Permafrost Thermal Responses to Asymmetrical Climate Changes: An Integrated Perspective

Abstract

Abstract An integrated perspective of permafrost dynamics is a key bridge between permafrost and global socioeconomic assessments. This study investigated the air temperature changes (1976–2020) among permafrost zones in the Northern Hemisphere and their potential impacts on permafrost. We found that continuous permafrost zones experienced faster warming than other regions. The freezing index declined 724°C‐day while the thawing index increased only 166°C‐day over continuous permafrost zones. This may explain why the temperature of cold permafrost increased rapidly but the active layer thickness changed only slightly. Assuming permafrost carbon emissions arise only from thaw processes may miss a significant source of the emissions. An often‐neglected factor is that cold‐season snow amplifies permafrost warming caused by summertime air temperature changes. Due to seasonal effects, using mean‐annual air temperature to depict permafrost evolution under integrated assessment frameworks may lead to significant errors.