Scientists blame climate change for shrinking Montana glaciers, say they'll disappear soon

Climate change has reduced the 37 glaciers in Montana's Glacier National Park and two on nearby U.S. Forest Service land by 39 percent since 1966, with some glaciers having seen reductions as much as 85 percent, says a study by the U.S. Geological Survey and Portland State University.

Daniel Fagre, a research ecologist with the USGS's Northern Rocky Mountain Science Center, told CNN's Steve Almasy and Mayra Cuevas, "The trend right now is that they are inexorably going into their final demise. There is no chance they will go into rebirth. In several decades they will be mostly gone. They will grow so small that they will disappear. They will certainly be gone before the end of the century."

Perimeter of Sperry Glacier in Glacier
National Park in 1966, 1998, 2005 and 2015.
Click on photo for larger version.

Using digital maps from aerial photography and satellites, scientists measured the perimeters of the glaciers in late summer, when seasonal snow has melted to reveal the extent of the glacial ice, in 1966, 1998, 2005 and 2015/2016. They found that of the 39 glaciers, "only 26 glaciers are now larger than 25 acres, which is used as a guideline for deciding if bodies of ice are large enough to be considered glaciers."

Portland State geologist Andrew G. Fountain said, “While the shrinkage in Montana is more severe than some other places in the U.S., it is in line with trends that have been happening on a global scale." Fagre told CNN that "in the mid-1800s there were about 150 glaciers on the land, which was designated a national park in 1910. Rising temperatures caused the others to disappear."