An international study led by researchers at the George Washington University indicates clear global evidence that permafrost is thawing across much of the planet. Using more than two decades of field observations from 156 monitoring sites across the Arctic, Antarctic and high-mountain regions, the study found increases in the thickness of the active layer, the uppermost layer above permafrost that thaws and refreezes each year. The findings confirm that permafrost degradation accelerated globally between 2000 and 2024.