Aqueduct Water Stress Projections: Decadal Projections of Water Supply and Demand Using CMIP5 GCMs


With the goal of producing information for decadal-scale planning, adaptation, and investment, this analysis models potential changes in future demand and supply of water over the next three decades. Globally we estimate indicators of water demand (withdrawal and consumptive use), water supply, water stress (the ratio of water withdrawal to supply), and intra-annual (seasonal) variability for the periods centered on 2020, 2030, and 2040 for each of two climate scenarios, RCP4.5 and RCP8.5, and two shared socioeconomic pathways, SSP2 and SSP3. We derived estimates from general circulation models (GCMs) from the Coupled Model Intercomparison Project Phase 5 (CMIP5) and mixed-effects regression models based on projected socioeconomic variables from the International Institute for Applied Systems Analysis (IIASA)’s Shared Socioeconomic Pathways (SSP) database.