Writing on Stone, Writing in the Wind

The preservationist mission—to shield nature from human manipulation, intrusion, and above all, destruction—has inspired generations of American environmentalists to take action on behalf of threatened species and wild landscapes. The movement's visionaries are revered figures in the tradition, from Henry Thoreau and John Muir, to Aldo Leopold, David Brower, Rachel Carson, and Ed Abbey. The preservationist policy record, too, is widely celebrated and imitated around the world (though often with mixed results): The Wilderness Act (1964) and the Endangered Species Act (1973) have for decades served as legal bulwarks against the march of human development and ecological exploitation.

"Saving American nature," however, has never been easy. The historical record is also strewn with the wreckage of failed campaigns and cratered with ecological losses: the extinction of the passenger pigeon; the damming of Yosemite's Hetch Hetchy Valley; the relentless pressure on American wildlands exerted by countless chainsaws, bulldozers, roads, cities, and summer homes. And even the signature victories—protecting the spotted owl in the Pacific Northwest; keeping the Arctic National Wildlife Refuge closed to oil exploration; saving the California condor from the passenger pigeon's fate—remain tenuous and incomplete. Brower, who did as much as anyone in the tradition (and more than most) to make preservationism a potent political and cultural force in American life in the postwar era liked to say, in fact, that "when they [exploitationists] win, it's forever; when we win, it's merely a stay of execution." The preservationist challenge as he saw it was to maintain a sharp-eyed perseverance in the face of unrelenting environmental threats. If they wanted to ensure a human future rich in wild species and wilderness experiences, Brower implored, preservationists had better be "eternally vigilant."

Yet what exactly are preservationists to be "vigilant" in protecting? We've learned that this is far from a simple question in the time since Brower's zenith in American environmentalism. Rapidly changing biophysical conditions and shifting ecological baselines have at the very least seriously complicated the preservationist agenda. For some, especially for those who view "wild" as the essence of wilderness, it hardly matters because what results may be prompted by human actions but lies beyond human control.

For others these forces have made the very idea of preservation anathema to good conservation stewardship and environmental management in this century. Accelerating climate change, rapid urbanization and suburban sprawl, agricultural intensification, metastasizing fire regimes, the spread of invasive species, and other quickening anthropogenic forces—all appear to be collectively undermining venerable preservationist standards and sentiments. The traditional mantra—"preserve the wilderness!"—no longer seems very useful or compelling to those scientists, conservationists, and environmental writers today who argue that this celebrated object of preservationist passion and political concern is being radically challenged and transformed by global environmental change, most of it driven by humans. If it survives at all, they write, the future of the preservationist model in this "new normal" of global impact and disruption of earth systems will not resemble its past.

Many of these ideas about human influence and environmental control have converged recently around the idea of the "Anthropocene," a term that has migrated to environmentalist circles from its origins in discussions about the naming of the current geological period of human dominance on the planet. Originated by the Nobel Prize–winning atmospheric chemist Paul Crutzen and first promoted to the wider scientific community in an article published in the journal Nature in 2002, the term was an attempt to recognize the full suite of planetary changes driven by humans: extensive land transformation, control of the nitrogen cycle, water diversion, and especially anthropogenic alteration of the atmosphere through the emission of greenhouse gases (GHGs). People no longer just talked about the weather: they were changing the climate, although without much control. What had been an environmental fixture against which people acted was now another expression of the human presence. Crutzen argued that these changes, which he traced to the beginnings of the industrial era in the late eighteenth century, mark the beginning of a new geological period, the "Age of Man."

The "Anthropocene" has proved to be a polarizing designation. For some, the notion that humans have become a geological force on the planet—a species able to write its presence in the rocks—is a liberating revelation. It means that we should get on with the business of smart planetary management and get over outmoded myths of a separate, pristine, wild nature that exists free from human influence (and an environmental politics that limits human manipulations of nature). For others, the Anthropocene idea signals the tragic consummation of the destructive human domination of the earth, a last threshold crossed on the march to total ecological despotism. Even for those skeptical of its scientific basis, the Anthropocene remains a reminder of the singular power of humans on the landscape, and stands as a warning of what might lay ahead for us (and for nature) if we do not try to reverse the current course. The Anthropocene, in short, has...