Glaciers in Washington, Montana, British Columbia, Alberta and the Swiss Alps lost an unprecedented amount of ice between 2021 and 2024, new research reveals.
The cumulative losses over the past four years are twice as many as recorded between 2010 and 2020, reducing the glacier by up to 13%, researchers found. Glaciers in the US and Canada lost an average of 24.5 billion tons of ice (22.2 billion tons) of ice per year, while glaciers in the Swiss Alps lost 1.7 billion tons (1.5 billion tons) of ice per year.
“The previous records have been crushed,” Matthias Huss, a lecturer at the Faculty of Civil, Environment and Geoengineering in Eth Zurich, Switzerland, told Live Science in an email. “We knew the melting rate of these extreme glaciers would increase. And yet, the day we went outside based on our measurements and witnessed these results, it was still surprising and difficult to accept.”
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The glaciers studied are located in areas with “very good, near real-time observational coverage,” Huss said. The annual loss of ice from these glaciers from 2021 to 2024, as well as the total ice loss measured during this period, is a record.
“Weather conditions that favored high mass loss rates included long periods of low winter snow accumulation, early seasonal heat waves, and warm, dry conditions,” the researchers wrote in a new study published in the Journal Geophysical Research Book on June 25th.
Between 2000 and 2023, glaciers around the world lost 301 billion tonnes of ice in bulk (273 billion tonnes) of ice per year, contributing about a fifth of the observed sea level rise. The aim of the new study was to determine whether glacial melts over the past four years have stood out from the past few years.
Related: Glaciers around the world are losing enough ice to fill three Olympic pools per second, scary new research finds
Researchers have found 2021-2024 was the worst period of ice loss since glacial monitoring began in the 1960s. Glacier ice losses have been extreme in four years, with one-tenth of all Swiss glacial ice melting in just two years between 2022 and 2023.
“It is interesting, but we are also wary of seeing these extremes become widespread and occurring globally, not just in a single territory.
Glacier ice losses not only exacerbate sea level rise, but also threaten freshwater availability, increase the risk of geohazards, and significantly alter the mountain landscape.
Heat waves and wildfires
To investigate glacial melts, the team used the World Glacier Monitoring Service and data from aerial surveys, as well as climate records and satellite observations. They fed this information to computer models to assess the massive changes in two US glaciers, three Canadian glaciers and five Swiss glaciers. Two US glaciers were the South Cascade Glacier in Washington and the Sperry Glacier in Montana. The three Canadian glaciers were their locations: Pey and Helm Glacier.
In both North America and Switzerland, one of the biggest drivers of glacial melts was the extremely high summer temperatures. The June 2021 heatwave in the US and western Canada caused enormous losses in snow, and another heatwave in 2023 caused an early start to the wildfire season.
Dark surfaces from soot and other impurities absorb radiation from the sun more than surfaces of light, leading to more melting. More melt exposes the vegetation. Vegetation is darker than darkened ice, thus leading to increased heat absorption. This additional heat absorption at the Earth’s surface gradually contributes to global warming as heat is no longer reflected into space.
Another important factor driving the glacier melt was the loss of the FIRN zone, an area where snow was not yet compressed into ice. Snow in these zones has a granular texture that helps to retain meltwater and prevent spills. Research also shows that sunlight returning to space rather than ice is reflected.
The computer model of the glacier does not currently describe the effects of SOON and other impurities. The study authors argued that the effects of extreme weather phenomena such as wildfires and heat waves should also be considered.
Peak Glacier Ice Loss
The study said ice losses from the glaciers peaked between 2021 and 2024, causing serious concerns about water management in some areas, Huss said.
“While there is no future reduction in fusion and additional warming will not reduce blending, large losses have rapidly reduced ice cover and even the complete disappearance of small glaciers in some areas,” he said.
This means that even if glaciers continue to raise the temperatures on the Earth, they will release less water into rivers and streams than they did until 2024. Therefore, communities, agriculture and industries that rely on glacial meltwater may have a decline in supply over the next few years.
The results are surprising and “clearly fits with global trends,” Hass said. However, it is important to note that it emphasizes two regions. [western U.S.-Canada and the Swiss Alps] There have been absolutely exceptional changes over the course of a year and that doesn’t immediately reflect in all regions,” he said.
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