Datensatz

Zusammenfassung

Water availability per capita is among the most fundamental water-scarcity indicators used extensively in global grid-based water resources assessments. As the concept of Anthropocene spreads, it has extended to include the economic aspect recently, a proxy of the capability for water management which we applied globally under SSP–RCP scenarios using gridded population and economic conditions. We found that population and economic projection choices significantly influence the global water scarcity assessment, particularly the assumption of urban concentrated and dispersed population. Using multiple SSP–RCP scenarios, GCMs, and two gridded population datasets, capturing future extremities, we show that the water-scarce population ranges from 0.32–665 million in the future. Uncertainties in the SSP–RCP and GCM scenarios are 6.58–489 million and 0.03–248 million, respectively. The population distribution has a similar impact, with an uncertainty of 169.1–338 million. These results highlight the importance of the subregional distribution of socioeconomic factors for future global environment prediction. The study further confirmed the predominant effect of socioeconomic factors (i.e., GDP and population) over climate-related ones (i.e., available freshwater) for future water scarcity. To contribute to evidence-based policy makings, such as the formulation of adaptation measures based on more reliable climate change assessments, it is necessary to estimate future population and GDP distributions that take into account the interaction between the global environment and human society.