A worldwide change of sea level, which may be caused by the growth and decay of ice sheets, by the deposition of sediment, or by a change in the volume of the oceanic basins. ‘It is commonly assumed that melting of polar ice sheets induced, for example, by climate warming yields a nearly eustatic trend in sea level, although it has long been recognized that self-gravitation and loading effects will lead to significant departures from eustasy’ (Mitrovica et al. (2001) Geophys. J. Int. 147, 3).