The food and water security of approximately 2bn people will be negatively affected by the rapid retreat of glaciers, the United Nations has warned, and accelerating melt rates are expected to have severe and unpredictable consequences, The Guardian reported on March 24.

Two-thirds of all irrigated agriculture globally could be impacted by shrinking glaciers and reduced snowfall driven by the Climate Crisis, according to a Unesco report released alongside the World Water Development Report 2025,

More than 1bn people reside in mountainous regions, with up to half of those in developing countries already experiencing food insecurity. The situation is expected to worsen, as food production in these areas relies heavily on mountain waters, melting snow and glaciers. “Regardless of where we live, we all depend in some way on mountains and glaciers. But these natural water towers are facing imminent peril. This report demonstrates the urgent need for action,” said Audrey Azoulay, Director General of UNESCO, The Guardian reported.

The issue is not confined to developing countries. In the United States, the Colorado River basin has experienced drought conditions since 2000. Warmer temperatures mean more precipitation falls as rain rather than snow, leading to faster runoff and exacerbating drought.

Recent research from the World Meteorological Organisation highlights that the pace of glacier loss is the worst on record. The largest three-year loss of glacier mass occurred over the past three years, with Norway, Sweden, Svalbard and the tropical Andes among the worst-affected regions. In Eastern Africa, up to 80% of glaciers have disappeared, while the Andes have lost between a third and a half of their glaciers since 1998. European glaciers in the Alps and Pyrenees have shrunk by about 40% over a similar period.

Beyond water supply concerns, the melting of glaciers is also contributing to climate change. “Glaciers melting have an impact on the reflectivity of [solar] radiation and that will impact the whole climate system,” warned Abou Amani, Director of Water Sciences at UNESCO. The loss of reflective ice surfaces, replaced by heat-absorbing dark soil, is contributing to further warming.

The risks extend beyond gradual changes. More avalanches are expected, as rain falling on snow is a major factor behind avalanche formation. Melting glaciers can also cause sudden flooding in valleys, while permafrost melt releases methane previously trapped in the soil, further exacerbating climate change.

A study published last month in Nature predicted that half of the world’s glacier mass could be lost by the end of the century if global warming is not halted. The British Antarctic Survey noted the far-reaching impacts. Mountain glaciers contain some of the largest freshwater reservoirs on Earth. Meltwater released in the summer provides the water supply to a billion people and sustains an enormous amount of industry and agriculture.