The ski season is a month shorter than it was 50 years ago. It will be nearly two weeks shorter still by 2030, and it will continue to shrink in subsequent decades. In the spring, wet slab avalanches – in which an entire slope slides slowly down a mountain, devouring the trees, rocks, and ski lifts in its path – will become increasingly common. The slope most prone to avalanches lies directly above Spar Gulch, an intermediate ski trail that is one of Aspen Mountain's main thoroughfares, and one of the only routes off the mountain. The beginner slopes will become pockmarked with rocks and turf, requiring snow machines to make up the difference. By 2100, should current conditions persist, there will no longer be any snow at the base of Aspen Mountain.
But Aspenites may not worry very much about skiing then. They will have larger concerns. As the mountain's snowpack shrinks, the waterways will languish. Streams will flow higher in midwinter, from January to March, but they will run dangerously low in June and July, threatening the survival of the riparian ecosystem – its brown and cutthroat trout, chorus frogs, aquatic snails, and backswimmers; the common muskrats, American beavers, and moose that drink from it; the olive-sided flycatchers, Brewer's sparrows, and bald eagles that roost on its banks; and the wetlands and forests it nourishes. Eighty percent of Colorado's wildlife needs access to a riparian habitat in order to survive, but today these habitats make up only 1 percent of the state's land. Aspenites also need access to waterways in order to survive – two frail mountain creeks, Castle and Maroon, provide the city with its water. During early spring and autumn, the creeks will flood more often, while during summer, when water demand from crops and residents is at its highest, they will be more likely to run dry. A 2006 report by the Aspen Global Change Institute concluded that the Roaring Fork River, the repository of all of the mountains' streams, "could be dried up in most years."
With less snowmelt, fighting the forest fires will be more difficult. During the first half of this century, fires are expected to burn as much as three times larger than in the previous half. In the second half of the century, the fires will be smaller but more frequent; they will occur, on average, every other year. But that is not taking into account the damage done by increased outbreaks of insect infestation. As fewer winter nights drop below freezing, the populations of gypsy moths and various types of bark-eating beetles will thrive. The Aspen study concluded that "the risk of unprecedented insect outbreaks could be one of the most dramatic effects of climate change on Aspen's forests." So far the Roaring Fork Valley has been spared the fires that have victimized so much of the West, but in recent years, a ravenous population of pine beetles has been busily preparing the lodgepole pines that surround Aspen for future conflagrations.
Many of the trees aren't waiting around for that eventuality, however. Species that thrive in cold temperatures and high altitudes, like firs and spruces, have begun migrating up the mountains, fleeing the increasingly inhospitable valley. "One might expect a slow creep of the tree line and vegetation upward," says Kevin Trenberth, a senior scientist at the National Center for Atmospheric Research's Climate Analysis Section. The dominant vegetation type will shift from taiga-tundra to boreal conifer forest. Aspen is even losing its aspens.
Yet many of Aspen's current homeowners don't seem to have noticed. This might be because the typical Aspen homeowner lives there only a couple of months a year. A majority of the homes are second homes, or third or fourth or fifth homes, but, like the automated house in Ray Bradbury's "There Will Come Soft Rains," they are programmed to run in perpetuity. The heat runs in the winter, lest the pipes freeze, and the air-conditioning in the summer, lest the oil paintings drip. The wine coolers and refrigerators never sleep. Aspen's homes – which belong to owners like the Koch brothers, Walmart's Walton family, the cofounder of Amway, and a fleet of oil magnates – have solved problems that most Americans don't even realize they have. To avoid the unsavory sensation of stepping from a hot shower onto tepid marble, the bathroom floors are heated; so are towel racks. Driveways and roofs are undergirded by snowmelt systems. The heating tape that zigzags around most Aspen roofs, sometimes kept electrified throughout the summer, can alone cost more than $1,000 in annual utility bills – particularly since the homes these roofs cover are among the largest in the world. To deter burglars, homeowners keep their exterior and interior lights on year-round, simulating occupancy. There were 25 burglaries in Aspen in 2012, though police were summoned by home alarm systems 1,263 times.
This profligacy doesn't take into account the ubiquitous SUVs, which in Aspen never went out of fashion; the cost of shipping meat and other supplies over the mountains; or the Gulfstreams and Bombardiers lining the runway of Aspen/Pitkin County Airport. In 2012, the airport welcomed 11,000 private planes. Aspen's population is only 6,680. But it has been living much larger.
This makes it all the more surprising that Aspen has taken it upon itself to save the world from catastrophic ecological collapse.
"I get annihilated," says Auden Schendler, an executive at the Aspen Skiing Company, when I ask whether he appreciates the irony. "People call me a hypocrite. They say, 'Shut up; you're from Aspen.' But who ought to lead, if not Aspen? Bangladesh?"