An international study published in Science, has found that only 24% of present-day glacier mass will remain if the world were to warm to 2.7°C above pre-industrial level, the trajectory set by current climate policies. In contrast, limiting warming to 1.5°C — the target of the Paris Agreement — would preserve 54% of glacier mass.
A team of 21 scientists from ten countries used eight glacier models to calculate potential ice loss of the more than 200,000 glaciers outside of Greenland and Antarctica under a wide range of global temperature scenarios. For each scenario, they assumed that temperatures would remain constant for thousands of years.
Substantial global glacier loss even without any further global warming
The results are striking: even without any further global warming – that is, if global temperatures were stabilised at today’s level of 1.2°C — 39% of global glacier mass would eventually disappear, contributing over 10 cm to global sea-level rise.
Crucially: for each additional 0.1°C of warming, the world stands to lose roughly another 2% of its glacier ice.
“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.
Retreating glaciers may find a new balance in higher altitudes
In all scenarios, the glaciers lose mass rapidly over decades and then continue to melt at a slower pace for centuries, even without further warming. This means they will feel the impact of today’s heat for a long time before settling into a new balance as they retreat to higher altitudes.
“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.
Beyond its impact on sea levels, glacier loss poses far-reaching consequences for freshwater availability, increases the risk of glacier-related hazards, and threatens ecosystems and glacier-fed tourism.
These changes will be felt across regions and generations, underscoring the importance of global climate policies.
Glaciers on Svalbard and on the Norwegian mainland are severely affected
One researcher behind the new study of the status and forecast of the world`s glaciers is Regine Hock, a Professor of Glaciology at University of Oslo. She emphazises the critical situation for the glaciers in Scandinavia.
“The situation is particularly dire for Scandinavia and Svalbard. Even without any further global warming two thirds of Scandinavia's ice and nearly half of Svalbard's would melt before the glaciers eventually reach a new balance with the climate. This will have major consequences for river flow, hydropower generation, glacier-related hazards”, and tourism centered around glaciers.
International alertness on preservation of the worlds glaciers
To tackle the alarming loss of glaciers and raise awareness, the United Nations made 2025 the first international year of glaciers' preservation. March 21st of each year will be observed as 'World Day for Glaciers' starting in 2025.
In Norway, this day was marked with an open seminar and an exhibition at the Climate House at the Natural History Museum, University of Oslo. The exhibition was titled 'The Little Ice Age: How did we handle the last climate crisis?'.
This international study, published in Science, is a key contribution to the United Nations International Year of Glaciers' Preservation 2025, underlining 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 Programme (WCRP).
Publication and reference:
Zekollari, Schuster, Maussion, Hock et.al. Glacier preservation doubled by limiting warming to 1.5°C versus 2.7°C, Science, may 2025.
