Some 15 million people worldwide are at risk from flooding caused by glacial lakes, half of them in India, China, Pakistan and Peru, according to the latest study published in the journal Nature Communications. As the most densely populated mountain country in the world, Nepal is at higher risk. Glacial Lake Outburst Floods (GLOFs) in the Nepal Himalaya can be even more catastrophic for towns along valley floors as well as downstream infrastructure. <a href="https://www.nepalitimes.com/banner/climate-smarter-himalayan-infrastructure">What happened in Melamchi </a>in July 2021 is a sign of things to come. Nepal’s largest infrastructure project to supply water to Kathmandu was nearly destroyed by a massive debris flow after a cloudburst upstream in the Langtang National Park. “What make GLOFs worse in Nepal is that they are often combined with the monsoon,” explains watershed expert Madhukar Upadhyay. “Every year we have seasonal floods. When a weakened moraine is breached, more water is added to already swollen rivers. Making matters worse is high-intensity rainfall in higher altitudes as we saw in Manang in 2022.”&nbsp; Read more: <a href="https://www.nepalitimes.com/opinion/climate-risk-to-hydropower-investment/">Climate risk to hydropower investment</a>, Ajaya Dixit  <figure> <img src="https://publisher-publish.s3.eu-central-1.amazonaws.com/pb-nepalitimes/swp/asv65r/media/20230602040624_e60a90be970842d53f6e236b1a59612c82aa035635a3ae4838481a31710f1446.jpg" data-media-id="editor_2" data-image-id="20230602040624_e60a90be970842d53f6e236b1a59612c82aa035635a3ae4838481a31710f1446" data-rendition-name="original" width="853" height="640" loading="lazy" alt="Melamchi amage NT"> <figcaption>The damage from a massive debris flow on the Melamchi River in June 2021 to the channel diverting water from the Melamchi to the tunnel at the project headwork. Photo: SHIVA BASKOTA</figcaption> </figure>  Scientists say that the permafrost binding loose moraine material is also melting, and without the cementing action of the ice the moraine walls can collapse easily in heavy precipitation. Rain falling where there used to be snow is making matters worse.&nbsp; <a href="https://www.nepalitimes.com/here-now/living-below-nepal-s-melting-mountains">The Himalaya is melting</a> faster than the global average, and even in the best-case scenario, the mountains will lose more than one-third of their ice by 2100.&nbsp; A paper published in the journal Climate and Atmospheric Science last year revealed that the rate of ice loss on the South Col of Mt Everest is shocking: what took 2,000 years to accumulate is melting in a mere 25 years.&nbsp; Read also: <a href="https://www.nepalitimes.com/banner/tracing-past-glacial-floods-in-kangchenjunga/">Tracing past glacial floods in Kanchanjunga</a>, Alton C Byers  <figure> <img src="https://publisher-publish.s3.eu-central-1.amazonaws.com/pb-nepalitimes/swp/asv65r/media/20230602040632_f3e5d9e3eb4dca842d715afab7ee68899e0fa3c0d2f9f039d9b288b1492f4955.png" data-media-id="editor_5" data-image-id="20230602040632_f3e5d9e3eb4dca842d715afab7ee68899e0fa3c0d2f9f039d9b288b1492f4955" data-rendition-name="original" width="891" height="500" loading="lazy" alt="Map"> </figure>  There are 3,252 glacial lakes in Nepal, including the Khumbu Glacier where Base Camp is now 50m lower than when Hillary and Tenzing climbed Everest<a href="https://www.nepalitimes.com/here-now/everest-70-years-on"> seventy years ago</a>.&nbsp; Imja was a debris covered glacier on trekking maps even 25 years ago, but is now a 2km long lake. Tso Rolpa glacial lake at 4,580m in the Rolwaling Valley has grown seven times in size in the past 60 years. “There is a lot of evidence that the number of glacier lakes in Nepal and worldwide is increasing,” says Miriam Jackson, glaciologist with the International Centre for Integrated Mountain Development (ICIMOD). “The size of existing lakes is also increasing. For example, the area of glacier lakes increased by 12% in the Kosi basin and 8% in the Gandaki basin.” The water level in Imja has been lowered by 3.4m and by 3m in Tso Rolpa at a cost of $7.2 million and $9 million respectively. Scientists now say the water level in Tso Rolpa needs to go down by another 20m to reduce risk of bursting. Read