If global temperatures continue on their current path, up to 75% of the world’s glaciers could disappear over time, even without any further warming.
An international study using glacier models shows that even stabilizing temperatures at today’s levels would still cause nearly 40% loss due to the delayed response of glaciers. Researchers stress that every fraction of a degree makes a difference, and the consequences of today’s climate choices will resonate for centuries.
Dire Future for Glaciers Under Current Climate Policies
If global temperatures rise by 2.7 degrees Celsius, which aligns with current climate policies, only about one-quarter of the world’s glacier ice would remain. That’s the sobering conclusion of a major international study, which includes researchers from the University of Bremen and was published in the journal Science.
The study also offers a sliver of hope. If global warming can be limited to 1.5 degrees Celsius, the goal of the Paris Climate Agreement, just over half of all glacier ice could still be saved.
To reach these findings, 21 scientists from ten countries used eight independent glacier models to simulate the long-term fate of more than 200,000 glaciers around the world, excluding those in Greenland and Antarctica. They tested a range of global temperature scenarios and assumed temperatures would hold steady over thousands of years in each case.
Even Today’s Warming Spells Major Glacier Loss
One of the most striking results is that glacier loss will continue even if global warming stops today. At the current global temperature of 1.2 degrees Celsius above pre-industrial levels, nearly 40 percent of glacier ice is already expected to vanish. This is because glaciers respond slowly to climate change, meaning their melt is largely locked in. That alone will contribute over 10 centimeters to sea level rise. And for every additional 0.1 degree of warming, scientists predict another 2 percent drop in global glacier mass.
Professor Ben Marzeion from MARUM – Center for Marine Environmental Sciences at the University of Bremen is involved in the study. “The results underline the fact that current climate policy plays a decisive role in how glaciers will develop in the future. Not just concerning the coming decades, but also in several hundred years’ time. It illustrates the responsibility we carry for generations to come,” emphasizes Marzeion.
“Our study makes it painfully clear that every fraction of a degree matters,” says co-lead author Dr. Harry Zekollari from the Vrije Universiteit Brussel. “The choices we make today will resonate for centuries, determining how much of our glaciers can be preserved.”
Glaciers Set to Shrink for Centuries
In all scenarios, glaciers lose mass rapidly over decades and then melt more slowly for centuries, even if it does not get any warmer. This means that the current warming will continue to affect the glaciers for a long time before they have retreated to higher altitudes and reached a new equilibrium.
“Glaciers are good indicators of climate change because their retreat allows us to see with our own eyes how climate is changing. However, since they adjust over longer timescales, their current size vastly understates the magnitude of climate change that has already happened. The situation for glaciers is actually far worse than visible in the mountains today,” says co-lead author Dr. Lilian Schuster from the University of Innsbruck.
Glacier retreat not only affects sea levels, but also has far-reaching consequences for the availability of fresh water, increases the risk of glacier-related hazards, and threatens glacier-based tourism. These changes are already making themselves felt in many regions and underline the importance of a global climate policy.
Contribution to the International Year of Glacier Preservation 2025
The study is an important contribution to the United Nations International Year of Glacier Preservation (2025) and underlines the urgent need for global climate action to save the world’s glaciers. The research was conducted as part of the Glacier Model Intercomparison Project (GlacierMIP), coordinated by the Climate and Cryosphere (CliC) project of the World Climate Research Program WCRP.
Explore Further: Nearly Half of Earth’s Glaciers Are Already Doomed, Even Without Future Warming
Reference: “Glacier preservation doubled by limiting warming to 1.5°C versus 2.7°C” by Harry Zekollari, Lilian Schuster, Fabien Maussion, Regine Hock, Ben Marzeion, David R. Rounce, Loris Compagno, Koji Fujita, Matthias Huss, Megan James, Philip D. A. Kraaijenbrink, William H. Lipscomb, Samar Minallah, Moritz Oberrauch, Lander Van Tricht, Nicolas Champollion, Tamsin Edwards, Daniel Farinotti, Walter Immerzeel, Gunter Leguy and Akiko Sakai, 29 May 2025, Science.
DOI: 10.1126/science.adu4675
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2 Comments
“The choices we make today will resonate for centuries, determining how much of our glaciers can be preserved.”
Ultimately, NONE can be preserved. Glaciers are ephemeral features that are always moving downhill and spreading out from their accumulation centers. During the Eemian interglacial, virtually all of the Greenland Ice Sheet melted, leaving, at best, scattered alpine glaciers along the crest of the mountains ringing the central basin. Then, all the ice came back.
It isn’t just a concern about anthropogenic warming during the post-industrial age. The massive accumulations of ice originating in Canada during the most recent glaciation reached their peak about 20,000 years ago and started to melt back; melting accelerated significantly about 11,000 years ago. Melting may well have accelerated even more post Industrial Revolution, but has been melting for at least 20,000 years. Inasmuch as there is still considerable ice in Greenland, a similar course could be expected with or without anthropogenic warming.
“Glacier retreat not only affects sea levels, but also has far-reaching consequences for the availability of fresh water, …”
That’s true. However, meltwater will continue to be available until all the alpine glaciers are gone. On the other hand, were the current Holocene interglacial to end, the cooling would reduce the availability of meltwater until the ice eventually overrides the farmland that needs the water.
Are glacier tourists so important that we would overturn the world economy by banning fossil fuels? There was a time not so long ago (the Little Ice Age) that expanding glaciers in the Alps were threatening small towns and villages and people prayed for the glaciers to stop their advance. There was good news and bad news: Their prayers were answered. We are now complaining that their prayers were answered.
The one thing that is constant on Earth is change. We should accept it and not think that we are smart enough to prevent it without having unintended consequences. Had the timing been a little different, and the people living in the Alps had had the ability to alter the climate, we might not have accumulated the reservoir of ice that provides the Alps and Himalayas with water today. Humans are so short-sighted. Most seem unable to look more than a few days into the future. We can be, and often are, our own worst enemy.
They tested a range of global temperature scenarios and assumed temperatures would hold steady over thousands of years in each case.
GOOD!
Please ask researchers to think deeply:
1. Is the temperature difference between the Earth’s poles and equator affected by the distance between the Earth and the Sun?
2. Is the temperature higher the closer to the sun on Earth?
3. How does the sun heat up objects?
If researchers are interested in this, please browse https://zhuanlan.zhihu.com/p/1916783850291466914.