Do you like to ski? If so, get out there and enjoy it while you can. Dryer and warmer weather is shortening the ski season and reducing the number of resorts that will have enough snow to remain in business.

Within the next 20 years, the number of days at or below freezing in some of the most popular ski towns in the United States will decline by weeks or even a month, according to a new report by the Climate Impact Lab. In Park City, Utah, for example, an average of 194 days each year between 1981 and 2010 were at or below freezing, but that figure could be cut in half by late century if emissions continue to rise at the current rate.

In the Alps, the eight-nation mountain range that accounts for 40 percent of the world’s skier-days, resorts are facing the loss of up to 70 percent of their snow cover by the end of the century, and the snow line will be a kilometer higher – above the base of most ski areas. Even in the best-case scenarios, global warming is likely to cause snowfall to be replaced by rain across the Alps, according to a report in the European Geosciences Union journal Cryosphere.

If you’re a skier, you’ve seen the evidence already. “From 1960 to 2017, the Alpine snow season shortened by 38 days—starting an average of 12 days later and ending 26 days earlier than normal,” Jeffrey Kluger wrote in Time magazine. Europe experienced its warmest-ever winter in the 2015–16 season, with snow cover in the southern French Alps just 20 percent of its typical depth.

Problems from the Northeast to Alaska

For skiers in the northeastern United States, Daniel Scott, who directs the University of Waterloo’s Interdisciplinary Centre on Climate Change in Ontario, has similar news: Even under the most optimistic climate change models, ski areas in southern New England will no longer be economically viable by 2040.

Lower-altitude resorts are most vulnerable. By Scott’s account, as reported by Maine Public’s Fred Bever, low-snow casualties will include Mohawk in Connecticut, Blue Hills outside of Boston, and some bigger places, such as Jiminy Peak in western Massachusetts. Creeping into the northern tier, New Hampshire’s Attitash is in the climate change crosshairs, as is Maine’s Shawnee Peak -- the starter hill for many Portland families.

In just the past decade — the warmest in Earth's recorded history — the snow line rose between 1,200 and 1,500 feet in the northern Sierra Nevada. "The storms are not pushing over the crest like they used to. They don't have the same intensity any more," said Jamie Shectman, a founder of the Mountain Rider’s Alliance, which strives to establish healthy and profitable local ski areas.

Alyeska Resort in Alaska typically posts one of the world’s biggest snowfall totals by the end of each ski season, but in August 2017 announced that it was delaying its planned opening date by three weeks. Traditionally, Alyeska opened for the long Thanksgiving weekend. The resort ultimately was able to open on December 9.

Marketing Director Eric Fullerton said the decision to delay was based on “shifting weather patterns,” meaning that snow cover was unpredictable early in the season, despite the investment of millions of dollars in snowmaking in recent years. “Sometimes we’ll get the inversion where there’s rain on the bottom and there’s a lot of snow on top, and it makes it difficult to ski all the way to the bottom. Or it flip flops, and there’s not enough snow on the top and we got snow on the bottom,” he told local media. Fullerton added that it was difficult to get a return on investment when the ski area could not guarantee top-to-bottom skiing.

Over the past 60 years, Alaska has warmed more than twice as rapidly as the rest of the United States. The statewide average annual air temperature has increased by 3°F and average winter temperature by 6°F. The lack of snow in Anchorage has forced organizers of the famous Iditarod dogsled race to alter the course twice in recent years.

Canary in the coal mine

If nothing is done to stop global warming and our planet continues to burn greenhouse gases as we do now, the ski industry will be a shadow of what it is today, according to a 2017 study titled “Projected climate change impacts on skiing and snowmobiling: A case study of the United States” and published by Global Environmental Change. As summarized by Powder Magazine, the study found: “Climate change will scrape weeks off both sides of the season at ski resorts from California to Maine, and the losses will be so much that even population growth won't be enough to sustain business in skiing. Ski resorts at lower elevations--especially in the Northeast and Upper Midwest, but also in the Pacific Northwest and towns like Park City, Utah--will suffer the most, some places seeing their season cut by upwards of 80 percent.”

The ski industry is seen a bit like the canary in the coal mine of climatology, wrote John Branch in The New York Times. Sensing this, the industry was among the first to push for awareness of the threat of global warming, long before the turn of the century, led by resorts like Aspen, in Colorado. The National Ski Area Association adopted a climate-change policy in 2000. In 2007, the snowboarder Jeremy Jones founded Protect Our Winters to further rally the winter-sports community.

Globally, the ski industry generates up to $70 billion per year. In Colorado, downhill skiing accounts for $4.6 billion in economic activity and 45,000 jobs.

Snow-making helps, but it is no panacea. "We may have reached a sort of peak season era in the 2000s when we had a lot of snow-making penetration," Scott told Maine Public’s Bever. "And it’s still growing in different markets, but now the climate has shifted just that much that, in these last five years anyway, the average season-length has tipped down for the first time in over 30 years.

"And adding snow-making capacity isn’t necessarily the answer," Scott said. "We’ve seen that in the last couple of years, where it’s just too warm to even make it, or even when you do make it and it just melts so quickly so you’re throwing money out the door. So yeah, they’ll have to look at how to diversify their revenues, and not every ski area is able to do that."

Scott, along with Robert Steiger of the University of Innsbruck and others, have looked at future warming in the context of the cities chosen to host the Winter Olympics, from Chamonix in 1924 to Pyeongchang in South Korea and Beijing in 2022. Even if emissions are cut enough to meet the target of the Paris climate agreement, only 13 of the 21 look certain to be cold enough to host snow-sports in the 2050s. With high emissions, the number would drop to just eight in the 2080s.

As The Economist summed it up in a January article, “The sight of helicopters rushing snow to Olympic sites in Vancouver in 2010 may be a harbinger of the future.”