What are the main consequences of landslides

The consequences

What do climate change and the melting of glaciers mean for the Alps?

In the Alpine region, the risk potential increases with the temperature: the rapid melting of the glaciers exposes large areas of rubble, the so-called glacier forelands. The loose rock can endanger valleys and settlements in heavy rain as debris flow or landslide. Here, too, new and rapidly rising glacial lakes are an increasing threat.


Glacier lake on the Trift glacier, Switzerland, 2002 and 2006 © GöF

Glacier lake above Macugnaga, Italy, 2002 © GöF

In the summer of 2006, a glacial flood with debris flow breaks through in Vadret da l’Alp Ota. A tourist is killed in the process.
The most spectacular event in 2006 was the rock fall on the eastern flank of the Eiger. Hundreds of thousands of cubic meters of rock fell on the Lower Grindelwald Glacier. The retreat of the Lower Grindelwald Glacier is believed to be the main cause. This means that there is no pressure on the rocky area.

The permafrost is thawing:
Permafrost - that is the 20 to 100 meter thick layer of ice and soil in the high mountains that normally remains frozen all year round. In the last 100 years, the permafrost limit has already shifted 150 to 200 meters upwards. The temperatures of the permafrost soils in the mountains rise at a similar rate as the air temperatures.

“In many places, the meanwhile 10–25 year-old series of measurements reached new highs. The warming in the cold permafrost is particularly noticeable. For example, the ground temperature at the summit of the Stockhorn (3400 m) near Zermatt (VS) rose from -2.6 ° C in October 2011 to -2.0 ° C in October 2016. In the same period of time, the ground on the northern slope of the Pointe des Lapires (2500 m, Nendaz VS) only warmed from -0.15 to -0.08 ° C. It should be noted that the permafrost can also contain a certain amount of liquid water. As a result of the warming, this water content increases, especially in warmer locations with soil temperatures close to 0 ° C ”((www.permos.ch)).

Rock glaciers move much faster than 20 years ago

Block glaciers are masses of debris that creeps down into the valley and consists of blocks of stone and ice. They are still moving fast. The record values ​​of 2015 were not reached in 2016 at many locations. Nevertheless, most rock glaciers move several times faster than 20 years ago, that is in many places with several meters per year ((www.permos.ch)).

If the ground ice thaws, the mountain slopes start to move. Sometimes they slide down into the valley in slow motion, but there can also be sudden landslides and rockfalls, scree and mudslides. All ten major landslides in Switzerland over the past ten years have occurred in permafrost zones. ((Interview with Felix Keller, in: Dolomiten Nr.67, 21.3.01))

Thawing permafrost was probably also a trigger for the catastrophic landslide in the rainy summer of 1987 in Valtellina in the Italian Alps.

Rockslide Bormio, Valtellina, Italy, 1987 © GöF

The permafrost on the Schafberg above the village of Pontresina is thawing.
That is why the municipality in the Swiss Engadine has built a huge dam that is supposed to stop debris, mudslides and avalanches - costs: almost eight million CHF.

Catchment dam above Pontresina, Engadin, Switzerland, 2003 © GöF

The frequency and strength of extreme weather events with catastrophic consequences have already increased: While storms such as “Vivien” and “Wiebke” (1991) and “Lothar” (1999) were still referred to as “storms of the century”, storm strengths have increased in recent years strengthened worldwide. Cyclones and gale-force squalls with unusually high wind speeds also hit the Alpine region. Rapid changes between warm and cold, wind drift from snow and unusually heavy snowfall can trigger huge avalanches - as in 1999 in Galtür in Tyrol's Paznaun Valley, where 38 people were killed.

Lawine Valzur, Paznauntal, Austria, 1999 © GöF

The "century" floods, floods and mudslides of the last few years

Mudslide Aosta Valley, Italy, 2000 © GöF

and the great heat wave and drought in 2003 and July 2006 made it clear what still lies ahead.
These climate extremes will continue to intensify. This in turn accelerates glacier retreat.

Climate change affects Europe's moated castle:

  • Large European rivers such as the Rhine, Rhone and Po have their source in glacier regions in the Alps. The runoff from the glacier areas has increased sharply.

Rhone below the Rhone Glacier near Gletsch, Switzerland, 2003 © GöF

  • Water bottlenecks can follow after more frequent and severe flood events. The long-term drinking water reserve, bound in the glacier ice, is at risk. Worldwide, the glaciers (with the Arctic and Antarctic) represent the largest freshwater reserves on earth.


Climate change leads to a loss of biodiversity:

The alpine flora is already rising uphill. Competitive species migrate upwards, while the rare and highly adapted high mountain flora is in distress. Once the peak of the mountain is reached, there is no further evasion: plant species (and animal species) die out. Estimates assume that of 400 endemic (only occurring here) plant species in the Alps, a quarter is threatened with extinction ((Grabherr, Georg: Climate change changes the summit flora, in: Alpenreport 2)).

