Greenhouse gas emissions from thawing permafrost could result in an additional US$43 trillion in economic impacts by the end of the twenty-second century, reports a paper published online in Nature Climate Change. These extra impacts justify the need for urgent action to reduce emissions from thawing permafrost.

Permafrost soils, which contain about 1,700 gigatonnes of carbon in the form of frozen organic matter, have begun to thaw in response to Arctic warming over the past few decades. Carbon dioxide and methane are released into the atmosphere as the permafrost degrades, thereby amplifying the effects of emissions from human activity. The economic impacts of these extra emissions have not yet been investigated.

Chris Hope and Kevin Schaefer now model the range of possible global economic impacts of permafrost emissions under various IPCC scenarios. Under the A1B scenario, which assumes rapid economic growth and projects increased anthropogenic emissions until the atmospheric concentration of CO2 reaches about 700 parts per million in 2100, the authors assume zero anthropogenic emissions after 2100. They find that the total, cumulative permafrost emissions raise the economic impacts of climate change by 2200 from US$326 trillion to US$369 trillion, an increase of 13%. This suggests that policies aimed at reducing emissions from thawing permafrost as soon as possible could substantially reduce the economic impacts of climate change.