Whether this winter turns out to be warm or cold, scientists say that climate change means the long-term outlook for skiers everywhere is bleak. The threat of global warming hangs over almost every resort, from Sugarloaf in Maine to Squaw Valley in California. As temperatures rise, analysts predict that scores of the nation’s ski centers, especially those at lower elevations and latitudes, will eventually vanish.

Image

Under certain warming forecasts, more than half of the 103 ski resorts in the Northeast will not be able to maintain a 100-day season by 2039, according to a study to be published next year by Daniel Scott, director of the Interdisciplinary Center on Climate Change at the University of Waterloo in Ontario.

By then, no ski area in Connecticut or Massachusetts is likely to be economically viable, Mr. Scott said. Only 7 of 18 resorts in New Hampshire and 8 of 14 in Maine will be. New York’s 36 ski areas, most of them in the western part of the state, will have shrunk to 9.

In the Rockies, where early conditions have also been spotty, average winter temperatures are expected to rise as much as 7 degrees by the end of the century. Park City, Utah, could lose all of its snowpack by then. In Aspen, Colo., the snowpack could be confined to the top quarter of the mountain. So far this season, several ski resorts in Colorado have been forced to push back their opening dates.

“We need another six or eight inches to get open,” said Ross Terry, the assistant general manager of Sunlight Mountain, near Aspen, which has delayed its opening a week, until Friday.