On strategies for reducing greenhouse gas emissions

Equity is of fundamental concern in the quest for international cooperation to stabilize greenhouse gas concentrations by the reduction of emissions. By modeling the carbon cycle, we estimate the global CO2 emissions that wou ld be required to stabilize the atmospheric concentration of CO2 at levels ranging from 450 to 1,000 ppm. These are compared, on both an absolute and a per-capita basis, to scenarios for emissions from the developed and devel oping worlds generated by socio-economic models under the assumption that a ctions to mitigate greenhouse gas emissions are not taken. Need and equity have provided strong arguments for developing countries to request that the developed world takes the lead in controlling its emissions, while permitt ing the developing countries in the meantime to use primarily fossil fuels for their development. Even with major and early control of CO2 emissions b y the developed world, limiting concentration to 450 ppm implies that the d eveloping world also would need to control its emissions within decades, gi ven that we expect developing world emissions would otherwise double over t his time. Scenarios leading to CO2 concentrations of 550 ppm exhibit a redu ction of the developed world's per-capita emission by about 50% over the ne xt 50 years. Even for the higher stabilization levels considered, the devel oping world would not be able to use fossil fuels for their development in the manner that the developed world has used them.