Climatic Asynchrony and Hydrologic Inefficiency Explain the Global Pattern of Water Availability

Abstract The mechanisms underlying observed global patterns of partitioning precipitation ( ) to evapotranspiration and runoff are controversially debated. We test the hypothesis that asynchrony between climatic water supply demand is sufficient explain spatio‐temporal variability availability. developed a simple analytical model for determined by four dimensionless characteristics intra‐annual asynchrony. model, populated with gridded climate data, accurately predicted within 2%–4% independent estimates from models, spatial closely correlated observations ). supply‐demand provides physically based explanation availability using easily measurable climate. revealed widespread responsiveness budgets changes in almost every region. Furthermore, averages independently reproduced Budyko curve providing theoretical foundation this widely used empirical relationship.