Alpine flora © GöF

Destabilized forest ecosystems

More frequent weather extremes destabilize forest ecosystems and increase existing damage.

The trees and forest ecosystems are significantly polluted and damaged by air pollution - especially on the northern and southern chains of the Alps and along the transit routes: see also ((www.waldarchiv.de)).
The statement: “When forest dieback was mentioned earlier, it was about air pollution and acid rain. Today climate change is changing the forests "- that ignores:

  • Air pollution is still far too high: Air pollutants that are responsible for acid rain and breathing difficulties, such as sulfur dioxide, particulate matter, ammonia and nitrogen oxides, are blamed for damage amounting to 38 to 105 billion euros per year. Of the ten plants that cause the most costs, five come from Germany alone ((www.eea.europa.eu. Publication s / cost of air pollution)). The largest share of damage costs in the EU is made up of CO2Emissions of around € 63 billion.


  • Air pollutants and greenhouse gases have largely the same cause: combustion processes, especially the combustion of fossil fuels - such as crude oil, coal, natural gas and all secondary products such as gasoline, diesel, kerosene, coke and liquid gas - emit pollutants, including greenhouse gases such as CO2 free. Added to this are the emissions from the agricultural industry from fertilizers and pesticides (ammonia, pesticides and nitrous oxide, methane).

Mountain forests are particularly endangered
Storm throws are becoming more frequent and mass reproductions of insects are being promoted by air pollution and climate change.

Mountain forest in constant stress: forest damage and storm throw, Allgäu, Bavaria © GöF

Forest fires threaten in the hot years: In 2003, 450 hectares of mountain and protective forest burned in Valais

Burned down protective forest above Leuk, Valais, Switzerland, 2003 © GöF

November 2011 was the driest and warmest on record. As a result, 14 hectares of mountain forest burned above the Sylvenstein reservoir near Bad Tölz. The forest burned again in the winter of 2016 - above the Walchensee. This time it was arson, whereby the forest fire could only spread over a large area due to the drought in winter.
The mountain forest is of elementary importance for the settlements and the infrastructure of the Alpine region. Without mountain forest, the risk of avalanches, rock and landslides, soil erosion, erosion and flooding increases.

Protective forest above Andermatt, Uri, Switzerland, 1998 © GöF

Avalanche protection, St. Anton, 5.1.1998 © GöF

Endangerment of alpine tourism

Climate change endangers important foundations of alpine tourism:

  • The disappearance of the white mountains detracts from the aesthetic attraction of the Alps.
  • The end of many ski areas: The limit for guaranteed snow is rising. The operators of ski resorts are reacting with a forward strategy - with additional lifts and, above all, with technical snowmaking. The ski circus is already rising.

Snow cannons: construction on Patscherkofel, operation above Kitzbühl © GöF


Madonna di Campiglio, 1997 © GöF

For ski areas below 1500 meters, this expansion will bring little other than debt and ecological damage. The temperatures for artificial snow are already more and more often too high. Due to the high water consumption of the systems, drinking water becomes scarce in some areas in winter. Valuable mountain forests are cleared and moors are drained for the construction of large snow-making basins. To meet the high water demand, drinking water is also pumped from the valley.

Garmisch, Kreuzwankl, construction of a snow basin 2006, 2007 and 2013 © GöF

In the higher areas, the ecological consequences of construction work and leveling for snowmaking and slopes are to be assessed even more critically ((http://www.goef.de/_media/der_gekaufte_winter_20151212.pdf)).

Laying work for snow cannons and slope planning, Kitzsteinhorn © GöF

Even glacier ski areas are artificially snowed.

Glacier ski area with snow cannons, Hintertux, Tyrol, Austria © GöF

Almost untouched high mountain regions are particularly affected. Glaciers are not spared either. Glacier ski areas offer - especially in summer - a very bleak picture.

Snowerner glacier ski area, Zugspitze, Bavaria in the summer of 2003 ... and in the winter before that. © GöF

New glacier interventions with "additional" developments and lift superstructures are planned. The existing glacier protection will be suspended with these projects

see "Single images: Weißseeferner"

Climbing routes

Mountaineering in the high mountains is also becoming more dangerous. Famous ice walls are thawing.

North face Jamspitze, Silvretta, Austria 1929 and 2001 © GöF

High-altitude tours are increasingly threatened by falling rocks and huts had to be evacuated, such as the Lobbia hut in the Adamello group in summer 2003. Glacier crossings are often no longer possible. In the summer of 2003, mountaineers on the Matterhorn had to be flown out in helicopters after a landslide, and Mont Blanc was closed to mountaineers due to acute danger.