Countries around the world, including Nepal, marked International Mountain Day on Thursday to raise awareness of growing threats to mountain ecosystems and the communities that depend on them.

This year’s theme, “Glaciers matter for water, food and livelihoods in mountains and beyond,” highlights the role of glaciers in sustaining agriculture, water supplies and jobs, the U.N. Food and Agriculture Organization (FAO) said.

Mountains cover about 27% of the Earth’s land surface, shelter 15% of the global population and contain nearly half of the world’s biodiversity hotspots. They also act as natural “water towers,” supplying freshwater to more than a billion people.

Scientists warn that rising temperatures are accelerating glacier retreat, threatening water security, energy production and agriculture for billions. The 2025 observance coincides with the U.N.-proclaimed International Year of Glaciers’ Preservation.

Nepal is already experiencing the impacts of warming, including faster glacier melt. Climbers say changes in the Himalayas are visible even on the highest peaks.

“A knee-deep stream runs along parts of the Khumbu Icefall and above. There’s no need to break ice anymore; water is readily available at Camp I,” said Dorji Gyaljen Sherpa, who has summited Everest 26 times.

He said conditions on the route change noticeably each year. “The changes are too obvious to the eye, as water flows where it never used to. This is concerning,” he said. Scientific studies are needed for precise measurements, he added, but climbers consider the Icefall the most treacherous section of the ascent.

Nepal is home to eight of the world’s 14 highest peaks, including Mount Everest, and has opened 414 mountains for climbing, 72 of them above 7,000 metres.

The country records some of the world’s highest fatality rates from landslides and flash floods. In October, three days of incessant rain killed more than 60 people and displaced hundreds of thousands. Heavy snowfall left trekkers missing, and rains caused extensive damage to crops at the tail end of the monsoon.

Last year, a glacial lake outburst flood swept away Thame, a Sherpa village at 3,800 metres. An avalanche on Manaslu triggered a breach of Birendra Lake, while an unexpected dry landslide destroyed a micro-hydropower plant, water and irrigation infrastructure, a wooden bridge and farmland in Til village in Humla district.

The FAO, which has coordinated International Mountain Day since 2003 through its #MountainsMatter campaign, said mountain communities, many of them Indigenous, are disproportionately affected by climate change. For many Indigenous groups, glaciers also hold cultural and spiritual significance.

Pema Gyamtsho, Director General of the International Centre for Integrated Mountain Development (ICIMOD), said glacier mass loss in the Hindu Kush Himalaya (HKH) has risen by 65% in a decade. The region contains more than 54,000 glaciers and the largest volume of ice outside the polar areas, feeding 10 major rivers that support more than two billion people.

“If current emission trends persist, up to 80% of the region’s ice could disappear by the end of the century,” Gyamtsho said.

An ICIMOD update released this week reported three consecutive years of below-average snowfall in the HKH, reduced spring snow cover and disrupted melt cycles. The changes are already affecting hydropower output, household water access and agriculture, it said.