Progress Reports on International Studies of Climate Change Impacts

Global warming could raise sea level by expanding ocean water, melting mountain glaciers and causing ice sheets to melt or discharge into the ocean waters of Greenland and Antarctica. Previous estimates of a likely rise by the year 2100 generally range from 30 to 200cm increases. Based on the assumption that increased snowfall over Antarctica - whose contributions remains a source of great uncertainty - will more tha offset any increase in melting there, the IPCC Work Group 1 estimated that the rise in sea level would be 30 to 110cm by the year 2100. Nevertheless, because of the practical difficulty of assessing impacts of a rise of less than one meter, IPCC Work Group 2 focused on the implications of a one-meter rise. This report follows that convention.