Future Tense

When Disaster Is Always Looming

How people in Nepal live with the threat of a dangerous glacial lake outburst flood caused by climate change.

Imja Tsho—a glacial lake (elevation 16,437 feet)—is identified by the government of Nepal as one of the three potentially dangerous glacial lakes in the country. Nothing more than a small pond back in the 1960s, Imja Tsho rapidly transformed into a supraglacial lake by the early 2010s. The parent glaciers for this lake are Lhotse, Lhotse sar, and Imja glaciers.
Imja Tsho is identified by the government of Nepal as one of three potentially dangerous glacial lakes in the country.
Milan Shrestha

In the Himalayas, as in a lot of places, the impacts of climate change have a “gradual until they aren’t” quality. Rising temperatures melt more of the snowpack that collects on peaks like Mount Everest. This water trickles down, filling into dips in the mountain landscape to form high-altitude glacial lakes. Slowly, as the planet warms, these lakes grow. Sometimes they grow too big.

Glacial lakes are often penned in with moraines—loose accumulations of rock and regolith shoved into piles by the slow movements of glacial ice. Bigger lakes put more hydrostatic pressure on their moraines. Occasionally this pressure is enough to push through the unsteady sediment, or an avalanche or earthquake may perturb the moraine. There’s no way to know for sure when this will happen, but there’s no mistaking the results. The icy, dirty water will widen the gap until the lake can drain out of the moraine with startling speed. The lake water flows downhill, often with enough force to wipe out roads, fields, even whole human settlements unlucky enough to be built in the path of the flood.

This phenomenon is called a glacial lake outburst flood, or the unceremonious GLOF for short. It’s a rare event, but one of increasing concern in our age of weather chaos and shifting landscapes. GLOF events can be deadly and can wash away the livelihoods of fragile rural communities. The stakes are high, but the risks are complicated and hard to assess. And so, as with climate-impacted areas all over the world, talk turns to mitigation and relocation—discussions that inevitably surface deep social and emotional contradictions.

Nepal’s Khumbu Valley, in the Mount Everest region, sits in the shadow of a glacial lake called Imja Tsho. Imja Tsho contains 2.6 billion cubic feet of water—a number that grows by the year. For the people of Khumbu, the fear of what might happen if this water were unleashed is not wholly abstract. In 1985 another glacial lake above the valley, Dig Tsho, burst on a sunny August afternoon. The flood wrecked several villages and killed three people. More glacial flooding in Khumbu accompanied the devastating 2015 earthquake. Following these events, experts began an assessment of GLOF risks in the country and the likely costs of various GLOF disasters. This study placed Imja Tsho at the top of the list, with an astonishing $11 billion potential price tag.

So what do people do about a water bomb dangling over their heads? Answering that turns out to not be simple. Recently, social scientists (including one of us, Milan Shresthra) have joined the engineers and physical scientists studying the Imja Tsho problem and are in the process of completing a survey of how residents of Khumbu Valley perceive the GLOF threat. The researchers were surprised to find that while 45 percent of the respondents considered GLOF a major threat to their life, no one was planning to relocate to get out of the flood zone.

This is a contradiction that bears some consideration. Much of our narrative about climate change unfolds on two different time scales: Ever-unprecedented hurricanes appear suddenly to flood Houston and batter Puerto Rico, while rising seas gradually swallow island nations like the Maldives. How do we deal with slow-moving but hard-hitting dangers like GLOFs, which defy this easy dichotomy? Often the answer lies in a tangle of a social and psychological frictions we are only beginning to unravel.

Religion and cultural belief systems have great influence on how many people perceive threats—often intermingling perceptions of natural and supernatural forces. When we experience disasters over which we have little control, we often turn to spiritual connections for explanation, consolation, or relief. For instance, Sherpas’ religious and spiritual culture does not conflict with scientific claims about the climate, but their worldview does influence how they engage with the local landscape. Spirits are said to inhabit the lakes and the mountain terrain, and this tradition comes into play when experts propose large-scale engineering projects to mitigate threats, such as the 2016 emergency draining at Imja Tsho by the Nepalese army, which lowered the lake by about 11.5 feet to reduce GLOF dangers. Khumbu Valley is also considered a sacred sanctuary, and this attachment complicates suggestions that Sherpas should relocate out of danger.

Other conundrums lie in the way individual calamities compete with one another—and with the daily requirements of economic survival—for our headspace. Many of the locals surveyed listed another major earthquake, like the one that hit Nepal in 2015, as their biggest disaster concern—despite the presence of a potential GLOF right above their homes. Does this mean that experience trumps proximity? As the threats brought by climate change pile up—erratic rain and snowfall, or prolonged droughts that threaten Himalayan subsistence agriculture—how will people rank and prioritize their responses? What’s the point of moving to escape one threat if it puts us in greater danger from another? This potential for paralysis makes planning long-term adaptation and mitigation projects difficult to muster community support for.

Ghat Village in the Mt. Everest region.
Ghat Village* in the Mount Everest region.
Milan Shrestha

And of course some are unwilling to relocate simply because they don’t feel that they have alternatives. They have homes, jobs, crops. Many are invested in making the most of opportunities that come with the booming Everest tourism industry. And so a calculation must be made: risk dying in a flood or give up assets that may take years or even generations to recoup.

We’re already in the disaster. We live in a world where the stakes of economic survival feel equal to any physical struggle for life and death. These stakes become more real through the erosion of social safety nets, the private capture of public goods, the visions of inequality in global media that let us know where we really stand.

Call it precarity. Call it the Anxiety. Call it what novelist Amitav Ghosh names The Great Derangement—the difficulty modern humans have acting on slow-moving dangers. Society everywhere has struggled to respond to climate impacts, even as the science becomes more clear. Action on climate change will require deeper and more nuanced engagement with individuals and communities that aren’t attuned to the unique threat that phenomena like GLOFs represent. And we will need a deeper understanding of fear: as more than just the instinct to flee, but as a dread that can be lived with because the disaster is everywhere.

*Correction, March 15, 2018: The caption for the second photo in this piece originally misidentified the village as Chheplung. It is Ghat.

Andrew Dana Hudson writes climate fiction and studies sustainability at Arizona State University.
Milan Shrestha, Ph.D., is an assistant research professor and lecturer with the School of Sustainability at Arizona State University.