Popular ski destinations are resorting (pun not intended) to "snow farming" as they work to overcome unpredictable seasonal weather. Rather than relying on regular snowmaking to keep the slopes powdery and bright, resorts are turning toward insulation methods that allow snow to be kept over the summer and reused when the ski season begins again.
Climate change—the "number one threat to the snowsports industry," according to the National Ski Areas Association—is jeopardizing previously reliable winter wonderlands. As Earth's annual mean global near-surface temperature increases, so does the temperature in skiing and snowboarding havens worldwide. A study published in Nature Climate Change last year warns that more than half of Europe's 2,234 ski resorts are at "very high risk" of losing their natural snow supply if the annual mean global near-surface temperature warms by more than 2 degrees Celsius. Meanwhile, some lower-altitude resorts are struggling to maintain the slopes they rely on to survive.
"Snow cannons" have allowed ski resorts to supplement their snow supplies for roughly half a century. These machines use compressed air to split water into tiny frozen droplets: the "snow seeds" that help mist freeze into snow as the cannon blasts both into the air. But this process has its own environmental implications. Not only does it consume vast amounts of water, but it's energy-intensive, requiring either electricity or diesel. When manufactured snow melts, the process starts again, resulting in even more water consumption and atmospheric pollution.
A centuries-old snowkeeping strategy is helping resorts maintain their artificial snow supplies. Snow farming, or the practice of "harvesting" snow to save it for later, involves packing manufactured snow into piles in semi-shaded outdoor areas. Before the warmth of spring hits, the piles are covered in insulating layers that reflect heat to keep the piles cool. In some cases—like with snow farmed by Snow Secure, a Finnish startup—wood chips fill in the cracks left by large polystyrene insulating panels.
This practice allows tightly-packed snow piles to persist through the summer and early autumn. When temperatures are again cool enough to prevent snowmelt, resorts uncover their snow piles and redistribute them across the slopes. The method preserves anywhere from 72% to 83% of piled snow, according to a study published in The Cryosphere.
Snow farming in this way can be pricey, ranging from €50,000 to €100,000 ($53,195 to $106,390) for a pilot with Snow Secure. (Covering enough snow to supply an entire slope costs "several hundreds of thousands," according to a quote provided to the BBC.) Depending on the vehicles used to redistribute the snow, pollution could still be an issue: front-end loaders, snow groomers, and other service vehicles almost always run on diesel. This means snow farming isn't a one-size-fits-all solution but rather a supplement certain resorts can use to reduce their impact on drought-ridden communities, depending on their needs.
