GLOBAL MEAN TEMPERATURE AND SEA-LEVEL CONSEQUENCES OF GREENHOUSE-GAS CONCENTRATION STABILIZATION

The Intergovernmental Panel on Climate Change (IPCC) has defined a set of scenarios for future CO2 concentrations stabilizing at levels of 3 50 to 750 ppmv. Using models previously employed by IPCC, the implied global-mean temperature and sea level changes are calculated out to 25 00. While uncertainties are large, the results show that even with con certed efforts to stabilize concentrations of greenhouse gases, substa ntial temperature and sea level increases can be expected to occur ove r the next century. Increases ia sea level are likely to continue for many centuries after concentration stabilization because of the extrem ely long time scales associated with the deep ocean (which influences thermal expansion) and with the large ice sheets of Greenland and Anta rctica.