Regional Welfare Impacts from Options for Limiting Global Average Temperature

Abstract Extrapolation of historical trends in anthropogenic atmospheric carbon dioxide emissions is compared to results with new policy options. One approach is to multiply historical extrapolation of global emissions by a factor with a decline from 1 to a smaller multiple, e.g. on a timescale of about 30 years. Another allows for solar radiation management via anthropogenic stratospheric sulfur injection by one or more of sixteen geographic regions, in order to limit global average temperature to a chosen target level. An economic measure of impacts on human welfare is compared for different versions of these two approaches. That measure is time-integrated discounted utility of per capita consumption. That measure is computed with and without empathy, which involves geographical regions counting part of others’ welfare as part of their own. Inter-regional fund transfers that cover all or part of a region’s expenditures used for limiting carbon emissions can be used to encourage broader inter-regional cooperation. These exercises pose interesting questions about how choices will ultimately be made between use of one or both of carbon emissions limitations and solar radiation management.