Winter is getting weirder, and a coalition of Olympic athletes has seen enough. As Sochi's Winter Olympics threaten to become the warmest in history, more than 100 Olympians have signed a petition urging world leaders to take action against climate change.

Sochi is just the latest in a string of summery Winter Games, and the athletes say their sports are in danger unless an Olympic-style effort is launched to rein in greenhouse gas emissions. Although climate change can also promote wild winter weather like a recent spate of U.S. snowstorms, those unusual outbursts do little to offset the long global slog toward warmth, especially in winter-sports hotspots like Vancouver or Sochi.

"Snow conditions are becoming much more inconsistent, weather patterns more erratic, and what was once a topic for discussion is now reality and fact," U.S. cross country skier Andrew Newell says in a statement released this week by the U.S.-based Protect Our Winters campaign. "Our climate is changing and we are losing our winters."

At least 105 Olympians from 10 different countries have signed the petition so far, including 85 Americans. They want world leaders to carry on their Olympic spirit from Sochi to Paris, where a major U.N. climate summit will be held in 2015.

"For the next two weeks, I'll be in Sochi giving it my all on the ski course, just like thousands of Olympic athletes from around the world putting politics, religion, all of our differences aside," Newell says. "Coming together for something that is bigger than one individual, or even one country. Next year in Paris, world leaders will also have that chance. Previous climate conferences have ended with nothing to show for it, but Paris needs to be different. We can't risk inaction any longer and we're asking our world leaders to come together in the spirit of something bigger than just our individual goals."

Temperatures in Sochi have already topped 60 degrees Fahrenheit this week, creating slushy conditions that have frustrated many skiers and snowboarders. But the problem goes far beyond Sochi, as highlighted in a recent study led by University of Waterloo researcher Daniel Scott. Of the 19 cities that have previously hosted a Winter Olympics, as few as 10 may still be cold enough by 2050 to host again, according to the study.

With average global temperatures projected to rise up to 10 degrees Fahrenheit before this century ends, that number of cities could fall to six by 2100. "In a substantially warmer world," the study warns, "celebrating the second centennial of the Olympic Winter Games in 2124 would be challenging."

The pool of potential host sites may also be dwindling, Newell notes. While low-altitude areas can have logistical benefits for the Olympics, they're also often the places most vulnerable to climate change. By 2040, the average ski season in the U.S. Northeast is forecast to last fewer than 100 days, and the U.N. has predicted winter sports overall will become more concentrated at higher elevations as snow grows less reliable near sea level.

And even more troubling, the long-term popularity of skiing, snowboarding and other winter sports could suffer if snow becomes too erratic and unpredictable, the U.N. warned in a 2003 report. "One of the most important questions will be how young people would start skiing/snowboarding if there is only little snow in the big towns," the report says. "Although indoor skiing is a growing industry in European towns, it is uncertain that indoor ski domes can replace the role of little ski resorts for beginners in the foothills."

In the U.S. alone, snow-based recreation supports more than 600,000 jobs and contributes about $67 billion to the economy per year, according to Protect Our Winters. And among countless other ecological effects, AWOL snow on mountains can trigger far-reaching water shortages, as seen recently in California and throughout much of the Sierra Nevada. "I'm not a scientist," Newell writes, "but just like most Americans, I know that as the snow dwindles so does our water supply, our food, our health and our economy."

For more about how climate change is affecting snow sports and Olympic athletes, check out this recent video released by Protect Our Winters:

Russell McLendon ( @russmclendon ) writes about humans and other wildlife.

Olympic athletes rally in defense of winter
A coalition of Olympic athletes is fighting to save their sports from climate change.