Alarming new research has found that 4 billion people around the globe — including close to 2 billion in India and China — live in conditions of extreme water scarcity at least one month during the year. Half a billion, meanwhile, experience it throughout the entire year. The new study, by Mesfin Mekonnen and Arjen Hoekstra of the University of Twente in the Netherlands, uses a high resolution global model to examine the availability of “blue water” — both surface and underground freshwater — in comparison with the demand for it from agriculture, industry and human household needs. The model — which zoomed in on areas as small as 60 kilometers by 60 kilometers in size at the equator — also took into account climatic factors, ecological ones (how much water is needed to sustain a river ecosystem or lake) and other causes of depletion such simple evaporation. “We […]