SALT LAKE CITY — Ski resorts across the country are using the Thanksgiving weekend to jump start their winter seasons, but with every passing year comes a frightening realization: If global temperatures continue to rise, fewer and fewer resorts will be able to open for the traditional beginning of ski season.

Warmer temperatures at night are making it more difficult to make snow and the snow that falls naturally is melting earlier in the spring.

In few places is this a bigger concern than the American West, where skiing is one of the most lucrative segments of the tourism industry and often the only reason many people visit cash-strapped states like Utah during winter.

But even as world leaders descend on Copenhagen next month to figure out a way to reduce carbon emissions blamed in global warming, the industry is still grappling with leaders in some of their own ski-crazy states who refuse to concede that humans have any impact on climate change.

Chief among them is Republican Utah Gov. Gary Herbert, who says he will host what he calls the first "legitimate debate" about man's role in climate change in the spring.

While the world's leading scientific organizations agree the debate was settled long ago, the former Realtor who took office when Jon Huntsman resigned to become U.S. ambassador to China maintains that it wasn't.

"He's said to me that the jury is out in his mind whether it's man-caused and he thinks and believes that the public jury is still out," said Herbert's environmental adviser, Democrat Ted Wilson.

Herbert's reluctance to acknowledge that greenhouse gases contribute to global warming quietly frustrates Utah ski resorts that depend on state marketing money, but it openly infuriates industry officials elsewhere who liken it to having a debate about whether the world is flat.

"That's just kind of raging ignorance," said Auden Schendler, executive director of sustainability for Aspen (Colo.) Skiing Co. "We're not environmentalists, we're business people. We have studied the hell out of the climate science. To have a neighboring governor not believe it ... It's absurd."

A climate study by the Aspen Global Change Institute is forecasting that if global emissions continue to rise, Aspen will warm 14 degrees by the end of this century, giving it a similar climate to that of Amarillo, Texas.

Many ski companies and the mountain towns they've created have been working to reduce their carbon footprints and advocating for significant policy changes for years. In California, the ski industry was one of the first groups to support legislation requiring the state to reduce greenhouse gases to 1990 emission levels by 2020.

Aspen Skiing Co. is widely recognized as a national leader, but Schendler readily acknowledges that the nation's ski resorts can do little on their own to affect climate change.

He said company resorts like Aspen and Snowmass are at their best when they educate their highly affluent — and politically connected — guests about global warming's effects.

"You need federal legislation in the U.S.," he said. "You need it to help drive an international agreement."

Herbert and Utah's senior U.S. Senator, Orrin Hatch, recently teamed up to oppose federal cap and trade legislation that many in the ski industry support, saying it could cost jobs in a state that's heavily dependent on coal for energy.

In the posh ski resort town of Park City, a former mining town that played host to the 2002 Winter Olympics, Mayor Dana Williams says some state leaders don't seem to grasp how important the ski industry is to the state and what a threat global warming is.

Tourism is a growing $7 billion a year industry in Utah and the state's 13 ski resorts are directly responsible for roughly $1 billion of that. Williams says the very future of the city that hosts the Sundance Film Festival each winter is at stake with rising temperatures.

A consultant's report released by the nonprofit community Park City Foundation this fall warned that by 2030 the decrease in snowpack caused by global warming could lead to the loss of more than 1,100 jobs and a $120 million economic loss in that community alone. By 2050, the report says those figures could jump to more than 3,700 lost jobs and a $392 million economic loss as fewer and fewer slopes in the area are able to open and lure visitors from around the world.

The CEOs of Park City's three resorts — The Canyons, Deer Valley and Park City Mountain Resort — have teamed up to educate anybody who will listen about how global warming threatens their businesses, with Park City Mountain Resort taking the lead.

That resort's corporate parent, POWDR Corp., owns resorts in and near Las Vegas, Killington, Vt., Lake Tahoe, Calif. and central Oregon.

Brent Giles, POWDR Corp.'s director of environmental affairs, says regardless of what anyone believes about global warming, it makes good business sense for everyone to become more energy efficient and environmentally friendly.

"All you can do is give them what science you've got and show how easy it is to make some of these changes and tell them they're going to save money," Giles said.

"Why can't we just do it because it makes sense?"