The valley is lit with dim winter light. In the distance, faint threads of smoke rise from a village toward the snow-laden clouds. Beyond, there are whitewashed mountain peaks, snow-covered fir trees, and immense frozen waterfalls running down dark rock faces.
It’s a typical winter scene in Switzerland’s Bernese Highlands—with one exception. Climbing one of those sheer walls of ice, solo, is Swiss mountain enthusiast and ice climber Dani Arnold. It is a skillful, tough, physical endeavor—a meticulous, cyclical dance of hacking axes and kicking crampons into the ice, finding stability, and then pushing and reaching for new fastenings higher up. Over and over, Arnold attaches and detaches his limbs from the ice. Foot by foot, he slowly ascends the icefall.
Ice climbing is arguably the most treacherous mountain sport. It takes place in tough, often subzero conditions, on extremely smooth surfaces with few holds. Climbers move on a changeable element, having to ascertain the difference between compact and fragile ice. “It only takes small changes in temperature or humidity to change the state of an icefall,” Arnold says. Despite—or perhaps because of—these risks, the sport is becoming more and more popular. But soon it could be extinct.
In the European Alps, glaciers are disappearing, snow is becoming rarer, and winters are shortening. In the last two summers alone, Switzerland’s glacier stock has lost 10 percent of its volume. Scientists warn that alpine regions are warming exceptionally fast compared to the global average temperature, which continues to march upwards. For sports that rely on snow and ice, this spells major trouble.
For ice climbing, the general prognosis is clear: Climbable ice will become less and less available. But specifically what changes can be expected, and when, is a mystery. Changes to river and stream freezing patterns are among the least explored impacts of climate change in mountain areas. There’s almost no research on ice-climbing environments, and the freezing of mountain streams and waterfalls receives little attention in the latest IPCC report on the world’s ice- and snow-covered regions.
Climbers themselves are the ones currently with the best knowledge of how icefalls are changing. What’s become clear to them is that the sport’s environment is getting increasingly precarious. “Ice on mountain streams is becoming more erratic, and winter freezing is shortening,” Arnold says. This means less ice to climb, but also that the ice that remains is less dependable. “We have had unstable conditions in the past, but they were not as frequent as today,” Arnold says.
Climbers typically describe icefalls as being alive. “In certain situations, the ice is extremely solid; it’s safe,” he says. But that can radically change in just a couple of hours if the ambient temperature rises, Arnold explains. And as the world warms, dramatically quick changes in temperature are becoming more common. From a ladder to paradise, an icefall then turns into a deadly trap. When weakened by melting, a frozen waterfall can shed pieces of ice as massive as a van, with these crashing down the mountainside below. For climbers, such a collapse can be fatal.
“The waterfall is something plastic. Ice and hanging icicles are kind of glued to the rock, and the most critical situation is when a rise in temperatures causes the ice mass to detach from the rock,” says Anna Torretta, a former Ice Climbing World Cup athlete from Italy. “In the sun in winter, a waterfall can switch from below zero in the morning to as high as 20°C in a matter of a few hours,” says Torretta. Today’s climate means having winter-long spring-like weather, Arnold says.
Changes to mountain river freezing patterns stretch far beyond the world of sport. “Ice climbing is the tip of an iceberg,” says Francesco Avanzi, a hydrologist at the Cima Research Foundation in Italy, which researches climate-related hazards. “Mountain water supplies are critical to economies downstream.” Global warming means less snow and more rain in mountain areas, Avanzi explains, meaning that water, instead of staying frozen for months in the mountains and then being released in spring and summer, flows into rivers and streams in winter, when it is least needed by agriculture.
“Without climate protection measures, towards the end of the century there will be on average 30 percent more water in rivers in winter, but 40 percent less in summer than in the past,” reports the Swiss National Centre for Climate Services.
Michela Rogora, a researcher at Italy’s national water research institute, IRSA-CNR, points out that less ice on glacial streams and lakes, as well as a reduction in ice cover, also affects mountain ecosystems. “In the case of lakes, early thawing changes the lake stratification and circulation of water, the chemistry, UV exposure, and consequently impacts biological communities, affecting biodiversity—from plankton to fishes,” Rogora says.
Ice climbers and ecosystems will be forced to adapt as winter patterns change—and Arnold believes the sport will survive. People who engage in outdoor activities are adaptive, he says. “Sometimes I am concerned. But I don’t think it will happen,” he says of the possibility of ice climbing going extinct.
There is already research showing that mountaineers and climbers don’t want to give the sport up, and that they are ready to adapt their behaviors in order to keep climbing. Strategies include modifying when they chose to climb, shifting to activities that are related to but more compatible with the new environment, or looking for new places to practice the sport.
In fact, the sport is still attracting more and more people. “This is a problem. There are fewer iced waterfalls, in tighter periods, but at the same time more practitioners,” says Torretta. Finding good ice will become more competitive. Plus, a simple law of nature says that if something becomes more hazardous, and the number of people exposed to that hazard increases at the same time, then the risk of accidents increases.
“To find ice, we will have no choice but to move further north or higher,” Torretta says. Moving higher is what some alpine animal and plant species are already doing. But there is the limitation, though, that at some point the mountain doesn’t go any higher.
However, there is another way to keep climbing with axes and crampons. It’s called dry tooling, and involves climbing with ice-devised tools on bare rock. It’s a technique that used to be considered a compromise, to get over rocky parts on frozen waterfalls, but has now become a sport in itself. “I think that the future is dry,” Torretta says, though she’s not looking forward to it. “I still prefer climbing on ice.”
But some cliffs, slopes, and mountain faces are becoming inaccessible altogether as ice melts. “The North Face of the Matterhorn is a good example,” says Arnold. “In the last two years there have not been any ideal days for a climb.” And dry tooling isn’t an option, because rising temperatures are melting the mountain’s permafrost, which used to act as a natural glue, holding the mountain rock in place—but no longer. “There are constant rock falls,” Arnold says.
And the Matterhorn isn’t the only peak affected—in general, permafrost is disappearing from alpine regions. “The mountains are coming apart,” says Torretta.
Current books on mountains are therefore no longer reliable references. “We can no longer trust mountain guidebooks, or reports on previous climbs. When they say the best time is in certain months, you can’t trust them anymore,” says Arnold. For anyone who wants to ice climb, he advises checking on the safety of a line day by day. “Ask the local mountain guides, who have an eye on the changes” he says.
Ultimately, with the sport riskier than before, changes to the ice more erratic, and uncertainties higher, climbers have to be more perceptive than ever as to when it’s time to call off a climb. And sadly, calling it quits is something that climbers will have to do more and more frequently. “I’m going with a client tomorrow,” says Arnold. “It will be hard to make a decision.”