Colorado Glaciers Thinned Fast in a Record Heat Year

Colorado glaciers thinned at a startling pace this year, and the numbers are hard to scroll past. According to the Associated Press via ABC News, the state's most prominent ice masses lost far more thickness in a single year than they did across the previous decade, driven by record low snow and record heat.

What the Colorado State team measured

Glaciologist Dan McGrath at Colorado State University usually studies change over long stretches of time. This time he wanted to know what one exceptional year had done, so his team looked specifically at 2026. The state recorded its worst snowpack on record, followed by record summer heat, which left the year-round ice in the Rocky Mountains exposed.

The Andrews Glacier thinned by more than twelve feet, or about three point seven meters, in one year. The Arapaho Glacier lost nearly ten feet, and the Isabelle Glacier lost about six and a half feet. McGrath said that doubled the thinning rate of the prior five years, and in the decade before that the loss was a foot or less per year.

A record-low snow year set the stage

Snow matters because it is both a blanket and a refill. A thick winter layer shields ice from summer sun and adds new mass. Without it, bare ice melts faster. Sentinel Colorado reported that statewide snowpack peaked at just fifty-one percent of average, about a month early, and then melted quickly during an unprecedented March heat wave, according to the CSU research team.

St. Mary's Glacier, a perennial snowfield popular with hikers and skiers, melted completely in September. McGrath called it a loss of part of Colorado's identity, and he stressed it is not just a Colorado story. He pointed to the same consistent patterns in the Alps and other western mountain ranges.

It is happening everywhere

The Colorado findings fit a global pattern. The AP notes that more than seven trillion tons of ice have been lost worldwide since 2000. Swiss glaciers lost five and a half percent of their volume this year, the second-biggest percentage drop on record, while researchers in Washington state found the fastest average retreat since 1950 on Mount Baker.

A new study co-authored by Brian Menounos of the University of Northern British Columbia found that about one quarter of mountain glaciers in the contiguous United States have vanished since the mid-1900s. The rest have lost a third of their area and volume. Wildfire soot and dust darken the ice, Menounos said, which makes it soak up even more sunlight.

Why a Gen Z student is documenting it

The human angle might be the most striking part. Harlan Ulmer, a twenty-year-old CSU student, has photographed these glaciers every year since 2022 and volunteers on McGrath's project. His before-and-after photos of the St. Vrain Glacier, taken in 2024 and 2026, went out with the AP story.

"Being Gen Z, I came in too late to ever see the glaciers at their largest," Ulmer said, adding that he has the chance to document the changes in his time to preserve them for future generations. That line lands because it frames recording the loss as an act of care, not just grief.

What happens next

McGrath thinks the remaining Colorado glaciers could soon disappear. The Andrews Glacier has already lost half of its ice since 2017, and he said the current thinning rate could lead to their demise within twenty years. Meltwater from these glaciers feeds alpine ecosystems and downstream water supplies across the West, so their loss could leave those areas more exposed to extreme drought.

There is a sliver of hope, though a long one. Menounos said glaciers could re-form if carbon pollution drops substantially and temperatures fall enough for snow to build up year-round, but that could take several hundred years. For anyone tracking the planet's health, the Colorado data is another sign that the clock is running. Follow more on the climate emergency and science beats at GenZ NewZ.

The takeaway is simple: one record-breaking year can erase what took centuries to build. Whether Colorado's glaciers survive past the next generation now depends on choices made far beyond the Rockies, and young researchers like Ulmer are making sure the evidence is on record.