Global Warming Could Increase Western States Water Woes

Space Daily ^ | February 18, 2003 | L. Ruby Leung

[cogitator]

Global Warming To Squeeze Western Mountains Dry By 2050

Seattle - Feb 18, 2004 Global warming will diminish the amount of water stored as snow in the Western United States by up to 70 percent in the coastal mountains over the next 50 years, according to a new climate change model released here today. The reduction in Western mountain snow cover, from the Sierra Nevada range that feeds California in the south to the snowcapped volcanic peaks of the Cascades in the Pacific Northwest, will lead to increased fall and winter flooding, severe spring and summer drought that will play havoc with the West's agriculture, fisheries and hydropower industry.

"And this is a best case scenario," said the forecast's chief modeler, L. Ruby Leung, a staff scientist at the Department of Energy's Pacific Northwest National Laboratory in Richland, Wash. Leung delivered the sobering report at the American Association for the Advancement of Science annual meeting, and the full results of her study will appear soon in the journal Climatic Change, now in press.

Leung emphasized the estimate's conservativeness, noting that the climate projections of warming devised by DOE and the National Center for Atmospheric Research are on the low end compared to most other models. Leung's clumping of the models is part of the DOE's Accelerated Climate Prediction Initiative, or ACPI.

ACPI assumes a 1 percent annual increase in the rate of greenhouse gas concentrations through the year 2100, for little change in precipitation and an average temperature increase of 1.5 to 2 degrees centigrade at least through the middle of 21st century.

The result: more winter precipitation falling as rain instead of snow, two-tenths of an inch to more than half an inch a day, pushing the snowline in the mountains up from 3,000 feet to higher than 4,000 feet.

Where we now have snow in the mountains into April, "at mid-century snow will melt off much earlier than that," Leung said, noting research that shows in the past 50 years coastal mountain ranges have already lost 60 percent of their snowpack.

"The change in the timing of the water flow is not welcome," Leung said. "The rules we have now for managing dams and reservoirs and irrigation schedules cannot mitigate for the negative effects of climate change."

If this picture isn't bleak enough, Leung noted that the model does not even address the possibility of population growth and increased demand on water resources.

Mountain streams supply power and drinking water to Seattle, Portland and the San Francisco Bay Area and points south in densely populated Northern California, and they feed the booming agricultural industries in the Columbia and Willamette valleys of Washington and Oregon and the San Joaquin Valley in California.

If there is any good news, it can be found farther east, in the Rockies. There, the winters are so much colder that small temperature increases have will have less effect on the snowpack, Leung said.

[cogitator]

A recent NASA study also indicated that there will be more rain in a warmer global climate.

[My2Cents]

The headline today in local papers in Northern California is about flood warnings from the lastest storms.

[Alberta's Child]

I saw a fascinating article last year about the water problems in the western U.S. There is some speculation that the main culprit in declining flowrates in some rivers is not global warming, but excessive tree growth on the eastern slopes of the Rockies. Moisture that used to run off these slopes is now being retained in the soil by vegetation that is thicker now than it ever has been.

[lewislynn]

Global Warming Could Increase Western States Water Woes...or not.

[swilhelm73]

Well that's the deal.

Global warming will cause both more rain and less. It will cause both higher and lower termperatures. It will cause a new ice age and make the polar ice caps melt.

As a matter of fact if there is ever any sort of change in global climate it will be because of global warming. Gotta love undisprovable "scientific theories".

[Redbob]

"...will lead to increased fall and winter flooding,..."

Not if they leave the dams alone.

[Redbob]

"Leung noted that the model does not even address the possibility of population growth and increased demand on water resources."

Translation: "This is without even considering the millions of illegal aliens..."

[appleharvey]

I seem to remember reading years ago about it snowing in Boston on the 4th of July. It was in the 1700's I believe. What caused that?

[cogitator]

There is some speculation that the main culprit in declining flowrates in some rivers is not global warming, but excessive tree growth on the eastern slopes of the Rockies.

This article indicates that the effect on snowpack in the Rockies would be minimal from global warming; but if the factor you indicate is also happening, then that would affect the central-western states, and the decline in snowpack would affect the far western states. Not a good picture either way.

[cogitator]

I seem to remember reading years ago about it snowing in Boston on the 4th of July. It was in the 1700's I believe. What caused that?

I'll help. It was a lot colder in the 1700s. Look at how much ice was on the Delaware River when Washington crossed to attack Trenton, for example. In the early 1800s, a massive eruption of Tambora volcano in Indonesia led to a very severe cold year, in which phenomenon like snow in summer occurred.

[metesky]

Eighteen Hundred and Froze to Death.

Krakatoa.

[swilhelm73]

IIRC, Krakatoa caused the freak Boston summer snow storm.

Which of course really does lead one to wonder what caused the mini Ice Age of the medieval ages that we only fully finished recovering from rather recently...

[MD_Willington_1976]

Wouldnt doubt it, for the air to get over the mountains it has to dump its moisture somewhere...hey had any good Chinooks latelly? My mother-in-law is freezing her backside off in OLDS...

Later

[geedee]

Global Warming Could Increase Western States Water Woes

Really?

BREAKING NEWS!!! Mandatory chastity belts would ruin Pee Wee Clinton's day.

[HardStarboard]

Global Warming Could Increase Western States Water Woes
Global Cooling Could Increase Western States Water Woes
Global Warming Could Decrease Western States Water Woes
Global Cooling Could Decrease Western States Water Woes

Those are the possibilities. Take your pick, cause THEY don't know!

[Jacquerie]

You can't trust a two day local weather forecast, why would anyone respect a 50 year forecast?

[Mike Darancette]

Northwest, will lead to increased fall and winter flooding, severe spring and summer drought that will play havoc with the West's agriculture, fisheries and hydropower industry.

Of course you could build more resevoirs to hold the Fall and Winter flood water to ease the Spring and Summer droughts like they do in Central California.

[cogitator]

Of course you could build more resevoirs to hold the Fall and Winter flood water to ease the Spring and Summer droughts like they do in Central California.

That would be good long-range planning.

[cogitator]

"Eighteen hunderd and froze-to-death" was caused by Tambora and not Krakatoa, though Krakatoa did cool things off a bit.

[cogitator]

Well, one thing that is known is what happens during an
El Nino year: more rain, less snow in winter. This model essentially extrapolates warm El Nino year conditions to a longer-term prediction.