The scruffy group of scientists had taken their first showers in more than a week after trekking the snow-capped Himalayan mountains, and were eager to tell officials in Kathmandu about the growing dangers they witnessed at Nepal's fastest-growing glacier lake.
But Andreas Schild, director-general of the International Centre for Integrated Mountain Development (ICIMOD), was not impressed. Lake Imja, he said, is low on Nepal's list of vulnerable lakes -- and he suggested it might be in greater danger of overflowing with scientists than with water.
|
| In the 1960s, this massive lake in Nepal's Himalayan mountains was just a handful of small melt ponds. Now it threatens to wipe out everything in its path, including the popular trail to Mount Everest Base Camp. Photo courtesy of Daniel Byers. |
"Be careful," Schild warned the stunned group of glaciologists, geologists and engineers working with the Mountain Institute, a Washington, D.C.-based conservation and research group that led the expedition with funding from the U.S. Agency for International Development. "If you are cocksure about your findings, remember that others are equally sure of their findings. Some think that there are areas that are more risky, but not as easy to access as Imja Lake."
The lake, a massive pool of concrete-gray waters in Nepal's Dudh Kosi Basin, barely existed a half-century ago. But as the Imja Glacier southeast of Mount Everest receded, the accumulating waters steadily swelled a handful of melt ponds that grew together to form Imja Tsho, or Imja Lake.
Perched at an altitude higher than 16,000 feet, and the size of about 200 football fields, Imja drains through a valley that traces the country's only trail to Mount Everest Base Camp. The glacier continues to lose about 35 meters of ice each year, and the lake has grown an average of half an acre each year.
If Imja were to burst in what is known as a glacier lake outburst flood, or GLOF, it could kill hundreds and perhaps thousands of people, the Mountain Institute scientists and others warn. It could also cripple the region's economy, sweeping away the Everest trail, which beckons 30,000 tourists each year, as well as the hundreds of tea houses and lodges whose owners' livelihoods depend on trekking traffic.
"At the moment, the lake looks stable, but we don't know how long it will be stable," said Ugan Manandhar, manager of the climate change team at the World Wildlife Fund's Nepal office. Nepal already has suffered 24 GLOFs, including one in 1985 that destroyed 14 bridges and a nearly completed hydroelectric project. If a flood from Imja took out the Everest trail, it could effectively eliminate the $350 million in tourist dollars that feeds Nepal's economy each year.
"If Imja becomes unsafe, not only the economy of that region will suffer but the whole country will be impacted," Manandhar said.
Over the years, dozens of scientists have made their way to Imja, following a well-worn trail from Lukla -- an airstrip town at an altitude of 9,800 feet that serves as the gateway to the Everest region -- up steep terrain through Sherpa villages and forests of fir and rhododendron, past colorful Tibetan prayer flags and stupas, spinning Buddhist prayer wheels along the way.
It can take about 10 days to trek to Imja, and that makes it one of the most accessible glacier lakes in the Himalayas.
Teiji Watanabe, a professor of environmental science at Hokkaido University in Japan, has been studying Imja Lake since the 1980s. Chatting in a Himalayan lodge a day after he descended from Imja in September, Watanabe recalled the first time he saw a picture of the lake.
"I knew it was very special. Like a holy something," he said. He felt that same rush of emotions on his first field visit. "Again, I felt a very ... something I cannot explain in English," he said. And, he added, "Compared to other places, it's much easier to research."
Yet the relative ease with which hardy scientists can access Imja also makes it a target of suspicion to some experts who say it's not overflowing -- just overstudied. In 2009, ICIMOD scientists conducted extensive field studies at Imja and two other potentially dangerous glacier lakes, and put Imja at the bottom of the list.
The study noted that while the lake is growing in volume, the "end-moraine complexes" -- dams that hold water in place -- are stable, and free-flowing water outlets serve to reduce pressure.
At the top of the dangerous list was Tsho Rolpa Lake, which threatens to burst through its unstable dam, destroying lives and livestock in Nepal's scenic Rolwaling Valley just south of the Tibetan border. Tsho Rolpa was the object of a partially successful $4 million attempt to lower the water levels and a failed experiment in installing an early warning system.
"Tsho Rolpa is the most dangerous lake, and it has to be a priority, but it's very difficult to access," said Pravin Raj Maskey, a hydrologist with Nepal's Ministry of Irrigation who joined the expedition.
Like Thulagi Lake, another vulnerable glacier lake in the Upper Marsyangdi River Basin that ICIMOD listed as second in vulnerability, Tsho Rolpa is not on a tourist route. That means in addition to the days or weeks it takes to hike up to the lakes, scientists must carry in all their food, supplies and research equipment. Imja, Maskey said, "is a place where scientists like to come, but it is not the first-priority place where they should be working. It is the third."
Local villagers also have a beef with the multitude of scientists who come to study Imja.
"So many scientists do global warming projects at Imja Lake," said Ang Nuru Sherpa, 44, a former Everest trekking guide who is building a lodge at the edge of Namche Bazaar. "They make people scared. That's not good," he said.
