A glacier collapses in Nepal. A dangerous glacial lake grows above a tourism city in Peru. Thousands of kilometers separate the Himalayas from the Andes, but climate change is raising an increasingly similar question for both destinations: are governments and the tourism industry adapting fast enough to mountains changing beneath their feet?

On August 26, the mountain moved. High on Nepal’s Langtang Lirung massif, an enormous mass of rock and glacial ice collapsed and plunged toward the valley floor. What followed was not simply an avalanche.

Water, rock, ice and sediment became a catastrophic torrent racing through the Lhende Khola and Trishuli river systems, destroying communities, roads, bridges, hydropower infrastructure and tourism and pilgrimage routes.

Satellite analysis by the European Space Agency says the resulting torrent travelled nearly 100 kilometers downstream, devastating towns used by mountaineering tourists and pilgrims and overwhelming the Nepal-China border crossing.

Two weeks later, the disaster has killed at least 1,399 people and left more than 5,400 missing in Nepal and Tibet. But travel 16,000 kilometers from Nepal to Peru and the mountains are delivering a related warning.

From Langtang to the Andes

Peru has lost more than half of its glacier surface over roughly six decades. Its glaciers are retreating, lakes are changing and communities and tourism destinations below them are being forced to reconsider what constitutes an acceptable mountain risk.

One particularly important example hangs above Huaraz. Lake Palcacocha, at approximately 4,500 meters in Peru’s Cordillera Blanca, has increased dramatically in volume as the surrounding glaciers have retreated.

It isn’t a theoretical threat. In 1941, an outburst from Palcacocha devastated part of Huaraz and killed thousands.

Today, Peru monitors the lake and has developed an early-warning system because tens of thousands of people could potentially be exposed to another major outburst.

Now throw the ball back to Nepal.

Could Nepal’s catastrophe have been predicted?

This is where the uncomfortable questions begin. It would be wrong to claim that scientists knew the Langtang glacier would collapse on August 26 and that Nepal simply ignored the warning. They didn’t.

Researchers working on cascading disasters in Nepal have explicitly said that nobody — in Nepal, China or the international scientific community — had identified this particular location as an imminent danger.

But there is another side to the story. Satellite imagery examined after the catastrophe showed changes before the collapse. ABC reported that a rapid international hazard assessment found indications of acceleration and surface changes in the glacier before it failed.

Even more strikingly, Nepalese and Chinese experts and officials had met in Kathmandu in May to discuss cross-border floods, glacier hazards, monitoring and disaster response. Yet no glacier-hazard early-warning system had been installed in the affected area.

That doesn’t prove negligence. It does raise a legitimate question.

If satellites can reveal an unstable mountain after a disaster, how do we get better at identifying instability before the disaster? Peru has been asking precisely that question.

Peru: What happens when you know the danger is above you?

Huaraz knows that Palcacocha is there. Scientists know the lake has expanded. Authorities know which communities could be affected. Monitoring therefore isn’t based on knowing the precise date when something will happen. It is based on accepting that something could happen. That distinction may become fundamental to climate adaptation.

Tourism has traditionally been built around probability: Is this road normally open in July? Does this river usually flood in September? Is this trekking route normally safe? Climate change is weakening the value of the word “normally.”

Hedder Quispe Puente de la Vega, a travel expert at Machu Travel Peru, says travelers need to prepare for variability rather than assume historical weather patterns will repeat themselves. “Rising temperatures don’t mean that every part of Peru will simply become hotter,” he says.

Instead, changing temperatures can alter rainfall, water availability, ecosystems and the predictability of conditions.

• In the Andes, that can affect trekking.
• In the Amazon, changing rainfall can alter river levels and transportation.
• And in glacier country, changes can have consequences much farther downstream

Back to Nepal.

Nepal had already received smaller warnings

The August 2026 disaster did not occur in a country unfamiliar with glacier-related flooding. In August 2024, a glacial lake outburst flood hit Thame in the Everest region. Homes, hotels, a school and a health facility were damaged or destroyed.

Researchers subsequently determined that the event involved a cascade: an avalanche affected one lake, whose escaping water contributed to the failure of another.

