SOURCE: Inside Climate News, Nature Climate Change

DATE: April 10, 2017

SNIP: More than 40 percent of the world’s permafrost—landscape covered in frozen soil—is at risk of thawing even if the world succeeds in limiting global warming to the international goal of 2 degrees Celsius, according to a new study.

Currently, permafrost covers about nearly 5.8 million square miles, and scientists found as much as 2.5 million square miles of that could thaw—about twice the area of Alaska, California and Texas combined—in a 2 degree Celsius scenario.

This new study did not estimate the greenhouse gas emissions that would be released from the thawing, or how those emissions could then spur greater rates of permafrost loss in a vicious cycle.

Instead, the international team of scientists focused on how warming air temperatures would affect the extent of permafrost.

They said their calculations suggest a much more extensive loss than previously thought.

“These results alarm me because they predict even greater permafrost loss than shown in the global models for the 2°C warming target,” Kevin Schaefer, a researcher at the National Snow and Ice Data Center, wrote in an email to InsideClimate News. “Even hitting the global 2°C warming target implies major impacts to people and infrastructure in the Arctic.”

“[W]e estimate a sensitivity of permafrost area loss to global mean warming at stabilization of million km2 °C−1 (1σ confidence), which is around 20% higher than previous studies,” say the study’s authors.