"They make their project and they forget it, just like that," said Nyima Tsering Sherpa, 31, who owns a trekking gear shop in the region. "Lots of people are scared of the GLOF, and other people say the scientists are the ones that bring the problems. They're just studying; they don't care. They bring the problems, but not the solutions."
|
| Scientific expeditions to Lake Imja, like the one led by the Mountain Institute, are all too common, some experts and community members complain. Villagers say they want action, not more studies. Photo courtesy of Daniel Byers. |
That, however, was precisely the problem that the Mountain Institute and the 30 glaciologists, engineers and social scientists from 15 countries who made the climb to Imja were trying to remedy. In what many villagers in the region described as an unprecedented collaboration, the scientists not only met with members of local communities in the town of Dingboche but trekked with them to Imja to observe it together.
"Local people are very tired of researchers who parachute in and never provide results to the local people," said Alton Byers, a mountain geographer who has spent decades working in Nepal and led the Mountain Institute's expedition.
Together, Byers said, they saw dangers at Imja Lake that have either been overlooked or have developed in the two years that have passed since ICIMOD researchers conducted field research. Not only had the volume of the lake grown, but the researchers found new ponds that were not there in 2009, as well as cracks and seepage in the moraine.
Watanabe, who only a few years ago wrote a report noting the lake's stability, said he left Imja worried. "The changes are getting more rapid," he said. "It's larger if you compare to the late 1980s, but even if you compare to three years ago, it's bigger." Watanabe said Imja may not be in immediate danger of flooding, but "10 years later, nobody knows. We really need to monitor it every year."
It remains unclear if that monitoring will happen or who will be in charge. ICIMOD scientists ended a two-day conference with the Mountain Institute scientists in Kathmandu saying they had heard nothing to change their position. Most remain lukewarm about acting at Imja, preferring to focus on Tsho Rolpa, which, they say, might not capture the attention of the international community but is more important locally.
"Both lakes are classified as dangerous. Depending on the resources, we have to monitor this, and depending on the resources, we have to do something about it," said Madhav Karki, deputy director-general of ICIMOD.
That concerns environmental activists, who note that the magnitude-6.9 earthquake that hit the Nepal-India border last month, causing landslides throughout the Himalayas, was a worrisome reminder that anything could set off dangerous changes at Imja.
"What trigger will it take?" Manandhar asked. "Just saying that Lake Imja is safe doesn't take away the vulnerability."
Return to the top of the page.
The Sherpa stew sloshed out of my bowl as the wooden table in our Himalayan lodge swayed back and forth. Someone yelled "Earthquake!" and I bolted for the door with other panicked trekkers, tumbling into the chilly mountain night.
Farther up the mountain, the international group of glaciologists and engineers I was climbing to meet were huddled outside their own lodge in the village of Lobuche below Everest Base Camp. At higher than 16,000 feet in the dark, they could hear -- but, terrifyingly, not see -- an avalanche of snow falling from one of the highest peaks in the world.
|
| Scientists from 15 countries led by the Mountain Institute trekked to Lake Imja, a flood-prone glacier lake in the Himalayas, to study the dangers it poses as well as gain a better understanding of glacier lakes in their own countries. Photo courtesy of Daniel Byers. |
They were just a day's hike from Imja Lake, a sweeping body of gray water along the Everest trail that had swelled from a few ponds in just half a century as the seemingly indestructible glacier above it steadily melted away. Many of them experts in a phenomenon known as glacier lake outburst flooding, or GLOFs, the scientists knew a magnitude-6.8 temblor like the one that struck that night had the power to make a fragile lake empty itself, destroying everything in its path.
Some had seen it before in Peru's Cordillera Blanca range, when a 1970 earthquake shook a section of glacier off Mount Huascarán. The glacier plummeted thousands of feet into the Rio Santa Valley, collecting boulders as it fell to overflow the banks of the Rio Santa and kill more than 10,000 people in the towns below.
"It just came down the valley, a massive ice rock that just created a huge, gigantic avalanche. That one avalanche killed around 10,000 people. Imagine the size of it," said Jorge Recharte, director of the Mountain Institute's South America programs. "Mountains are fragile," he said. "It's gravity acting, and even though it seems like rocks are well set in the mountains, you're in a vertical landscape, and earthquakes just trigger instability."
Recharte was one of the 30 experts I met in the Khumbu mountain range last month who, under a program funded by the U.S. Agency for International Development, were trying to marry the decades-long experience of the Andes with Nepal's needs. Hailing as well from Japan, Bhutan, Pakistan, China, Tajikistan, Kyrgyzstan, Uzbekistan, Chile and Bolivia, the scientists also hoped to develop a global understanding of the new threat that melting glaciers are delivering to all their countries.
"This is almost unprecedented in human history," said Alton Byers, science and research director at the Mountain Institute, who organized the expedition.
"We have no real frame of reference for glacier lake outburst floods," he said, noting that the rate of glacier melt brought about by climate change is fundamentally changing the need to understand disaster risk management in different parts of the world. "This is all new, and suddenly we're being smacked in the face with something we had never had to deal with before."
