UPSC Key: Glacial Collapse, Kailash-Mansarovar Yatra and Ethanol Blended Petrol Programme

Hanging glacier collapse in focus, NDMA for hard look to reduce future risks

Syllabus:

Preliminary Examination: Indian and World Geography-Physical, Social, Economic Geography of India and the World.

Mains Examination: 

• General Studies I: Important Geophysical phenomena such as earthquakes, Tsunami, Volcanic activity, cyclone etc., geographical features and their location-changes in critical geographical features (including water-bodies and ice-caps) and in flora and fauna and the effects of such changes.

• General Studies III: Disaster and disaster management

What’s the ongoing story: With the spotlight now on the collapse of a hanging glacier as the likely trigger for the devastating flash flood in Nepal, the incident is being closely monitored by the disaster management set-up in India where similar disasters have happened in the recent past.

Key Points to Ponder:

• What is a glacial?

• What are Glaciers?

• What is glacial collapse?

• What is a glacial lake outburst flood (GLOF)?

• What happened in Nepal and Tibet?

• Did global warming cause it?

• How vulnerable are the Himalayas to glacial lake outburst flood?

• How can the risks from GLOFs be reduced?

• How well is India prepared to handle situations such as these?

• What is the status of India’s Early Warning Systems (EWS) for such situations?

• What are the guidelines for rescue operations in case of a disaster?

Key Takeaways:

• The National Disaster Management Authority (NDMA) said Thursday it was planning to initiate a comprehensive study on the Nepal event.

• “Many areas in India are vulnerable to the kind of disaster we have just seen in Nepal. We have had such events in the past. So it is important for us to study this, and understand this. We do plan to look at it in detail,” Krishna Swaroop Vatsa, Member, NDMA, said.

• “This programme is progressing well. It will take some time, but this will help in significantly reducing the risks from glacial outbursts. The Nepal incident just reinforces the importance of this programme. Simultaneous efforts to create capabilities in forecasting landslides, and develop a landslide early warning system, are also extremely crucial. Experimental landslide forecasts are already being done in some areas. These are very important,” Vatsa said.

• While scientists are still trying to ascertain the exact trigger for the Nepal flash flood, glaciologist Anil Kulkarni of the Indian Institute of Science said the collapse of a large chunk of snow and rocks from a hanging glacier was the most likely cause. He likened the fall of this chunk to “a high-intensity bomb blast”.

• The National Remote Sensing Centre Thursday released satellite images of before and after the event, which, too, indicated the collapse of a glacier mass and the swollen channel of the Bhote Koshi river.

Do You Know:

• A glacial collapse is the detachment of a large mass of glacier ice from its bed – sometimes involving millions of cubic metres of ice, rock, and water – that can transform into a highly mobile ice-rich avalanche or debris flow.
This collapse is not a formally defined scientific term in glaciology, but is widely used to describe the event.

• India has had several major flash flood incidents in recent years, including the Kedarnath tragedy in 2013, the Chamoli disaster in 2021, the Sikkim lake burst in 2023 and in Dharali last year. These incidents claimed hundreds of lives and caused large-scale damage.

• Following the Chamoli incident in 2021, the NDMA had initiated an effort to mitigate the risks from such events through the installation of early warning systems on glacial lakes considered vulnerable to breaches.

• The National GLOF Risk Management Programme seeks to strengthen the boundaries of these glacial lakes in the four hilly states of Arunachal Pradesh, Sikkim, Uttarakhand and Himachal Pradesh, and equip them with early warning systems. The programme covers the Union Territories of Jammu and Kashmir and Ladakh as well. In April 2024, ISRO has revealed that of 2,431 glacial lakes larger than 10 hectares in size in the Indian Himalayan River basins 676 had expanded notably between 1984 and 2023.
The NDMA guidelines say that risk reduction has to begin with identifying and mapping such lakes, taking structural measures to prevent their sudden breaches, and establishing mechanisms to save lives and property in times of a breach.

• According to the NDMA, potentially dangerous lakes can be identified on the basis of the condition of lakes, dams,
associated mother glaciers, and topographic features around the lakes and glaciers.

