Permafrost is Thawing Globally

Permafrost is thawing in different regions across the word. A new global assessment has found widespread permafrost degradation across the Arctic, Antarctica and high-mountain regions. These places show that the ground layer thaws each summer, becoming significantly deeper at many monitored sites. The study analysed field measurements of active-layer thickness from 156 monitoring sites between 2000 and 2024. It consists in one of the most extensive observational assessments of global permafrost change during the first quarter of the 21st century.

The active layer is the upper layer of ground above permafrost that freezes and thaws each year. As this layer becomes deeper, more previously frozen ground is exposed to seasonal thaw. This potentially contributes to greenhouse gas emissions, ecosystem changes, ground instability and other hazards. Active-layer thickness increased significantly at 55% of Arctic sites and 38% of Antarctic sites. Other significant increases were found in more than 90% of monitored sites in European mountains and high-elevation Asia. Significant increases were also observed at sites in South America.