Peru, though, actually does have solid experience with the type of devastating floods that can occur when the dam containing a glacier lake fails. The tropical Andes has been susceptible to the problem since the 1940s. Learning from tragedy, Peru has over the past half-century successfully managed 34 lakes, drilling tunnels or channels to slowly siphon out water and prevent future flooding.
Much of that work was overseen by Cesar Portocarrero, the head of the glaciology department at Peru's national water agency. A civil engineer by training, Portocarrero started to work with dangerous lakes in the 1970s because, he said, "the glaciers were right in front of me." By the 1980s, he said, "I started to see the glaciers were retreating faster than before."
The question the Mountain Institute set out to answer was whether Portocarrero and his team could use their experience to help Nepal lower Imja Lake.
If Imja bursts, it could destroy dozens of villages along the Everest trail as well as the trail itself, which brings in badly needed tourist dollars to Nepal. But the Nepali government has become deeply suspicious of major engineering endeavors -- and with good reason. In 1995, Nepal and European donors installed a siphon at Tsho Rolpa, the country's largest glacier lake, with the intent of lowering it 20 meters. About 11 years and millions of dollars over budget later, they had managed to siphon away only 3 meters.
But the engineers who went up to the Khumbu last month weren't put off by the numbers. Byers, for one, said that while flying or paying porters to carry pipes and other supplies 16,000 feet up in the mountains would present a unique challenge, the mechanical problems are not insurmountable.
"Based on one experience which has resulted in a conventional wisdom that says it's impossible to do engineering, we don't accept that," he said. "We don't agree that's necessarily gospel." Added Portocarrero, "I am a civil engineer like many in the world, but I know about this kind of work, and I can help."
The real question, Byers, Portocarrero and others said once they had spent time in the Khumbu, was whether communities living downstream of Imja want that help.
The group did something no scientists have ever done in the Khumbu: They worked with a local community group from the village of Dingboche to survey the glacier lake and discuss what recent findings may mean for downstream villages. That appeared to have alleviated a good deal of frustration among locals who said they are sick of researchers who leave Imja with notebooks full of data but not a word to those who could lose their lives and livelihoods if a major flood struck.
The scientists and development experts, on the other hand, emerged from the experience with more questions than answers. Many said they left with the distinct impression that communities were simply waiting for foreigners to protect them, and pay for it. They saw an absence of community involvement and civil infrastructure, as well as government neglect.
"If we can't find a partner, we're not going to succeed, so there's no point in starting work here," said John Furlow, a climate change specialist at USAID who accompanied the group. He pointed to black rubber pipes snaking out of each mountain home and lodge toward the river, and said it suggested an every-family-for-itself system that could make finding a partner in the region difficult. And, he noted, neither the International Centre for Integrated Mountain Development, an international mountain research group based in Kathmandu, nor the Nepali government appeared enthusiastic about Imja.
"I want to make sure that any engineering is based in a social structure that's acceptable," Furlow said.
Upon my return to Kathmandu, though, nonprofit groups that do extensive work in the region told me the Khumbu most certainly has a civic structure. Villagers routinely trek miles up and down the valleys to public hearings -- though, noted Ugan Manandhar, manager of the climate change team at the World Wildlife Fund's Nepal office, "When you start a meeting at 10 o'clock, it will never start at 10 o'clock. It will start at 2 o'clock."
The pipes, Manandhar said, might not look like an organized system, but they are, and villagers pay for their water use. He described long-standing committees that successfully lobby for -- as well as pay for and maintain -- mini-hydropower plants in remote villages off the Everest trail. He and representatives of other Kathmandu non-governmental organizations suggested that the U.S.-funded expedition should have done more legwork to understand the region, or to reach out to different groups that could easily answer questions.
While confusion over Imja and how best to approach downstream communities to determine what level of protecting they want from glacier lake flooding persists, it also is clear that a potentially groundbreaking partnership is on the horizon.
Talking over a plate of french fries at a Kathmandu hotel after three weeks of tea and steamed Nepali dumplings on the trail, Byers began to speak of Imja more as a laboratory for global understanding of glacier lakes -- not just in the Himalayas, but also in Central Asia and Latin America.
"In all cases, all these countries are mountainous. All of them are experiencing a warming trend and the enlargement of glacier lakes. And all have governments, with the exception of one or two, that are probably not equipped to handle a GLOF," he said.
Over the next five years, Byers said, he wants to see communities in the Himalayas receive the attention they need to decide if an engineering solution to Imja is something they want. But he also outlined a vision for a global partnership where scientists in other parts of the world can go to learn how to work with glacier lake communities.
"We're going to do prevention and mitigation of hazards. It's going to save lives, and it's going to operate in a dozen countries worldwide," he said. The endeavor could also make way for more scientists to put down the satellite data and hike their way up mountains to see the glacier lakes they study for themselves.
"I see a new generation of mountain geographers who focus on the culture and environs of mountains," Byers said. "It's what I call the climber-scientists. We have a new generation of scientists who are hungry to get into the field, and we need to combine the best of muddy boots research with the best science can give us."