also: <a href="https://www.nepalitimes.com/here-now/danger-nepal-s-glacial-lakes-are-filling-up">DANGER: Nepal’s glacial lakes are filling up</a>  <figure> <img src="https://publisher-publish.s3.eu-central-1.amazonaws.com/pb-nepalitimes/swp/asv65r/media/20230602040628_4ac8ea629de0f69bfb27fe9b783f126c7eea6dcadda7e812436d393d7c21c13e.jpg" data-media-id="editor_8" data-image-id="20230602040628_4ac8ea629de0f69bfb27fe9b783f126c7eea6dcadda7e812436d393d7c21c13e" data-rendition-name="original" width="1843" height="1000" loading="lazy" alt="Imja lake NT"> <figcaption>A frozen Imja Lake looking east from the outlet. Photo: SHARAD JOSHI</figcaption> </figure>  There are other potentially dangerous lakes like Thulagi below Himalchuli, and new lakes are emerging on both sides of the Himalaya in China and Nepal that have not even been mapped. Nepal’s glaciers are shrinking three times faster than in 1998 and Jackson says that the possibility of flooding, whether from glacial lakes or other sources, is taken into account when building close to the rivers. When Nepal’s only reservoir project on the Kulekhani was commissioned in 1982, engineers had designed it to function for 100 years. But a cloudburst in the catchment area in 1993 deposited so much debris into the lake that its lifespan was reduced by 30 years. “Melamchi and Kulekhani are proof that the entire Himalayan region including Nepal are not suited for mega projects. Our focus and investment should instead be on multiple small-scale projects spread out across the country,” says watershed expert Madhukar Upadhyay. As for infrastructure already under construction, there are several mitigating measures that can be deployed, such as early warning and real-time information systems in the catchment area, not only about rainfall but GLOFs and landslide blocked rivers. Experts say Nepal and the countries in the Himalaya should not overlook the phenomenon of permafrost melting that is making the mountains and moraines much more prone to erosion. Permafrost is a thick subsurface layer of frozen soil that is generally not visible and thus harder to identify. Besides Melamchi, thawing permafrost is thought to have been partly responsible for the Chamoli disaster in the Indian Himalaya in 2021. Read also: <a href="http://archive.nepalitimes.com/news.php?id=2391#.XoyO8MgzbIU">The day after tomorrow in the Himalaya</a>, Navin Singh Khadka “Generally, moraines have an ice core, which is one reason why moraine-dammed lakes are so dangerous. The ice could be hundreds or even thousands of years old and melt very slowly but the moraine is constantly settling,” explains Jackson. “Thawing permafrost makes mountains unstable, thus causing rockfalls. If there is a landslide into a glacier lake, then that could trigger a flood.” GLOFs also have a transboundary dimension since so many of Nepal’s rivers and their tributaries originate in glaciers in Tibet. Of the 47 high-risk glacial lakes in Nepal, 20 of them start in Tibet (see map, below). Mitigating measures such as artificially lowering the water level are expensive which makes cross-border early warning of GLOFs so crucial. ICIMOD has launched the Kosi Initiative with a transboundary working group collaborating with the Chengdu-based Institute of Mountain Hazards and Environment (IMHE) and others. It has also done computer modelling of flood hazard and an assessment called WeACT that integrates local knowledge with science to improve community preparedness. But GLOF risk can be reduced if vulnerable communities are aware of the danger, are given decision-making powers and have the resources to be prepared, as has been seen in Chunkung in Khumbu and Langtang, where villagers are adapting to climate change by building embankments on their own, and avoiding construction along river banks. Says Madhukar Upadhyay: “We need to strengthen our local science to better understand the geology and glaciology, make local communities and the national government aware of the dangers and take the risk into account in building settlements, hydropower plants, bridges and roads.” &nbsp; Read also: <a href="https://www.nepalitimes.com/banner/human-face-of-a-himalayan-climate-crisis/">Human face of a Himalayan climate crisis</a>, Rastraraj Bhandari

