For the past few days, impressive images of the massive torrent of water, ice and rubble speeding down the Himalayan mountains in Northern India, destroying everything in its path, have been circling around social media.
Some experts suggest that climate change is the culprit. While the exact cause of the disaster is yet to be determined, India’s event is a grim reminder that rising temperatures are overall increasing the risk of such tragedies happening.
Sunday morning, a massive block of ice and rock broke off at about 5,600 metres of altitude and fell into a river in the state of Uttarakhand, triggering floods and smashing through a dam downstream. At least 31 people have died and 165 are still missing.
Scientists have been scrambling through the data to understand what happened. Satellite images show that it is likely a glacier, along with a part of the rock it was attached to, that broke-off and fell into the river.
“We believe the failure happened within the rock and the glacier ice on top just collapsed together with the glacier,” says Holger Frey, a glaciologist from the University of Zurich and part of the Glacier and Permafrost Hazards in Mountains, a scientific group who has worked with the Indian government to provide guidelines for managing such risks.
Frey and his network have been contacted by the India’s National Disaster Management Authority to help analyse the data from the incident.
The climate link. While some experts have been quick to point to climate change as the main culprit, establishing a direct link between a particular event and global warming is more complicated, Frey says.
“There are many factors that influence and can lead to such a catastrophic avalanche,” he says, adding that some of these are related to man-driven climate change while others have to do with other processes, such as stress fields in the rock.
Some experts pointed at first at the possibility of a glacier lake outbursting, which is when a lake formed by glacier retreat is suddenly released when the natural structure holding it fails. The satellite images show no evidence of such a lake, Frey notes.
So, the great question is where such a huge amount of water could have come from and what role did it play in the incident, he adds.
“Satellite imagery has shown that there was liquid water in the scar that is now left where the bloc fell off from the mountain, which could imply that water entering these cracks and clefts had an important role in triggering the avalanche,” he explains.
He suspects the water in the flood could have come from several sources, including from glacier ice melting, snow on ground and sediments from the river containing large amounts of water. “We’re still learning about this event,” he says.
Having this kind of event in the middle of the winter, when no liquid water would be expected at this elevation, is unusual. While attributing this one event to climate change is difficult, Frey says, broadly speaking, rising temperatures have increased the risk of landslides, avalanches and other hazards.
Glacier lakes outbursts are among the biggest hazards. They can potentially wipe out whole communities and infrastructures. “An avalanche normally stays up the mountain, but if water is involved, the reach can be hundreds of kilometres downstream,” he says.
In 2013 in Kedarnath, in the state of Uttarakhand some 63 km from the site of Sunday’s incident, an outburst flood killed thousands of people and affected thousands of villages.
With rising temperatures, new lakes are emerging all over. In the Himalayas, glaciers have been melting twice as fast since 2000, with over 8 billion tonnes of ice lost every year.
Avoiding tragedies. As such incidents will undoubtedly continue to happen, monitoring high risk areas and putting in place measures to limit the damages is key.
Early warning systems are an important security measure that are too often neglected. Despite increasing frequency of natural disasters, a recent UN report warns that one in three people worldwide are still not adequately covered by warning systems that could help save lives.
“Nobody could have avoided that this material collapsed and the damages to the power plant. But the workers could have been saved if they were warned 10 to 30 minutes beforehand,” Frey explains.
He cites the example of Switzerland, where avalanches and landslides are common. Sensors are used to monitor any movement in the Alpine mountains and warn people. But while Switzerland may use high end technology to do this that not all countries have access to, disaster risk management doesn’t have to be expensive, he says. Having someone watching and warning others in case of an avalanche can be good enough.
But as climate change accelerates, these events get more unpredictable. “Snow avalanches and glacier hazards have probably been more common in the past when glaciers were further down the valleys than they are now. But 100 years ago, it was the same glacier that broke off in the summer and the same avalanche that came in winter from time to time and maybe the same lake that burst every other year,” Frey says. “Today, we have situations that have never existed before. We have no experience, and we cannot rely on historical information as we once did.”
Climate change is not the only factor that has to be taken into account. As populations continue to grow and so does energy demand, infrastructures in vulnerable places will continue to be built, in turn increasing the risk of damage.
Environmentalists had previously voiced concerns over the Indian government building dams in such high-risk areas. Satellite imagery from the zone of the incident shows that another big avalanche took place in 2016 on a neighbouring glacier, meaning that the area was prone to such events.
Frey points out the importance of investing in adaptation: “If you can afford a station, then you can consider the risks and hazards that are around. It is actually in your best economic interest to invest in protection and disaster management.”