• The identification of these lakes are based on field observations, processes and records of past events, geomorphological and geotechnical characteristics of the lake/ dam and its surroundings, and other physical conditions.

Other Important Articles Covering the same topic:

📍Risk of glacial lake outburst floods in ‘Third Pole’ increasing: Study

Previous year UPSC Prelims Question Covering similar theme:
1) Consider the following pairs (UPSC CSE, 2019)

	GLACIER	RIVER
1.	Bandarpunch	Yamuna
2.	Bara Shigri	Chenab
3.	Milam	Mandakini
4.	Siachen	Nubra
5.	Zemu	Manas

Which of the pairs correctly matched?

(a) 1, 2 and 4

(b) 1, 3 and 4

(c) 2 and 5

(d) 3 and 5

Previous year UPSC Mains Question Covering similar theme:
📍How do the melting of the Arctic ice and glaciers of the Antarctic differently affect the weather patterns and human activities on the Earth? Explain. (UPSC GS1, 2021)
📍How will the melting of Himalayan glaciers have a far-reaching impact on the water resources of India? (UPSC GS1, 2020)
📍Bring out the relationship between the shrinking Himalayan glaciers and the symptoms of climate change in the Indian sub-continent. (UPSC GS1, 2014)

Nepal Disaster

Kailash Mansarovar Yatra bookings saw a marked surge in ’26

Syllabus:

Preliminary Examination: Current events of national and international importance.

Mains Examination: General Studies II: India and its neighbourhood- relations.

What’s the ongoing story: For five years between 2020 and 2025, the Kailash Mansarovar remained out of bounds for Indian visitors in the wake of the Covid-19 pandemic and the Galwan standoff that strained India-China ties.

Key Points to Ponder:

• Map Work-Lipulekh pass, Nathula Pass, Lake Manasarovar, Mahakali River, Mount Kailash Limpiadhura, Kalapani, Indian states bordering Nepal, China-Nepal border.

• What is the importance of Kailash-Mansarovar Yatra?

• Know the cultural, economic, and strategic implications of Kailash Mansarovar Yatra

• How does cultural diplomacy complement traditional diplomatic mechanisms?

Key Takeaways:

• In late 2024, as New Delhi and Beijing began efforts to repair ties, the resumption of the Kailash Mansarovar Yatra in the summer of 2025 was the first tangible takeaway of the thaw.

• As people waited to see how the resumption of the yatra panned out in 2025, when the Ministry of External Affairs (MEA) took 750 Indian passport holders in batches, this year saw a rebound in the number of visitors to Kailash Mansarovar after the cautious optimism of last year.

• While the MEA marginally increased the quota from 750 to 1,000, the private operators — who take visitors through Nepal checkpoints such as Rasuwagadhi and Hilsa — saw a marked surge in 2026. Though an exact count of the number of Indians who signed up for Kailash Yatra through private operators this year is not officially compiled yet, China had announced a cap on the total permissible quota for Indian passport holders via Nepal routes at 24,000 for the season. The quota was 20,000 in 2025.

Do You Know:

• Mount Kailash is about 6,638 m above sea level, while the nearby Mansarovar Lake is at an altitude of 4,590 m, among one of the world’s highest freshwater lakes. Pilgrims traditionally undertake the 52-km Kailash Parikrama, or Kora, which is now reduced to 13 km through some routes.

• Before the yatra suspension in 2020, the government programme generally accommodated around 800-1,000 pilgrims annually. For 2025, the announced capacity was 750 pilgrims — 250 through the Lipulekh route in five batches and 500 through the Nathu La route in 10 batches.

• Beyond its spiritual significance, the yatra is also one of the world’s most logistically complex pilgrimages. Located in China’s Tibet Autonomous Region, it requires extensive diplomatic coordination between New Delhi and Beijing, meticulous planning and strict medical screening because of extreme altitude and inhospitable terrain.

• Pilgrim groups having to halt yatra for days en route owing to inclement weather is a norm rather than an exception. But a tragedy of this scale has not happened before. The worst recorded tragedy associated with the Kailash Mansarovar Yatra before 2026 has been the 1998 Malpa landslide in the Pithoragarh district of Uttarakhand, which claimed over 220 lives, including 60 pilgrims who were on their way to Kailash.

