Trends in Temperature, Precipitation, Potential Evapotranspiration, and Water Availability across the Teesta River Basin under 1.5 and 2 °C Temperature Rise Scenarios of CMIP6

Considering the linkages between climate change and water management, a lack of effort has been observed in analyzing the imprints of climate change over the transboundary Teesta river basin, where the changing climatic conditions can trigger substantial changes in eco-hydrological and socio-politico-economic setups. Therefore, to stimulate effective basin management, we investigated the trends in temperature, precipitation, potential evapotranspiration, and water availability under 1.5 and 2 degrees C warming levels across the transboundary Teesta river basin. The ensemble median of five bias-corrected model outputs from the Coupled Model Intercomparison Project Phase 6 (CMIP6) was used for this purpose. The results indicate that the temperature is expected to significantly increase (decrease) in the near (far) future, along with an overall significant increasing trend in monsoon precipitation. The evaporation paradox is found in the near future, and the water availability is likely to increase, with some exceptions for the pre-monsoon season. The perpetuation of such changes might result in environmental degradation through snow melting, glacial recession, and floods. Anticipating the changing climatic scenarios and their possible impacts, in this study, we recommend a variety of short- and long-term strategies for the concerned stakeholders to implement the Sustainable Development Goal 13, i.e., "Climate Action", over the Teesta river basin.