By Staff Reporter
ISLAMABAD: The number of glacial lakes in Pakistan’s mountainous north that have thawed this summer has climbed from 40 to 105 in under two months, according to satellite data released by the country’s national space agency, in a finding that has sharpened warnings over the risk of sudden, catastrophic flooding in communities living beneath them.
The Space and Upper Atmosphere Research Commission (Suparco) said the increase, recorded between early July and 5 August, was consistent with what scientists had anticipated as summer temperatures climbed across the Hindu Kush, Karakoram and Himalaya ranges. But the pace of the change, and the fact that several of the lakes have grown beyond any size previously recorded, has unsettled specialists who argue that satellite tracking alone cannot capture the full danger building in Pakistan’s high valleys.
In a press release, Suparco said its latest assessment relied on temporal satellite imagery — successive images taken over time that allow analysts to detect changes in a lake’s boundary and surface area. All of the lakes identified were mapped using optical satellite images, both to estimate their extent and to establish whether they remained frozen or had thawed. The agency said some lakes had already exceeded their previous maximum recorded size, a finding it described as a signal worth close attention, since an expanding lake can indicate a build-up of water pressure against the natural debris dam, known as a moraine, that normally contains it.
That distinction matters because, according to Suparco, a glacial lake becomes a far greater concern once its water extent pushes past its historical maximum. Such growth can point to increased water storage behind the moraine and a heightened chance that the dam will weaken or fail outright — the trigger for what scientists call a glacial lake outburst flood, or Glof, in which a wall of water, mud and debris is released without warning into the valley below.
Suparco cautioned, however, that the picture this time was harder to complete than usual. Persistent cloud cover in the weeks following its previous report, submitted in July, had restricted the number of cloud-free images available, making it more difficult to accurately track how far individual lakes had grown or shrunk.
The trajectory nonetheless points firmly upward. On 2 July, Suparco had recorded 40 unfrozen lakes and noted then that most remained within their previously observed limits — a comparatively reassuring finding at the time. Within five weeks, the number of thawed lakes had risen by 65, and the pattern of some lakes breaking past their historic maximums had begun to emerge.
Suparco said it was continuing to monitor a wider list of what it terms “potentially dangerous glacial lakes”, or PDGLs — water bodies flagged for their capacity to cause serious harm downstream if they burst. A total of 131 such lakes were identified in the August assessment, drawing on locations supplied by the Khyber Pakhtunkhwa Provincial Disaster Management Authority, the Gilgit-Baltistan Disaster Management Authority, and the Glacier Monitoring and Research Centre run by the Water and Power Development Authority (Wapda). The findings were passed on to the Ministry of Climate Change’s technical committee on Glof monitoring, the agency said.
Given the continued rise in temperatures and in the number of thawed lakes, Suparco said it had advised the relevant authorities to remain on a heightened state of readiness, “particularly in downstream valleys of potentially dangerous glacial lakes”. It said satellite monitoring would continue for the rest of the melt season in order to catch any sudden lake expansion or other early indicators of rising Glof risk, so that warnings could be issued and disaster planning put into motion before a lake fails rather than after.
Not everyone is convinced that watching from orbit is sufficient. Dr Karamat Ali, a glaciologist at Karakoram International University who has studied the region’s ice fields for two decades, said satellite imagery on its own could not substitute for sustained work on the ground. He described a system in which government departments, researchers and disaster agencies were often working in isolation from one another, with little coordination and, in his assessment, limited trust between them — a gap that has left significant blind spots in what is actually known about the glaciers themselves.
Those blind spots, he said, include basic information about the shape and structure of individual glaciers, the microclimates that form around them, and how much mass they gain and lose across summer and winter — all data that can only be gathered through field studies rather than pulled from space.
“Glacial melt is a serious concern,” Dr Ali said. “Numerous parameters are ignored which can only [be] verified from field studies, and mere satellite imagery will not suffice.”
He pointed specifically to the gap in knowledge around hanging glaciers — ice formations perched on steep slopes rather than settled into a valley floor — as an example of the kind of hazard that satellite monitoring is poorly equipped to flag in advance. It was a hanging glacier that broke away above Nepal’s Langtang valley on 26 August, sending a wall of ice, rock and water crashing down through the Bhote Koshi river system into Rasuwa district and across the border into Tibet. The disaster, which struck with a seismic signature initially mistaken for an earthquake, has killed more than a thousand people in Nepal and China combined, with thousands more still unaccounted for in the weeks since.
Dr Ali argued that comparable thoroughness was needed for Pakistan’s own glaciers, calling for detailed field investigations into their depth, the terrain surrounding them, and their end moraines — the accumulations of rock and debris deposited at a glacier’s leading edge — in order to properly understand the hazards and vulnerabilities each one presents. He also questioned how much the government had actually invested in addressing the problem of rapidly melting glaciers, a issue on which he said millions of lives ultimately depend.
Pakistan’s exposure to the problem is considerable. A national glacier inventory completed in 2024 found the country home to more than 13,000 glaciers, one of the largest concentrations found anywhere outside the polar regions.
Mohammad Saleem Shaikh, spokesperson for the Ministry of Climate Change and Environmental Coordination, earlier said following Suparco’s earlier July assessment that the accelerating rise in temperatures across the Hindu Kush-Karakoram-Himalaya region was fundamentally reshaping Pakistan’s cryosphere and speeding up glacier melt, raising the risk of both Glofs and other hazards linked to a changing climate.
He said that while melting glaciers had initially increased water availability downstream, unchecked warming was now expanding unstable glacial lakes capable of bursting without warning, unleashing flooding that could devastate downstream communities, damage infrastructure, destroy agricultural land and disrupt essential services.
“The science is unequivocally clear that rising temperatures are reshaping Pakistan’s mountain ecosystems at an unprecedented pace,” Shaikh said. “Every fraction of a degree of warming increases the risk to communities living downstream. Our response must therefore be science-driven, technology-enabled and translated into timely action to protect lives, livelihoods and critical infrastructure.”
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