• For those taking the government-operated Lipulekh route, the journey from Delhi to the Kailash covers roughly 1,000 km by road, besides the 52-km parikrama. The alternative Nathu La route through Sikkim is longer by road but involves comparatively less trekking. The Nathu La route is generally considered less strenuous, making it more suitable for older pilgrims.

• The journey typically lasts about three weeks, including acclimatisation, medical examinations, border formalities and travel in Tibet, although schedules may vary depending on weather and administrative requirements. In 2025, of the 750 pilgrims who registered for the yatra, 688 participated and completed the journey, as per the MEA.

Other Important Articles Covering the same topic:

📍Kailash-Mansarovar yatra resumes after five years: history of a storied pilgrimage

Explained

Echoes of past, warning for future

Syllabus:

Preliminary Examination: Indian and World Geography-Physical, Social, Economic Geography of India and the World.

Mains Examination: 

• General Studies I: Important Geophysical phenomena such as earthquakes, Tsunami, Volcanic activity, cyclone etc., geographical features and their location-changes in critical geographical features (including water-bodies and ice-caps) and in flora and fauna and the effects of such changes.

• General Studies III: Disaster and disaster management

What’s the ongoing story: The devastating flooding in Nepal’s Bhotekoshi-Trishuli river, which has already claimed more than 350 lives, is yet another reminder of the vulnerability of the Himalayan region to major disasters.

Key Points to Ponder:

• What happened in Nepal?

• What is a cascading disaster?

• Why are the Himalayas particularly vulnerable?

• Why Himalayas are earthquake prone?

• Why are Himalayan glacial lakes increasing?

• Why glacier retreat matters

• Himalayan rivers and transboundary implications-know in detail

• Why Nepal floods matter for India and especially for Bihar and Uttar Pradesh?

• How is climate change altering the nature of hydrological hazards in the Himalayan region? •

Key Takeaways:

• Though they were all triggered by a unique set of circumstances, the Nepal tragedy is not very different from similar disasters seen in India over the last 15 years — Kedarnath in 2013, Chamoli in 2021, Sikkim’s South Lhonak lake in 2023, and Uttarakhand’s Dharali last year.

• Each of them involved a very large and sudden release of waters in the mountainous rivers, either due to a breach in a glacial lake, or because of a large block of glacial ice breaking off and falling into the river.

• The breach in the lake or the breaking off of the ice-block can be spontaneous — under accumulated stress over time — or be caused by an extremely heavy rainfall, a landslide or an earthquake.

• The end result, however, is the same — a series of cascading events in which a mass of water, stones and soil gushes downstream at great speeds, eroding river banks, uprooting trees, triggering landslides, and destroying buildings, roads and bridges. All the debris being collected by the river on the way further strengthens its force, and its potential to cause damage. The situation continues till the river arrives at a flatter landscape, offering the raging flow an opportunity to spread out and disperse.

• Wednesday’s event, which started in the northeastern district of Rasua in Nepal, is currently understood to have been triggered by a rock and ice avalanche, a result of a large block of glacier in the upper reaches of the Bhotekashi river (the lower side is also called the Trishuli) falling off. What caused this break-off is not very clear as of now. There was no heavy rainfall incident recorded in the area, so that factor is largely ruled out.

Do You Know:

• The US Geological Survey had reported a 4.4 magnitude earthquake in the region on Wednesday, which was initially believed to be the trigger. On Thursday morning, however, it said the signal that was captured by its sensors was most probably a result of a landslide and not a seismic event.

• “This event was initially reported as a magnitude 4.4 earthquake. Additional analysis of nearby seismic stations, long period seismic waves and satellite imagery led to the determination that the seismic event was instead a glacial collapse and debris flow, and that no earthquake had occurred,” said the USGS update.

The deadly path of the Nepal flash flood

• That could mean that a large chunk of snow broke off from the glacier on its own, possibly under its own internal stress, and caused a landslide which triggered the chain of events.
But Syed Iqbal Hasnain, a veteran glaciologist and former vice-chancellor of University of Calicut, pointed out that ice-blocks were not visible in any of the videos of the disaster. “The ice that breaks off from a glacier is almost like a solid rock. It does not melt immediately. But no ice block is visible in the videos of the incident. It is possible therefore that the incident was caused not by ice blocks breaking off from a glacier, but from a glacial lake outburst,” he said.

