Over four intensive days on 6-9 October 2025, more than 200 participants from around the globe came together for the Virtual Workshop Series on Stratospheric Aerosol Injection (SAI), hosted by the WCRP Lighthouse Activity- Research on Climate Intervention and the Core Activity Atmospheric Processes and their Role in Climate.
Featuring 52 speakers, the event provided a lively forum for in-depth discussions on SAI, a proposed climate intervention that would aim to reduce the impacts of global warming through the injection of reflective particles in the stratosphere. As this topic becomes more widely discussed, it is important that robust scientific discussions are had to better identify potential risks and impacts of SAI across different scenarios, to understand and reduce uncertainties in future projections using Earth System Models, and to address SAI science questions using small scale deployment that may not be answered by studying natural analogues only
The workshops explored a wide range of topics, from observational strategies and modeling of stratospheric aerosols to climatic, societal, and ecological impacts, as well as the ethical considerations of studying and testing SAI. Participants shared the latest research, debated potential risks and uncertainties, and considered strategies for robust monitoring and simulation of future scenarios.
By fostering an inclusive, international dialogue, the series emphasized collaboration across observational and modeling communities, aiming to advance our understanding of Earth system responses to climate interventions and inform evidence-based policy and governance.