Projection of effects of changes in population and climate on changes in water stress between 1990 and 2025. This projection used the Hadley 2 Climate Model with sulfates included to project precipitation and air temperature out to 2025; U.S. census demographic projections to 2025; and 1992 Multi-Resolution Land Characteristics (MRLC) vegetation data. Credit: S. McNulty, USDA/Forest Service.