• Safi Ahsan Rizvi, an IPS officer who worked with the National Disaster Management Authority (NDMA) before his retirement, suggested that it could have been a result of a breach in a “supra-glacial lake”. Lakes are generally formed at the end of a glacier, but sometimes, mainly as a consequence of climate change, lakes emerge within the glaciers themselves, and are known as supra-glacial lakes. A breach in this kind of lake could explain the lack of ice blocks in the visuals.

• The reason these events in the Himalayan region become so risky is that while they start off as individual events — extreme rainfall or landslide or lake overflow — they soon transform into a multi-hazard disaster, involving multiple landslides, flooding and building collapse episodes.

Disasters in the Himalayas

• A study published in Science magazine last year about a 2023 event in Sikkim captured the cascading impact of such flash flood events in the mountains. This event had been triggered by the collapse of a large chunk of glacier into the South Lhonak lake, situated over 5,000 metres above sea level, in northern Sikkim. This led to a GLOF event that took the shape of flash floods.

• The study found that a landslide had resulted in the collapse of nearly 14.7 million cubic metres of rocks, soil and snow deposited around a glacier into the South Lhonak lake, which triggered a series of cascading events. The volume of the flowing sediment downstream had grown to about 270 million cubic metres.

• Azam said the entire Himalayan region was “out of balance entirely” because of population pressure and climate change.
“The whole ecosystem is vulnerable. Because of climate change and increasing instances of extreme weather events, newer areas are getting exposed. Earthquakes or heavy rainfall events are quite common, and any of them can trigger these kinds of disasters,” he said.
Incidentally, the Himalayan region is also one of the most dangerous places for earthquakes. The region has recorded some of the biggest earthquakes in the past. Nepal itself was the victim of a 7.2 magnitude earthquake in 2015.

Other Important Articles Covering the same topic:

📍 Nepal lake formed after flash flood breaks banks

Previous year UPSC Prelims Question Covering similar theme:
2) When you travel in Himalayas, you will see the following: (UPSC CSE, 2012)
1. Deep gorges
2. U-turn river courses
3. Parallel mountain ranges
4. Steep gradients causing land-sliding
Which of the above can be said to be the evidence for Himalayas being young fold mountains?
(a) 1 and 2 only
(b) 1, 2 and 4 only
(c) 3 and 4 only
(d) 1, 2, 3 and 4

India-China boundary talks: Some progress, but a long road ahead

Syllabus:

Preliminary Examination: Current events of national and international importance.

Mains Examination: General Studies II: Bilateral, regional and global groupings and agreements involving India and/or affecting India’s interests.

What’s the ongoing story: The eight-point consensus reached at the 25th round of talks between Special Representatives (SRs) Ajit Doval and his Chinese counterpart Wang Yi in Beijing is a welcome step ahead of the expected visit of President Xi Jinping to India for the BRICS Summit.

Key Points to Ponder:

• Standoff between India and China-what you know about the same?

• Friction between India and China-what are the reasons?

• India-China Relations during Nehruvian Era-Know in detail

• The 1962 India-China War-Know the background

• India-China Border Dispute- what is the present situation?

• What are the major factors responsible for the persistence of the India-China boundary dispute?

• Map Work– Line of Actual Control, McMahon Line, Chang Chenmo river, Gogra-Hot Springs, Kongka Pass, Galwan Valley, Depsang Plains, and Charding Nala region

• Know the terms ‘De-induction’ ‘Disengagement’ and ‘De-escalation’?

• What ‘De-induction’, ‘Disengagement’ and ‘De-escalation’ means in India-China Context?

• What is the present situation?

Key Takeaways:

• Some of the outcomes concern the maintenance of peace and tranquillity in the border areas, and advancing negotiations on a framework for the settlement of the boundary question in accordance with previous agreements. There is a specific reference to advancing discussions through an Expert Group and Working Group respectively, to explore an “early harvest” of boundary delimitation in appropriate sectors, and effective border management.

