An aerial view of the Pamir Mountains in Central Asia. Often called the “Roof of the World,” this vast range is defined by its glaciers, which act as a vital “water tower” sustaining millions in the dry lowlands below. Credit: Wikimedia Commons

Even glaciers that once resisted climate change are now cracking. Across the Pamir and Tien Shan mountains, ice that held steady for decades is vanishing at unprecedented speed.

New measurements from Kangxiwa Glacier in the eastern Pamir and regional studies across Central Asia reveal that 2025 brought record-breaking ice loss.

In a single year, glaciers shed billions of tons of ice, driven by persistent heat, early melt seasons, and shrinking snowfall. The consequences ripple far beyond the mountains: these glaciers feed rivers that sustain millions of people downstream, providing water for drinking, farming, and hydropower. Scientists warn that the “last stable glaciers” are now part of the global pattern of ice decline, signaling an accelerated threat to regional water security and the communities that rely on it.

Retreating Ice

The clearest warning comes from Kangxiwa Glacier, a 3-kilometer-long river of ice in the eastern Pamir of China’s Xinjiang Uyghur Autonomous Region. The glacier sits high in the mountains, rising to 5,350 meters above sea level, and scientists have measured its mass directly since 2011.

Before 2022, Kangxiwa lost ice at a fairly modest rate, with some years of slight growth. Then the losses accelerated. In 2025, the glacier lost the equivalent of 1.5 meters of water spread across its entire surface—about 4.1 times its average annual loss from 2011 to 2024. Even the glacier’s highest zones, which usually hold onto snow and ice, melted sharply.

The study, led by Fan Yu of the Chinese Academy of Sciences, points to a simple cause: heat. Specifically, heat that did not let up.

Earlier hot years hit Kangxiwa hard, but their worst temperatures were concentrated in a single month. In 2025, unusual warmth lasted from May through September, spanning almost the entire melt season. The glacier also grew darker as snow disappeared from its surface. Its average melt-season albedo—a measure of how much sunlight a surface reflects—fell to its lowest level since satellite records began in 2003. By September 2025, the glacier was nearly snow-free.

That change creates a feedback loop. Fresh snow reflects sunlight. Bare ice absorbs more of it. Once the protective snow cover vanishes, the glacier heats and melts faster.

The Pamir glacier during winter time. Credit: Wikimedia Commons It’s Everywhere

The Kangxiwa result was not isolated. Other monitored glaciers across the Pamir also showed extreme mass loss in 2025, suggesting that the event reached beyond a single glacier valley.

A second study, led by Lander Van Tricht of Vrije Universiteit Brussel and ETH Zürich, widens the lens. Using field observations from 16 glaciers across the Tien Shan and Pamir, combined with regional modeling, that team estimated that Central Asian glaciers lost 30 ± 6 cubic kilometers of ice in 2025—about 2% of their remaining glacier mass.

The regional study found that 64% of glaciers larger than 1 square kilometer had their most negative mass-balance year in the study period. The strongest losses occurred in the western Tien Shan and western Pamir, where some glaciers lost 2 to 4% of their total volume in a single year.

Khan Tengri is a 7,010-meter peak in the Tien Shan mountains, pictured here alongside the Southern Inylchek Glacier. Credit: Wikimedia Commons A Water Tower Under Strain

If glaciers in Central Asia collapse, millions of people are in big trouble.

These glaciers help feed rivers that sustain agriculture, hydropower, ecosystems, and drinking water across dry lowlands. They’re essentially a “water tower” for the region, storing snow and ice in winter and releasing meltwater during hot, dry months when demand rises.

But that role can also create a dangerous illusion. As glaciers shrink, meltwater may rise for a time. But once enough ice disappears, runoff declines. The same process that can briefly swell rivers can leave future summers with less reliable water.

The regional study found that 2025 combined several damaging ingredients: warm spring and summer temperatures, an early melt season, fewer snowfall days, and early exposure of darker ice. In many places, total snowfall was not dramatically low, but snow fell less often during the months when fresh snow would usually shield the ice.

Scientists caution that one year does not define the full future of a mountain range. Kangxiwa’s direct mass measurements go back only to 2011, making it hard to place 2025 in a much longer local history. Shaun Eaves of Victoria University of Wellington told New Scientist that the results fit expectations under human-driven warming, but that it is too early to say the current level of melt is locked in.

Still, the direction is clear. A region once known for resisting glacier loss has joined the global pattern. The roof of the world is no longer standing apart.

The studies were published in the journals Advances in Climate Change Research and Environmental Research Letters.