Bright peaks – Alps starry skies in danger due to unprecedented light pollution

The Alps are under immense pressure by tourism, urbanization and future climate warming impacts. But there is another threat, that puts the last dark sky areas within the 1200 m long mountain range at risk: Unprecedented strong light pollution. Urban Alpine areas are major sources, as is the change to LED lights in the near future. TWAN Astrophotographer Christoph Malin knows both the environmental impact and fascination of city lights below Alpine peaks all to well. A call for action.

Imagine standing on a skyscraper at night, watching the city lights glow below. It is equally breathtaking upon a 2400 m high mountain in the Alps. Especially when you stand on ski, beautiful deep powder slopes are ahead, and the city below is Innsbruck.

Surrounded by cable cars and ski-lifts the “Capital of the Alps” offers many options for open horizons, the most outstanding being the famous panorama cable car ride with the Nordkettenbahn. From 560 m downtown to 2256 m in about 20 minutes. Breathless Tourists, happy Skiers.


The true magic however starts, when the cable car has closed, silence conquers the mountains, alpenglow vanishes and the earth’s shadow melts into the ridges and caverns around. It is the time of day when the city lights start to glow, when the real adventure begins.

Spectacular views like the above are the reason why there is a huge culture of night ski touring around Innsbruck, and many say that without the lights in the valleys and the starry skies above it would be half the fun. Carve a turn into the powder and see the spray glitter against the lights! Unforgettable and addicting scenery at the same time.

Gallery: The Fascination of Sports, Starry Skies and City Lights



Sirius above a sea of lights.

Unfortunately, all the – understandable – fascination with bright lights in the valleys comes with an environmental price tag: light pollution.

Simply put, it is scattered light where it is not needed. In our case the sky – above the open horizons. Naturally a city like Innsbruck, but also many other towns like Chamonix, St. Moritz, Bozen as well as the many smaller villages in the Alps emit lots of scattered light. That is the downside of the fascination the night Skitourer experiences. And it puts the starry skies we love at risk.

Ironically, living in the Alps, we are still spoiled with starry skies. Super transparent winter nights, the clear skies of autumn, or summer stormfronts that wash the sky clean… Since I am a kid, I remember stunning starry nights over the mountains – even near larger alpine urban areas.

Mountains illuminated by the City

Of course, compared to the German Ruhrgebiet or Northern Italy which suffer from heavy light pollution, we still see amazing starry sky nights in the Tyrol, Bavaria or the Dolomites. Once a month or two, there’s always a night, where the Milky Way sparkles from the sky above, reminding me of the dark skies seen in the Atacama desert. (Sky transparency however can never be as excellent in the Alps as in the Atacama, with its ultra low 5% humidity average. Low humidity = excellent seeing of stars).


The Milky Way and some green Airglow above Innsbruck before dawn.

The Milky Way and some green Airglow above Innsbruck before dawn.

During nights with excellent sky transparency (reduces light scattering), applying low-light astrophotography techniques and going to high view points, I love to chase the Milky Way above Innsbruck and the surrounding valleys. Being able to capture our home galaxy above city lights is quite unique for a alpine city that big.

This even surprised TWAN founder and Lennart Nilsson laureate Babak Tafreshi on the first of several imaging trips to Innsbruck, where we joined forces. With my film “Urban mountain sky” I even managed to capture constellation Orion from the famous Hungerburg cable car station plateau – just 200 m above the bright city.

All this gave me a deceptive feeling that all is OK with the starry sky above the Alps. But it’s not. And that feeling got a first persistent dent during early 2013, when inversion layers and overcast weather was ruling most of Austria and the Alps. called it the darkest winter since 43 years.


Light pollution boosted by backscattering light at inversion layers. In the valley, a shopping are is illuminating a whole mountainface (Martinswand, Völs).

Light pollution boosted by backscattering light at inversion layers. In the valley, a shopping are is illuminating a whole mountainface (Martinswand, Völs).

What are “inversion layers?” Temperature inversions occur, when colder air is trapped below layers of warmer air with no exchange between. The mostly V-shaped alpine valleys then fill with smog resulting from transit traffic, as well as industry and household emissions.

Besides health problems due to increased levels of fine particles in the air, hazy or foggy temperature inversion layers boost light pollution, backscattering light, bouncing it within the inversion layers.

The unfavorable blend of bright city lights and inversion layers makes one soon feeling like being trapped in a “light cage”. Who can, then goes on a night skitour to escape the polluted layers – mountains are our skyscrapers.

But climbing a mountain is just a temporary solution.


Light domes above Ötztal

Light domes above Ötztal

It needed a TWAN comet watching expedition trip to high altitude mountain (by means of the Eastern alps) to finally connect the big picture about how severe light pollution in the Alps really has got.

For capturing comet PanSTARRS and to escape the inversion layers, Dr. Wolfgang Kausch (Institute for Astro- and Particle Physics Univ. Innsbruck), Dr. Michael Winkler (Austrian Weather Service) and me headed to a 3000 m high mountain peak above Oetztal. The comet show was spectacular. After the flying iceball was gone, our eyes soon adapted well to the night. We all stood there, gazing stars in awe. But, wait a moment, what night?

It was 1:00 a.m. Except some faint natural green airglow it should have been dark. But it wasn’t – there was clearly visible light dome glow above the horizons all around. The peak’s altitude and central position provided free sight to another hundred peaks, ridges and ravines – and massive light domes above, viewable with the naked eye.

We were quite shocked. The feeling of being encircled by light domes was present like never before. I had seen them before at different occasions and locations, but not 360 degree.

