Future changes in precipitation extremes over Southeast Asia: insights from CMIP6 multi-model ensemble

Abstract

Past assessments of coupled climate models have indicated that precipitation extremes are expected to intensify over Southeast Asia (SEA) under the global warming. Here, we use outputs from 15 climate models from the Coupled Model Intercomparison Project Phase 6 (CMIP6) to evaluate projected changes in precipitation extremes for SEA at the end of the 21st century. The results suggest that CMIP6 multi-model ensemble medians show better performances in characterizing precipitation extremes than individual models. Projected changes in precipitation extremes linked to rising greenhouse gas (GHG) emissions (represented by the latest proposed Shared Socioeconomic Pathways) increase significantly over the Indochina Peninsula and the Maritime Continent. Substantial changes in the number of very heavy precipitation days (R20mm) and the intensity of daily precipitation (SDII) indicate that such locally heavy rainfall is likely to occur over a short time and that more precipitation extremes over SEA are probable in a warmer future. This is consistent with projections from the Coordinated Regional Downscaling Experiment and CMIP5 models. The present study reveals the high sensitivity of the precipitation extremes over SEA, and highlights the importance of constrained anthropogenic GHG emissions in an ambitious mitigation scenario.