Fig. 3: Physical and economic water-scarce regions.

a Historical (2000) considering the GPWv4 dataset, (b) Historical (2000) considering the HYDE3.2 population dataset, (c) Future (2099) considering the MY19 population dataset, and (d) Future (2099) considering the JO16 population dataset scenarios. The future (2099) case shows the possible combinations of scenarios with different colours; the values inside the circular legend show the number of people (in millions) facing scarcity with ranges representing the minimum and maximum values considering scenarios combination.