Sonia Awale

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For destruction, ice is also great and will suffice

<figure><img src="https://superdesk-pro-c.s3.amazonaws.com/sd-nepalitimes/20221110161148/636d1d359c7e80680e0af39ejpeg.jpg" alt="" width="3600" height="2400"/><figcaption>Tilicho Lake in Manang. The SAARC member states are among the countries most at risk from effects of climate change, yet a regional approach to tackle the issue is lacking. Photo: RSS</figcaption></figure>At the <a href="http://archive.nepalitimes.com/article/editorial/saarc-summit-should-help-us-start-thinking-locally-and-regionally,1809" target="_blank" rel="noopener noreferrer">18th SAARC Summit in Kathmandu in 2014</a>, member countries committed to work together against climate change, and raise a collective voice at international fora. That promise has been forgotten as India-Pakistan tensions have nearly derailed the South Asian Association for Regional Cooperation.Even though member states like Bangladesh, Bhutan and Nepal are among the countries most at risk from <a href="https://www.nepalitimes.com/banner/human-face-of-a-himalayan-climate-crisis/" target="_blank" rel="noopener noreferrer">effects of climate change</a>, and share river basins, a regional approach has been missing.The next summit was originally planned to be held in Islamabad in 2016, was indefinitely postponed. India alleged that Pakistan was involved in an attack at its military base in Kashmir, and <a href="http://archive.nepalitimes.com/blogs/thebrief/2016/10/13/saarc-minus-x/" target="_blank" rel="noopener noreferrer">boycotted the conference</a>. Collective dialogue between the member countries on climate have been in limbo ever since.Ahmad Kamruzzaman Majumder, head of the Department of Environmental Sciences at Stamford University in Dhaka, says that the need for South Asian solidarity to combat the effects of climate change is now more urgent than ever.According to<a href="https://germanwatch.org/en/19777" target="_blank" rel="noopener noreferrer"> a report published by Germanwatch in 2021</a>, Bangladesh is the seventh, Pakistan the eighth and Nepal the tenth most impacted country by the climate crisis."South Asian countries have not been able to sit together, discuss common issues, and come up with a unified vision," Majumder said. “Doing so would make it easier to pressure developed countries in the international forum."SAARC countries also failed to raise their collective concern at the <a href="https://www.nepalitimes.com/editorial/good-cop-bad-cop/" target="_blank" rel="noopener noreferrer">2021 United Nations Climate Change Conference (COP26)</a> and did not even sit together for discussions on the sidelines.However, the Minister for Climate and Forest Environment of India, Bhupendra Yadav, says that the discussions were held at ministerial level: "Informal talks took place between the concerned ministers." No statements were made about what was discussed.Stretching over 3,500km and across eight countries, <a href="https://www.nepalitimes.com/banner/a-terrifying-assessment-of-himalayan-melting/" target="_blank" rel="noopener noreferrer">the Hindu Kush Himalaya</a> region is the source of 10 of Asia’s largest rivers as well as the biggest volume of ice and snow outside of the Arctic and Antarctica. Considered a biodiversity hotspot, the region is also home to about 1.3 billion people.But at present, <a href="https://www.nepalitimes.com/banner/global-heating-melts-mountains/" target="_blank" rel="noopener noreferrer">the mountains are warming</a> between 0.3-0.7°C faster than the global average, snowlines are receding, glaciers are shrinking or their lakes in danger of bursting.Coastal areas of Bangladesh, Sri Lanka and the Maldives are threatened by sea-level rise.Read also: <a href="https://www.nepalitimes.com/banner/the-third-pole-is-warming-faster-than-expected/">The Third Pole is warming faster than expected</a>, Kunda DixitHarjeet Singh, a senior advisor to the International Climate Network, said that SAARC, adds, "The entire region of South Asia is at red alert, it is <a href="https://www.nepalitimes.com/editorial/shared-futures/" target="_blank" rel="noopener noreferrer">imperative that the member states work together</a> in this crisis."However, India has been opposed to the multi-lateral approach involving its neighbours even though they are all at high risk – their oceans, rivers, deserts and mountain systems.According to <a href="https://reliefweb.int/report/india/assessment-climate-change-over-indian-region-report-ministry-earth-sciences-moes" target="_blank" rel="noopener noreferrer">the 2020 report</a> 'Assessment of Climate Change over the Indian Region' published by the Ministry of Earth Sciences of India, sea levels in India rose by 3.3mm per year between 1993-2017. By the end of this century, the levels are projected to rise by a whoping 300mm.Yet, India has actively <a href="https://www.nepalitimes.com/banner/climate-denial-in-the-himalaya/" target="_blank" rel="noopener noreferrer">evaded discussions with neighbouring nations</a>. "Climate issues have been overshadowed by geopolitical issues," says Ahmed Kamruzzaman Majumdar. “Pakistan also does not seem interested in holding talks with India.”Nepal’s former Foreign Minister Pradeep Gyawali also says that SAARC has become a victim of bilateral tensions between India and Pakistan. "SAARC could be more active, but tensions between them have severely hindered regional cooperation,” he says.India's interest seems to be strengthening the <a href="https://www.nepalitimes.com/banner/bimstec-facelift/" target="_blank" rel="noopener noreferrer">Bay of Bengal Initiative for Multi-Sectoral Technical and Economic Cooperation (BIMSTEC)</a>, essentially overshadowing SAARC. Apart from SAARC countries, Thailand and Myanmar are also members of BIMSTEC, while Pakistan is not.Nepal, however, disagrees about <a href="https://archive.nepalitimes.com/article/nation/connecting-Bangladesh-China-India-Nepal,2966" target="_blank" rel="noopener noreferrer">moving BIMSTEC forward</a> at the detriment of SAARC. Kathmandu had even proposed to hold the 19th SAARC summit in nations other than Pakistan."BIMSTEC is also necessary, but the fact that South Asia is our common identity cannot be overlooked. We actively raised our voice in the government to ensure that SAARC is not overlooked in favour of BIMSTEC," says Gyawali.Former Foreign Secretary Madan Bhattarai says that other common problems have been exacerbated by SAARC’s inactivity. "When issues like climate change are dealt with through a forum like SAARC, our collective bargaining strength increases," he says, "As president, Nepal will have to take initiatives with other member nations.”He adds that besides climate, other issues like health, tourism, aviation and COVID are common burning issues that require cooperation through bodies like SAARC.According to Raju Pandit, a climate expert who has participated in various international forums on climate change from Nepal, the issue of climate change has stark differences in outlook among the members of SAARC."We are talking about reducing carbon emissions. However, India does not like the idea of cutting back on coal use,” he said. "SAARC is now in a complete coma. If there are regional issues like climate change to deal with, we should lobby for the formation of a separate organization of small landlocked countries like Nepal.”Translated from <a href="https://www.himalkhabar.com/news/126993">the original</a> by Aryan Sitaula.

