Detail Abstract

Towards a new set of high-resolution climate scenarios for Vietnam

Abstract

The latest downscaling activities in Vietnam have been mainly based on the dynamical approach for a limited number of Global Climate Models (GCMs) of the Coupled Model Intercomparison Project Phase 3 (CMIP3) and Phase 5 (CMIP5). To date, no attempt to downscale the latest GCMs of the CMIP Phase 6 (CMIP6) has been done in Viet Nam. Here, we first apply the Bias Corrected Spatial Disaggregation (BCSD) statistical method to downscale the outputs of 31 CMIP5 and 35 CMIP6 GCMs for inland Viet Nam. The new sets of data, including four variables: daily precipitation, daily average, and maximum and minimum temperatures, are at 10-km spatial resolution and respectively called CMIP5-VN and CMIP6-VN. CMIP5-VN and CMIP6-VN cover the historical period of 1980–2005 and 1980–2014, and the future projection period until 2100 with four Representative Concentration Pathways (RCPs; RCP2.6, 4.5, 6.0, and 8.5) and seven Shared Socioeconomic Pathways (SSPs; SSPs 1-1.9, 1-2.6, 2-4.5, 3-7.0, 4-3.4, 4-6.0, and 5-8.5) scenarios, respectively. Then, we establish the joint probability density functions (PDFs) of temperature and precipitation change over the 21st century for every region in Viet Nam using the surrogate/model mixed ensemble (SMME) method. The new SMME data facilitates the assessments of local and regional climate change risks, including tail risks, which are known to have low probability but severe consequences. The newly built CMIP5-VN, CMIP6-VN, SMME-CMIP5, and SMME-CMIP6 datasets have been made online available and free of charge. We recommend the use of these datasets for studies on climate change assessment, as well as into climate change impacts on socio-economic activities in Viet Nam.