This paper surveys the issues involved in cooperation among nations to slow down the climate change which many believe the extensive consumption of fossil fuels and other aspects of modern life are generating, through emissions of greenhouse gases, especially carbon dioxide. It addresses the possible social and economic impacts of global warming, the elements involved in evaluating the pros and cons of taking steps to reduce those impacts, and the issues involved in engaging most of the world's states, with diverse economic circumstances, in a cooperative endeavor to reduce greenhouse gas emissions. It expresses doubts about the efficacy of a global approach based on national emission targets, such as those set by the 1997 Kyoto Protocol, and favors instead mutually agreed actions, focused on a common emissions tax.