Impacts of Solar Radiation Management on Hydro-Climatic Extremes in Southeast Asia

[Geoengineering News]

https://www.mdpi.com/2073-4441/15/6/1089

Authors

by 

Mou Leong Tan,

Liew Juneng,

Heri Kuswanto,

Hong Xuan Do

 and

Fei Zhang

 8

Water 2023, 15(6), 1089; https://doi.org/10.3390/w15061089

13 March 2023 

Abstract

Solar radiation management (SRM), or solar geoengineering, reduces the earth’s temperature by reflecting more sunlight back to space. However, the impacts of SRM remain unclear, making it difficult to project the benefits as well as consequences should this approach be adopted to combat climate change. To provide novel insight into the SRM impact on hydro-climatic extremes in Southeast Asia, this study conducts a simulation experiment for the Kelantan River Basin (KRB) in Malaysia by incorporating three bias-corrected Stratospheric Aerosol Geoengineering Large Ensemble (GLENS) members into the Soil and Water Assessment Tool Plus (SWAT+) model. The study found that SRM practices could generate substantial cooling effects on regional temperatures, leading to a reduction in projected annual precipitation and monthly precipitation during the flooding season (from November to mid-January) under SRM relative to the Representative Concentration Pathway 8.5 (RCP8.5) scenario. In addition, SRM could reduce the number of days with heavy precipitation as well as the intensity of maximum daily precipitation as compared to RCP8.5, during the 2045–2064 and 2065–2084 periods, leading to a reduction in high flows. Nevertheless, under SRM impacts, the driest months from February to May would experience comparable decreases in monthly precipitation and streamflow.

Keywords: 

climate change; solar radiation management; geoengineering; hydrology; flood; SWAT+; Malaysia 

Figure 2. The conceptual framework of SRM hydro-climatic impact assessment using SWAT+.

Figure 6. Relative changes in the R10 mm, R20 mm, R50 mm and Rx1d indices under the RCP8.5 and GLENS simulations across the stations during the 2025–2044, 2045–2064 and 2065–2084 periods.

Figure 10. Relative changes of maximum daily flow at the sub-basin level in the KRB for GLENS and RCP8.5 during the 2025–2044, 2045–2064 and 2065–2084 periods as compared to the 1985–2004 baseline period.

Source: MDPI