‘The mountains are changing’: What the floods tell us about the future of India’s Himalayas

It has been hard not to despair while watching the ruinous floods swallow parts of Nepal, and harder, still knowing that the agony compounds each passing day for dozens of Indian families whose members remain unaccounted for.

Social media is awash with desperate pleas, photos and details of the young and old, men and women, from Mumbai to Kolkata, posted by families searching for traces of life. The disaster unfolded when a melting glacier slammed into the valley below, unleashing a deadly cascade of rock and ice down the Bhote Kashi River, which flows from Tibet into Nepal, reports The Guardian.

Among the 275 Indians missing at the time of writing are workers of a hydropower project and people undertaking the Hindu pilgrimage to Mount Kailash in Tibet. Another 128 people of Indian origin, including a large group of Sadhguru’s Isha Foundation spiritual group, are also missing; 149 Indian people have been rescued as of Monday.

For Gauri Joshi, whose five relatives remained unaccounted for over the weekend, the last few days have been a blur of calling their numbers in vain, watching news of rescue operations and trying to reach Indian officials – over and over again. What she has pieced together so far is that her relatives, part of a pilgrim tour group from Maharashtra, cleared immigration at the Gyirong border between Nepal and Tibet and boarded buses shortly before the flood waters destroyed the crossing.

“Chances appear very bleak now. But maybe a miracle will happen,” Joshi said.

The tragedy has reignited the question of how vulnerable the Himalayas are to climate change, and what its implications are for India. To understand the risks of glacier collapse and thawing permafrost leading to sudden floods and debris flows, I spoke to Dr Ashim Sattar, a professor at Indian Institute of Technology Bhubaneswar and an expert on glacial lake outburst floods. The conversation has been edited and condensed.

What are the climate- or glacier-related risks emerging across the Himalayas?

“There are different forms of cryosphere and how they pose a hazard. In a layperson’s terms, the cryosphere is where water exists in solid form, for example a glacier. When it melts, it forms glacial lakes. If they have an outburst, they can cause damage downstream.

Another cryospheric component is glacier ice. This is what we’ve seen in Nepal, where a glacier detachment happened. The frontal part of the glacier detached from the main glacier and eventually led to a debris flow.

The third component is permafrost. They exist widely in the Himalayas, but there has not been much monitoring because it’s very difficult. Everything – these lakes, glaciers and permafrost – are all hazards. Unless they’re triggered, they would not cause damage.

With climate change, these grounds will go above zero degrees and will start to degrade. These would need very little … to mobilise debris. We might expect a higher frequency of debris flows in the future. We won’t know how they are getting conditioned, unless we have some monitoring stations and scientific investigation.

And given the Himalayas are very vast, monitoring every part of it becomes tricky. It can be the mountain ranges within India, or maybe outside India, eventually, which drains into the Indian subcontinent. That needs to be well studied.”

How big are the downstream risks for India?

“Right now, this is a gap in scientific studies; nothing [is] quantified yet. There is direct evidence of climate impacts, even in the Indian part of the Himalayas. The number of glacial lakes is increasing, the size of glacial lakes is increasing, the volume of glacial lakes is increasing, and glaciers are retreating. The risk exists because it might happen any time.”

Which parts of India are the most vulnerable?

“Everyone in the Himalayas, every Himalayan state has hazards. We can’t deny it. If you look at the eastern side, they have a lot of glacial lakes. They have already reached their maximum extent. Most full-grown lakes are about to reach their limits, like maximum extent. In the western Himalayas or even the central Himalayas, there’s a lot of scope for the lakes because they have not reached their full extent. As the glaciers would retreat, they would keep on growing.

We are still unsure when the status is going to change for any of these states. That’s a very, very difficult question, and I don’t think anyone [can] answer it at this moment without any scientific investigation.”

How would you describe India’s early warning systems and disaster preparedness?

“The National Disaster Management Authority is taking proactive steps now with the glacial lake outburst flood (GLOF) Risk Mitigation Programme to install early-warning systems.

Maybe an early warning system should be community-based. It should be for the people and by the people. It’s not always the scientist or the policymakers who can actually make this work at its full potential. We need to have local knowledge, involve the communities to make them more effective.”

How long will it take to have these systems in place?

“I have no idea because each of these organisations are working at their own pace. They have their own style of working. I’m sure it is going to happen soon. I can just comment on the areas where I know, and I’ve been in touch.”

Is prevention possible, or can it only minimise the damage?

“Prevention is possible, but it is very expensive: computationally, financially and manpower-wise. Minimising is also possible. It would require a lot of intervention in the high mountains, which is very difficult in those terrains.

We know that the mountains are changing and the hazard levels are increasing, so the only way forward is to minimise the exposure to the risk below. That means how much of the hazard is going to interact with the downstream. If something is in the path, we remove them.”

Writer: Niha Masih is the writer of the Guardian's This is India newsletter