• Last year, there was agreement in principle on working towards setting up additional General-Level Mechanisms/Senior Highest Military Commander (SHMC) meetings in the Eastern and Middle sectors akin to the existing mechanism in the Western sector at Chushul/Moldo.

• This time, the two sides agreed to implement that understanding along with establishing two hotlines in the Eastern and Middle Sectors. Going forward, the implementation will have to be handled carefully.

Do You Know:

• In 1992, the Joint Working Group (JWG) on the Boundary Question decided on confidence building measures (CBMs) such as border personnel meetings (BPMs), complementing forward movement on border trade.

• A sub-group of the JWG was created following the border peace and tranquillity agreement (BPTA) of 1993 — the India-China Expert Group of Diplomatic and Military Officials (EG), a precursor to the Working Mechanism for Consultation and Coordination on India-China Border Affairs (WMCC), an institutional mechanism for border management set up in 2012.

• After the success achieved in 1995 on disengagement at Sumdorong Chu (along the India-China Line of Actual Control in Arunachal Pradesh), Lipulekh (Middle Sector) and Dichu (Eastern Sector) were subsequently identified as additional military meeting points. The plan for BPMs at Lipulekh was abandoned due to lack of infrastructure and adverse weather conditions. A trial meeting at Dichu in the Kibithu sector in Arunachal Pradesh was finalised. Dichu is a sensitive area in Anjaw district, and the site of a famous battle in 1962 at Hill 100, in which the Kumaon Regiment did the Indian Army proud. The site chosen for the BPM on Madan Ridge proved contentious. No further meetings could take place.

• It was not until 2014 that the proposal for additional points for BPMs was revived. Eventually, it was decided to have regular BPMs at Wacha/Kibithu in the same sector opposite Damai on the Chinese side, in addition to existing venues across Bum La in Arunachal Pradesh and Nathu La in Sikkim.

Other Important Articles Covering the same topic:

📍Explained: China-India state of play

Previous year UPSC Mains Question Covering similar theme:
📍‘China is using its economic relations and positive trade surplus as tools to develop potential military power status in Asia’, In the light of this statement, discuss its impact on India as her neighbour. (UPSC CSE GS2, 2017)
📍With respect to the South China sea, maritime territorial disputes and rising tension affirm the need for safeguarding maritime security to ensure freedom of navigation and overflight throughout the region. In this context, discuss the bilateral issues between India and China. (UPSC CSE GS2, 2014)

Economy

‘No reversal to E10, choice for old vehicles being explored’

Syllabus:

Preliminary Examination: Current events of national and international importance.

Mains Examination: General Studies II: Government policies and interventions for development in various sectors and issues arising out of their design and implementation.

What’s the ongoing story: Amid the public debate around E20 petrol — 80% petrol and 20% ethanol — being the only standard petrol variant in the country, the option of additionally offering petrol with 10% ethanol blending, or E10, is being explored specifically for older vehicles, Sanjay Khanna, chairman of the country’s second-largest fuel retailer Bharat Petroleum (BPCL), said Thursday in an interaction with reporters.

Key Points to Ponder:

• What is E10 and E20?

• Why does ethanol is blended with petrol?

• What is the Ethanol Blended Petrol Programme?

• Why E20 is currently at the centre of the controversy?

• Why are older vehicles particularly relevant?

• Why is E10 being proposed alongside E20?

• What are the merits and limitations of India’s transition from E10 to E20 petrol?

• Ethanol is classified into four “generations” (1G to 4G) based on the raw materials used-can you recall that?

• Which country uses 100% ethanol?

• Should Government offer consumers both E10 and E20 petrol?

• What are the economic, environmental and administrative implications of both E10 and E20 petrol?

• What policy measures can enable India to increase ethanol blending without worsening water stress and food insecurity?

Key Takeaways:

• But no concrete decision has been taken yet as discussions are on regarding supply chain and logistical challenges that selling two variants of base fuel are likely to pose. Khanna also said that there is no proposal to fully replace the E20 blend with E10.

