That was among the scenarios laid out in Utah's premier ski town Tuesday evening by a pair of Colorado climatologists, who said that global warming and an average temperature increase of four to five degrees Fahrenheit in the Wasatch Mountains by mid-century will turn the greatest snow on earth to sierra cement.

The prospect of global warming is getting serious attention from ski resorts this year. The "Save Our Snow" program, presented before 1,200 people packed into the Eccles Center for the Performing Arts, was sponsored primarily by Park City Mountain Resort and Park City radio station KPCW.

Mark Williams, University of Colorado, and Brian Lazar, Stratus Consulting, presented three scenarios for temperature and snowpack for each of the years 2030, 2075 and 2100. Their predictions were based on computer models that combined temperature change with precipitation averages in the Park City area.

Best case and worst case scenarios were not much different in 2030 for Park City Mountain Resort, which varies in elevation from 6,900 feet to 10,200 feet. Average temperatures may climb 1 degree by then, but the snowpack and skiing will be similar to what they are now.

But by 2075, average temperatures on the mountain may have increased by 10 degrees, resulting in a short season with variable snow conditions.

If greenhouse gas emissions increase from present rates, skiing could be found only at the top of the mountain by then. But if man-made emissions of CO2 and other gases are reduced, snow could be found as low as the base lodge.

If greenhouse gases continue to build in the atmosphere as they are doing now, by the year 2100 skiing at Park City and throughout the Wasatch Mountains could be a memory.

"The good news is, the more we control emissions, the more snow we'll see," Lazar said.

Williams and Lazar qualified their predictions, saying that global warming will make for very wet years and very dry ones. "We're not quite certain what precipitation in Park City is going to do," Lazar said.

Blair Feulner, station manager at KPCW, said a 10-degree change in Park City would yield a climate similar to Salt Lake City's.

"This is the single most important issue in Park City since the silver mines closed," Feulner said. "What happens if the snow runs out?"

The future for snow sports doesn't look bright, said Park City resident Leah Corey, 14, who is an avid skier and snowboarder.

"I'm afraid that when I get older, I won't be able to ski," she said after the presentation.

Salt Laker Jeff Niermeyer found the presentation startling.

As the deputy director of Salt Lake City's Department of Public Utilities, Niermeyer tracks water from mountain snow pack.

"If what they are saying is true, Salt Lake City could have at least 30 percent less water by 2075 than it does now," he said. csmart@sltrib.com