Permafrost thaws worldwide as active layers deepen from 2000 to 2024

An international study led by researchers at George Washington University has found clear global evidence that permafrost, the permanently frozen ground found in the Arctic and Antarctic, is thawing. Using data from more than two decades of observations at 156 monitoring sites across the Arctic, Antarctic, and high-mountain regions, the study shows that the thickness of the active layer, the uppermost layer that thaws and refreezes annually, has increased.

This confirms that permafrost degradation has accelerated globally between 2000 and 2024. Permafrost, which covers nearly 15% of the Northern Hemisphere's land surface, contains around 70% of the organic carbon stored in permafrost soils. As the ground thaws, this carbon is released into the atmosphere as greenhouse gases, accelerating climate change.

The study, published in Communications Earth & Environment, marks the first global assessment of long-term active layer monitoring data. It highlights that the issue is not isolated to specific hotspots but is a widespread global phenomenon impacting infrastructure stability and contributing to greenhouse-gas emissions.