ECONOMIC AND ENVIRONMENTAL CHOICES IN THE STABILIZATION OF ATMOSPHERIC CO2 CONCENTRATIONS

THE ultimate goal of the UN Framework Convention on Climate Change is to achieve ''stabilization of greenhouse gas concentrations...at a lev el that would prevent dangerous anthropogenic interference,vith the cl imate system''. With the concentration targets yet to be determined, W orking Group I of the Intergovernmental Panel on Climate Change develo ped a set of illustrative pathways for stabilizing the atmospheric CO2 concentration at 350, 450, 550, 650 and 750 p.p.m.v. over the next fe w hundred years(1,2). But no attempt was made to determine whether the implied emissions might constitute a realistic transition away from t he current heavy dependence on fossil fuels. Here me devise new stabil ization profiles that explicitly (albeit qualitatively) incorporate co nsiderations of the global economic system, estimate the corresponding anthropogenic emissions requirements, and assess the significance of the profiles in terms of global-mean temperature and sea level changes . Our findings raise a number of important issues for those engaged in climate-change policy making, particularly with regard to the optimal timing of mitigation measures.