The Permafrost Thaw Energy Sink: Latent Heat as a Term in the Surface Energy Budget

Thawing ground ice absorbs latent heat. Complete thaw of near-surface (0-3 m) ground ice would absorb 1.2772e+21 to 4.1880e+21 J, equal to 0.088 to 0.289 of one year of Earth's current energy imbalance (0.90 W/m2 global mean). The present-day net sink from observed active-layer deepening is only 0.00097 to 0.01553 W/m2 over the permafrost region (central 0.01165 W/m2) - a rounding error against regional surface fluxes of order 100 W/m2, although the gross seasonal term is a real few W/m2. This is heat accounting only; no carbon feedback is computed. AI use is disclosed: this paper was prepared with the assistance of Dave, an AI system, under the author's direction.