The implication was important. You don’t necessarily need one gigantic glacial lake to create a serious disaster. Smaller features can interact.

In April 2024, another unexpected flood occurred near Nepal’s Birendra Tal when an ice avalanche entered the lake. And the river system involved in the 2026 disaster had experienced another significant flood before this catastrophe. These were not miniature versions of August 26. But collectively they were messages from a changing mountain environment.

Now return to Peru.

Peru has its own messages from the mountains

Peru’s glaciers have been sending them for decades.

The country’s glacier research institute, INAIGEM, reported that the Peruvian Andes have lost 56.2% of their glacier surface over approximately six decades.

For tourists, that may initially sound like an environmental story: disappearing ice, changing landscapes and perhaps altered trekking experiences.

It is much more than that. Glaciers store and release water. Their retreat can create or enlarge lakes. Changing ice and permafrost can affect slope stability. Water availability changes. And communities, roads, hotels and tourism infrastructure may sit many kilometers downstream from the original hazard.

In Nepal, the August avalanche demonstrated just how far away the consequences can travel. The flood and debris torrent travelled nearly 100 kilometers downstream. A hotel does not have to sit underneath a glacier to be exposed to glacier risk. Neither does a hydropower plant. Neither does a tourist.

Nepal asks Peru a question: Is monitoring enough?

Peru’s monitoring of Palcacocha represents progress. But Nepal demonstrates the limits of monitoring only hazards we already know. Langtang was particularly terrifying because the specific failure site had not been identified as an imminent threat. The avalanche also moved extraordinarily quickly.

One analysis estimated that the initial flood wave reached the Nepal-China border facilities in approximately seven and a half minutes. No conventional siren provides much comfort when the wall of debris is already coming.

That means the future of mountain safety cannot depend exclusively on detecting a disaster after it begins. It must increasingly include identifying instability before failure.

Satellite monitoring. Artificial intelligence capable of identifying unusual movement. Ground sensors. Glacial-lake monitoring. Permafrost and slope studies. Cross-border information sharing. And constant reassessment of what is considered dangerous.

Which throws the ball back to Peru again.

Peru asks Nepal: Who gets the warning?

A sophisticated sensor at 4,500 meters is useful only if its information reaches people below. A satellite image is useful only if someone analyzes it. A government alert is useful only if a hotel receptionist, trekking guide, bus driver and foreign tourist understands what it means.

This is where tourism becomes part of climate adaptation. Imagine a visitor arriving in Huaraz, Kathmandu or another mountain destination.

• Does the hotel know its evacuation route?
• Does the trekking operator receive government emergency alerts?
• Does the guide know what a glacial flood warning sounds like?
• Can tourists receive emergency instructions in English, Chinese, Hindi, Spanish, German and other languages?
• What happens when cellular service disappears?
• Where is higher ground?
• Who accounts for tourists after an evacuation?
• These are no longer theoretical tourism-management questions.
• Nepal has just demonstrated why.

Peru’s travel industry already recognizes unpredictability

Quispe says visitors should not abandon Peru because of climate change. They should change the way they travel. Travelers heading into the Andes should prepare for strong sunshine, cold temperatures and rain — potentially during the same day.

They should carry waterproof layers, sun protection and appropriate footwear. More importantly, they should leave flexibility in their itinerary. If weather closes a trekking route, blocks a road or affects a train connection, the itinerary needs room to change.

And tourists need to accept that a local guide saying “no” may be providing the most valuable service of the entire trip. “Responsible travel starts with respecting local guidance and being willing to adapt plans when conditions change,” Quispe says.

That advice could just as easily be issued in Nepal.

Nepal demonstrates why tourism cannot separate climate from infrastructure

The August disaster struck far more than villages. At least 11 hydropower projects were affected. Roads and bridges disappeared. Border facilities were overwhelmed. Tourism and pilgrimage routes were caught in the disaster. Rescuers are still concentrating on hydropower tunnels where workers may remain trapped.

This is an important lesson for Peru. Tourism resilience isn’t just about whether a trekking trail survives. Tourists depend on electricity, bridges, roads, airports, trains, telecommunications, water systems and hospitals. Climate vulnerability anywhere in that network can become tourism vulnerability.

