Global water resources: Vulnerability from climate change acid population growth

The future adequacy of freshwater resources is difficult to assess, owing t o a complex and rapidly changing geography of water supply and use. Numeric al experiments combining climate model outputs, water budgets, and socioeco nomic information along digitized river networks demonstrate that (i) a lar ge proportion of the world's population is currently experiencing water str ess and (ii) rising water demands greatly outweigh greenhouse warming in de fining the state of global water systems to 2025. Consideration of direct h uman impacts on global water supply remains a poorly articulated but potent ially important facet of the larger global change question.