"Two paths lie before us," Jonathan Schell concluded his remarkable essay The Fate of the Earth more than twenty years ago. "One leads to death, the other to life. If we choose the first path…we in effect become the allies of death, and in everything we do our attachment to life will weaken: our vision, blinded to the abyss that has opened at our feet, will dim and grow confused; our will, discouraged by the thought of trying to build on such a precarious foundation anything that is meant to last, will slacken; and we will sink into stupefaction, as though we were gradually weaning ourselves from life in preparation for the end. On the other hand, if we reject our doom, and bend our efforts toward survival…then the anesthetic fog will lift: our vision, no longer straining not to see the obvious, will sharpen; our will, finding secure ground to build on, will be restored; and we will take full and clear possession of life again. One day—and it is hard to believe that it will not be soon—we will make our choice."

That essay of course proved a clarion call in the then burgeoning (if subsequently somewhat stunted) movement to banish nuclear weapons, and as such, alas, it remains as urgent as ever. It had broader resonance, though, as the nuclear question was seen by many as but a single instance of man's increasingly rampaging (technological) assault on the world—the war on terra, as it were. Either way, Schell was clearly onto something fundamental in his assertion that the nuclear and environmental crises were, before anything else, crises of vision. As such, these crises made a specific call on the attentions not just of scientists and politicians but on those of writers and artists—people, that is, whose very vocation is vision.

Today, as global warming threatens being, time, presence, co-presence, tradition, posterity, dominion and stewardship, the very capacity to imagine and then originate something new—the fundamentals out of which art has always sprung—some artists have been rising to the challenge. In the notes that follow I hazard a tentative, impressionistic, admittedly idiosyncratic tour d'horizon—less an exhaustive survey than the beginnings of a stab at a typology of the way some visual artists have been addressing the crisis very much at hand.

For starters, of course, there are the artists who address the environmental issue head-on, often in the form of exhibitions with massive science fair-like wall postings, lots and lots of words, all quite earnest though in the end not terribly satisfying as art (and as a result perhaps not terribly effective as agitprop either). Sometimes the underlying project may even be quite suggestive and inspired, but the documentation would work much better as a book, say, than a white-box exhibit (see, for example, Bruce Mau's Massive Change volume, based on a touring show that was arguably the most impressive recent instance of this sort). For the purposes of this survey, however, I am simply going to bracket such pieces over to the side.

Occasionally, artists go out and literally plant fields, and the result can be startlingly evocative. I am thinking, for example, of the sublimely rustling Wheatfield Agnes Denes spread across a landfill off the edge of the rapidly developing Battery Park City in downtown Manhattan in 1982. Or the miniature representation of a wild grass prairie, recently slotted into the 2.5-acre Lurie Garden of Chicago's Millennium Park.

In this context, Chicago's Dan Peterman stands as a sort of bridging figure, a protean character who has given his whole life over to practical interventions (devising fresh ways of building with recycled materials, etc.) but at the same time flitting in and out of the gallery and academic contexts. In his recent show at the Andrea Rosen Gallery in New York City, for example, he included a full-scale 2-by-4 wood-beam frame of a mysterious structure, which turned out to be an exact elaboration of a Han Dynasty funerary object representing a combination latrine/pigsty (people ate, defecated, the pigs would eat the results, get eaten and so forth—a perfect cycle whose inclusion within a gravesite suggested its own perfect cycle). The installation was all the more telling in light of the fact that the preference of the burgeoning Chinese middle class for wood-frame rather than traditional brick construction is having a devastating effect on the world's surrounding forests (with all the macro-funerary premonitions that fact portends).

Other artists traffic in more conventional forms: silkscreens, paintings, sculptures. Thus, for example, Andy Warhol with his "Endangered Species" colored screen prints from 1983 (tree frog, panda, bald eagle and so forth)—but what subject didn't Warhol address across his promiscuously heterodox life production? Or, Alexis Rockman, across his entire career, loopily imagining and then vividly realizing wildly colorful paintings of all manner of over-fecund naturescapes, from paradisiacal jungles to infernos of industrial process. And Maya Lin, who in her most recent touring show, "Systematic Landscapes," rendered the Caspian, Red and Black seas out of Baltic birch plywood (topographically scooped-out basins hovering out into space, their bottommost depths barely kissing the supporting plinths).