Now Nepal can look back toward Peru for another lesson.

Palcacocha: living with a known threat

Peru cannot remove Lake Palcacocha from the mountain. It cannot guarantee that another outburst will never happen. What it can do is study the hazard, monitor it and prepare the population below. That may be the most realistic definition of climate resilience.

Not eliminating risk. Living intelligently with it. Nepal now faces the same challenge on a vastly larger scale.

Thousands of glaciers and glacial lakes span the Hindu Kush Himalaya. It is impossible to put a scientist beside every one. The challenge is therefore to determine which ones are changing fastest — and to identify dangerous changes that may not fit yesterday’s definition of risk.

And then Peru should look back at Nepal

Because Peru should not assume that Palcacocha is the only kind of danger it needs to watch. Nepal’s disaster appears to have involved catastrophic failure of rock and ice rather than the classic bursting of a known large glacial lake. That distinction matters.

Climate adaptation cannot become a checklist:

• Dangerous lake? Monitor it.
• No dangerous lake? Safe.
• Nepal just demonstrated why that thinking is inadequate.
• Entire mountain systems need to be considered.
• Ice.
• Rock.
• Permafrost.
• Water.
• Rainfall.
• Rivers.
• Infrastructure.
• Settlements.
• And tourists.
• They are connected.

Two mountain countries, one tourism challenge

Nepal and Peru have very different geographies, cultures and tourism economies. Yet both sell something remarkably similar to international travelers.

The mountains. Nepal offers Everest, Annapurna, Langtang and the gateway toward Kailash. Peru offers Machu Picchu, the Cordillera Blanca, the Sacred Valley and extraordinary Andean trekking.

Their mountains are not simply scenery. They are national brands. They are tourism products. They are livelihoods. And increasingly, they are laboratories demonstrating what a warmer planet looks like.

This creates a difficult balance. Telling tourists that climate change is increasing mountain hazards could frighten visitors away. Pretending nothing is changing could be far more damaging. The answer is not fear. It is preparedness.

Nepal today. Peru tomorrow. Then Nepal again.

The most important lesson of Nepal may not be that this particular catastrophe should have been predicted. Scientists themselves say the specific Langtang failure was extremely difficult to identify beforehand.

The lesson is that the category of what must be monitored is expanding. Peru’s lesson is that when a hazard is identified, monitoring and early-warning systems can be built.

Nepal’s lesson back to Peru is that the next disaster may come from somewhere that isn’t currently at the top of the risk list.

And Peru’s lesson back to Nepal is that uncertainty is not an excuse for doing nothing. This is the conversation mountain destinations around the world now need to have.

Nepal to Peru. Peru to Nepal. The Himalayas to the Andes.

And eventually Switzerland, India, Bhutan, Pakistan, and every tourism economy dependent on glaciers and high mountains.

Should tourists still go?

Absolutely — but differently. Tourism provides critical income to mountain communities. Abandoning destinations affected by climate change would punish many of the very people living on its front line. Travelers can instead become part of a more resilient tourism model.

Choose experienced local operators. Check conditions immediately before mountain activities. Accept itinerary changes. Don’t cross a closed trail because the Instagram photograph is important. Know where to evacuate. Carry appropriate equipment. Allow extra days. Listen to guides.

And understand that historical weather patterns are becoming a less reliable guarantee of tomorrow’s conditions. As Quispe says of Peru:

“Climate change should not mean that travelers have to stop experiencing places such as the Andes or the Amazon. It means that we need to be more conscious about how and when we travel.”

Nepal has just given those words devastating additional meaning.

The mountains are talking to each other

• What happened in Nepal is not what is happening at Palcacocha.
• What is happening at Palcacocha will not necessarily happen at Machu Picchu.

And climate change should not be used as a simplistic explanation for every avalanche, flood or landslide.

But put Nepal and Peru side by side and a pattern becomes difficult to ignore.

• The mountains are changing.
• Glaciers are retreating.
• Water is moving differently.
• Previously frozen landscapes are changing.
• Extreme events can cascade through river valleys and infrastructure networks.
• And tourism remains deeply embedded in those landscapes.

Nepal asks: How do we detect the hazard we didn’t know we needed to watch?