SRM's socioeconomic cost - Bronsther & Xu

Jacob Bronsther & Yangyang Xu discuss their recent paper on the socioeconomic costs of Solar Radiation Modification. While SRM’s direct technical costs appear modest (~$18B/°C cooling), the authors argue that its broader costs are far greater. They estimate that Stratospheric Aerosol Injection could generate between $0 and $809 billion annually in side-effect harms, with potentially higher figures for Marine Cloud Brightening. The conversation also explores SRM’s reliance on unprecedented global cooperation, the political risks of weather accountability, and the dangers of termination, which could impose major financial costs. They contrast these challenges with large-scale Carbon Dioxide Removal, noting that although CDR entails immense technical expenses, it avoids some of SRM’s political and termination risks. The discussion highlights the complexity of weighing the full spectrum of costs and benefits when evaluating climate-engineering strategies.Paper: Bronsther, J., & Xu, Y. (2025). The social costs of solar radiation management. npj Climate Action, 4(1), 69. https://doi.org/10.1038/s44168-025-00273-y