The Intergovernmental Panel on Climate Change (IPCC) has defined a set of scenarios for future CO2 concentrations stabilizing at levels of 350 to 750 ppmv. Using models previously employed by IPCC, the implied global-mean temperature and sea level changes are calculated out to 2500. While uncertainties are large, the results show that even with concerted efforts to stabilize concentrations of greenhouse gases, substantial temperature and sea level increases can be expected to occur over the next century. Increases in sea level are likely to continue for many centuries after concentration stabilization because of the extremely long time scales associated with the deep ocean (which influences thermal expansion) and with the large ice sheets of Greenland and Antarctica. ¿ American Geophysical Union 1995