| Greenhouse gas emissions by human activities are expected to alter the heat balance of the earth, leading to significant warming of the earth's climate over the next several generations. From a resource use point of view, the upper atmosphere is a global commons. Each country is motivated to continue its own discharges without considering the damage of degradation, which is shared by all countries. Since property rights are not defined and a world government does not exist, global warming can only be avoided by voluntary cooperation among countries.; In this study, the world is divided into five regions. Making computations based on results of prior studies, abatement cost and benefit projections through 2100 are assembled and interpreted with respect to various levels of emission reduction. Mathematical expressions describing regional costs and benefits as a function of abatement strategy are developed.; Using these data and expressions, outcomes of fully cooperative solutions are compared to fully non-cooperative behavior (Nash strategy). It is shown that full cooperation is feasible if China can be compensated for the losses it would incur. This modified cooperative solution is the most efficient (Pareto optimal), and would lead to an average emissions reduction of 21.7 percent over the 1990-2100 period. Most reduction would be accomplished by non-OECD countries, who are projected to have the lowest abatement costs.; But other objectives may be more important than efficiency. A notion of fairness between the industrial and developing worlds, for example, could lead to agreement on a uniform percentage reduction. This arrangement is tested in a partially cooperative model, where all countries except China participate. If OECD countries stabilize emissions at 1990 levels, and developing countries adopt a uniform 16 percent reduction, global emission could be reduced by 27.7 percent. This and several other policies are analyzed with respect to climate impact, global efficiency, and distribution of gains and losses among countries or regions.; The results show clearly that effective solutions to the problem of global climate change are possible, but can only be regarded as feasible after resolving difficult questions of fairness and political acceptability. |