Other artists have gone in for the single grand gesture, a sort of political cartoon pumped up on aesthetic steroids and writ large. For example, Chris Burden's stunning Medusa's Head of 1990, now in the collection of the Museum of Modern Art, a huge, looming, several-ton rock-and-cement planetoid, hanging like a slab of rotting meat from a ceiling chain, taking up virtually its entire room, the entire mass gagging on skeins of toy train tracks and other representations of industrialization run amok. Or, at the other extreme, the even vaster floating globe of uncannily radiating light that constituted the mesmerizing centerpiece to Olafur Eliasson's legendary installation The Weather Project in the multistory vault of the Turbine Hall of London's Tate Modern in 2004. Or the noisy black rainbow (gunpowder explosively hurled into sky across a one-minute sequence) that Cai Guo-Qiang unfurled high above a downtown park on an otherwise gleaming afternoon in Valencia, Spain, in May 2005. And then, there have been the hauntingly suggestive roomwide installations of Ann Hamilton and Tara Donovan.

Somewhat more modestly scaled, though equally compelling, have been some of the more recent efforts of the young Brooklyn artist David Opdyke: a tabletop rendition of a United States gone parch dry and given over to desert badlands; a wall piece cross-section of the geographic strata layered beneath an uninhabited bucolic scene, with one layer, deep deep down, consisting of bombs, undegraded plastics and other human detritus; and, most recently, a freestanding skyscraperscape, the soaring buildings abandoned and starting to sag and crumple under an encroaching jungle invasion.

Some projects have been engaging the global warming crisis more directly, such as photographer David Buckland's remarkable Cape Farewell enterprise, which over the past several years has taken teams of scientists, architects, choreographers, writers (Ian McEwan, Gretel Ehrlich), composers (Max Eastley), along with several artists (including Antony Gormley and Rachel Whiteread) aboard a 100-year-old Dutch schooner for weeks-long expeditions into the high, high arctic, yielding all sorts of urgent responses, including Eastley's Arctic Symphony (rendered entirely out of recorded sounds—wind and walrus, cracking iceberg, throbbing engines) and Whiteread's own icefield-like intervention in the Tate Modern's Turbine Hall last year.

Other artists, who don't seem at first glance to be engaging the issue at all, are in fact producing work that might be seen, considered more attentively, to be utterly suffused with it. David Hockney, for example, has embarked on a painterly production of achingly lyric attentiveness: hundreds of canvases portraying the passing seasons across the fragile countryside—farmland and forest, hillsides and hollows—of the beloved East Yorkshire of his youth. California artist Robert Irwin, for his part, has always shied away from explicitly political or socially themed engagement, insisting rather that his is an art of pure inquiry, trying at most, as he often says, "to get people to perceive themselves perceiving." But Dan Peterman, for example, counts Irwin as a huge influence ("I've always considered him a fundamentally ecological artist"), and Irwin himself, when I recently raised the question with him, replied, "It comes back to this question of the individual's taking his or her own responsibility, based on his or her own embeddedness, which is to say, awareness of the world. In all its dazzling complexity and immediacy and interconnectedness. In a civilization where people had been sensitized to act on that level, to be present in that way, things like global warming would be addressed immediately. They would have to be."

A final category of artistic response comes with the performative artists. People, for example, like the Yes Men, who, last May, perpetrated another of their sublimely subversive Candid Camera-like exposés of corporate America. Breaching a select conference of high-level reinsurance types considering the implications of "catastrophic loss" at a luxury retreat on Amelia Island, Florida, the performers cast themselves as representatives of a Halliburton company eager to display their latest technological innovation, "Survivaball suits"—orblike inflatable outercoverings (packed inside with all manner of gee-whiz high-tech gadgetry) that, for $100 million each, promised to keep individual corporate managers safe from the ravages of any future global warming. The conference-goers listened attentively and even volunteered to try on the clownish-looking suits. (The results, naturally, getting immediately posted to the web.)

