Summary
This research publication examines how reflecting sunlight (SRM) might affect Eastern Africa’s future climate. Solar dimming generally lowers temperatures but causes inconsistent rainfall changes depending on greenhouse gas levels. Meanwhile, injecting sulphur aerosols consistently reduces rainfall, yet models disagree on whether it will actually cool the region or cause warming. These results suggest that while SRM targets global cooling, it may trigger unpredictable and risky shifts in local rainfall and heat.
Abstract
This study explores the implications of Solar Radiation Modification (SRM) on the rainfall and temperature spatial patterns over the Eastern Africa region. The Geoengineering Model Intercomparison Project (GeoMIP) models under the SRM scenarios of G6solar and G6sulfur are evaluated against the Shared Socioeconomic Pathways (SSPs). First, six GeoMIP models are evaluated against historical data and are found to capture the climate spatial patterns in the region fairly well but with a dry bias for all the models. Secondly, the models are run under both the SRM scenarios and the SSP scenarios for 2051–2080. Results show that G6solar SRM scenario predicts increased annual precipitation in the region compared to SSP245 but predicts reduced annual precipitation compared to SSP585 in the same period. The G6sulfur scenario predicts reduced annual precipitation compared to both SSP245 and SSP585 in most parts of the region with more reductions expected over SSP585 compared to SSP245 in the same period. For temperature, the G6solar scenario predicts a reduced annual mean temperature compared to both SSP245 and SSP585 in most parts of the region, with more reductions in temperature against SSP585 compared to SSP245 in the same period. However, G6sulfur shows some inconsistent results, with some models predicting increased temperatures under SRM compared to SSPs, especially for SSP245, while other models predict reduced temperatures in the same period.
