Global pattern of trends in streamflow and water availability in a changing climate

• Published in: Nature Vol. 438; no. 7066; pp. 347 - 350
• Main Authors: Milly, P.C.D, Dunne, K.A, Vecchia, A.V
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 17.11.2005; Nature Publishing; Nature Publishing Group
• Subjects: Africa; Asia; Climate change; Climate models; Climatology. Bioclimatology. Climate change; Earth sciences; Earth, ocean, space; Ecological function; Ecosystem; Europe; Exact sciences and technology; External geophysics; Global warming; Greenhouse Effect; History, 20th Century; Humanities and Social Sciences; Humans; Hydroclimate; Hydrologic cycle; Hydrology; Hydrology. Hydrogeology; Latitude; letter; Meteorology; Models, Theoretical; multidisciplinary; North America; Precipitation; Rain; Rivers; Runoff; Science; Science (multidisciplinary); Simulation; Stream discharge; Stream flow; Time Factors; Vapor pressure; Water availability; Water Movements; Water resources; Water Supply - history; watershed hydrology; Asia; North America; Europe; Africa; Middle East; Eurasia; Argentina, La Plata Basin; Ensemble simulation; Century 21st; hydrology; atmospheric precipitation; Climate models; digital simulation; Forecast model; troposphere; Rainfall rate; Dynamical climatology; environment impact; Hydrometeorology; climate modification; water resources; hydrologic cycle; global change; warming
• ISSN: 0028-0836; 1476-4687; 1476-4687; 1476-4679
• DOI: 10.1038/nature04312

Water availability on the continents is important for human health, economic activity, ecosystem function and geophysical processes. Because the saturation vapour pressure of water in air is highly sensitive to temperature, perturbations in the global water cycle are expected to accompany climate warming. Regional patterns of warming-induced changes in surface hydroclimate are complex and less certain than those in temperature, however, with both regional increases and decreases expected in precipitation and runoff. Here we show that an ensemble of 12 climate models exhibits qualitative and statistically significant skill in simulating observed regional patterns of twentieth-century multidecadal changes in streamflow. These models project 10-40% increases in runoff in eastern equatorial Africa, the La Plata basin and high-latitude North America and Eurasia, and 10-30% decreases in runoff in southern Africa, southern Europe, the Middle East and mid-latitude western North America by the year 2050. Such changes in sustainable water availability would have considerable regional-scale consequences for economies as well as ecosystems.