The climate crisis is crumbling the Dolomites before our eyes

The climate crisis is crumbling the Dolomites before our eyes

In the past few hours, a new collapse has affected the Sorapiss mountain range, in the Belluno area. As professor Francesco Comiti explains, climate change makes rock faces increasingly fragile.

The Dolomites are slowly and inexorably crumbling. A piece of mountain on Punta dei Ross, in the Sorapiss mountain range, came down leaving a blanket of white dust on the roads, roofs and cars of the villages below, such as San Vito di Cadore, fortunately without causing damage and injuries.

(photo: Flickr) There is no bad weather or landslides, the sun had been shining on the Belluno massif for days. The crumbling is part of a long process that marks new and more frequent episodes and that has to do with climate change, which is putting one of the greatest Italian natural heritage at risk.

The latest collapse of a long series

There were three different discharges of debris over the last weekend in the Sorapiss Dolomites area, in the province of Belluno. Two in the evening of Saturday 9 October, when in two moments close but distinct avalanches of debris left from 2,400 meters of altitude of the Croda Marcora to roll towards the valley, scaring the residents of the villages, with some uninhabited houses that were affected from the event. On Sunday morning there was another detachment on the Croda dei Ros, which today appears cut by a large crack.

The situation is monitored by fire brigade helicopters while teams of geologists are ready to carry out surveys to verify if there are other imminent risks and to better understand the origins of the detachments. It is a tumultuous period for the chain of the Dolomites. In August, a piece of wall broke off from the base of Sass Maor, in the province of Trento, causing a massive landslide. The same area had been hit by other collapses in May, when the Val Canali was affected by two different events on the same day. In September 2020 a piece of the west face of Cima Canali had come down, on the blades of San Martino, while a few months earlier the same fate had befallen the Torri del Cimerlo.

These are just some of the episodes, the most impressive ones, that have affected the Dolomites in recent times. In reality, however, many others of smaller entity occur monthly, part of a process of chronic crumbling of the chain inscribed since 2009 in the UNESCO list of Natural World Heritage Sites.

Why the Dolomites are crumbling

"There are two different reasons behind the collapses in the mountains", explains to Wired Francesco Comiti, professor of Management of natural risks in mountain areas at the University of Bolzano. "In one case we are dealing with mountain slopes subject to permafrost, the frozen ground for the whole year. The ice holds the ground and creates a glue but slowly we are observing that the permafrost is deteriorating and therefore the ground loses consistency and resistance, increases its fragility. Another case concerns the degradation of rocks due to freeze-thaw, the so-called frost cracking. The water from the rains or snowfalls that melt due to the high temperatures enters the cracks in the rocks which then expand when the ice forms until it breaks ".

Comiti underlines that in the case of the Dolomites and the collapses of the Sorapiss in the past few hours, the motivation must be sought precisely in the frost cracking, part of a larger-scale process: "These phenomena have always existed but now they are raising in altitude. Before it was colder and there were not optimal conditions for the water to be liquid at certain times, frozen at others, in a continuous freeze-thaw process. There was no thaw at high altitudes as it is now ".

This poses a safety problem for the human being: if the collapses have not been born in recent years, their frequency is increasing because the vulnerable surface due to the new climatic conditions increases. "There is a situation of basic fragility that we have had for millions of years and then there is the change in the climate that is causing a shift in these collapses", continues Comiti. "It is not that the mountains would be intact without climate change but there is undoubtedly an increase in the altitude of these collapses: the location of the dangers is changing, the possibility of sudden detachments at higher altitudes is increasing and this determines a problem for us because the dangers increase. Attending the mountains at high altitudes will be increasingly risky ".

A gray future

Changing climatic conditions, rising average temperatures but also continuous temperature changes are creating a problem in mountainous areas. In the case of glaciers, their melting dictated by global warming is changing the physiognomy of the peaks and even their altitude: in just four years Mont Blanc has lost 91 centimeters in height, for example. But also elsewhere, such as in the Dolomite areas not subject to permafrost, the changes due to the climate make us question what future awaits these mountains, between collapses and constant erosion of the rocks.

“The Dolomites will change shape, as will also happen for other local mountains with particular shapes such as spiers and vertical walls but which are subject to lose their typical features”, explains Comiti. A constant but invisible process as a whole in the present, if not in the localized collapses that increasingly attract our attention. In the very long term, however, the scenario, the views, will be very different. “The beauty of our mountains with their particular shapes will be diminishing. The changing climate will lead these particular peaks to become more monotonous, similar to the chains of other continents characterized by older mountains with more rounded shapes and less charm ”.

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