Via EB: Climate--Jan 2
US drought 'man-made' says study
Jim Giles, New Scientist
The water shortages gripping the western US are the result of global warming, not natural variations in climate, according to a bleak study by hydrologists. The results suggest that water disputes will plague the region in the future and damage economic growth unless action is taken now, warn researchers.
About 60% of the changes seen in river flow in the western US are due to warming caused by humans, their study suggests.
Key indicators have hinted at looming water problems for many years. More rain and less snow has been falling in mountain ranges such as the Rockies, for example. River levels, which depend on melting snow from the mountains during the spring and summer, have fallen as a result.
...Hopes that the drought is temporary have been dashed by the analysis, prompting leading researchers to intensify their calls for policy change.
Peter Gleick, a water policy expert at the Pacific Institute, an independent think tank based on Oakland, California, says that water use in his state could be reduced by a fifth by 2030, even if the population and economy continue to grow.
Many sectors need to change to achieve that goal. Agriculture would have to shift towards drip irrigation, in which small amounts of water are focused on individual plants, rather than whole areas being sprayed. Home owners would also have to adopt toilets and washing machines that use less water, he says.
(31 January 2008)