Cycles of ice-sheet loading during glacial periods of the Earth's history induce horizontal velocities in the uppermost mantle which may be of the same order as those of continental drift. Given some non-linear mechanism which ensures preferential movement in the one direction, a climatically induced component of continental drift is therefore possible during glacial periods such as the Quaternary. If so, one might expect that component of drift is intermittent on time-scales between 20 and 100 ka, i.e. on time-scales of observed ice-volume variations which, at least over the last 700 ka, have been related to the Earth's orbital variations.