ENVIRONMENT - Climate Change in the West

"Climate change affecting mountains most" by Eric Newhouse, Greatfalls Tribune

The swift meltdown of the glaciers in Glacier National Park has led scientists to a surprising realization: Mountains are more susceptible to global warming than the lowlands around them.

"During the past 15 years, there has been a faster rate of temperature increase for mountains than for lower elevations," said U.S. Geological Survey ecologist Dan Fagre in West Glacier.

"For the Glacier Park area, that annual increase is almost 2 degrees Fahrenheit ... almost as much as occurred over a century for low elevation sites," he said. "This helps explain why we are seeing fairly dramatic reductions in glaciers and changes to our annual snowpacks."

The evidence is striking, as anyone can see by looking at a before-and-after photographic comparison of the park's glaciers on a Web site run by the U.S. Geological Survey.

Today, Glacier National Park has only 25 of the 150 glaciers that were large enough to name in 1850.

"Temperatures here (in western Montana) have gone up at higher elevations two or three times more than just global warming would suggest," Fagre said.

But it's not just us.

"Across the globe, the rates of temperature increase in the mountains have been greater than in the adjoining lowlands," Fagre said.

Now geologists are seeking an explanation for this scientific puzzle.

One theory is that global warming leads to greater evaporation, more moisture in the system and greater cloud cover.

"Under clear skies, particularly at night, the mountains radiate heat, but under a cloud cover they retain that heat," Fagre said.

That cloud cover may also generate additional heat, he said.

"When clouds come to the mountains, they rise and condense and turn into rain," he said. "When they do so, they release heat.

"Now they do it more in the mountains than down in the lowlands so they're warming the mountains more than the lowlands," he said.

Or perhaps the lowlands are used to that warming, where the mountains have not been.

At any rate, western Montana's nine weather stations have found a 2.03-degree increase in the average daily high temperatures since records were first kept in 1892.

But the average daily low temperature has gone up 2.79 degrees since then, Fagre said.

"The greater increase in minimum temperatures is because our winters are not getting as cold and nighttime temperatures don't drop as much," he said.

"Both of these affect glaciers because the ice doesn't get as cold and, therefore, can begin melting earlier in the summer melt season," he said.

Both Shepherd Glacier and Boulder Glacier, which were hundreds of acres in size a century ago, have been reduced to small slivers of ice that no longer function as a glacier, he said.

"And Grinnell Glacier has lost 400 to 500 feet of its ice depth," Fagre said. "It has not only shrunk to about 28 percent of its original area, but it has lost 90 percent of its ice mass.

"Most of our major glaciers are only a quarter of what they had been," he said.

That's the message that USGS is presenting on its Web site.

USGS scientists paired historic glacier images with contemporary photographs of the same areas.

USGS researcher Lisa McKeon spent numerous hours in the backcountry of Glacier National Park taking repeat photographs of the remaining glaciers.

"While our original intent was to use the photography for science, through time we've found that these photographs do more than document; they inspire," McKeon said.

The concept was inspired by the discovery of historical park images from as far back as 1861, when the first photographs were taken of the boundary markers between Canada and the U.S.

The USGS, based out of the Northern Rocky Mountain Science Center in West Glacier, began the repeat photography project in 1997. Scientists set out to replicate exact historical images to illustrate glacier recession over a century.

Since the onset of the project, over 70 photographs of 19 different glaciers have been repeated in Glacier National Park.