In ski seasons without much snowfall, skier numbers across the U.S. drop by more than 10 percent. Subsequently, ski towns and the ski industry take a $1 billion hit in revenue, and 17,400 jobs are lost.

A report published earlier this month by Protect Our Winters (POW), a climate advocacy group based in Colorado, studied winters for the past 15 years to determine the economic impact of climate change on skiing. It updates POW’s previous economic analysis on climate change and the ski industry, published in 2012.

Ski resorts have recorded an average of 55.4 million skier visits annually between 2001 and 2016 in the United States. Those skiers bought gas and lift tickets, rented skis, chugged beers at après, slept in comfy hotel beds, ate breakfast burritos, and bought tacky t-shirts at the gift shop to show friends they "got high" at 8,000 feet in Vail, Colorado.

But that number fluctuates. During years of low snowfall, skier visits dropped by 5.5 million.

POW believes the correlation is simple: when there's less snow, fewer people go skiing. Mountain towns across the U.S. rely on winter tourism to survive. For these towns, snow is the most valuable currency they have. As snow becomes less predictable and reliable, the economy and stability of these towns is going to be put at risk.

READ MORE: How ski towns are combatting climate change.

The 2015-16 winter was a good year for snowfall in many parts of the West. Some 20 million people went skiing, snowboarding, and snowmobiling, and those people sparked $20.3 billion in the U.S. economy. That season supported over 191,000 jobs, generated $6.9 billion in wages, and contributed $11.3 billion to the national economy. POW found that good winters add more money and jobs to the economy. Bad winters do the opposite.

As yearly snowfall becomes less reliable and more unpredictable, POW's study shows that these numbers are not guaranteed to remain a constant. There is a lot more at risk during a low snow year than our ability to score sick face shots and ski deep pow.

"To me, a big take away from this is that this community (the ski industry) has as big a stake as any other in the world to voice our concerns on this issue," says Mario Molina, the executive director of POW. "You can't argue that you care about American jobs and the American economy and not take climate change seriously."

Read more: In the face of climate change, Park City has become a leader. Is it enough?

While last season was defined by record-breaking snowfall across most of the west, according to the report, freak snowstorms are a symptom of a general warming trend. Data from NASA shows we could see a rise in temperature between 2 and 6 degrees Celsius by the end of the 21st century. Recent storms are possible due to what the report calls an atmospheric "sweet spot," where the perfect mix of mid-level temps and moisture-rich air form massive snowstorms. "While larger snowfall events are likely in a warming climate," the report states, "the overall impact of warmer temperatures is a reduction in snowfall as more precipitation falls as rain instead of snow."

These adverse effects are also seen by those at the top of the industry, who have made skiing into their career. "Snow isn't the reliable source that it used to be," says Caroline Gleich, a professional skier and POW alliance member. "When you can't reliably guess where the snow will be, it becomes harder and harder to travel or plan trips."

What can be done to help try and save the industry and all those that depend on it? For a start, Molina says, you can vote. "Before these next midterm elections, we need to let our candidates know that we will be voting on them based on what they will bring to the table in terms of climate action."

READ MORE: Why ski resorts are getting into the utility business.

We can also push brands and businesses to set an example and operate on a small footprint. "We can support brands that have taken a public position to make a difference, and not support those who haven't," says Molina. "What is political about wanting cleaner air, clean water, energy dependence, saving American jobs, and the economy and planning for a better future?"

One of the most powerful statements in the 70-page report really cuts to the core of the issue: "Snowfall is diminishing, and the consequences are severe. The rising monetary toll is dwarfed by the insult of a lifestyle in decline." At our current rate, snowfall will continue to decline and be far more unreliable than ever before. Attached to this decline is the economy and livelihood of those places dependent on snowfall to survive. Without action, mountain towns and ski destinations across the country will be fighting to stay afloat.

You can read the full report published by Protect Our Winters here.