The era of the glacier will end in the United States within decades, according to researchers who worked on a major new study of glacial health in Montana.
A report released by Wednesday the United States Geological Survey follows 39 glaciers in Montana — 37 of them in Glacier National Park — from 1966 to 2015.
During that period of significant warming around the world, those 39 glaciers — lumbering, ancient bodies of ice that still move through high altitudes — shrank by an average of 39%. Some shrank by as much as 85%.
At the beginning of the 20th century, there were as many as 150 glaciers in the region. But in the time studied, 13 of the 39 glaciers shrank to less than 25 acres, the minimum size to be considered a glacier. That leaves just 26.
The shrinking Montana glaciers are part of a larger story. Humans are now the leading driver of glacial melt on Earth, since climate change has led to warmer winters that carry more rain into frigid glacial zones.
NASA estimates that around the world, glaciers have lost 400 billion tons of ice per year every year since 1994. That’s about 67,000 Great Pyramids of Giza worth of landlocked water melting into streams and oceans.
The 48 states in the continental US have a significant but rapidly declining glacier population distributed across Montana, Colorado, Washington, Wyoming, California, Oregon, Idaho, Nevada, and Utah. In Colorado, a 1,000-year-old glacier is expected to disappear within 25 years.
Speaking to the Guardian, Daniel Farge, the lead scientist on the study, said it is now “inevitable” that all of those glaciers will disappear within decades.
“It’s inevitable that we will lose them all over the next few decades,” Farge said. “The Colorado glaciers started melting before Montana’s and while there are larger glaciers in the Pacific north-west that will hold on longer, the number vanishing will steadily grow until none are left.”
So if you’re hoping to get a look at the US’ ancient, wandering ice blocks, now is probably the time.
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