What will winters mean for our children and our grandchildren? PHOTO: Christian Pondella

In just 70 years, the ski season will be markedly shorter, no matter what happens in the near future.

Subsequently, revenue from ticket sales alone will drop in the coming decades by hundreds of millions to billions of dollars. But how much depends on whether or not the planet limits greenhouse gas emissions with policy change—lightbulbs and carpools are not going to move the needle.

A study released in April by a group of scientists in Colorado underscores what many have already known will happen to the ski industry as a result of climate change. But their research paints a clearer picture of the future. The scientists ran five climate models under two different scenarios of greenhouse gas emissions for the years 2050 and 2090, and then monetized the impact by using average lift ticket prices. The two scenarios are not based on any official targets like the Paris Agreement, but they are a standard adopted by the International Panel on Climate Change in 2014. One models a peak in greenhouse gas emissions in 2040 and then a decline—so a future where the planet takes action now to shift toward renewable energy, cut emissions significantly, and stabilize the carbon in the atmosphere. The other is more grim. It is based on emissions continuing to rise throughout the 21st century—assuming nothing changes from the global society's current dependence on greenhouse gases.

"At a national scale, we wanted to evaluate what the impacts of climate change might be for the ski industry," said Cameron Wobus, the lead author and Boulder-based scientist on the study. "It was to really look from a physical modeling standpoint at how ski season lengths would change and how that would translate into monetary impacts by way of lost lift ticket sales."

The study’s findings juxtapose two futures with a difference of $2 billion. After running 300,000 years of climate model simulations, with data by the hour, the study concluded that "virtually" all ski areas in the United States will not have the snow to operate like they do today. That is depressing news to any skier, but the results present a clear choice with one outcome better than the other.

“It's important that the study points out that this is still a choice, in the sense that we can determine our future based on how aggressively we as a society choose to cut emissions.”—Auden Schendler

If steps are taken to aggressively reduce greenhouse gases, and the amount of carbon stabilizes in the atmosphere, ski seasons will still be shorter by the end of the century. But the losses won't be so much that business could not adapt and continue on. Assuming skier growth mirrors trends in population growth, ticket sale revenue would actually increase by about $126 million nationwide in 2090 (though the study does not account for inflation). In other words, even though the ski season will be shorter, there will be more skiers to make up for any lost revenue (and slopes will be more crowded).

On the other hand, 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. 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.

Snowmaking has already become a vital business component at ski resorts worldwide. But according to the study, if emissions are left unchecked, the planet will be so warm that even with snowmaking, 90 percent of ski resorts in the United States will not be able to open by Christmas—a time stamp that will put most ski resorts out of business. The fallout in ticket sales translates to a loss of $2 billion—not counting the repercussions that will ripple in the economy. (A 2012 study published by the National Resource Defense Council and Protect Our Winters estimated a $12.2 billion U.S. winter tourism industry.)

"This study just puts another exclamation point behind what we already knew: that winter is badly threatened. In this case, not in some far-off timeframe, but just around the corner in 2050," says Auden Schendler, Aspen's VP of Sustainability, who advised Wobus and his team early in their research. "It's important that the study points out that this is still a choice, in the sense that we can determine our future based on how aggressively we as a society choose to cut emissions. For the snowsports community, this means using heavier weapons in the policy fight, and not deluding ourselves that cutting resort carbon footprint has anything to do with stopping climate change."

According to Wobus, the three biggest takeaways of the study are:

1. No matter what, in the mid and late century, the length of the ski season will decrease
just about anywhere in the United States.

2. Elevation makes a big difference. The higher elevation ski resorts in the Rockies, the Wasatch, and the Sierra Nevada will be somewhat insulated from climate change, while the lower elevation guys will take much bigger hits.

3. A climate scenario with lower greenhouse gases in the atmosphere looks a lot better for the ski industry than one where runaway emissions are left unchecked, as they are now. The difference is a matter of "preserving skiing and snowmobiling in the eastern half of the country and losing these activities almost completely by 2090," the report states.

If anything, the study underestimates the gravity and threat climate change poses to the ski industry—and mountain communities. The scientists didn't account for businesses struggling to operate during back-to-back marginal winters. They also assumed the same percentage of people will ski in 2090 as do now, though the most common reasons people cite for not skiing are "no one to go with" and "poor weather."

SIA's research director Kelly Davis analyzed the report in a blog post and pointed out a couple of ways the ski industry could adapt to climate change, like new ski resorts opening in higher elevation locations, improvements to snowmaking, and changes in equipment to "reduce dependency on snow conditions."

"In addition to any technological solutions, the report strongly suggests that the snow sports industry has a vested interest in taking every possible step to stop or slow the rate of change in climate," Davis wrote.

What is clear is that climate change will have a profound impact on skiing this century—and will affect whether your kids or grandkids have the same passion for skiing that you enjoy.

Do the research yourself and read the report, "Projected climate change impacts on skiing and snowmobiling: A case study of the United States."

The study was designed to stay at a broad national-level vantage. Wobus and his team based opening dates on when a ski resort would have either 10 centimeters of snow-water equivalent (that fell from the sky) or 450 hours of temperatures cold enough to make snow. They determined those parameters by consulting with environmental advocates like Schendler and Aspen's snowmaking department as well as industry snowmaking expert Robin Smith. "They were critically important throughout this process in helping us understand the rules for snowmaking, what the temperature needs to be, how much time you need to make snow," said Wobus.

The group did not dive deep into any specific ski area. For skier visit data, they relied on public reports published by the National Ski Areas Association. "There's a whole lot more that could be done if we had more granular data on which areas are people going to and when and how many visits an average area in Colorado gets versus another state," said Wobus.

Read more: Campaign donations link ski industry leaders to climate change deniers.