Francesco Citterich – Vatican City
There are tragedies that unfold in just a few minutes, yet tell of processes that began much earlier. The event that struck Nepal and the Himalayan region of Tibet in recent days falls into this category. A mass of ice and rock detached from high altitudes, triggering an extremely violent flood wave that swept through the Bhotekoshi and Trishuli river system, carrying water, mud, boulders, and debris.
Within a few hours, entire stretches of valleys were devastated, infrastructure destroyed, and communities cut off from the world. The confirmed death toll stands at over 700 people, but more than 3,000 are missing. This dramatic toll will certainly continue to rise as the situation in the region develops.
Difficulties in conducting rescue operations
Today, however, the question is not only about what happened. It is also about why these kinds of events are becoming an increasingly real threat to people living in the mountains.
The first response is, of course, the rescue operation: searching for the missing, reaching those cut off from the world, securing the most vulnerable areas, and restoring communication links. Yet precisely the speed at which this disaster unfolded shows how difficult it is to intervene when the mountain suddenly changes its face.
The water arrived with immense speed: in some places, the level of the Bhotekoshi rose by several meters in just half an hour. Roads, bridges, and monitoring stations were damaged or destroyed, making rescue efforts even more difficult.
The threat remains real
There is also a second element that makes this tragedy particularly alarming. The danger has not yet passed.
Debris carried by the flood wave may have temporarily blocked the riverbed, creating a sort of natural dam. If the accumulated water is suddenly released, another destructive wave could form, heading down the valley.
This is the paradox of disasters in mountainous environments: a primary event can trigger subsequent ones, turning a crisis into a whole sequence of cascading hazards. Therefore, authorities and scientists are closely monitoring the situation and assessing the risk of further floods.
Not merely a twist of fate
However, it would be a mistake to limit ourselves to a chronicle of events and dismiss them purely as an inevitable natural disaster.
The Himalayas are by definition an extreme environment: extremely high mountains, steep slopes, narrow valleys, turbulent rivers, and communities that often live along the very natural corridors through which water and debris travel. Under such conditions, even a relatively minor phenomenon occurring high in the mountains can rapidly turn into a disaster felt dozens of kilometers away.
Furthermore, research conducted in recent years shows that cryosphere-related phenomena can develop in cascades. In such a scenario, the detachment of ice or rock, the emptying of a lake, a landslide, and a flood begin to reinforce one another.
This is where the climate crisis enters the narrative—though with necessary caution. We cannot automatically attribute every single cataclysm to global warming. In this case as well, scientists are still trying to accurately reconstruct the sequence of events and determine the role played by temperature, snowmelt, glacier condition, terrain characteristics, and other factors.
The International Centre for Integrated Mountain Development (ICIMOD) emphasizes that it is still too early to determine the exact extent to which climate change contributed specifically to this disaster. However, the same organization warns that warming is rapidly changing the glaciers, snow cover, permafrost, and slopes of the Hindu Kush–Himalaya region, increasing the complexity of hazards.
The problem is therefore not only that glaciers are retreating. It is that their disappearance can alter the entire mountain system.
The formation and expansion of glacial lakes, the loss of slope stability, the degradation of permafrost, and greater seasonal water availability can create new conditions that are difficult to predict based on past experience.
In 2024, for example in the Mount Everest region, a similar phenomenon showed how a cascade of geological and glacial processes can turn an event taking place high in the mountains into a destructive wave of water and debris rushing down the valley.
Connections between atmospheric phenomena
Perhaps the most important lesson emerging from Nepal today is that we can no longer view natural hazards as isolated phenomena.
The glacier, the river, the landslide, the lake, and the community are not separate elements, but parts of the same system.
Disaster prevention therefore means observing the mountains as a whole, investing in monitoring networks, early warning systems, infrastructure protection, and the preparation of evacuation plans.
It also means cross-border cooperation, because water does not stop at borders. An event that begins high in the mountains can subsequently affect neighboring territories and requires a coordinated response from Nepal, China, and other countries in the region.
Climate change as a real threat
The Himalayas have thus become one of the places where the effects of global warming can turn into concrete crises with particular speed.
Rising temperatures do not only mean that there will be less ice in the long term. Under certain conditions, they can also mean more unstable ice and greater volumes of water capable of fueling extreme events.
When these processes combine with narrow valleys, steep slopes, and communities clustered along rivers, the consequences can be catastrophic.
In the mud covering these valleys today, there is therefore something more than just the result of a single glacial detachment. It is a sign that the natural balance is shifting.
Precisely determining the extent to which global warming contributed to this specific event will require time and further research. However, the overall picture is already clear: in an increasingly warm Himalayas, hazards linked to glacier destabilization are becoming a growing danger for people who live, work, or travel at their foothills.
The disaster of recent days may therefore serve once again as a dramatic warning of the speed with which the climate crisis can transform an extreme event into a human tragedy.
This is a warning that, in an increasingly vulnerable world, can no longer be ignored.
