From informal to formal governance of solar radiation management

There is growing interest in the potential for solar radiation management (SRM) to address rising global temperatures, both at global and regional levels. SRM schemes are highly controversial; their governance has come under close scrutiny from researchers and policymakers. Key challenges include how best to govern SRM to mitigate risk, promote social acceptability and encourage responsible research, development, and deployment. In the absence of formal targeted laws and policies, a proliferation of academic – and NGO-led voluntary principles have been proposed, to develop governance norms from the bottom up. In the past fifteen years, ten prominent governance proposals identified common principles, including: SRM to be governed as a public good; public consultation and research transparency; and impact assessment, monitoring and review. We systematically reviewed and categorized the principles in these governance proposals, demonstrating that there is a high level of commonality between the principles they contain. While more informal governance frameworks are currently being advocated and/or developed, we argue that further specificity in over-arching principles is not required because existing frameworks already provide policymakers with a basis for developing robust domestic instruments to govern SRM research and development. The priority now is to see these principles incorporated into more formal instruments, such as institutional research policies and domestic legislation, and adapted to local and national contexts. This next step is also necessary to evaluate how these principles operate in practice, especially in the event where SRM experiments are upscaled, and promote accountability and oversight.Formal domestic governance is needed for SRM research and development (R&D), as existing informal governance proposals lack specificity, oversight and enforcement.Existing informal proposals provide consistent expectations for SRM governance and can inform domestic law and/or institutional rules for SRM R&D, including overarching objectives, timing and form of governance, and procedural/operational principles.Domestic policymakers should implement these principles in law to promote accountability and oversight of SRM R&D, and shouldevaluate how these principles operate in practice.The way in which each nation implements these principles will vary and requires multistakeholder consultation, including with neighbouring states to account for diverse perspectives and priorities.