Climatic warming and permafrost

Permafrost is dependent upon the ambient temperature for its existence and is sensitive to climatic changes. Conduction heat transfer relations, with thawing and geothermal heat flow, are presented to predict the transient effects of surface temperature changes on the thermal state of permafrost. These relations can be used to examine past climate changes that could have resulted in the present permafrost thermal state. A number of phenomena may affect the thermal regime of permafrost, however some of these are not directly related to climate change, and may lead to spurious conclusions as to past climate warming. It is critical to understand the physical processes controlling the temperature and active layer of permafrost and to accurately relate them to past climate change. It is also possible to estimate the effect of climate change scenarios, manifested by air and surface temperature changes, on permafrost degradation. Realistic assessments require that the initial thermal regime of the permafrost be accurately known. Relatively small amounts of permafrost will disappear within 50-100 years due to the usual global alarming scenarios.