Very-not-good. Driving back I could not forget the comet – and the brightened horizons.


Milky Way above Brenner highway and Sterzing.

Milky Way above Brenner highway and Sterzing.

Days after the comet show, I was invited to provide images illustrating light pollution at the alps for an article cooperation with the Tiroler Landesumweltanwaltschaft. Good excuse to lock myself in the office for researching in my archive (12+ TB). While sorting images into situations / locations for two days, at a certain point it all connected.

My screens were flooded with glowing evidence how severe the situation in the (eastern) Alps to this day really is. “Scary” or “dramatic” – no more or less – is exactly what came to my mind. Put the puzzle in the galleries below together – you’ll immediately realize the current light pollution situation.

Lights below illuminates Mountains like Moonlight

Lights below illuminates Mountains like Moonlight

And light pollution will not improve with the EU’s directive EN 13201, that actually forces small towns and villages to increase brightness of street lights, while modernizing their infrastructure with LED lights. There’s currently probably enough scattered light in Europe to illuminate both the dark side of the moon and the Alps the same time.

Highways, skiing stations, ski areas, restaurants, churches, castles, train stations, shopping malls, gas stations, parking lots, toll stations, supermarkets, they glow, glow, glow in the night, and compete to be the brightest, as if there would be no tomorrow… A common example: If a church in one village is illuminated with a 1000 W light, soon the major of the next village will have his church illuminated with 1200 W. Oh, and do we have many many churches in Austria…

Total average brightness of the Earth’s night sky increases 6% per year and for parts of Italy even 10%. In about 10 years we will have lost the view to the Milky Way above the alps. If you want to know how that feels, take a train to Salzburg, Linz or Vienna. We don’t need more light, we need less, and that “less” must be dramatically optimized.


A skiing areas bright light patch is visible below the Patscherkofel Mountain.

A skiing areas bright light patch is visible below the Patscherkofel Mountain.

Some questions to those responsible for some of the light craziness… To start with:

For what do we need shopping centres and billboards burn up the night and illuminate mountain slopes after 12:00 a.m? The resulting light domes can be seen as far as 100 km, and, it gets worse with humidity and light backscattering.

Or what sense does it make to illuminate a skiing area (resulting in snow surface light backscattering) with some mega-watts after 12:00 a.m? Even after skiers have left the area? A whole night of lights-on at skiing areas is a no-go. Excessive light pollution from skiing areas is simply not necessary, and it’s time to ask why.

But these are just two examples out of hundreds. All those light sources add up. Today we waste light as if it is free and costs nothing, harming nature, nocturnal animals and ourselves. Since the last decade, light pollution has flooded and surrounded the alps in such a large scale and impact, that it is nothing less then dramatic.


Light polluted Milky Way

Light polluted Milky Way

Milky Way, La Palma

Milky Way, La Palma


Thus we need to act now, before it is too late. It helps to see examples, how an unspoiled night sky looks like. Dark sky images (world’s best by TWAN’s Stephane Guisard here) show a starry sky, we are about to lose forever in the Alps.

Further examples to the left and right show how it looked like, before we went crazy with lights.

Light polluted Milky Way

Light polluted Milky Way

Milky Way at dawn, La Palma

Milky Way at dawn, La Palma

Furthermore a view to the stars is a cultural heritage, a human right, a strong connecting element above all people and all nations. Standing amazed under the glowing Milky Way lets us immediately recognize where we come from and where we are. On a blue marble, in outer space. Nothing more, or less.

We have to act now. That, we owe to our kids. Every kid should have the chance to watch a starry sky, not only once but as often as possible. It connects Kids with the universe and makes them aware, that there is more to life than a playstation (should there be a need to point that out). So lets work together to improve sky quality in the Alps (or, at least preserve it as it is now).


Light Pollution. Image: Canadian Space Agency

Light Pollution. Image: Canadian Space Agency

It’s the stars were we come from. Looking into the Milky Way, we have first seats on a spectacular view into our home galaxy. Why throw that wonderful gift named Starlight away like junk?

Finally, if we do a good job optimizing the lights and minimizing light domes, the fascination of night skitouring above the city lights will be enjoyed even better. With the city lights a bit dimmed, we are going to see much more starry skies again. And wouldn’t that be great?

Note: I have compiled a link list (see below) as well as additional galleries that put the problem of light pollution at the Alps into perspective.

Gallery: Power Failure at a small village near Innsbruck, makes light pollution immediately visible.

10 Rare selections of images regarding


1) Selected examples of bad light pollution in the alps


2) When light scatters and gets reflected from below and above, a “light hell” is the result


3) When light pollution illuminates the mountain sides


4) When natural wonders are disturbed by light pollution


5) When skiing areas create light domes in the sky, adding up to more light pollution


6) Frightening sights – light polluted horizons that were once dark – at the Alps


7) General (panoramic) examples of light pollution in the Alps


8) Examples of much and less Light Pollution due to various light sources


9) Wonders of a dark sky – in the absence of light pollution


10) Zodiacal light – a natural wonder seen rarely in the alps


Some must see/read links (partly german):

[3] Dark Sky at it’s best – „Astronomer’s Paradise“ –
[6] Dark Sky over the Atlantic – „Island in the Sky“
[13] Urban. Mountain. Sky –
[16] As always – Canadians save our a… –
[17] The International Dark Sky association –
[18] US National Park Service on Light Pollution –
[19] The Blue Marble Navigator – Light Pollution Map –

Clear skies!
Christoph Malin

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