Global Warming Research Today is a free monthly online journal that collates and summarizes the latest research about Global Warming, including details on causes, effects, impact, facts, myths, information.

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

Barnett TP, Adam JC, Lettenmaier DP

Climate Research Division, Scripps Institution of Oceanography, La Jolla, California 92093, USA. timdotbarnett@ucsd.edu

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 climate--for example, on the frequency of heatwaves--this 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 availability--predicted with high confidence and already diagnosed in some regions--are likely to be severe.

Published 18 November 2005 in Nature, 438(7066): 303-9.
Full-text of this article is available online (may require subscription).

© 2004-2008 Global Warming Research Today. All Rights Reserved.