Estimation is made of the summer moisture content in the 1 m soil layer and the annual runoff under the global warming to 1° and 2°C. Calculations are based on a comprehensive method of determination of evaporation from the land surface and on analyzing paleoclimatic data for two past warm periods: 1) the Holocene optimum with the mean global air temperature higher by 1°C than the present one; and 2) the Mikulinsky interglacial epoch when the mean global air temperature was higher by 2°C. -English summary