March 28, 2008

Global Warming Wreaks Havoc Across the West

Global warming could be the cause behind a beetle infestation killing off lodgepole pine forests in Colorado.

About 60 percent of the lodgepole pines have turned red and brown.

"The population built up rapidly and exploded. It takes out the mature trees," said Ingrid Aguayo, an entomologist for the Colorado State Forest Service.

"Now we're seeing a new carpet of forest coming up," she said.

Whether global warming is to blame or not, the evidence is daunting. A new calculation of government temperature data shows that the average annual temperatures in the Colorado River Basin - the heart of the west - have risen by 2.2 degrees over the past 5 years - twice as fast as the global rate.

The Rocky Mountain Climate Organization, a coalition of local governments, businesses and others working to protect the climate, and the advocacy group National Resources Defense Council published the report. They say the West is heating up faster than any other region in the continental U.S. with more devastating wildfires among the results.

"It's already begun. We are already seeing the effects, and scientists are telling us it's going to get markedly worse," said Stephen Saunders, the organization's president in Louisville, Colo.

Researchers are hesitant to pinpoint a single cause of the warming, but most agree these changes can't be ignored.

Martin Hoerling, a meteorologist at the NOAA-funded Earth System Research Laboratory in Boulder, Colo. suggests the West could heat up much more, possibly by 5 degrees by the midpoint of the century, pending the level of greenhouse-gas emissions.

"By and large, there is a very detectable warming in this region," said Hoerling.

The report, "Hotter and Drier: The West's Changed Climate," crunched numbers kept by NOAA's Western Regional Climate Center in Reno, Nev.

"That sounds about right," the center's acting director, Kelly T. Redmond, said.

"It's been warming in this region for the past 35 years, after a cool period in the 1970s," he said.

Redmond made calculations similar to the report's 2.2-degree rise, meaning fewer subzero nights to control the pine beetle population that is devastating Colorado's lodgepole pines.

The results of the calculations came from a network of around 2,000 thermometers across the West, many coming from airports and weather hobbyists'.

"I didn't know whether to trust these numbers or not," said Redmond.

However, earlier snowmelt in the spring and earlier lilac and honeysuckle blooms convinced him the recordings were accurate.

"We can't definitely attribute it to human causes, but my suspicion is at least part of it is due to climate change," he said. "In 100 years, this is the largest change we've seen, so it catches your attention."

A decade long drought has gripped the West and raised temperatures making Hoerling hesitant to attribute the warming of the West exclusively on carbon emissions. Cyclical changes in the sea-surface temperatures may also be to blame.

The consequences, though, are evident. Aerial photographs taken over Yellowstone park show orange-needled forests of whitebark pine, those of which were green only three years ago. Colorado's signature aspen stands are drying, making them vulnerable to fungus.

U.S. Geological survey researchers have calculated that the glaciers at Montana's Glacier National Park could melt entirely by 2022.

The Rocky Mountain snow packs are melting earlier in the spring, leaving less water for summer irrigation that heats up trout streams.

The National Weather Service reported Phoenix had 47 days of 109 degrees or hotter, while Montana, Idaho and Wyoming had their hottest Julys on record last summer.

Powell and Mead reservoirs, the reservoirs that collect water from the Colorado River, supplying most of the Southwest, are half-empty. If they keep drying up, it could damage the Colorado River Compact of 1922, an agreement that allocates fixed amounts of water among seven states.

Bradley H. Udall, director of the Western Water Assessment Cooperative at the University of Colorado, said the upper basin states have the water, but lower basin states including California have senior water rights - a crisis in the making.

"There's an old saying, 'I'd rather be upstream with a shovel and a ditch than downstream with a decree,'" he said.


Photo Caption: Shore Pine with Burrows Bay and Rosario Strait behind. Courtesy Walter Siegmund


On the Net:

Rocky Mountain Climate Organization

National Resources Defense Council

Earth System Research Laboratory

NOAA's Western Regional Climate Center

National Weather Service

Colorado River Compact of 1922

University of Colorado