The largest glacier in mainland Norway and mainland Europe, Jostedalsbreen, is located in Vestland county in western Norway.
Jostedalsbreen covers area of 458 km² and is an ice cap – a large, thick ice mass with a high, relatively flat interior with ice flowing outwards in all directions. The ice cap is a part of one of the Norwegian national parks, Jostedalsbreen National Park, established in 1991.
A new study by Norwegian researchers at University of Oslo, University of Bergen, the Norwegian Water Resources and Energy Directorate, and Western Norway University of Applied Sciences shows what will happen to Jostedalsbreen in a warmer climate. The nine authors simulated the glacier’s future to year 2100 and 2300 using an advanced numerical model. The model calculated how the ice will melt and flow under different greenhouse-gas emission scenarios.
The researchers’ findings have been published in the journal The Cryosphere and are also included in the recent report about the Norwegian future climate released in October 2025.
Temperatures are rising, glaciers are retreating
The report Climate in Norway – Knowledge Base for Climate Adaptation, published in 2025, shows that the temperature in Norway increased by about 1.4 °C between 1901 and 2024. Most of this, roughly 1 °C, has occurred in the past 50–60 years.
The researchers’ new glacier projections indicate that Jostedalsbreen will lose a moderate amount of ice through about 2050 and then decline substantially thereafter. This is based on future temperature increases under moderate greenhouse gas emissions.
"This will result in the glacier fragmenting into several smaller units and in outlet glaciers retreating by several kilometres. These glacier arms will be far less visible and accessible from the nearby valleys," says Henning Åkesson, a researcher at University of Oslo who led the study.
The researchers’ calculations also show that, if the glacier were to disappear completely, today’s climate would not be favourable enough for it to regrow to its present size.
Small glaciers are melting away, and the largest glaciers are retreating
“This climate is changing, Norway’s glaciers are struggling in the heat, and this will continue. Our smallest glaciers are already disappearing. When the ice retreats and the landscape changes, future glacier hikers or those attempting the popular spring ski traverse “Josten på langs” will have to go much farther,” the researchers write in an popular‑science article on forskersonen.no.
“But it will take longer for Jostedalsbreen to disappear than for the smaller glaciers. This is a large plateau glacier covering an area the size of Oslo municipality, and the ice is up to 630 metres thick, with an average thickness of around 150 metres,” says Liss Andreassen of NVE, a co author of the study.
What is the history of Jostedalsbreen — was it part of the ice sheet covering northern Europe during the last Ice Age?
“Jostedalsbreen is believed to have existed here since about 6,000 years ago, when the climate gradually cooled. Most likely all, or nearly all, Norwegian glaciers melted away during a warm period roughly 5,000–7,000 years ago. Norwegian glaciers are therefore not remnants of the big ice sheet from the last ice age, even though it is easy to assume so,” says Åkesson.
What could happen to Jostedalsbreen after 2100?
“The scenario in which Jostedalsbreen is halved by the end of this century corresponds to what we can expect under the emissions reductions currently pledged by countries worldwide. But if those cuts fail and emissions continue to rise, the glacier will have only just over one third of today’s ice volume by 2100,” says Henning Åkesson.
The researchers warn that this trend will continue beyond 2100: under a high emissions pathway, Jostedalsbreen could lose 99% of its present volume by 2300. According to the scientists, future emissions pahtways will therefore determine whether coming generations will get to experience Jostedalsbreen.
The scientific study:
Åkesson, H., Sjursen, K. H., Vikhamar Schuler, T., Dunse, T., Andreassen, L. M., Kusk Gillespie, M., Robson, B. A., Schellenberger, T., and Clement Yde, J. Recent history and future demise of Jostedalsbreen, the largest ice cap in mainland Europe, The Cryosphere, 2025.
More about the research:
The research project: Natural and societal consequences of climate-forced changes of Jostedalsbreen Ice Cap (JOSTICE-prosjektet), read more at: jostice.no
Funding
The work behind this study was funded by the Research Council of Norway under the JOSTICE project (grant no. 302458).
Facts: Jostedalsbreen — ice cap in Vestland County, western Norway.
Size: ~458 km² (largest on mainland Norway/ mainland Europe); max ice thickness ~630 m (avg. ~150 m).
History: Post glacial ice cap (~6,000 years); expanded in the Little Ice Age, retreated in the 20th–21st centuries; mostly inside Jostedalsbreen National Park (est. 1991).
Outlook: Models project major shrinkage this century — roughly halving under current emission pledges or down to ~1/3 of current ice volume by 2100 if emissions rise, with further losses toward 2300.
Sources: NVE, JOSTICE project, The Cryosphere; Klima i Norge (2025).