permafrost (pictured), the greenhouse gases trapped within will escape, ramping up climate change’s economic toll by trillions of dollars, a new study finds. To make the calculations, researchers first determined how much carbon dioxide and methane the permafrost would release as the world warms. They used a model that estimates how climate factors like temperature affect absorption and release of these gases by land, plants, and microbes.
They then fed the results from that model into a different model that estimates economic damages based on future greenhouse gas emissions. The model assumed that human activities by themselves would boost carbon dioxide levels 75% from today to 2100. Total damages without the permafrost emissions would be $326 trillion globally, the researchers found. With permafrost-related emissions included, however, additional damages ranged from $3 trillion to $166 trillion, depending on how much human emissions warmed the Arctic, the team reports online today in Nature Climate Change; the average value was $43 trillion. Aggressive cuts in human emissions could reduce that average price tag to around $6 trillion, the researchers suggest.