December 7, 2021

I, Science

The science magazine of Imperial College

With the summer coming to a close, your mind might be starting to wander onto more wintery thoughts. For some, this will mean deciding on where to take your next skiing holiday! However, I doubt that when booking your trip, the environmental policy of the resort will have crossed your mind. Whilst conservation may not be the top of your agenda, skiing can actually be extremely detrimental to the environment.

There are few, if any, other forms of tourism that lead to the modification of landscape over such vast areas. For ski resorts to operate, vast tracks must be excavated, accommodation built, snow compacted, and new snow produced. Additionally, all of this takes place within fragile mountain ecosystems, which take much longer to recover than lowland areas.

And there is a lot to lose from mountain environments, which are home to a large array of unique animals, some extremely charismatic, such as golden eagles, ibex, and wood grouse. Wildlife such as this is under threat from the ski industry for many diverse and unusual reasons.

Bulldozing the Ecosystem

The next time you’re hurtling down a ski run, take a moment to listen out for the gentle chirping of birds. You won’t hear much. Birds, along with much other wildlife, find it difficult to live on, or near to, ski runs. This is because the process of creating a ski slope is (usually) not delicate and simply involves bulldozing a path through anything that happens to be in the way. Vegetation is removed, along with top soil (which has a unique chemical composition), and this effectively destroys the habitat. Birds, for example, avoid ski slopes because of the lack of insects. Studies have shown that ecosystems never recover from the construction of ski slopes.

But ski slope construction does not have to be so aggressive. A possible solution is to remove the topsoil from the slope, and replace it once works are complete. This then allows the reseeding of vegetation and the subsequent recovery of the habitat.

Living in Fear

Populations of the extravagantly coloured wood grouse have been declining in recent years and skiers are at least in part to blame. It appears that the birds are scared of the strange primates who slide down the snow on planks of wood! They perceive humans as predators which causes them to release excessive amounts of stress hormones. This has adverse effects on the grouse’s immune system, growth, and reproduction. Additionally, skiers cause the birds to abandon their ideal feeding areas, with further consequences for their health.

Just like the wood grouse, lizards perceive a greater risk of predation in ski resorts. For lizards, however, the greater perceived risk arises due to the clearing of vegetation to make way for ski slopes. They increase their speed to cross these dangerous open areas, which results in lost body mass and a decreased ability to defend against parasites.

The Double Edged Sword

Climate change is causing snowfall to become increasingly unreliable, and so ski resorts are under immense pressure to keep ski runs useable throughout the season. In order to do this many resorts utilise artificial snow which is sprayed over the slopes by large cannons.

Artificial snow is not as harmless as it may seem. The water used to make the snow originates from lakes and streams, and contains more nutrients than natural snow. This leads to the soil becoming over-fertilised. For endangered habitats that are naturally nutrient poor, such as oligotrophic fens, this can drastically alter the ecosystem.

But artificial snow poses a bit of a conundrum. To keep ski runs in top notch condition, huge machines called “piste bashers” prowl the mountains and smooth the slopes. Where the snow cover is thin, the piste bashers destroy the underlying vegetation. Artificial snow, by increasing the cover depth, can help prevent the loss of these plants. Whether or not artificial snow is considered advantageous or damaging to the ecosystem is a bit of a judgement call.

The Bigger Picture

It’s not just locally that skiing has an impact; the ski industry is hugely energy-intensive. Piste grooming, snow making, and ski lifts all guzzle up energy. This is not to mention the huge amounts of fuel used in bringing tourists and supplies up to the tops of mountains, often from far away countries. In this way, the ski industry is fuelling its own destruction, as climate change is causing ski seasons to become shorter and the snow less reliable.

Because of this, you might think that ski organisations are particularly savvy when it comes to promoting sustainable tourism. But green talk is rarely prominent in winter sport brochures, which is strange, considering many of them will be unlikely to exist in 100 years if emissions continue at their current rate.


But there are one or two ski resorts that are well ahead of the rest when it comes to sustainable skiing. Lech in Austria is one particularly notable example. For example, a new biomass plant has cut the villages CO2 emissions by 50%. Bus services, and ski lifts that run off hydroelectric power are yet more ways Lech has decreased its emissions.

All of Lech’s artificial snow comes from rainwater, which is captured in large reservoirs on the mountain, this prevents the over fertilisation of the soil when the snow melts. Additionally, Lech’s new ski runs are constructed using the top soil removal and replacement method, so that biodiversity remains unaffected.

So when you do get round to booking your next ski trip you might perhaps want to take a look at the resort’s eco-credentials. Apparently, Lech is the new place to be!

Image from Mountain Pass on