The sea level has been rising at a rate of around 1.8 mm per year for the past century, mainly as a result of human-induced global warming. This rate is increasing; measurements from the period 1993–2000 indicated a mean rate of 3.1 mm/year. Global warming will continue to increase sea level over at least the coming century. The contribution from thermal expansion is well understood; substantial changes to the rate and magnitude of increase are largely dependent on how rapidly ice caps disintegrate with increasing temperatures—which is very difficult to model. The thermal expansion of sea water is currently the dominant contributor to sea level rise, and to the predicted rise over the next century, which is 90 to 880 mm (with a central value of 480 mm). Only if glacial melt substantially i