Global warming is altering the identity of some national parks in the West, including in Washington, park officials and conservation groups warn.

The melting ice of mountain glaciers in Washington state, is providing one of the most visual accountings of global warming outside Alaska and the Arctic region, enhanced by federal officials' digital archiving last year of photos of park glaciers taken 50 years ago.

The changes over the decades are threatening the aesthetics and ecosystems of parks such as Washington's North Cascades National Park, imperiling the country's natural heritage, park officials and conservationists said. For example, Glacier National Park in Montana has lost 124 of its 150 glaciers in the last 150 years and is projected to have none left by about 2030, according to park officials.

"It's awful. We've got to change our ways," said Steve Shuster, 55, an architectural designer from Seattle and a regular North Cascades visitor for the past 10 years.

Another passerby enjoying the 360-degree panorama of white-capped summits, Sherry Cline, 75, agreed. "If they're all bare peaks up there, what's it going to be?" said the retired high school biology teacher from Lynden, Wash.

President Bush, criticized by some as dragging his feet on climate change, last month proposed an international gathering to address carbon emissions. At the same time, the Interior Department announced a new climate change task force to look at national parks and other agencies. Conservationist groups have long warned that many parks are facing damage from greenhouse gases.

As the G-8 summit put Earth's rising temperature on an international stage, park enthusiasts and their supporters say they were heartened to see the Bush administration say it was taking the issue seriously.

"They're finally starting to get it," said Rep. Norm Dicks, D-Wash., who attended a recent gathering of the state's three national park superintendents and others at Seattle's Mountaineers club, where discussion focused on repairing parks after last fall's extensive flooding in Mount Rainier National Park and other areas. "We take it as a serious problem," he said of global warming's impact.

Not everyone agrees that mankind's emissions are causing warming. Some scientists in Washington and elsewhere contend that natural cooling and heating cycles are at work.

In North Cascades and Mount Rainier National Parks, six glaciers under study have shrunk by 45 percent in the past 100 years, a park geologist said. The 312 glaciers in North Cascades park, spanning 42 square miles, account for a quarter of all glaciers in the lower 48 states, park officials said. The Natural Resources Defense Council, a conservation group, has identified 12 national parks in the West, including North Cascades and Mount Rainier, as most at risk from climate change, and seven face loss of snowfields and glaciers.

"Olympic, Mount Rainier, North Cascades and Glacier (National Parks) — you can look at a large geographic region using the parks as the sampling points of the impacts of global climate change," said North Cascades National Park Superintendent Chip Jenkins.

Emerging from the icy losses has been pristine land not seen or touched by humans for centuries, as well as new lakes, park officials said. Still, the big thaw is troublesome because the runoff may cause powerful, destructive flooding and could deprive high-altitude animals and organisms of cool water in the summer, park officials said.

Meanwhile, Philip Mote with the Climate Impacts Group at the University of Washington said a study of 11 states west of the Rockies shows that snowpack has shrunk by 10 to 15 percent from the 1950s to 2000. Scientists at the University of California, San Diego, found earlier springtime snow melts and lower summer river flows in the same 11 states from 1948 to 2002.