Indo-Pak tension hits SAARC climate action

<figure><img src="https://superdesk-pro-c.s3.amazonaws.com/sd-nepalitimes/20221109111140/636b84239c7e80680e06777ajpeg.jpg" alt="" width="1500" height="1037"/><figcaption>A view of the project from across the Langtang Valley showing the receding Langtang Lirung Glacier, and the location of the intake, penstock and powerhouse. There is a drop of 300m, and the turbines generate 100kW of electricity. Photos: KUNDA DIXIT</figcaption></figure>From the edge of the terminal moraine of the Langtang Lirung Glacier, there is a 360 degree view of icy peaks, and below is the monastery town of Kyanjin blanketed in overnight snow.Towering above is Langtang Lirung with snow being blown off its 7,227m summit, with the jagged peaks of Kimshun standing like bodyguards with Tserko Ri, Yala Peak and Gang Chhenpo. And to the south is the rampart of the Naya Kanga ridge.“When I was a boy we brought the yaks up here to graze, and they could cross the ice from one side of the glacier to the other,” says Gyalbu Tamang. “This lake was formed only in the last 20 years.”<figure><img src="https://superdesk-pro-c.s3.amazonaws.com/sd-nepalitimes/20221109111140/636b84269c7e80680e06777bjpeg.jpg" alt="" width="1500" height="1125"><figcaption> </figcaption></figure>As climate change thaws the mountains, right across the eastern Himalaya in Nepal, Bhutan and southern Tibet, hundreds of new lakes have formed at the snouts of glaciers. Some have found outlets and emptied themselves, while others, like this one, swelled up dangerously.In the past 40 years, there have been 26 <a href="https://www.nepalitimes.com/banner/langtang-copes-with-quake-and-covid/">glacial lake outburst floods on Nepal’s rivers</a>, and with newer and bigger lakes forming, they pose a serious risk to new roads, settlements and hydropower plants downstream.However, glacial lakes do not just need to be a threat, as has been shown by a unique project on the Langtang Lirung Glacier. This glacial lake at 4,100m is being drained to lower its level, and the water is used to generate electricity.The Langtang Microhydro Electricity Project was built three years after the 2015 earthquake-avalanche that devastated the valley, with help from the Hong Kong-based Kadoorie Charitable Foundation. The $534,000 scheme has a weir and spillway at the moraine, and the water is taken through a fibre glass-insulated penstock pipe to a powerhouse that generates 100kW of electricity, providing 24 hours of electricity to 120 households and tourist lodges in Kyanjin and Langtang.The project is a first-of-its-kind in Nepal to power a village, and holds promise for other remote Himalayan valleys where the risk posed by expanding glacial lakes can be mitigated, while at the same time providing electricity to tourism-dependent families.“It can be a plus-plus, you need to simply drive a glacial lake to turn a turbine while simultaneously lowering the water level and reducing the pressure on the moraine dam,” says energy economist and former Water Resource Minister <a href="https://www.nepalitimes.com/review/finding-the-nexus-between-water-food-and-energy/">Dipak Gyawali.</a>The only downside would be that most glacial lakes are at very high elevations where there are few settlements, and also the greater cost of transporting equipment by helicopter. But if the risk-reduction from glacial lake outburst floods is factored in, these multi-purpose projects would be cost-effective.<img src="https://superdesk-pro-c.s3.amazonaws.com/sd-nepalitimes/20221109111140/636b842a9c7e80680e06777cjpeg.jpg" alt="" width="1125" height="1500"><img src="https://superdesk-pro-c.s3.amazonaws.com/sd-nepalitimes/20221109111140/636b842d9c7e80680e06777djpeg.jpg" alt="" width="1250" height="938"><figure><img src="https://superdesk-pro-c.s3.amazonaws.com/sd-nepalitimes/20221109111140/636b84309c7e80680e06777ejpeg.jpg" alt="" width="1500" height="1125"><figcaption> </figcaption></figure>There are other dangerous glacial lakes in Nepal like <a href="https://archive.nepalitimes.com/article/from-nepali-press/Diverting-danger,3172">Imja</a> in the Everest region and <a href="https://www.nepalitimes.com/banner/human-face-of-a-himalayan-climate-crisis/">Tso Rolpa</a> in Rolwaling Valley, where the water level has been lowered at enormous cost, but the schemes have not added the hydropower component. Tso Rolpa had a small power unit to supply electricity to the project, but it is not in use. Imja was financed by the UNDP with funding from the Global Environment Facility, while Tso Rolpa was funded by the Dutch government.Glacial lakes have been used to generate power in the Peruvian Andes, and in the Swiss Alps existing reservoirs filled with glacial melt have been generating 4% more electricity because of accelerated melting. The Swiss are even <a href="https://www.nytimes.com/interactive/2019/04/17/climate/switzerland-glaciers-climate-change.html">mapping future hydropower plants</a> on glaciers for a time when all the ice will be gone. In <a href="https://www.nature.com/articles/nclimate2185.pdf?origin=ppub">Bhutan, a pilot scheme</a> on a glacial lake at 4,200m is trying to lower the water level using siphons, and plans to also see if it is feasible to generate electricity.<figure><img src="https://superdesk-pro-c.s3.amazonaws.com/sd-nepalitimes/20221109111140/636b84349c7e80680e06777fjpeg.jpg" alt="" width="1250" height="689"><figcaption> </figcaption></figure>Experts say that with a little more investment, the moraine dams on glacial lakes can be strengthened for a fraction of a cost of building a new artificial dam for electricity generation. For this, the Langtang Microhydro Project presents a working model for other glacial lakes in Nepal where there are plans to lower the water level."In previous decades it used to be expensive to build power plants on glacial lakes because they were so remote, but now that roads have reached many valleys, they are more feasible," says glaciologist Pradeep Mool.Gyalbu Tamang lost his parents and many relatives in the <a href="https://www.nepalitimes.com/banner/langtang-copes-with-quake-and-covid/">catastrophic earthquake-avalanche in 2015</a> that killed as many as 300 people in Langtang. But for him and other trekking lodge owners who used to depend on solar panels, the 24-hour electricity has transformed the quality of life.He says: “We can charge our phones, use appliances, the children can read at night, it is like living in a city.”Read also: <a href="https://www.nepalitimes.com/banner/danger-nepals-glacial-lakes-are-filling-up/">DANGER: Nepal’s glacial lakes are filling up</a>, Nepali Times

