HOW LONG UNTIL WE MUST HANG UP THE SKIS?

Declining seasonal snow has more serious consequences than just depriving skiers of fun. Climate change is causing some major upheavals on the slopes. JONICA NEWBY casts a skier’s- eye view on global warming.

LAST JANUARY I was in Japan – my first time – having a “ski-bunny” adventure in Hokkaido. The nation’s most northern and coldest island has some of the best and most consistent seasonal snow in the world, so I wasn’t surprised to meet a lot of fellow Aussies on the slopes. What did surprise me, though, was the number of skiers from northern Europe – Finns, Germans, Swedes and Austrians. I spent a delightful day skiing with a pair of clichéhandsome Swiss ski instructors. “What on earth is a Swiss ski instructor doing on a ski holiday in Japan in the middle of the European ski season!?” I asked lightly, but it was no laughing matter. “We came to find snow,” was the reply.

It had been a Green Christmas in the Swiss Alps. The month before had seen the least snowfall for any December on record since 1864. Switzerland’s mountains now experience 40 fewer days of snow a year, on average, than in the 1970s. “The snows are melting earlier and arriving later,” says climatologist Martine Rebetez. The researcher, who works at the Swiss Federal Research Institute for Forest, Snow and Landscape research, is also a keen skier. “I’m particularly sad for my children and grandchildren,” she says.

Around the world seasonal snow is retreating. From the alps of Europe to the Rocky Mountains of North America, from China to Australia, spring melt is arriving earlier and earlier – and traditional ski resorts are feeling the heat. The mountains of Hokkaido may be one the few places where the ski industry can chill, with the Japan Meteorological Agency predicting more frequent heavy snowfalls for the area even though less snow will fall across Japan as whole.

So the question for snow enthusiasts is: how long until we have to hang up our skis – or snowboards – for good?

In the short term, at least, ski resorts can maintain their slopes by making their own snow (see How to make snow, page 103). In the longer term, if temperatures keep rising, even snow machines won’t be able to keep many ski resorts in business.

Declining seasonal snow has more serious consequences than just depriving skiers of fun. Alpine winter snowfall plays a crucial role in supplying water to streams, rivers and reservoirs – on which millions depend for their water supply.

Take, for example, the Colorado River in the United States, which begins high in the Rocky Mountains of Colorado, and supplies water to seven states – Colorado, Wyoming, Utah, Arizona, New Mexico, Nevada and California (including the city of Los Angeles). Seasonal snow is the major reservoir for the Colorado river. As the snow disappears, so too does the yearround water supply.

“When I give a talk, I ask people a trick question,” says Brad Udall, a hydrologist with the Colorado Water Institute. “What is the biggest reservoir in our water supply? People suggest Lake Mead or Lake Powell. Not even close. Our biggest reservoir by far is our snowpack.”

The snowpack, by locking up water over winter and releasing it slowly over spring and into summer, evens out the flow that feeds streams and rivers during the dry seasons. If the same amount of water fell as rain in winter, it would quickly cause reservoirs to overflow, with the excess flowing straight to the sea. “I’m very worried,” says Udall, who cites research that the Colorado River’s water flow declined 20% between 2000 and 2014: “We’ve shown a third of the drop is directly due to higher temperatures and climate change.

Is it a harbinger of things to come? That’s a complex question. Other major snow-melt-fed river systems include those in the Himalayas and the Andes – both with enormous populations dependent on their water. Seasonal snow has been less measured in those regions, and no clear trend has yet been discerned. In some of the higher, colder parts of the world snowfall may increase in the near term even as temperatures rise. But what is clear is that global warming will continue the trend of later snow onset and earlier melt. “This is likely to hurt water supplies,” Udall says. “Hydrologists are particularly afraid for the people of the Andes, as the glaciers disappear and snow is eventually replaced by rain.”

Yet even as rivers and ski days dwindle, blizzards seem to be getting worse. In 2015, the US experienced one of its biggest snowstorms of all time, stretching from Texas to New England. But this too can be explained by rising temperatures. One leading theory is that it is to do with the polar jetstream – the tight ribbon of air that whips around the poles. As the Arctic and Antarctic heat up more than the rest of the planet, the jetstream is becoming looser and loopier. The result is polar air

seeping out to blast our continents. So we can expect more crazy snow storms, even as seasonal snow declines.

That leaves the million-dollar question for skiers – can skiing be saved? If not, how long do we have left?

Australia is the canary in the coal mine when it comes to seasonal snow. Its highest mountain is just 2,228 metres, with most ski resorts sitting below 1,900 metres. Records kept by the Snowy Hydro scheme show that at Spencer’s Creek, one of the highest points of the Australian snowfields, total seasonal snow has declined by a third since 1954. Despite this, Australia’s ski resorts have thrived due to advances in snowmaking technology. Snowmaking, however, is temperature dependent. How long can the resorts continue making snow?

This question prompted the Victorian Alpine Resorts Co-ordinating Council to commission Australia’s Antarctic Climate and Ecosystems Cooperative Research Centre to undertake modelling of the future of natural and human-made snow in Victorian ski resorts. Based on the high emissions scenario calculated by the Intergovernmental Panel on Climate Change’s 5th assessment report, the researchers found average alpine temperatures would rise by four to five degrees by 2070, and the length of the ski season contract by 65-90%. Only the highest peaks would be left with snow.

Nearer-term impacts are harder to calculate, though the scientists could model conditions relevant to snowmaking. These calculations suggest that by the 2030s snowmaking opportunities will be half that of 2010.

“We’re seeing the impacts of climate change much earlier than I expected when I first started researching climate 20 years ago,” says Rebecca Harris, the alpine report’s lead author.

In the US, snow is expected to decline a further 30-60% in the next 30 years, varying according to region. On the east coast of the US, say goodbye to downhill skiing by the middle and certainly the end of the century if we continue to track at current emissions.

Across the western US, a new multiinstitute study published in Nature Communications in April shows a 10-20% loss of total snowpack since the 1980s. In Colorado’s most famous ski resort town, Aspen – a name synonymous with fakefur clad celebrities and “sick as” powder riding – the equivalent of one month of good skiing conditions has been lost since 1980, according to Auden Schendler, vicepresident of sustainablity at Aspen Skiing Company. “Last year every single month of winter had a rain event. It’s becoming the new normal”. Aspen could even lose up to 75 more ski days by 2050. That doesn’t leave a lot of winter.

With tens of thousands of jobs relying on winter tourism, the estimated revenue lost between 2000 and 2010 was about US$1 billion, according to an industry report, “Climate Impacts on the Winter Tourism Economy in the United States”.

So, can we save winter? The latest study by Switzerland’s Institute for Snow and Avalanche Research is bluntly titled: “How much can we save? Impact of different emissions scenarios on future snow cover in the Alps.” For co-author Mathias Bavay, the most striking finding is that even at altitudes above 2,000 metres, 70% of the snow could be gone by the end of the century. Achieving the emissions targets set in the 2016 Paris Agreement would limit the loss to 30%. “It’s the difference between saving skiing or not,” he says.

The world’s snow lovers have banded together in a 100,000 member-strong organisation called “Protect our Winters”, aimed at using industry clout to pressure governments to act.

So what about me? Am I ready to hang up my skis? Not on your life. I will be getting every last bit of joy I can out of riding this magical mystical substance while I still can – and joining “Protect Our Winters” to take up the fight. Japan is also one of the places skiable snow will last longest. So I guess I’ll see my handsome Swiss ski instructor there next year.