Summary
The study uses GLENS simulations to evaluate how Solar Radiation Management (SRM) would affect extreme precipitation across Southeast Asia. SRM moderates the strong rainfall increases projected under RCP8.5 but produces highly uneven regional outcomes. Indonesia often becomes wetter, with more wet days and fewer dry spells, while mainland Southeast Asia (Vietnam, Thailand, Cambodia) and the Philippines experience fewer wet days, longer dry periods, and reduced heavy‑rainfall events. These contrasting responses highlight complex hydrological trade‑offs and significant regional risks associated with SRM deployment.
Abstract
This study evaluates the impacts of Solar Radiation Management (SRM) on precipitation-related climate extremes in Southeast Asia. Using simulations from the Geoengineering Large Ensemble (GLENS), we assess spatial anomalies and differences in extreme precipitation indices—number of wet days (RR1), very heavy precipitation days (R20mm), maximum 5-day precipitation (Rx5day), consecutive dry days (CDD), and consecutive wet days (CWD)—relative to historical (1980–2009) and Representative Concentration Pathway 8.5 (RCP8.5) baselines. The results reveal that SRM induces highly heterogeneous precipitation responses across the region. While SRM increases rainfall frequency in parts of Indonesia, it reduces the number of wet days and lengthens dry spells over Vietnam, Thailand, and the Philippines. Spatial variations are also observed in changes to heavy precipitation days and multi-day rainfall events, with potential implications for flood and drought risks. These findings highlight the complex trade-offs in hydrological responses under SRM deployment, with important considerations for agriculture, water resource management, and climate adaptation strategies in Southeast Asia.
