Solar geoengineering is often framed as a stopgap measure to decrease the magnitude, impacts, and injustice of climate change. However, the benefits or costs of geoengineering for human health are largely unknown. We project how geoengineering could impact malaria risk by comparing current transmission suitability and populations-at-risk under moderate and high greenhouse gas emissions scenarios (Representative Concentration Pathways 4.5 and 8.5) with and without geoengineering. We show that if geoengineering deployment cools the tropics, it could help protect high elevation populations in eastern Africa from malaria encroachment, but could increase transmission in lowland sub-Saharan Africa and southern Asia. Compared to extreme warming, we find that by 2070, geoengineering would nullify a projected reduction of nearly one billion people at risk of malaria. Our results indicate that geoengineering strategies designed to offset warming are not guaranteed to unilaterally improve health outcomes, and could produce regional trade-offs among Global South countries that are often excluded from geoengineering conversations.

These are large climate files derived from two climate model experiments that simulate the effects of geoengineering. They are processed or subsetted from original climate model outputs, and are only provided for study reproducibility.

We suggest you not reuse these data outside of replication of the study; instead, we would encourage you to contact GeoMIP (for the G3 scenario) or the Stratospheric Aerosol Geoengineering Large Ensemble (GLENS) Project at NCAR for the raw data that are best tailored to your needs.