By LES BLUMENTHAL
June 12, 2007
Dam operators, water district managers, farmers, conservationists and scientists all predict mounting problems as scarce water supplies dwindle further in an area stretching from the Pacific Northwest to the desert Southwest.
"The warming in the West can now confidently be attributed to rising greenhouse gases and are not explained by any combination of natural factors," said Philip Mote, head of the Climate Impacts Group at the University of Washington.
Mote said some models show temperatures in the West could rise by 6 degrees Fahrenheit in the coming years.
Signs of climate change, such as lilacs blooming earlier in the spring, are just a "harbinger of changes to come," he said.
Among other things, the Senate Energy and Natural Resources water and power subcommittee learned:
-- Spring snowpack has declined at nearly 75 percent of the weather recording stations in Washington, Oregon and California, and the spring runoff is coming two weeks earlier than in the past.
-- Southern California is experiencing its driest year on record, and Lake Mead, which supplies water to large parts of the fast-growing Southwest, could be empty in 10 years.
-- By some estimates, populations of Pacific salmon in the Northwest could drop between 20 percent and 40 percent by 2050, with even greater losses in California and Idaho. Western trout populations eventually could decline more than 60 percent.
-- A dead zone of "very low dissolved oxygen" has appeared every year in the Pacific Ocean off the Oregon coast since 2001, and unlike other ocean dead zones, pollution or other human activity isn't believed to be the cause. Instead, some scientists say there may be a "fundamental change" occurring in the ocean off the West Coast, changes that may involve wind patterns "modified" by climate change.
-- Tens of thousands of irrigated acres will fall out of production as water supplies tighten, and tensions over water supplies will only be exacerbated as the effects of climate change deepen.
"These changes will force us to adapt how we manage irrigation and agriculture, our hydropower system, salmon recovery, municipal water supplies and flood control," said Sen. Maria Cantwell, D-Wash., who chaired the Congressional hearing.
All of the witnesses said more scientific modeling is needed to provide a more focused picture of climate change effects on specific regions in the West. But Cantwell seemed impatient that federal, state and local agencies might not be doing sufficient planning.
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