Impacts of Potential Solar Radiation Modification: Systematic Review Reveals Challenges and Opportunities

Zachary Decker , Lisa Moore, Brian Buma, Stavroula S. Sartzetakis, Lisa Dilling

Solar radiation modification (SRM) is a proposed temporary intervention to limit global warming while mitigation efforts continue. Understanding its potential consequences for human and natural systems is essential for informed deliberations. We conducted a systematic review of the peer-reviewed literature on SRM impacts published through May 2024, identifying 289 studies, including 261 primary articles and 28 reviews. Studies on the potential impacts of SRM on human systems (9%) and ecosystems (25%) were infrequent. Further, primary literature is dominated (97%) by global models and thus the SRM impacts that are most reported reflect the variables available from global models, such as global mean temperature, global mean precipitation, sea ice and net or gross primary production. Those studies that did report impacts on human systems or ecosystems typically relied on chained modeling frameworks using uncertain regional-scale climate outputs. While studies relying on such frameworks are informative for identifying model sensitivities and parameterization challenges, their results remain highly uncertain. Despite this, model studies constitute an increasing majority of SRM research on human and natural systems. In contrast, empirical research using SRM-analogous events (e.g., volcanic eruptions) was rare and is declining in relative frequency. Analog studies have informed model development, revealed sensitivities rarely examined in global models, and reduced reliance on modeling’s regional-scale compounding uncertainties. Our results indicate that a more integrated research strategy, one that combines climate modeling with analog studies and intermediate-scale modeling approaches, is needed to improve fidelity in assessing potential SRM impacts on human and natural systems.