The inability of the international community so far to materially affect the trend in anthropogenic emissions demonstrates the urgent need to formulate an effective response to the threat of climate change. We offer a detailed picture—disaggregated by country—of the social changes necessary to reduce the rate and risk of climate change. We recognize two broad types of social change—changes that either reduce energy intensity or reduce carbon intensity. Through the Kaya identity, we demonstrate that the current business as usual scenario expects a carbon concentration of approximately 660 ppm by 2100, which corresponds to a potentially catastrophic 4.9°C temperature increase. Through a low-carbon-emissions scenario built on principles used by the Center for Energy and Environmental Policy over the past 20 years, we show the social changes required to realize a hopefully sustainable 450 ppm carbon dioxide concentration with an equitable 3.3 ton/capita annual carbon emissions budget. We conclude that all members of the international community—even Non-Annex 1 members—face major and immediate challenges in any common effort to address climate change. Our analysis supports exploratory efforts for the formulation of menus of social change. As a preliminary basis for identifying such menus of social change, we suggest priority be given to bottom-up discourses that position the principles of sustainability, equity, development autonomy, and justice at the core of decision-making.