Kunda Dixit

Nepal’s first hydropower from a glacial lake

<figure><img src="https://superdesk-pro-c.s3.amazonaws.com/sd-nepalitimes/20221109111140/636b83d99c7e80680e06775ejpeg.jpg" alt="" width="1843" height="1000"/><figcaption>A frozen Imja Lake looking east from the outlet. Photo: SHARAD JOSHI</figcaption></figure>It is now looking doubtful if countries around the world can cut their greenhouse gas emissions as agreed in Paris six years ago, so that global temperature rise will be limited to 1.5 Celsius by 2050. The earth is going to heat up by more than that.Even if it is 1.5 Celsius, the average temperature in the Himalaya will go up by 1.8 degrees because of a phenomenon called ‘altitude effect’. The best-case scenario is that one-third of all remaining Himalayan glaciers will have melted during this century. However, if greenhouse gas emissions continue to rise at the present rate, two-thirds of Himalayan ice will be gone by 2100.All this will have a catastrophic effect on water supply for 1 billion people downstream on rivers that originate in the Himalaya, as well as throw off kilter weather systems.  It will also increase the danger of <a href="https://www.nepalitimes.com/here-now/nepals-glacial-lakes-in-danger-of-bursting/" target="_blank" rel="noopener noreferrer">glacial lake outburst floods</a> (GLOF) within Nepal.Till the 1960s, the Imja Glacier near Mt Everest had only a few melt-pools. Since then, the ice has been replaced by a lake nearly 2km long, 600m wide and up to 150m deep. The ice is receding 70m a year.As glacial lakes expand, there is a danger of them bursting due to water pressure, or because of earthquakes and avalanches falling into them. As the average temperature in the mountains rises by 0.056 Celsius every year, the threat of glacial lake outbursts will only grow.On top of the perennial risk of earthquakes, new hydropower stations, highways along rivers, bridges and towns will also have to take into account the threat of GLOFs. The flash flood near <a href="https://www.nepalitimes.com/latest/non-climate-cause-of-nanda-devi-flood/" target="_blank" rel="noopener noreferrer">Nanda Devi in India’s Uttarakhand state</a> in March washed away two hydroelectric plants that were under construction.There is a warning there for Nepal, which is building cascade projects on the two Bhote Kosi rivers that flow down from China, Tama Kosi, Marsyangdi, and the Arun. In the Gandaki Basin is the particularly dangerous Thulagi glacial lake below Himalchuli, which would directly threaten three major hydroelectric projects along the Marsyangdi River. Scientists monitoring Thulagi have found the glacier has receded by 2km since 1984, the ice replaced by a lake.<a href="https://www.nepalitimes.com/banner/tracing-past-glacial-floods-in-kangchenjunga/">Tracing past glacial floods in Kanchanjunga</a>, Alton C Byers<figure><img src="https://superdesk-pro-c.s3.amazonaws.com/sd-nepalitimes/20221109111140/636b83dc9c7e80680e06775fjpeg.jpg" alt="" width="1500" height="1080"><figcaption> </figcaption></figure>“If Thulagi were to burst, the flood would go down 100km downstream on the Marsyangdi and Narayani, taking out hydroelectric projects, highways and towns along the way,” says Pradeep Mool, a glacial scientist formerly with ICIMOD.A survey last year showed that GLOF risk is highest in eastern Nepal. There are 42 dangerous lakes on the Kosi basin alone, like Imja, Tso Rolpa, Lower Barun and Hongu. The bursting of any one of these would send a wall of water and debris downstream to the Kosi.There is also the danger of <a href="https://www.nepalitimes.com/editorial/more-himalayan-tsunamis/" target="_blank" rel="noopener noreferrer">transboundary GLOFs</a>. In the past, even the bursting of relatively small glacial lakes in Tibet have caused major damage in Nepal. The earliest recorded one was in 1934, when a flash flood from a glacial lake burst in Tibet caused destruction along the Bhote Kosi.In 1981, another glacial lake burst in China caused a flood on the same river in Nepal, damaging the Sun Kosi power plant and washing out a 25km section of the Arniko Highway, cutting Nepal’s only road to China for three years.