permafrost thaw

Syllable breakdown

Dictionary meaning

the process by which permanently frozen ground in Arctic and subarctic regions melts due to rising temperatures, releasing organic carbon stored for thousands of years; permafrost covers approximately a quarter of the Northern Hemisphere's land surface and stores an estimated 1.5 trillion tonnes of organic carbon; as it thaws, microbial decomposition releases carbon dioxide and methane into the atmosphere, creating a powerful positive feedback loop that accelerates climate warming beyond what human emissions alone would produce