Impacts of Solar Geoengineering on Projected Climate of South Asia

Solar geoengineering (SG) is an interim solution to combat global warming, which involves scattering back a tiny fraction of the incoming sunlight. Hence, SG and its potential impacts are important to study for the identification of changing weather patterns over regions of climate vulnerable South Asia. This study explores the projected spatio-temporal patterns of two meteorological parameters, temperature and precipitation, under SG numerical experiment (stratospheric aerosol injection), relative to projected climate change. Furthermore, future projections of same meteorological parameters without SG under a representative concentration pathway (RCP 4.5) will also be studied for comparative analysis. Offsetting climate parameters are associated with multiple risk factors. Thus, both SG and non-SG scenarios will be studied for the future time period. The results indicate that the temperature reduces by −0.62°C under the SG G4 scenario and spatial distribution patterns of temperature also depicts an overall cooling effects during the G4 implementation (2020–2029) and continuation (2030–2069) phase. Moreover, on a regional scale, a cold bias (less severe) is projected as compared to projected climate under RCP 4.5. Our findings show that, precipitation is also projected to be decreased by −0.02 mm day⁻¹. Dry bias pattern is projected during implementation phase only. The G4 based SG continuation and termination (2070–2090) phases depict no drastic change in precipitation over South Asia.