With a variable or changing climate, short-term energy imbalances between the active layer and permafrost result in transient departures from the equilibrium condition. This study examines the effects of such variability on an equilibrium permafrost
-climate model, the temperature at the top of permafrost (TTOP) model. In the presence of a warming trend, the equilibrium model prediction tracked the changing top-of-permafrost temperature until permafrost temperatures reached 0°C, after which