<figure><img src="https://superdesk-pro-c.s3.amazonaws.com/sd-nepalitimes/20221109111140/636b83e09c7e80680e067760jpeg.jpg" alt="" width="1000" height="1506"><figcaption> </figcaption></figure>Of the 47 very dangerous lakes that threaten Nepal’s valleys, 25 originate in glaciers in Tibet. Since 1977, there have been at least 20 GLOFs of which 14 were caused by glacial lakes in Nepal bursting, and the rest were in China.To understand what a GLOF looks like, we have the<a href="http://archive.nepalitimes.com/article/nation/Anatom-of-a-Himalayan-tsunami,1330" target="_blank" rel="noopener noreferrer"> Seti flood of 2012</a> which killed nearly 70 people north of Pokhara. Although not caused by a glacial lake burst, it demonstrated the destructive power of such a flood.Although Nepalis may not be responsible for global heating, it does not mean we can sit back and do nothing. While scientists try to figure out exactly how fast the glaciers are melting, Nepal’s policy-makers need to start planning to be prepared for floods that are bound to be unleashed.The danger of GLOFs are compounded by Nepal also being on a seismically active zone. Many of these fragile Himalayan glacial lakes could burst simultaneously during a large earthquake.<img src="https://superdesk-pro-c.s3.amazonaws.com/sd-nepalitimes/20221109111140/636b83e39c7e80680e067761jpeg.jpg" alt="" width="1369" height="630">This calls for hazard mapping, early warning systems through SMS or radio, as well as mitigation efforts like those carried out to <a href="https://archive.nepalitimes.com/article/from-nepali-press/Diverting-danger,3172" target="_blank" rel="noopener noreferrer">reduce water levels on Imja</a> and Tso Rolpa. The microhydro scheme on the Langtang Lirung Glacier that reduces the water level on a recently-formed glacial lake, and also generates electricity could be a model for other remote valleys in Nepal.Because glacial lakes are located at such high altitudes in remote roadless areas, lowering their water level can be expensive. Most of the equipment has to be flown in by helicopter, and work is often hampered by altitude and weather. The question is: who should pay for these risk-reduction measures?“Even if the water level is reduced they can burst and come down like tsunamis, we have to keep monitoring the lakes, and install effective early warning systems in Tso Rolpa and Imja to at least save lives if we cannot save the infrastructure,” says Sarju Baidya of the Department of Hydrology and Meteorology.There are no feasible methods to prevent a glacial lake from bursting, and it is not in our power to stop the lakes expanding. So the only thing Nepal can do is to reduce the level of the most dangerous lakes, design downstream infrastructure taking the dangers into account, and to have an early warning system.Says Pradeep Mool: “What we can do immediately is to install measurement stations and monitor them by satellite, prioritise the high-risk lakes for site inspections to gauge the strength of the moraines, and make a short list of the most dangerous ones for early warning, and mitigation measures.”Read also: <a href="https://www.nepalitimes.com/banner/human-face-of-a-himalayan-climate-crisis/">Human face of a Himalayan climate crisis</a>, Rastraraj Bhandari

