Solar Climate Intervention

Solar climate intervention (SCI) refers to deliberate large-scale modifications of the climate system designed to offset some impacts of global warming. Among proposed SCI strategies, stratospheric aerosol injection (SAI) has received particular attention. Analogous to natural volcano eruptions, SAI would introduce reflective aerosols into the stratosphere, reducing incoming solar radiation and partially counteracting greenhouse warming.

Much of what we know about SAI has come from coordinated modeling efforts, including GeoMIP, GLENS, and ARISE, which have significantly advanced understanding of the large-scale climate response. However, the potential effects of SAI on hazardous convective weather remain poorly understood. Coarse-resolution global climate models cannot fully represent the fine-scale processes—such as convective updrafts, mesoscale organization, and storm dynamics—that govern severe weather.

Build on previous Pseudo-Global Warming (PGW) framework, we develop the similar Pseudo-SAI with regional convection permitting regional model. This framework enable physically consistent assessment of how solar climate intervention could influence high-impact U.S. convective weather.

Scientific Questions

How would SAI modify the large-scale environmental conditions that favor severe convective storms?
In what ways might SAI alter the frequency, intensity, and structural characteristics of convective storms?
How large is the uncertainty arising from internal variability and differing forcing scenarios in shaping future convective-storm environments?

Recent Findings

To assess how solar climate intervention (SCI) may influence future U.S. convective storms, we developed a new high-resolution framework that links CESM global climate projections with a 4-km convection-permitting WRF simulation of the March–August 2011 convective season. Three simulations were performed: a control run driven by ERA5, a Pseudo-Global-Warming (PGW) run representing a warmer climate without intervention, and a Pseudo-SAI (PSAI) run representing a climate with stratospheric aerosol injection. Climate perturbations applied to PGW and PSAI boundary conditions were derived from ensemble-mean differences between baseline and future CESM simulations from GLENS and ARISE, with PSAI additionally incorporating an aerosol-optical-depth perturbation. This design provides a physically consistent bridge between global and regional scales, and early results show that warming increases deep convection and extreme precipitation across the Eastern U.S., while SCI dampens these increases, indicating potential moderation of storm-related hazards.

Changes in the number of days with a severe thunderstorm environment (NDSEV) in the ARISE SSP2-4.5 projection and SAI simulations using CESM2-WACCM6. (a) Global land (50°S–50°N) mean NDSEV anomaly time series. Gray curves represent individual SSP2-4.5 members; thick black curve is the ensemble mean. Light green curves represent individual SAI members; thick green curve is the ensemble mean. (b) Spatial patterns of NDSEV anomalies for SSP2-4.5 (top) and SAI (bottom), averaged over 2060–2069. Adopted from Sun et al. (2025). — Changes in the number of days with a severe thunderstorm environment (NDSEV) in the ARISE SSP2-4.5 projection and SAI simulations using CESM2-WACCM6. (a) Global land (50°S–50°N) mean NDSEV anomaly time series. Gray curves represent individual SSP2-4.5 members; thick black curve is the ensemble mean. Light green curves represent individual SAI members; thick green curve is the ensemble mean. (b) Spatial patterns of NDSEV anomalies for SSP2-4.5 (top) and SAI (bottom), averaged over 2060–2069. Adopted from *Sun et al. (2025)*.

Impacts of SAI on U.S. convective environments (Glade et al. 2023)
Future projections of the 2011 super tornado outbreak under global warming and SAI (Summers et al. 2025)
Machine learning methods for SAI detection (Barnes et al. 2022)

On-going Work

Assessing the SAI impact on U.S. billion-dollar disasters

References

Barnes, E., J. Hurrell, L. Sun, 2022: Detecting changes in global extremes under the GLENS-SAI climate intervention strategy, Geophys. Res. Lett., 49, e2022GL100198. [Link].
Glade, I., J. Hurrell, L. Sun, K. Rasmussen, 2023: Assessing the impact of stratospheric aerosol injection on U.S. convective weather environments, Earth’s Future, 11, e2023EF004041. [Link].
Summers, B., K. Rasmussen, J. W. Hurrell, L. Sun, and H. Yu, 2025: Future Projections of the 2011 Super Tornado Outbreak Under Global Warming and Stratospheric Aerosol Injection, Earth’s Future, manuscript nearly ready for submission.
Sun, L., J. Hurrell, K. Rasmussen, B. Kravitz, B. Summers, 2025: Assessing the Impact of Solar Climate Intervention on Future U.S. Weather Using a Convection-Permitting Model. Geosci. Model Dev., in review. [Preprint].

Learn More

See additional details in the Publications section.