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, 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 the potential ice loss of the more than 200,000 glaciers outside 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.
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 and ETH Zurich. "The choices we make today will resonate for centuries, determining how much of our glaciers can be preserved".
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 glacier-fed tourism. These changes will be felt across regions and generations, underscoring the importance of global climate policies.
This study 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).
