Potential impacts of a warming climate on water availability in snow-dominated regions

• Published in: Nature Vol. 438; no. 7066; pp. 303 - 309
• Main Authors: Barnett, T.P, Adams, J.C, Lettenmaier, D.P
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 17.11.2005; Nature Publishing; Nature Publishing Group
• Subjects: Aerosols; Animals; Climate change; Climate effects; Climate models; Climatology. Bioclimatology. Climate change; Earth sciences; Earth, ocean, space; Exact sciences and technology; External geophysics; Freshwater; Geography; Glaciers; Glaciohydrology; Global warming; Greenhouse Effect; Greenhouse gases; Heat waves; Humanities and Social Sciences; Humans; Hydrologic cycle; Hydrology; Hydrology. Hydrogeology; Ice Cover; Impact analysis; literature reviews; Melting; Meteorology; Models, Theoretical; multidisciplinary; Oceans; Precipitation; Rain; Rainfall intensity; review-article; River flow; rivers; Runoff; Salmon; Science; Science (multidisciplinary); Seasons; Snow; snowmelt; Spring; stream flow; Surface temperature; Water availability; Water resources; Water Supply; watershed hydrology; Winter; hydrology; river discharge; water supply; Impact study; ice; evapotranspiration; troposphere; Dynamical climatology; Hydrometeorology; climate modification; water resources; hydrologic cycle; global change; Snow melt; Planetary scale; warming; Timing
• ISSN: 0028-0836; 1476-4687; 1476-4687; 1476-4679
• DOI: 10.1038/nature04141

All currently available climate models predict a near-surface warming trend under the influence of rising levels of greenhouse gases in the atmosphere. In addition to the direct effects on climatefor example, on the frequency of heatwavesthis increase in surface temperatures has important consequences for the hydrological cycle, particularly in regions where water supply is currently dominated by melting snow or ice. In a warmer world, less winter precipitation falls as snow and the melting of winter snow occurs earlier in spring. Even without any changes in precipitation intensity, both of these effects lead to a shift in peak river runoff to winter and early spring, away from summer and autumn when demand is highest. Where storage capacities are not sufficient, much of the winter runoff will immediately be lost to the oceans. With more than one-sixth of the Earth's population relying on glaciers and seasonal snow packs for their water supply, the consequences of these hydrological changes for future water availabilitypredicted with high confidence and already diagnosed in some regionsare likely to be severe.