Scenario Forecasts of Climate Change in Belarus Based on Regionally Optimized Ensembles of Cmip6 Climate Models

The results of computing future climate changes in Belarus using CMIP6 (Coupled Model Intercomparison Project Phase 6) global hydrodynamic models are presented. Average air temperature, total precipitation, and evapotranspiration for years, seasons, and months with spatial aggregation by regions of Belarus are considered as estimated climatic parameters. For each climatic parameter and each region of Belarus, an optimal ensemble of hydrodynamic models was compiled taking into account the results of their retrospective testing. The optimized ensembles of models simulated almost perfectly the changes in all analyzed climatic parameters for the historical period 1955-2015. According to ensemble climate projections, the largest temperature rise by the end of the current century is expected in summer in the south of the country (by 3.5-8.4°C relative to the baseline period 1961-1990), the smallest warming (by 2.9-5.7°C) is expected in spring in the north of the country. The amount of precipitation in the winter and spring seasons is expected to increase by 22-55 and 22-36%, respectively. In summer, no precipitation increase is expected in Belarus. It is also projected that annual evapotranspiration in the country is expected to increase by 18-27% by the end of the current century. The modern trends in the climatic parameters in Belarus are most consistent with the SSP3-7.0 scenario, in which the increase in annual mean temperature will be 5.5°C by the end of the century.