Projection and Uncertainty Analysis of Future Temperature Change over the Yarlung Tsangpo-Brahmaputra River Basin Based on CMIP6

Accurate predictions of future climate change are significant to both human social production and development. Accordingly, the changes in the daily maximum (T-max) and minimum temperatures (T-min) in the Yarlung Tsangpo-Brahmaputra River Basin (YBRB), along with its three sub-regions (Tibetan Plateau-TP, Himalayan Belt-HB, and Floodplain-FP) were evaluated here using the Bayesian model average (BMA) results from nine climate models in the CMIP6 under four future scenarios, and the corresponding uncertainty of the projected results was analyzed. The results showed the following: (1) The BMA can simulate the T-max and T-min of the YBRB well. (2) Future T-max and T-min over the YBRB exhibited an overall fluctuating upward trend. Even under the most ideal sustainable development scenario examined (SSP126), the average T-max (T-min) over the YBRB was projected to increase by 3.53 (3.38) degrees C by the end of this century. (3) Although the future changes in the YBRB are predicted to fall below the global average, the future temperature difference in the YBRB will increase further. (4) The uncertainty increased with prediction time, while spatially, the regions with the uncertainty were the TP > HB > FP. These findings can provide a reference for the YBRB climate change adaptation strategies.