In the last 50 years, some of Montana's ice formations have lost 85% of their size, and their average reduction is 39%, according to a study presented by the United States Geological Survey (USGS, for its acronym in English) and Portland State University.
And one day, the glaciers will cease to exist. That was the sentence of the scientist who led the study, this Wednesday.
“The trend, at this time, is that they are inexorably moving towards their disappearance. There is no possibility that they will be reborn, ”said Dan Fagre. “In several decades, most will have disappeared. They will grow so small that they will disappear. With certainty, they will disappear at the end of the century ”.
And humans are responsible, he says.
"There are variations in climate, but it is humans that have made all those variations warmer," he says. “The glaciers have been here for 7,000 years and will disappear in a few decades. That is not part of the natural cycle ”.
According to him, the glacial retreat has nothing to do with something that is happening underground. "All of this is atmospherically driven."
What is happening in this park is not unique. Glaciers around the world are shrinking as the planet warms, several experts have said.
Portland State University geologist Andrew G. Fountain claims that the amount of ice lost in Montana is more severe than elsewhere in the United States, but is in line with what is happening globally.
The researchers studied the situation of 39 glaciers, of which two were outside the park area.
Of these, only 26 today have more than 25 hectares, the standard by which an ice formation can be called a glacier.
The research used satellite photos and other images taken between 1966 and 2016.
For Fagre, the losses will impact the ecosystem in the park.
"The loss of ice in the park can have ecological effects on aquatic species, by changing the current and temperature of the water and the duration of the discharge at the highest heights of the park," explains Fagre, who is also the change director. climate in the Mountain Ecosystems project, of the USGS.
There are many reasons why this is important, he says.
“They just reflect what is happening in the system. We will see an effect on our forests, rivers and streams, but they are difficult to see and measure, ”he says. "It's easier to see it with the glaciers."
In the mid-1800s there were about 150 glaciers on that land, which was designated a national park in 1910. Rising temperatures caused the others to disappear, Fagre adds.
“Monitoring these small alpine glaciers has been instrumental in describing the effects of climate change on Glacier National Park to park managers and the general public,” says Lisa McKeon, a USGS scientist who has studied these and others. glaciers for 20 years.
So far, the change of scenery has not affected tourism. Last year, a record 2.95 million people visited the park.
"The best time to come is at the beginning of September," says Fagre.