Water demand is projected to change as a direct result of socioeconomic changes. For example, the global water demand for domestic, industrial and agricultural uses, at present about 4600 km3 yr-1, is projected to increase by 20-30% by 2050 , depending on the socioeconomic scenario. Changes in water availability and demand have been projected in several studies using climate models and socioeconomic scenarios . In such studies, the projected changes in water availability arise from differences in precipitation and evapotranspiration . However, both precipitation and evapotranspiration are also subject to very high uncertainty in key processes such as regional climate change patterns  and the influence of vegetation responses to elevated CO2 on transpiration .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report