2025 was the fourth consecutive year in which every major glaciated region recorded a net loss in ice mass, according to the World Meteorological Organisation’s (WMO) latest State of Global Water Resources 2025 report. In the year between October 2024 and September 2025, glaciers around the world lost 408 ± 132 gigatonnes of mass, equivalent to a sea level rise of 1.1 ± 0.4 mm.
The continued loss of glacier ice mass means that six of seven largest annual losses from glaciers have occurred in the last seven years. “Specifically, in 2025, the Central Asia, South Asia West, Russian Arctic, Iceland, and Western Canada and USA regions all recorded annual mass balances that ranked among the three most negative years on record for those regions,” according to the report. “Overall, the substantial loss of glacier mass throughout the twenty-first century represents a decline in global freshwater resources,” the report added.
The report highlighted that mountain glaciers lost 6.2 per cent of the ice mass between 2000 and 2025. In some regions there is a substantial decrease in overall mass of glaciers of up to 40 percent over the past many decades.
For instance, glaciers in the central Altai region of Russia have recorded a mass loss of 271.7 square kilometres or 40.2 per cent since the 1950’s. Out of this 18.8 per cent or 93.8 square kilometres was lost since 2001. The strongest losses were recorded in the South Chuya range.
“Since the 1990s, ice loss has been increasing in almost all regions, and it has considerably accelerated since 2000. This is mostly due to regions consistently presenting larger summer melt than winter accumulation after the 1990s,” as per the report.
Some regions that mostly have smaller glaciers such as the Caucasus, western Canada and United States, central Europe experienced little or no increase, or even a decline, in the minimum runoff (approximate) during the summer season known as the summer balance. This was despite a greater annual mass loss compared with the longer term 1991-2020.
“This indicates that these regions may already have reached peak water conditions”, according to the report authors. Peak water is the threshold where the glacier reaches its maximum run off due to melting, according to the report.