Headline: Emerging risk governance for stratospheric aerosol injection as a climate management technology

Stratospheric aerosol injection (SAI) as a solar radiation management (SRM) technology may provide a cost-effective means of avoiding some of the worst impacts of climate change, being perhaps orders of magnitude less expensive than greenhouse gas emissions mitigation. At the same time, SAI technologies have deeply uncertain economic and environmental impacts and complex ethical, legal, political, and international relations ramifications. Robust governance strategies are needed to manage the many potential benefits, risks, and uncertainties related to SAI. This perspective reviews the International Risk Governance Council (IRGC)’s guidelines for emerging risk governance (ERG) as an approach for responsible consideration of SAI, given the IRGC’s experience in governing other more conventional risks. We examine how the five steps of the IRGC’s ERG guidelines would address the complex, uncertain, and ambiguous risks presented by SAI. Diverse risks are identified in Step 1, scenarios to amplify or dissipate the risks are identified in Step 2, and applicable risk management options identified in Step 3. Steps 4 and 5 involve implementation and review by risk managers within an established organization. For full adoption and promulgation of the IRGC’s ERG guidelines, an international consortium or governing body (or set of bodies) should be tasked with governance and oversight. This Perspective provides a first step at reviewing the risk governance tasks that such a body would undertake and contributes to the growing literature on best practices for SRM governance.