DANGER: Nepal’s glacial lakes are filling up

<figure><img width="2560" height="1967" src="https://superdesk-pro-c.s3.amazonaws.com/sd-nepalitimes/20221110111152/636cd8519c7e80680e092e37jpeg.jpg" alt=""/><figcaption>The origin of the Nanda Devi massif rockslide and the debris flow on a CubeSat image at 10:30 IST, just before the flood reached the Tapovan Hydropower Project site 22km downstream. The dotted black line shows the sediment deposited on the adjacent slopes of the river valley, with the rockslide marked in red. Image: ICIMOD</figcaption></figure>More than a month after the catastrophic flashflood in Chamoli district of the Indian Himalaya, scientists say that the cause was failure of a rock face, and not just the result of a glacial lake burst caused by climate change.Early reports had suggested that the flood of water and debris that raced down the Rishiganga on 7 February, damaging four hydroelectric plants and killing more than 200 people, may have been caused by a glacial lake outburst flood (GLOF). <img width="640" height="463" src="https://superdesk-pro-c.s3.amazonaws.com/sd-nepalitimes/20221110111152/636cd8549c7e80680e092e38jpeg.jpg" alt="">However, analysis of satellite images before and after the disaster show that there were no lakes on the Ronti Glacier in the Nanda Devi (7,816m) massif, and the disaster happened in winter when the supra-glacial ponds were frozen. <figure><img width="2048" height="1449" src="https://superdesk-pro-c.s3.amazonaws.com/sd-nepalitimes/20221110111152/636cd8569c7e80680e092e39jpeg.jpg" alt=""><figcaption> </figcaption></figure>Scientists have concluded that a 500m wide section of the face of Ronti Peak broke off at 10:30am on 7 February at an elevation of 5,500m and fell with tremendous force on the glacier below. The kinetic energy of an estimated 22 million cubic metres of falling rock also melted ice deposits from a previous avalanche in 2016.Scientists say that the disaster was not directly caused by global warming, but <a href="https://www.carbonbrief.org/factcheck-did-climate-change-contribute-to-indias-catastrophic-glacial-flood" data-saferedirecturl="https://www.google.com/url?q=https://www.carbonbrief.org/factcheck-did-climate-change-contribute-to-indias-catastrophic-glacial-flood&amp;source=gmail&amp;ust=1615627463312000&amp;usg=AFQjCNFgdSlP7mXxpGofYUH2Q6dgxNd1xw">climate change could have contributed</a>. Uttarakhand state recorded its warmest January in six decades this year, and there had been winter storms the previous week that had deposited a lot of snow on the slopes. Ice also cements rock fissures at higher elevations, and when it melts the rocks can come loose.‘The Chamoli flood was not caused by a GLOF as there were no significant glacial lakes in the area,’ write a group of researchers led by Arun B Shrestha in a recent paper for the Kathmandu-based International Centre for Integrated Mountain Development (ICIMOD),  ‘… (but) the <a href="https://www.carbonbrief.org/factcheck-did-climate-change-contribute-to-indias-catastrophic-glacial-flood" data-saferedirecturl="https://www.google.com/url?q=https://www.carbonbrief.org/factcheck-did-climate-change-contribute-to-indias-catastrophic-glacial-flood&amp;source=gmail&amp;ust=1615627463312000&amp;usg=AFQjCNFgdSlP7mXxpGofYUH2Q6dgxNd1xw">increased thaw-freeze cycle of permafrost could have partially contributed to the event.’</a>Even so, researchers at the <a href="https://www.hindustantimes.com/india-news/uttarakhand-underground-glacial-lake-led-to-flash-floods-says-iisc-analysis-101612842535639.html" data-saferedirecturl="https://www.google.com/url?q=https://www.hindustantimes.com/india-news/uttarakhand-underground-glacial-lake-led-to-flash-floods-says-iisc-analysis-101612842535639.html&amp;source=gmail&amp;ust=1615627463312000&amp;usg=AFQjCNHUxxKYGuO-LH5Lmhia8nvW3Oi2HA">Divecha Centre for Climate Change at Indian Institute of Science in Bengaluru</a> used glacier thickness mapper data to detect a sub-surface lake containing 4.5 million cubic metres of water stored in a bedrock depression near the Nanda Devi Glacier terminus that could have caused the flood.  Scientists note that not all Himalayan hazards can be attributed to the climate crisis. An <a href="http://archive.nepalitimes.com/article/nation/Anatom-of-a-Himalayan-tsunami,1330" data-saferedirecturl="https://www.google.com/url?q=http://archive.nepalitimes.com/article/nation/Anatom-of-a-Himalayan-tsunami,1330&amp;source=gmail&amp;ust=1615627463313000&amp;usg=AFQjCNEsZOhcMFA8vxHbbwUxFh8HOESRwQ">identical rock slip on Annapurna IV</a> in Nepal on 5 May 2012 caused a flashflood on the Seti River that killed at least 72 people. The <a href="https://www.nepalitimes.com/banner/the-courage-and-endurance-of-the-langtangpa/" data-saferedirecturl="https://www.google.com/url?q=https://www.nepalitimes.com/banner/the-courage-and-endurance-of-the-langtangpa/&amp;source=gmail&amp;ust=1615627463313000&amp;usg=AFQjCNHonfzkoR0q5xry76GBTl4UyM05-w">deadly avalanche on Langtang</a> on 25 April 2015 killed nearly 200 people, and was triggered by an earthquake. Another flood that blocked the Arun River in eastern Nepal in July 2017 was traced to a <a href="https://www.nepalitimes.com/editorial/more-himalayan-tsunamis/" data-saferedirecturl="https://www.google.com/url?q=https://www.nepalitimes.com/editorial/more-himalayan-tsunamis/&amp;source=gmail&amp;ust=1615627463313000&amp;usg=AFQjCNFvsIDn5dmC06mGMdSJ_ogC8tBCYg">rock-fall that caused a glacial lake to top over.