乐鱼 体育

鈥淲e have never experienced so many potentially dangerous lakes in such a short period of time,鈥� said of during a roundtable discussion on glacial melt, glacial lakes, and downstream consequences at the 乐鱼 体育 on October 26. 鈥淭here have always been glacial lake outburst floods,鈥� said Byers. What has changed is how quickly these lakes now grow. 鈥淪uddenly, you wake up in the morning, and now there are hundreds and hundreds of these lakes above you 鈥� the threat from above,鈥� he said.

Nepal鈥檚 Fastest Growing Glacial Lake

The Imja Glacier in Nepal has been receding since the 1960s which has made Imja Lake the country, if not the entire Hindu Kush Himalayas, said Byers in produced by The Mountain Institute (TMI) about the group鈥檚 recent expedition to the region. The lake is now 鈥渕ore than a square kilometer in size, has more than 35 million cubic meters of water, and continues to grow at an alarming 35 meters per year,鈥� he said.

The lake鈥檚 鈥� the buildup of glacial debris that acts as a retaining wall holding the lake waters back 鈥� is all that keeps Imja from flooding the valley below, home to a number of communities and the starting point for many climbers scaling Mount Everest.

When these moraines break, the result is a glacial lake outburst flood (or GLOF). And 鈥渢hese aren鈥檛 floods in the normal sense,鈥� said Campbell. 鈥淭hese are floods that carry boulders the size of houses,鈥� because of all the debris that gets lodged in glaciers.

Critical Need for Research

It is tempting to say that what is happening at Imja Lake is representative of the thousands of glacial lakes believed to exist throughout the Himalayas, but the fact is that 鈥渁t this point in time, we don鈥檛 really know that much about these lakes,鈥� or how to control them, said Byers.

Glacial melting 鈥渋s an extraordinarily complicated story,鈥� said ClimateWire鈥檚 Lisa Friedman, who joined the Imja expedition for part of the trip. There is no 鈥渃lear understanding yet of how fast glaciers are melting, of where they鈥檙e melting, of whether greenhouse gases or black carbon soot is primarily responsible.鈥�

There is considerable disagreement over how many glacial lakes are even in the Himalayas, TMI Executive Director added, simply because of how prohibitively remote their locations often are. Byers explained that it can take as many as 10 days, plus semi-technical climbing, to reach these places, and even then some glaciers still aren鈥檛 accessible. The , for instance, has the distinction of being the world鈥檚 highest battleground (India and Pakistan have had since 1984).

And yet understanding what is happening not just at Imja, but throughout the Himalayas, has . Himalayan glaciers feed nine of Asia鈥檚 largest rivers: the Yellow, Yangtze, Mekong, Salween, Indus, Ganges, Brahmaputra, Syr Darya, and Amu Darya. Those rivers, in turn, feed some of . The sheer number of people who depend on these rivers mean that even minor changes in glaciers鈥� sizes can have .

Adapting Lessons Learned from Peru

The Mountain Institute鈥檚 expedition was aimed at bringing lessons learned about managing glacial change from . Peru is home to , but those that some have predicted within 15 years, they could disappear entirely.

Peru has been working to since 1941, when a GLOF killed thousands and devastated the capital of Ancash, said C茅sar Portocarrero of the Peruvian National Water Authority (also a member of the expedition to Imja). At first, risk management meant simply diverting water from glacial lakes to lower the risk of GLOFs. Over time, though, and with community input, that strategy has expanded to include more comprehensive resource management, so that water being diverted from lakes can be captured and put to use downstream.

Just as Peru鈥檚 mitigation work is a reflection of local needs, finding a long-term solution for Imja Lake will depend on local involvement. 鈥淲hen you think about science, and when you think about change, there鈥檚 something to be said for more demand driven approaches,鈥� Taber said. 鈥淲orking with local people鈥s more likely to lead to solutions and answers that will actually be picked up.鈥�

And yet, Byers said, local people have often been marginalized in research on glacial melt in the Himalayas. 鈥淭here鈥檚 been 30 years of research on this and other lakes and yet no researcher has ever involved them in their research, and they had no idea what the results were,鈥� he said. The TMI expedition made a point of incorporating local residents throughout the process.

Acting in Spite of Uncertainty

Portocarrero said that convincing people of the need for risk management can be difficult. 鈥淎round the world, it seems that people because we don鈥檛 have tangible results,鈥� said Portocarrero. And when risk is mired in uncertainty 鈥� as it is in the Himalayas 鈥� getting people to invest in risk management becomes even harder.

Portocarrero warned it might take a decade or more for people downstream to realize Imja and other glacial lakes pose a big enough danger and galvanize into action. 鈥淏ut the big question is,鈥� he added, 鈥渁re we going to wait 10 years to see the real danger?鈥�

, who led the CNA Military Advisory Board during its 2007 report on , said action can鈥檛 wait for perfect information.

鈥� for instability in fragile regions of the world,鈥� said Goodman. Considering those stakes, uncertainty 鈥渃an鈥檛 stop you from making smart decisions based on today鈥檚 information for adaptation.鈥�

Drafted by Kate Diamond and edited by Schuyler Null and Geoff Dabelko.