The single best performance-art piece I ever witnessed (I describe it in detail in my Wanderer in the Perfect City collection) occurred in the context of the anti-Pershing missile mobilizations in Europe in the early 1980s, though as with Jonathan Schell's comments in The Fate of the Earth, its symbolism holds far wider pertinence. Knud Jensen, the founding director of the Louisiana Museum of Modern Art—located on a bluff a half-hour north of Copenhagen, overlooking the Oresund and in the distance, Sweden—considered it part of his curatorial responsibility to allow antinuclear activists to stage fairs and rallies on the grounds of his museum. At one point, he invited a small group of local artist-activists, the Billedstofteatr, to contrive an intervention at a Peace Festival some months off. They in turn ran ads and gathered a motley crew of some 300 volunteers (businessmen, farmers, kids, grandparents) whom they then trained intensively over several weeks. Which is how it came to pass that on the afternoon of the festival, as thousands of celebrants milled around the museum grounds, when the neighboring church bell struck six, suddenly (and at first imperceptibly), hundreds of lone individuals scattered about the grounds went stark frozen still—only, not as still as all that. Gradually (for now one did begin to notice that something strange was going on), all of them began to turn, ever so slowly toward the Sound, and then to move, trancelike, ever so haltingly, ever so slowly congealing into three groups (minutes passed like hours, and now everyone else was watching, drop-jawed, dumbfounded), which proceeded down the bluff and presently, shockingly, straight into the water, shivering, inexorable, the water finally up to their necks, in a vast appalling lemminglike processional, until at last they veered to the side, under a jetty, back landward and into a barnlike boathouse (where, this being Scandinavia, they all stripped naked and back into dry clothes, passing around drafts of warmed rum). Talk about waking people up to how they have been sleepwalking!

A similarly compelling (though entirely different) project is taking shape under the aegis of the Los Angeles-based Institute for Figuring. The institute's identical twin Australian scientist directors, Margaret and Christine Wertheim, alarmed at the sudden bleaching death of vast swaths of the Great Barrier Reef off their native Queensland (directly caused by rises in ambient water temperature, which in turn accounts for the common characterization of coral reefs as the canary in the mineshaft of global warming), have launched a mass-based art project of their own. Go to their website (www.theiff.org) to more fully gauge the remarkable confluence of mathematics, physics and biology behind the project, but suffice it to say that the best way to model non-Euclidean space is by crocheting it, and that when you do so, you get a stunning approximation of the great variety of shapes that the microscopic seaborne polyps off Queensland secrete on their own as they generate coral reefs. And so, polyplike, the Wertheim sisters are instigating fellow crocheters all over the world to start generating colorfully mottled crocheted reefs as a way of calling attention to the dire straits of their natural counterparts. The project (which is currently being highlighted, through June 17, along with the Cai Guo-Qiang, Warhol, and Yes Men instances cited above, at a fine survey show on artistic responses to global warming at the Warhol Museum in Pittsburgh) taps into the feminist handicraft revival as well—a virtual perfect storm of aesthetic confluences: all this and sly community building too!

The challenge with all this work—a challenge that artists share with every other sort of activist in this field—is how to wake people up to our desperately urgent circumstance without blowing them completely away, such that they curl back into a terrified oblivious stupor.

In this context, it might be appropriate to give the final word to the late, great Ellen Willis (how we need her, how we miss her already), words she herself penned all the way back in the early '80s. To wit: "The modernists' once-subversive refusal to be gulled or lulled has long since degenerated into a ritual despair at least as corrupt, soft-minded, and cowardly—not to say smug—as the false cheer it replaced. The terms of the dialectic have reversed: now the subversive task is to affirm an authentic post-modernist optimism that gives full weight to existent horror and possible (or probable) apocalyptic disaster, yet insists—credibly—that we can, well, overcome. The catch is that you have to be an optimist (an American?) in the first place not to dismiss such a project as insane."