</a> <figure><img width="850" height="478" src="https://superdesk-pro-c.s3.amazonaws.com/sd-nepalitimes/20221110111152/636cd8599c7e80680e092e3ajpeg.jpg" alt=""><figcaption> </figcaption></figure><a href="https://www.nepalitimes.com/here-now/nepals-glacial-lakes-in-danger-of-bursting/" data-saferedirecturl="https://www.google.com/url?q=https://www.nepalitimes.com/here-now/nepals-glacial-lakes-in-danger-of-bursting/&amp;source=gmail&amp;ust=1615627463313000&amp;usg=AFQjCNFTEiergMkJv8bcv86ZOG8uUmM3_Q">GLOFs</a> happen when ice and snow melted by the climate thaw accumulates in enlarging lakes, which can burst due to increased water pressure, or when avalanches fall into them.  And while there are frequent GLOFs, especially in the eastern Himalaya, scientists agree that it was not the main trigger of the Nanda Devi disaster last month.  The other disasters on Himalayan rivers are caused by <a href="https://www.nepalitimes.com/editorial/more-himalayan-tsunamis/" data-saferedirecturl="https://www.google.com/url?q=https://www.nepalitimes.com/editorial/more-himalayan-tsunamis/&amp;source=gmail&amp;ust=1615627463313000&amp;usg=AFQjCNFvsIDn5dmC06mGMdSJ_ogC8tBCYg">bishyari</a>, a local word that refers to a floods due to a landslide blocking a river to impound a lake that suddenly bursts, as what happened in <a href="http://archive.nepalitimes.com/article/nation/One-month-after-the-mountain-fell,1637" data-saferedirecturl="https://www.google.com/url?q=http://archive.nepalitimes.com/article/nation/One-month-after-the-mountain-fell,1637&amp;source=gmail&amp;ust=1615627463313000&amp;usg=AFQjCNEpOyzNu1-11qUQhioHciDTUNZdGQ">Jure of Sindhupalchok on 2 August 2014.</a>Another catastrophic example is the co-seismic mountain slide that blocked the Seti River about 500 years ago, creating a huge lake that then burst depositing the 200m thick sediment layers on which the city of Pokhara is now located.   Nepal’s former water resource minister and hydropower expert Dipak Gyawali says that bishyari are known to happen in 10-15 year cycles in Nepal. The etymology of the word itself shows that human dwellers of the Himalaya have known of the phenomenon for thousands of years, he says.“Even if these floods are not directly caused by climate change, it can exacerbate the disaster because of extreme weather events,” Gyawali said in an interview.Himalayan floods therefore pre-date climate change, and are caused by the vulnerability of these young, fragile mountains to natural and human-induced processes like the indiscriminate use of heavy earth-moving vehicles on poorly-engineered roads.  Such ‘bulldozer terrorism’, has exacerbated the frequency of landslides in central Nepal  after the 2015 earthquake, according to a recently published paper in the journal, <a href="https://www.sciencedirect.com/science/article/pii/S2590061721000193" data-saferedirecturl="https://www.google.com/url?q=https://www.sciencedirect.com/science/article/pii/S2590061721000193&amp;source=gmail&amp;ust=1615627463313000&amp;usg=AFQjCNFfGOeUwHuVmX29jd0yc9zjQ9LTRg">Progress in Disaster Science.</a> <figure><img width="499" height="397" src="https://superdesk-pro-c.s3.amazonaws.com/sd-nepalitimes/20221110111152/636cd85d9c7e80680e092e3bjpeg.jpg" alt=""><figcaption> </figcaption></figure>After analysing remote sensing data, the researchers conclude that although the number of landslides had started falling after 2015, there has been an uptick since 2017 possibly due to the <a href="https://www.nepalitimes.com/opinion/dozers-and-nepals-development/" data-saferedirecturl="https://www.google.com/url?q=https://www.nepalitimes.com/opinion/dozers-and-nepals-development/&amp;source=gmail&amp;ust=1615627463313000&amp;usg=AFQjCNEh-pzzDl7j405T7swUxTKR34tVPg">proliferation of rural road construction</a> around the time of the elections. (See graph, above.) Gyawali suggests that a solution could be better-planned infrastructure and settlements that take into account known hazards. As the Chamoli flood showed, expensive hydroelectric projects located closer to the high mountains are more at risk. He suggests investing in smaller hydropower plants in side tributaries rather than the main stem of major Himalayan rivers to mitigate the danger, and to spread the risk. However, most of Nepal’s planned large hydropower projects are on rivers like the Tamor, Arun, Dudh Kosi, Bhote Kosi and Budi Gandaki. The Himalaya is a young and unstable mountain range that is battered by a heavy monsoon three months a year. Into this high-risk zone, there is now the added threat of climate-induced disasters. Says Gyawali: “We cannot completely remove these disasters from happening, but we can try to understand them and plan to minimise the risk.”

Non-climate cause of Nanda Devi flood

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For destruction, ice is also great and will suffice

Indo-Pak tension hits SAARC climate action

Nepal’s first hydropower from a glacial lake

DANGER: Nepal’s glacial lakes are filling up

Non-climate cause of Nanda Devi flood