Someday, Americans may be hard pressed to find a glacier in Montana’s Glacier National Park.

Twila Moon, a glaciologist at the University of Colorado Boulder, said that many of the park’s smaller glaciers have already disappeared and studies project that numerous others will be gone within decades.

Moon detailed the demise of glaciers around the world in a new paper published in the journal Science. She found that ice is disappearing at nearly every latitude.

“We’re no longer seeing phases of advance and phases of retreat, and those evening out over time. We’re seeing a global pattern of retreat and ice loss,” Moon said. Millions of people depend on glaciers for drinking water and irrigation, particularly in the Himalayas.

“If we are serious about climate action and we think about stabilizing emissions and stabilizing temperatures there are places where we can hope to stabilize some of our ice loss,” Moon said. “When we think about future ice loss, human action is still the biggest uncertainty. It’s going to make the biggest difference in how much ice we lose.”

Laura A. Shepard writes for Nexus Media, a syndicated newswire covering climate, energy, policy, art and culture. You can follow her @LAShepard221.