Materials of ISI-MIP International Project were used for global simulations of water balance components for the entire Earth surface (except for Antarctica) with a spatial resolution of 0.5° × 0.5° over a period of 1971−2099 with the use of physically based SWAP model, describing the processes of heat and water exchange between the land surface and the near-surface atmosphere layer, and the daily values of meteorological forcing data simulated by five global climate models (GCMs: GFDL-ESM2M, HadGEM2-ES, IPSL-CM5A-LR, MIROC-ESM-CHEM, and NorESM1-M) for each of the four scenarios of climate changes of RCP family (RCP2.6, RCP4.5, RCP6.0, and RCP8.5). The results of 20 simulated variants served as the basis for calculations, at the global scale, of climatic values of annual precipitation, runoff, and evapotranspiration for a historical and three projection periods (2006–2036, 2037–2067, and 2068–2099), which were used to estimate the possible changes of the water balance components for each projection period relative to the historical period and to evaluate their uncertainties caused by the use of various GCMs and RCP-scenarios.