By Alexander Wolff

	SI's SmithGroup-designed stadium, which is part of a hotel complex, draws its power from the sun and wind. Courtesy of SmithGroup

Sports condition us to notice first those things that happen at scatback speed, and until recently climate change took place in world-historical fashion, the way a nil-nil soccer match unfolds. But that perception is changing fast, especially for skiers, whose season has endured a whipsaw of extremes: One day in November enough snow fell at Colorado's Beaver Creek to cause the cancellation of practice for the men's downhill at a World Cup event. A day later on the other side of the globe, officials at the French resort of Val d'Isère called off another World Cup event on account of too little snow, as well as a forecast of prolonged warm temperatures -- one of seven World Cup events in Europe this season to have all races canceled for the same reason.

When the U.S. Nordic ski team returned home early from the European circuit after a December race was rescheduled four times in one week, it left behind resorts desperately trying to lure tourists with promises of spa weekends, Christmas markets and hiking to be enjoyed during this "extension of autumn."

Indeed, the world's signature dogsled race, Alaska's Iditarod, hasn't begun at its traditional starting point in Wasilla since 2002 because of too little snow there. The Elfstedentocht, an 11-city skating marathon that the Dutch stage whenever the canals freeze over, has been run only once in the past two decades. The highest ski slope on the planet, Bolivia's Chacaltaya (altitude 17,388 feet), will soon be unskiable for lack of snow, and the Swiss are wrapping an age-old glacier in an insulating blanket as if it were a foundling. Meanwhile backcountry skiing in North America and ice fishing in the upper Midwest are in jeopardy, and any ski resort below 4,000 feet is worried. Winter in Vermont is now the equivalent of winter in Rhode Island a generation ago.

Humans are accelerating global warming, and we can at least minimize its damage, if not reverse it. By acting quickly, the two countries that emit most of the world's carbon dioxide, the U.S. and China, might be able to avert that forecasted five-degree temperature increase, slowing the rise of the seas enough to allow for the development of new technologies to redress the problem. What would it mean to act? Decrease the burning of fossil fuels, improve fuel efficiency and conserve energy in our daily lives.

The good news is that stadiums and arenas, if built with green aforethought, can be more than symbolic Valhallas that remind us that we're all in this together. Site one near a public-transit line, and there's less need to build that most Earth-hostile of features, the vast parking lot. (The greenest ballpark in the country may be Fenway Park, because only an idiot would try driving and parking there.)

Turbines mounted on upper decks would catch the same wind that plays whimsically with pop flies, turning it into the source of power to offset at least some of the energy demands of a ball game. Gillette Stadium in Foxborough, Mass., features a water filtration and reuse system that collects and recirculates "black" and "gray water" to make the most of all that beer and all those flushes.

A very familiar sports facility is already poised to help the cause: A golf course is by definition conserved green space. If not turned into a repository for pesticides or a pretext for building strips of single-family homes along its fairways, it can serve as a huge filter, with the water draining from it cleaner than the water flowing in.