The Morteratsch glacier is seen from above, surrounded by rocks and bushes.

Two thousand metres up in the mountains above Switzerland's Engadin Valley, Felix Keller stands in a rocky ridge overlooking the Morteratsch glacier, one of the biggest in the Alps. He points to a rock-strewn plateau speckled with spruces and bushes far beyond him.

“In the early 1990s, all this used to be ice,” he says. “But now, look: it’s all trees and boulders. Things are changing very, very quickly.”
The Morteratsch glacier in 1900 and 2012

Like nearly all its Alpine neighbours, this frozen giant has retreated like a dying snake recoiling into its pit, as temperatures across the region have warmed faster than most other places on the planet over the past century.

Today, its broad white tongue unfurling from the snow-capped peaks towering above is 2.7 kilometres shorter than it was in 1860. As the glacier continues to dwindle at the brisk pace of 40 meters a year, experts predict it could be gone completely by 2100.

Above is a model of the disappearance of the Morteratsch glacier, including its projected melting by the end of the century.

But Keller, a glaciologist at Academia Engiadina in the nearby Swiss town of Samedan, thinks that this might be averted – and has come up with a plan to save the Morteratsch glacier from certain doom.

Keller’s plan – which is called MortAlive – is to cover the glacier’s most melt-prone section with a layer of artificial snow during summer months, when it’s most exposed to sunlight.

Beyond the idea lies a simple notion, says Keller.

“It’s easy: glaciers are created through a steady cycle of melting while fresh snow accumulates on top. But as temperatures rise and precipitation falls, there is more melting and less fresh snow, and this causes glaciers to retreat,” explains Keller. “Artificial snow acts as a protective shield, insulating the glacier from heat and thus slowing down the rate at which it melts.”
Snow machines would be used to cover a section of the glacier.

The concept originated a few years ago, when officials in the town of Pontresina enlisted Keller and his colleague Hans Oerlemans, a glacier expert from Utrecht University in the Netherlands, to look at solutions to try to save what had long been a draw for tourists and an economic mainstay for the town.

The local authority was spurred to action by the successful effort to slow down the melting of a nearby glacier called Diavolezzafirn, which used white fleece blankets to cover the ice in summer, resulting in the glacier thickening by almost ten metres in a decade.

For Morteratsch, however, a similar scheme wasn’t an option.

“It’s much bigger. You cannot cover a glacier of that size with fleeces,” says Keller. “We looked at other options, and we thought that perhaps we might use artificial snow to keep part of the Morteratsch covered in summer and slow down its retreat.”
The Morteratsch glacier is too big to cover in fleece.

Computer simulations validated the researchers’ hunch. Combining two decades of weather data from the glacier with a calibrated ice-flow model, they found that just a few centimetres of fresh snow covering under one square kilometre at the top of the ice mass during warm months would be enough to stall the effects of melting within ten to 15 years. Calculations suggested the snout could even grow back by 800 meters in two decades.

To see if reality matched with the theory, in the summer of 2017 Keller and Oerlemans ran a pilot scheme in which they sprayed, in two rounds, a 2.5-metre-deep coat of artificial snow onto a 200-square-meter ice patch the foot of the Diavolezzafirn glacier. The test, which lasted to the autumn, worked spectacularly: further melting was averted, and, in some areas, the ice even grew.

With the results in hand, the two began addressing the greater challenge of blasting man-made snow over the larger surface of the Morteratsch. Since standard snow lances used by ski resorts could not be used as they would be caught in the glacier’s slow-moving flow and ripped from their pipes, scientists considered attaching a snow machine to an aerial tramway suspended above the glacier, which would dump artificial snow as it went. The idea, however, came to a standstill when it came to providing the tramway with the water needed to produce the snow.

Then, one day, the researchers sorted out a cunning solution: free-hanging “snow cables”, set in a criss-cross pattern all over the width of the glacier. Working like a sprinkler, the cables would spray the snow from the air as the glacier slides underneath it toward the valley.

The snowmaking system patented by the Lucerne-based company Bächler Top Track can be operated without electricity.

Right now, the ingenious snow-generating system, which uses gravity to feed the sprinkler-like system from lakes further up the mountains and thus can be operated without electricity, is being developed by the Lucerne-based snow machine company Bächler, which has also patented the technology.

Meanwhile, Keller and Oerlemans’ glacier-building scheme is entering a second, crucial stage. Thanks to a CHF2.5 million (£2.1 million) grant the Swiss Agency for Innovation Promotion awarded to the project in October 2019, the researchers are working out details to run a second, larger-scale pilot project that will go on for 30 months at a site nearby the Diavolezza cable car, where the Morteratsch once stretched.

“We’ve crossed a critical threshold,” Keller says. “This is no longer just on paper; it’s taking place for real.”
Artificial snowmaking project on the Morteratsch glacier in Graubünden. Note the glacier boundary planned for 2040 by the project promoters with ('mit') and without ('ohne') artificial snow. ©Academia Engiadina

Keller hopes to generate interest in the idea not just in Switzerland and Europe, but also other parts of the world such as Latin America and the Himalayas, where hundreds of millions depend on glacier-fed rivers to drink or irrigate crops.

“The system could potentially work anywhere,” claims Keller. “But at a local level it could prove invaluable for those communities that rely on meltwater from glaciers for their survival.”