While the possible instability of the West Antarctic ice sheet has been widely recognized for some time as a potential source of sea-level rise in an enhanced greenhouse warming, the stability of the East Antarctic ice sheet has only recently become the subject of such a conjecture. We approach an aspect of this issue using a numerical experiment with an atmospheric general circulation model (GCM) coupled to a 3-dimensional ice-sheet model. Response of the ice sheet model to the external forcing generated by an atmospheric GCM due to doubling the CO2 concentration does not show any appreciable changes in the horizontal extent of the ice sheet due to normal creep and topographic instabilities, suggesting that an Antarctic collapse resulting from these factors is unlikely. The mechanics of basal sliding, non-isothermal effects, and ice shelves are as yet too poorly understood to make quantitative estimates of possible instabilities due to these processes. ¿ American Geophysical Union 1995