Soil in Alaska’s permafrost regions is warming faster than anywhere else in the state, a new Washington State University study finds. The research, published in Frontiers in Climate, tracked air and soil temperatures from 1997 to 2023.

In the continuous permafrost region, air temperatures rose at 1.15 degrees Celsius per decade, while soil temperatures rose at 0.64 degrees per decade across depths of 5 to 120 centimetres. Warming was fastest in winter in the permafrost regions.

The study synthesized data from 43 weather stations. Snow cover plays a key role: deeper snow at lower latitudes insulates the ground and slows warming, while the high-latitude permafrost regions lack that buffer.

Lead author Erin Oliver said the work offers one of the most comprehensive looks at the relationship between air and soil temperatures in Alaska. Thawing permafrost is a concern because it releases carbon dioxide and methane, and it can undermine roads, buildings and other infrastructure built on frozen ground.