8. Permafrost and Thawing Landscapes
Permafrost, permanently frozen ground, covers approximately 2 million km² in the Arctic. Recent rapid thawing, driven by unusual warming, releases greenhouse gases like carbon dioxide and methane, accelerating climate change. This thawing also transforms landscapes, leading to the formation of thermokarst—land surface collapse between 0.5 and 5 meters. Such changes disrupt ecosystems, alter hydrology, and pose challenges to infrastructure. For a comprehensive overview, refer to the USGS’s publication on permafrost and climate change. (usgs.gov)