MOUNTAINEERING: THE CHANGING MOUNTAINS

AI Summary

An avalanche on Broad Peak killed all 10 members of an international climbing expedition, including Pakistani guide Sohail Sakhi and mountaineer Nirmal Purja. The article examines whether warming contributed to unstable conditions, while noting that heavy snowfall and the timing of the summit attempt may also have played a role; climbers describe changing glaciers, routes and weather patterns across the Karakoram.

Climbing Broad Peak | Courtesy the writer On July 30, 2026, an avalanche swept through an internat­ional expedition on the 8,051-metre Broad Peak, killing all 10 climbers, among them a beloved Pakistani mountain guide, Sohail Sakhi, and renowned British-Nepali mountaineer Nirmal ‘Nims’ Purja. The obvious question, particularly in a year when climbers across the Karakoram range have repeatedly complained of unstable conditions, is whether climate change played a role. There is no evidence yet to say that it did, at least not directly. Fida Ali Arandu, a veteran Pakistani mountaineer and a member of the Purja’s Elite Exped team, believes climate change may have contributed, but also points to another factor: heavy snowfall in the days before the accident and what he considered an overly hurried summit push. His advice is simple: after heavy snowfall, wait, let the mountain settle and only move when conditions are clear. Naila Kiani, who has climbed 12 of the world’s highest mountains, says the question surrounding the serac collapse that triggered the Broad Peak avalanche remains unresolved. Was it the result of a normal accumulation of snow and ice, or had warming temperatures contributed to instability? “We’re still trying to analyse” what happened, she says. Glaciers are retreating, routes are shifting and rockfall and avalanches are becoming more common. Even the traditional seasons are no longer predictable. Is climate change rewriting the rules of mountaineering? That uncertainty is important. Not every avalanche is caused by global warming. Avalanches have always been part of mountaineering. What is changing, however, is the mountain environment in which those avalanches occur and, increasingly, the predictability of that environment. For mountaineers who have spent years travelling through the Karakorams, the changes are becoming impossible to ignore. MOUNTAINs IN FLUX Sajid Sadpara has spent nearly a decade climbing major peaks in the Himalayas and Karakorams. He says one of the most obvious changes has been the formation of new glacial lakes and the changing nature of established climbing routes. On Gasherbrum I this year, something as mundane as leaving a bottle of water outside the tent became an indication of a much warmer mountain. At Camp 1, water that previously would have frozen overnight did not. Climbers wearing heavy down jackets found themselves feeling hot. Then there were the crevasses. A familiar route between Camp 1 and Camp 2 had changed enough that the team had to find an alternative. The new route took considerably longer. “These changes are happening in front of our eyes,” Sadpara says. Fida Ali has witnessed a similar transformation over decades of travelling through the Karakorams. Glaciers that once appeared stable are retreating; large blocks of glacial ice are breaking away and falling into rivers. Even after August — traditionally the point when temperatures begin dropping and mountain surfaces start to refreeze — rivers, he says, are continuing to swell. The science supports the broader picture. A 2026 review published in Natural Hazards, an academic journal that publishes research on the causes and effects of natural disasters, found within the the Himalaya-Karakoram region widespread retreat and expansion of glacial lakes under a warming climate, with more than 388 documented glacial lake outburst flood (GLOF) events across the region. The researchers also identify ice avalanches and extreme precipitation among the important triggers of these events. For climbers, glacier retreat is not simply an environmental statistic. It changes the route beneath their feet. Snow bridges disappear. Crevasses widen. Ice becomes less predictable. Rock previously held together by frozen ground becomes exposed. And that can transform a route that has been considered familiar for generations. WHEN ROCK REPLACES ICE Kiani remembers seeing the Baltoro Glacier for the first time in 2018. Since then, she’s made multiple trips until her last in 2024. She says the landscape now looks dramatically different. “In several sections where there used to be ice and snow, there is now rock,” she says. “These changes used to take decades. And they are now happening in months.” She also experienced increased rockfall on Everest in 2023, an area where she had not expected to encounter such frequent falling rock. Fida Ali knows the danger personally. Last year, while climbing Nanga Parbat, he was struck in the head by falling rock. Bleeding heavily, he managed to descend to Camp 1 and eventually Base Camp himself. For climbers, rockfall can be particularly dangerous because it can be difficult to predict. The relationship between warming and rockfall is increasingly well documented in mountain environments. As temperatures rise, permafrost — ground that has remained frozen for years or centuries — can thaw. Glaciers also retreat, removing some of the physical support they provide to surrounding slopes.