Global warming's effect on river flow examined

[NVMojo]

September 23, 2005

Global warming is almost certain to change the way the Colorado River flows, but rising temperatures do not appear to present a direct threat to Southern Nevada's primary source of water.

During a conference Thursday in Las Vegas, researchers said there is no clear evidence that global warming will result in less precipitation along the Colorado River.

Though higher temperatures could cause Rocky Mountain snow to melt earlier in the year, the researchers said the water still will find its way to the river and its twin reservoirs of Lake Powell and Lake Mead, from which the Las Vegas Valley draws 90 percent of its drinking water.

"It's not that we're getting less precipitation, but that less of it is falling as snow," said Dr. Michael Dettinger, research hydrologist for the U.S. Geological Survey.

more...

http://www.reviewjournal.com/lvrj_home/2005/Sep-23-Fri-2005/news/27254272.html

[Lisa]

1. the decrease of the snowpack is going to cause major water problems

Many places in the western US and Canada depend on rivers which are only running during the summer due to meltwater (rainfall is either too scarce or evaporation too high, to supply enough runoff). Also, the effects of rising temperatures on evapotranspiration in general are not well understood. A lot of ecologists and planners are figuring it'll mean drier soils, more drought, more forest fires, etc.