Linking Solar Geoengineering and Emissions Reductions: Strategically Resolving an International Climate Change Policy Dilemma

Abstract

Solar geoengineering may be able to significantly reduce climate-change risks, but raises sharp controversy, the leading cause of which is the concern that its research, development, or use might inappropriately displace efforts to cut greenhouse-gas emissions (“mitigation”). Although well-crafted policies could in principle manage such possible mitigation displacement, describing how they could do so effectively and feasibly has proven elusive. A possible response would be to strategically link the international policies of mitigation and solar geoengineering. Here we explore and expand on this idea, including by disaggregating states based on their relevant characteristics (including willingness to increase mitigation, willingness to implement solar geoengineering contrary to any international consensus, and their desired intensity of solar geoengineering), the incentives that various policy linkages could foster, and considering the processes of developing linkages. We explore potential linkage of mitigation with the research and development of solar geoengineering, with decision-making regarding whether to deploy; and with that regarding how to deploy. These potential linkages are assessed on whether they could effectively reduce mitigation displacement (if not increase mitigation), appear feasible, and would not be inconsistent with widely-held norms. In the linkage mechanism with the greatest apparent potential, one or more states would proclaim their right to deploy solar geoengineering if they meet their own mitigation targets and the rest of the world insufficiently mitigates. We identify possible challenges, including legitimacy, credibility, optimal size, relations among nonmembers, mitigation targets, and complexity, none of which seem insurmountable.