Glacier meltdown threatens water and food security for 2 billion people, UN warns

The unprecedented melting of glaciers worldwide threatens the food and water supply of 2 billion people, with two-thirds of global irrigated agriculture likely to be affected, according to a United Nations report cited by The Guardian.

The UNESCO World Water Development Report 2025 warns that mountain regions, home to more than 1 billion people, face increasing water insecurity as climate change accelerates glacier retreat and reduces snowfall.

“Regardless of where we live, we all depend in some way on mountains and glaciers. But these natural water towers are facing imminent peril,” said UNESCO Director General Audrey Azoulay. “This report demonstrates the urgent need for action”.

The findings come as the World Meteorological Organisation (WMO) reported the largest three-year loss of glacier mass on record occurred in the past three years, with Norway, Sweden, Svalbard and the tropical Andes among the worst-affected areas.

Eastern Africa has lost 80% of its glaciers in some areas, while the Andes has seen between one-third and half of its glaciers melt since 1998. European glaciers in the Alps and Pyrenees have shrunk by about 40% over roughly the same period.

Up to half of people living in mountainous regions of developing countries already experience food insecurity, a situation likely to worsen as mountain waters, melting snow and glaciers are critical for food production, according to the report.

Even developed nations face significant risks. The Colorado River basin in the United States has experienced drought conditions since 2000, exacerbated by higher temperatures causing precipitation to fall as rain rather than snow, resulting in faster runoff.

Abou Amani, director of water sciences at UNESCO, highlighted an additional consequence of glacier retreat: “Glaciers melting have an impact on the reflectivity of [solar] radiation and that will impact the whole climate system“.

The loss of reflective ice surfaces exposes darker soil that absorbs more heat, potentially accelerating warming in a feedback loop.

Other hazards include increased avalanche risk, as rain falling on snow is a major factor in their formation, and sudden flooding from glacial meltwater pools. Melting permafrost is also releasing methane from previously frozen mountain soils.

A study published last month in the journal Nature found that half of global glacier mass would be lost by century’s end if global heating continues unabated.

“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,” said Alex Brisbourne, a glacier geophysicist at the British Antarctic Survey.

Alvaro Lario, president of the International Fund for Agricultural Development (IFAD) and chair of UN-Water, called for greater support for mountain communities.

“Water flows downhill, but food insecurity rises uphill. Mountains provide 60% of our freshwater, but the communities that safeguard these vital resources are among the most food insecure,” Lario said. “We must invest in their resilience to protect glaciers, rivers, and a shared future for all of us”.

(information from The Guardian)