Climate engineering can, if appropriately governed within a coherent overall climate change strategy, reduce risks beyond what mitigation and adaptation can achieve alone, and is probably essential to achieve the Paris Agreement temperature targets. Climate engineering also poses significant new risks, and needs expanded research and scrutiny in climate assessments.
Both types of climate engineering — carbon removal and solar geoengineering — also pose significant challenges to governance. The governance challenges of solar methods are particularly novel and severe, and urgently need international examination and consultation, both to learn how (and whether) climate engineering can deliver societal and ecosystem benefits, and to prepare for the likelihood that some states, facing mounting climate change impacts, will pursue climate engineering, and the international system will have to respond.
The needed international dialogue on geoengineering governance will have broad international participation; engage high-level expertise in international policy and institutions; draw closely on parallel advances in scientific knowledge and technical capability, while keeping governance the central focus; and facilitate open, exploratory investigations of governance needs and potential responses, rather than pursue specific decisions, at least in initial stages. Present institutions are not well equipped to support these needs.
A promising first step would be to establish a world commission on climate engineering or similar consultative body, with high-level political authorization, an appropriately broad mandate, adequate resources and wide participation.