This essay investigates the fit between solar radiation modification (SRM) and climate politics. Researchers, activists, and politicians often present SRM technologies as “radical.” According to this frame, SRM comes into view as a last-ditch effort to avoid climate emergencies. Such a rationale may be applicable to the scientists researching the potential of SRM, yet it only partially accounts for political and policy interest in SRM. In this contribution, I argue that there is an increasingly tight fit between the promise of SRM technologies and the global regime of climate politics. Within this regime, SRM may not be a radical option but is more of a logical extension of current rationales. I argue that SRM corresponds to tightly controlled discursive rules within which climate politics operates, leading to a shifting narrative on the feasibility, desirability, and necessity of SRM. The ethical implications of this tight fit are threefold. First, it implies that SRM might be an instrument of mitigation deterrence, implicitly as much as explicitly. Second, ethical responsibility and political value debates are at risk of becoming invisible once SRM becomes embedded in the prevailing regime. Third, SRM use might become inevitable, despite the good intentions of most people involved.

Recent years have seen increasing calls by a few scientists, largely from the Global North, to explore “solar geoengineering,” a set of speculative technologies that would reflect parts of incoming sunlight back into space and, if deployed at planetary scale, have an average cooling effect. Numerous concerns about the development of such speculative technologies include the many ecological risks and uncertainties as well as unresolved questions of global governance and global justice. This essay starts with the premise that solar geoengineering at planetary scale is unlikely to be governable in a globally inclusive and just manner. Thus, the ethically sound approach is to pursue governance that leads to the nonuse of planetary solar geoengineering. Yet is such a prohibitory agreement feasible, in the face of possible opposition by a few powerful states and other interests? Drawing on social science research and a host of existing transnational and international governance arrangements, this essay offers three illustrative pathways through which a nonuse norm for solar geoengineering could emerge and become diffused and institutionalized in global politics: (1) civil society-led transnational approaches; (2) regionally led state and civil society hybrid approaches; and (3) like-minded or “Schengen-style” club initiatives led by states.

This essay argues that the possibility of governing the development and deployment of solar radiation modification (SRM) technology is predicated on the assumption of a liberal international order informed by an understanding of state responsibility. However, this order is experiencing a period of disruption that has placed stress on extant and emerging global governance regimes and brought the assumption of their efficacy and viability into doubt. In addition, international order and existing global governance of technologies with planetary implications, such as nuclear weapons, have become the increasing focus of criticism because of the inequities embedded within these institutions, calling into question how much of a roadmap the existing governance architecture can or should provide. Leading developers and proponents of SRM have advocated for cooperative, transparent, science-led governance, which parallels the language of early nuclear governance advocates, but there is a long history of displacement and disruption of indigenous and otherwise marginalized populations without meaningful consultation to accommodate technological developments driven by powerful, industrialized countries. Developing an ethical framework for the governance of SRM will be challenging under the current conditions of increasing tensions and confrontations between major powers that may have non–climate-related interests in developing and controlling SRM technology. This essay will reflect on whether the current international order, stable or unstable, is capable of producing ethical governance of SRM.