From Snowpack to Soot: Glacier Melt Decades Ahead of Schedule
A new study finds that glaciers in Western Canada, the U.S., and Switzerland have lost more than 12% of their ice in just four years—twice the rate of the previous decade.
Breaking the Ice:
A new report reveals a stunning acceleration in glacier loss across Western Canada, the contiguous United States, and Switzerland. From 2021 to 2024, glaciers in these regions lost ice mass at double the rate observed from 2010 to 2020. This includes an alarming 12% drop in total glacier volume in Western Canada and the U.S., and a 13% drop in Switzerland—unprecedented figures for such a short span.
The report attributes this rapid melt to a combination of climate-driven factors: diminished winter snowfall, increasingly intense and early-season heatwaves, and the darkening of glacier surfaces due to soot from wildfires and dust storms. This darkening lowers glacier albedo, meaning less sunlight is reflected away and more is absorbed—accelerating melt.
Importantly, the researchers warn that we may have already passed "peak water"—the period when glaciers provide their maximum runoff to rivers. As glaciers shrink, even with continued melting, their water contributions to ecosystems and human use will diminish.
Quick Melt:
This study underscores the multifaceted consequences of glacier retreat—not just as a symptom of climate change, but as a driver of regional hydrological instability and risk. Glaciers act as natural water towers, releasing cold meltwater that sustains river flow in late summer and during droughts. As they shrink, these vital freshwater buffers dwindle.
But this isn't just a story of vanishing ice. It's also about compounding feedback loops. Wildfire smoke in Canada and Saharan dust in Europe settled on snow surfaces, causing them to darken. This lowered albedo amplified melt rates. In the Canadian Rockies, the darkening of formerly bright, reflective firn (compacted snow that feeds glaciers) is now a major contributor to enhanced melting. A modeling experiment at Haig Glacier found that low snowfall, elevated summer heat, loss of firn, and reduced surface albedo combined to drive a record mass loss of nearly 4 meters of ice in a single year.
The researchers call for urgent updates to glacier models, which often omit critical feedback processes like wildfire soot deposition, firn loss, and heatwave intensity. Without accounting for these variables, projections may underestimate how fast glaciers will disappear—and how soon communities will feel the loss.
The Thaw:
What is Really Happening Beneath the Surface? AccumulationZone Explains.
Albedo is a measure of a surface’s reflectivity. Fresh snow has a high albedo (around 0.8–0.9), meaning it reflects most incoming sunlight. In contrast, darker surfaces—like exposed glacial ice or soot-covered snow—have low albedo, absorbing more energy and thus melting faster. This creates a dangerous feedback loop: as more snow melts, more dark ice is exposed, which then accelerates further melt.
Now factor in impurities like black carbon and mineral dust, which are deposited on snow from wildfire smoke and atmospheric dust events. They don't just stain the surface—they change its energy balance. The study found that black carbon flux in Western Canada has doubled since 2010, peaking during record wildfire years in 2017, 2018, and 2023.
Firn loss is another key concern. Firn acts like a sponge, absorbing meltwater and releasing it gradually. Once firn is lost—either through melting or transformation into ice—the glacier loses this buffering capacity. More meltwater runs off immediately, and more solar energy goes into melting solid ice rather than snow or firn. Glacier systems, in other words, become faster-draining and more fragile.
Current glacier models don’t fully account for these dynamic processes. Most don’t simulate the evolution of firn layers, changes in albedo over time, or the effects of extreme weather like heatwaves and wildfire soot. Without these factors, models underestimate how fast glaciers will disappear.
These dynamics aren’t just theoretical. They’re already reshaping river flows, increasing landslide risks, and destabilizing long-term water availability for millions of people downstream. They also mean that climate models that fail to incorporate these feedback loops are likely painting an overly optimistic picture of our future.
Final Thoughts
While global conversations often focus on sea level rise or polar ice sheets, mountain glaciers are the "canary in the cryosphere"—vivid, local indicators of planetary warming. Their disappearance is not gradual. It is abrupt, it is accelerating, and it is happening now.