IMPACT OF ANTHROPOGENIC WARMING ON PERMAFROST CONDITIONS IN MODELS: VEGETATION EFFECT

O. A. Anisimov and M. A. Belolutskaya

Changes in permafrost characteristics present one of the most important consequences of warming in the northern regions. According to calculations, only the air temperature rise expected by the mid-21st century can result in a 15—30% reduction in permafrost area in the Northern Hemisphere. The depth of seasonal thawing can, on average, increase by 25%, and in individual regions by more than 50%. The model calculations, taking into account possible changes in the vegetation cover, indicate that in the near one or two decades the growth of the moss and lichen biomass, which has a high heat-insulation capacity, can hinder permafrost degradation, compensating the warming effect. Further on, mosses and lichens can be replaced by herbaceous, shrubby, and woody plants. This will accelerate the degradation of permafrost, and, as a result, by the late 21st century its area can be reduced by more than 50% compared to the present.

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