• On August 19, The Indian Express had reported quoting sources that early exploratory discussions within the government and the industry were underway on whether E10 petrol can also be retailed for older vehicles alongside the E20 fuel. Any decision on the matter is likely to be taken at the government level, and will be binding on all fuel retailers.

• India achieved 20% ethanol blending in petrol last year, five years ahead of the original deadline. There has been opposition over the E20 fuel from various quarters, with claims ranging from notable reduction in mileage and engine component wear in older vehicles whose engines were not designed for higher ethanol blends.

• On its part, the government has been attempting to allay fears, saying that the drop in mileage in older vehicles would be 3-5% at most, and would be outweighed by E20’s benefits as it is a superior fuel. It has also consistently rejected claims that E20 fuel could damage engine components. Questions have also been raised on why motorists aren’t being offered the choice of pure petrol, E10, and E20 fuels.

• According to sources in the know, the discussions — described as preliminary — are being held on various technical as well as non-technical aspects of the country’s complex fuel retail supply chain. They said that the backlash from certain quarters against E20 and the lack of choice for consumers, specifically those with older vehicles — particularly two-wheelers — that were certified for E10 petrol, led to the initiation of these discussions.

• In July, the government had said that offering multiple grades 0f base fuel across the country would create an “enormous logistical challenge”, apart from raising costs and reducing operational efficiencies in India’s complex fuel retail network. It also said that the current base fuel E20 is cleaner and superior than pure petrol and lower ethanol-petrol blends, has required massive investments, and reverting to a lower blend level wouldn’t be prudent on various counts. Petrol is the second most consumed petroleum fuel in India; about 43 million tonnes of petrol was consumed in the country in the last financial year.

• Notably though, an opinion piece co-authored by Chief Economic Adviser V Anantha Nageswaran, which appeared in The Indian Express on August 18, called for lower ethanol-petrol blend, say E10, to also be available alongside E20 fuel. While the views expressed in the article were personal, this was the first instance of a high-ranking government official publicly calling for more petrol options.

• According to auto industry insiders, only petrol vehicles manufactured and sold after April 2023 are considered fully E20-compliant. As per a senior oil industry official, making two base variants of petrol available simultaneously isn’t “simple and straightforward”, and would involve various complexities.

Do You Know:

• Given the skyrocketing fuel prices, the blending programme has a dual purpose – to reduce the crude oil import bill and to allow consumers access to environment friendly fuel. For this, Oil Marketing Companies (OMCs) have already been mandated to buy ethanol from sugar mills and clear payments within 21 days. The decision would help sugar mills diversify their portfolios faster from just sugar production and become self-reliant in paying cane-growers.

• Ethanol Blended Petrol (EBP) Programme has emerged as a key pillar of India’s energy transition and biofuel strategy. It aims to improve energy security, support farmers, and reduce environmental impacts. The programme also promotes greater use of domestically produced renewable fuel.
Under the EBP Programme, ethanol blending has increased from less than 1.5 percent in 2013-14 to 20 percent in 2025-26. India achieved the 20 percent blending target five years ahead of schedule. Ethanol procurement rose from about 38 crore litres in Ethanol Supply Year (ESY) 2013-14 to over 1,200 crore litres (projected) in 2025-26. Production capacity expanded nearly fivefold from 421 crore litres in 2014 to about 2,000 crore litres in 2026. This expansion has reduced crude oil imports and saved valuable foreign exchange. It has also lowered greenhouse gas emissions and strengthened farmers’ incomes through new market opportunities.

Other Important Articles Covering the same topic:

📍Ethanol blending in fuel: Why road ahead is bumpy

Previous year UPSC Prelims Question Covering similar theme:
3) According to India’s National Policy on Biofuels, which of the following can be used as raw materials for the production of biofuels? (UPSC CSE, 2020)
1. Cassava
2. Damaged wheat grains
3. Groundnut seeds
4. Horse gram
5. Rotten potatoes
6. Sugar beet
Select the correct answer using the code given below:
(a) 1, 2, 5 and 6 only
(b) 1, 3, 4 and 6 only
(c) 2, 3, 4 and 5 only
(d) 1, 2, 3, 4, 5 and 6

 

PRELIMS ANSWER KEY

1.(a)  2.(d)  3.(a)

  

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