 A global water scarcity assessment for the 21st century was conducted under the latest socioeconomic scenario for global change studies. In this paper, water availability and water scarcity were assessed using a global hydrological model called H08. The results suggested that by 2071 to 2100 the population living under severely water stress conditions for SSP1-5 will reach 2588 to 2793 times 106. This article was authored by N. Hanasaki as Fujimori, Tiyama Moto and others.