Largest glacier mass loss in past 3 years: World Meteorological Organisation

WMO and the World Glacier Monitoring Service (WGMS) reported on Friday that many regions’ so-called “eternal ice” will not survive the 21st century

The past three years have witnessed the largest loss of glacier mass on record, according to the World Meteorological Organisation (WMO).

Five of the past six years have seen the most rapid glacier retreat ever recorded, the WMO said. (AP/ Representative image)

WMO and the World Glacier Monitoring Service (WGMS) reported on Friday that many regions’ so-called “eternal ice” will not survive the 21st century. The announcement coincided with the first-ever World Glaciers Day.

Five of the past six years have seen the most rapid glacier retreat ever recorded, the WMO said. More than 275,000 glaciers worldwide cover approximately 700,000 square kilometres.

“Together with ice sheets, glaciers store about 70% of the global freshwater resources. High mountain regions are the world’s water towers,” the WMO said.

The organisation warned that glacier depletion threatens water supplies to hundreds of millions of people living downstream who depend on water stored over winter being released during hot, dry periods. In the short term, glacier melt increases natural hazards such as floods.

Last year, the United Nations General Assembly proclaimed 2025 as the International Year of Glaciers’ Preservation and established 21 March as the annual World Day for Glaciers.

WMO’s State of the Global Climate 2024 report, released earlier this week, confirmed that 2022-2024 saw the largest three-year loss of glaciers on record.

“Seven of the ten most negative mass balance years have occurred since 2016. Preservation of glaciers is not just an environmental, economic and societal necessity. It’s a matter of survival,” said WMO Secretary-General Celeste Saulo.

Based on worldwide observations, WGMS estimates that glaciers (separate from the continental ice sheets in Greenland and Antarctica) have lost more than 9,000 billion tonnes of ice since records began in 1975.

“This is equivalent to a huge ice block of the size of Germany with a thickness of 25 metres,” said Prof Michael Zemp, director of WGMS.

The 2024 hydrological year marked the third consecutive year in which all 19 glacier regions experienced a net mass loss. While the loss was relatively moderate in regions such as the Canadian Arctic or the Greenland periphery, glaciers in Scandinavia, Svalbard, and North Asia experienced their largest annual mass loss on record.

At current melt rates, many glaciers in Western Canada and the US, Scandinavia, Central Europe, the Caucasus, New Zealand, and the Tropics will not survive the 21st century, according to WGMS.

From 2000 to 2023, global glacier mass loss totalled 6,542 billion tonnes — an average of 273 billion tonnes of ice lost per year, the monitoring service reported. This equals water that the entire global population currently consumes in 30 years, assuming three litres per person per day.

WMO cited a February 2025 research paper published in Nature on global glacier mass loss since 2000. The study, led by researchers from the University of Zurich, found that glaciers have lost about 5% of their ice globally since 2000, with regional variations ranging from 2% on the Antarctic and Subantarctic Islands to 39% in Central Europe.

During this period, glacier melt contributed 18 millimetres to global sea-level rise.

“This might not sound much, but it has a big impact: every millimetre sea-level rise exposes an additional 200,000 to 300,000 people to annual flooding,” said Zemp.

Glaciers are currently the second-largest contributor to global sea-level rise, after ocean warming.

WGMS also declared South Cascade Glacier in Washington’s Cascade Range as the “Glacier of the Year 2025” because scientists have monitored it continuously since 1952.

“South Cascade Glacier exemplifies both the beauty of glaciers and the long-term commitment of dedicated scientists and volunteers who have collected direct field data to quantify glacier mass change for more than six decades,” said Caitlyn Florentine, co-investigator of the glacier from the U.S. Geological Survey.