Warmer climate conditions persisting for a period of many centuries could lead to the disappearance of the Greenland ice-sheet, with a related 7 m rise in sea-level. We address the question of whether the ice-sheet could be regenerated if pre-industrial climate conditions were re-established after its melting. We use the HadCM3 coupled atmosphere-ocean GCM to simulate the global and regional climate with preindustrial atmospheric greenhouse-gas composition and the Green-land ice-sheet removed. Two separate cases are considered. In one, the surface topography of Greenland is given by that of the bedrock currently buried under the ice-sheet. In the other, a readjustment to isostatic equilibrium of the unloaded orography is taken into account, giving higher elevations. In both cases, there is greater summer melting than in the current climate, leading to partially snow-free summers with much higher temperatures. On the long-term aver-age, there is no accumulation of snow. The implication of this result is that the removal of the Greenland ice-sheet due to a prolonged climatic warming would not be reversible.
Helmholtz Research Programs > MARCOPOLI (2004-2008) > MAR1-Decadal Variability and Global Change