408bn tonnes of glacier ice lost during 2025 leading to rise in global sea levels
Cassie Matias Unsplash
Glaciers around the world continued to lose ice at an exceptionally high rate in 2025 according to a major international assessment supported by University of Birmingham research.
The study published in Nature Reviews Earth & Environment looks at the majority of Earth’s glaciers which lost an estimated 408 billion tonnes of ice during the 2025 hydrological year. The ice loss, which excludes large ice sheets in Greenland and Antarctica, contributed approximately 1.1mm to global sea levels, underlining the growing impact of climate change on frozen regions of the planet.
The largest average glacier losses in 2025 were recorded in North America, Iceland and Central Europe, while the most unusual departures from long-term climate averages were seen in Western Canada, and Svalbard in Norway.
Dr Nick Barrand, a glaciologist at the University of Birmingham, contributed specialist datasets and expertise to the global analysis, which brings together observations from national monitoring networks and research institutions worldwide.
Glaciers are responding very quickly to a warming climate, and what we’re seeing now is the cumulative result of decades of rising temperatures. Continued, coordinated monitoring is essential if we are to understand how these changes will affect sea level, water resources and mountain communities in the years ahead.
The assessment forms part of an ongoing international effort to track glacier health and understand how rapidly glaciers are responding to climate change.
The findings highlight how glacier loss has accelerated exponentially over recent decades. Average global glacier mass loss has increased from less than 100 billion tonnes per year between 1976 and 1995, to around 230 billion tonnes per year between 1996 and 2015, and almost 390 billion tonnes per year over the past decade.
Since 1975, glaciers have lost a total of nearly 9,600 billion tonnes of ice, equivalent to around 26 millimetres of global sea-level rise. Alarmingly, six of the seven highest glacier-loss years on record have occurred in the past seven years.
2025 was another year in which glaciers continued to melt at a very high rate. To put this into perspective, the amount of ice lost that year would have filled five Olympic swimming pools every second
The 2025 results have been published in the Climate Chronicles of Nature Reviews Earth & Environment and featured in the European State of the Climate 2025 report, produced by the Copernicus Climate Change Service and the World Meteorological Organization.
Associate Professor of Glaciology
Dr Nicholas Barrand is a glaciologist specialising in mass balance and dynamics of the Earth's glaciers and ice sheets.
