When Ravi Chopra saw the devastating deluge of water and debris crash downstream from a Himalayan glacier on Sunday, his first thought was that this was exactly the scenario that his team had warned the Indian government of in 2014.
At least 31 people have died, 165 people are missing and many more are feared to have died, as the rescue operation continues in Chamoli district of northern Uttarakhand state.
The deluge first smashed into a small dam, gathering more energy as it grew heavier from the debris it collected along the way. Then it smashed into a larger, under-construction dam and gathered even more energy.
Chopra and other experts had been tasked by India’s Supreme Court to study the effect of receding glaciers on dams. They had warned that warming temperatures due to climate change was melting the Himalayan glaciers and facilitated avalanches and landslides and that constructing dams in this fragile ecosystem was dangerous.
“They were clearly warned, and yet they went ahead,” said Chopra, the director of the non-profit body People’s Science Institute.
What caused it?
Scientists had first suspected that a glacial lake had burst but after examining satellite images now believe that a landslide and avalanche were the more likely cause of the disaster.
What is not clear still is whether the landslide induced an avalanche of ice and debris, or whether falling ice resulted in the landslide, said Mohammad Farooq Azam, who studies glaciers at the Indian Institute of Technology at Indore.
What is known though is that mass of rock, boulders, ice and snow came crashing down a two-km (1.2-mile), near-vertical mountain slope on Sunday. And now scientists are trying to figure out if the heat produced during this crash due to friction would be enough to melt the snow and ice to result in the flood of water, he said.
Experts say that the disaster underscores the fragility of the Himalayan mountains where the lives of millions are being altered by climate change.
Even if the world was to meet its most ambitious climate change goals, rising temperatures would melt a third of the Himalayan glaciers away by the end of the century, a 2019 report by the International Centre for Integrated Mountain Development found.
Himalayan glaciers are melting twice as fast since 2000 as they were in the 25 years before due to human-caused climate change, a 2019 paper published in the journal Science Advances found.
Whether this particular disaster was caused by climate change is not known. But climate change can increase landslides and avalanches.
As glaciers melt due to warming, valleys that were earlier crammed with ice open up, creating space for landslides to move into. In other places, steep mountainous slopes may be partially “glued” together by ice frozen tightly inside its crevices.
“As warming occurs and the ice melts, the pieces can move downhill more easily, lubricated by the water,” explained Richard B Alley, a professor of earth sciences at the Pennsylvania State University.
With warming, ice is also essentially becoming less frozen. Earlier its temperature would range between minus 6 degrees Celsius to minus 20C and it it is now minus 2C (from 21.2 degrees Fahrenheit to minus 4F earlier to 28.4F now), said Azam.
The ice is still frozen, but is closer to its melting point, so it takes less heat to trigger an avalanche than some decades ago, he added.