A growing number of scientists and policymakers are pointing to a potential role for so-called climate engineering technologies in humanity’s response to climate change. These potentially transformative technologies include approaches that could reflect some small amount of sunlight back into space, cooling the Earth, and those that could draw greenhouse gases out of the atmosphere. Certain applications of climate engineering technologies could be beneficial. Climate engineering technologies also, though, present significant environmental, social, and political risks. Policymakers and others concerned with responding to climate change need credible scenarios and models that integrate climate engineering technologies if they are to make reasoned and informed decisions about the future. There is, however, a critical knowledge gap. Existing climate models consider climate engineering technologies in far too limited a fashion. This project responds to that gap. The project will produce the first set of scenarios and models that integrate both the social and environmental aspects of climate engineering technologies and that, in addition, help policymakers understand potential interactions between climate engineering technologies and existing mitigation efforts. The result will be a new set of powerful tools to guide policy decisions around climate engineering technologies, as well as guidance for the inclusion of socio-environmental dynamics into climate scenarios and models more generally.