G iven the environmental movement’s recent vitality–Al Gore’s Nobel Peace Prize is only the latest sign of robust health–Gregg Easterbrook, in his review of Michael Shellenberger and Ted Nordhaus’s Break Through, is wise to tip-toe around the authors’ notoriously false prophesy that environmentalism has outlived its usefulness in the face of global warming, and that it should thus quietly limp off and "die" ["Green Day," Issue #6]. Beyond that, though, the authors and reviewer are largely in agreement about what is wrong with the movement, of which I’m a proud part. Several of their shared criticisms are grounded in truth, and longtime environmentalists would be remiss in ignoring them. But the authors and their reviewer couldn’t be more off-base in their rejection of modern environmentalism’s core values.

At the root of the trio’s philosophical shortsightedness is their relentless anthropocentrism. For them, the rest of the biosphere is important only if it instrumentally assists human beings. Easterbrook favorably quotes his compatriots saying that a pristine fjord and a street corner in Brooklyn are both "good." True, but it’s good for different inhabitants–a Brooklyn street corner is a good place for a grackle or a hot dog vendor, but a bad place for a walrus or an Inuit subsistence hunter. The importance that environmentalism attaches to retaining the entire biosphere, with all its myriad moving parts, is anathema to them. As a line from Break Through, quoted in Easterbrook’s review, puts it, "Whether we like it or not, human beings have become the meaning of the earth." It is not surprising, then, that the three also abominate the environmental value of humility. "Human alteration of nature is nothing to be squeamish about," says Easterbrook, "since nature continuously alters itself, whether we act or not." Yet while all three proudly embrace their own hubris, none offers any substantive rebuttal to the environmentalist’s analysis that perhaps we are not wise enough to make a good job of becoming "the meaning of the earth."

Such hubris leads them to sidestep challenges to the fundamental premise of their argument. They concede that global warming happened as a result of humanity’s desire to transform the world; Shellenberger and Nordhaus at least seem very worried that we may not fix it in time. Easterbrook, for his part, has reported in the New Republic that, since the Jimmy Carter years, he has watched as the United States has continued its "energy policy status quo" and with it reaped the consequences of "constantly rising oil prices, as well as endless wars and entanglements with dictators in the Persian Gulf." But the dangers of global warming, and the increasing bloodiness of the global oil business, don’t lead them to question their position or add any nuance to it–or to question whether an anthropocentric relationship between humanity and the natural world might not be the best solution to the problem.

Indeed, while humans alter nature in ways that are not at all helpful to our long-term survival, Easterbrook, Shellenberger, and Nordhaus fall back on an overly simplistic, two-word argument: Optimism sells. Break Through cites extensively from public opinion data to argue, persuasively, that the environmental movement emerged in the 1960s not from an increase in the severity of pollution but from the relatively positive economic and political circumstances of the day. "Optimism, not doomsday talk, is what will motivate average people to support additional environmental reforms," Easterbrook concludes.

The point is well-taken. Optimism is necessary to motivate people, even in a crisis. Immiseration theory is wrong. Reform emerges from progress, not collapse; vision is necessary to move people off the status quo. But if optimism sells, change requires a tough-mindedness that our trio cannot stomach. Churchill was an optimist–but rather than professing to bring back "peace for our time," a la Chamberlain, he gave Britain a charge that was both rousing and realistic: "We shall fight on the beaches, we shall fight on the landing grounds, we shall fight in the fields and in the streets, we shall fight in the hills; we shall never surrender." This is environmentalism’s challenge: to look forward, to offer vision, to identify solutions, but to do so in an ecological and connected framework of tough-minded optimism, neither gloom-and-doom nor complacent. A rallying cry of "optimism!" that fails to include a realistic assessment of the challenges ahead is not rigorous enough to sustain the incredible tests our planet and our people will endure.

Environmentalism remains a key strand in any long-term progressive vision, because it champions an essential truth: There is only one ozone layer, only one global carbon cycle, and only one biosphere. These commons, the great collective inheritance of humanity, is the strongest argument for progressive politics in an age unlike any other in human history. For the first time, more than half of the world’s people live in societies that have mastered the art of rapid and sustained economic growth. The world’s oceans, lakes, rivers, forests, and grasslands–the biological commons that humanity exploited in previous eras of rapid economic growth–are either fully spent or so badly mismanaged that they produce less with each passing year. Consequently, there is no underutilized ecological frontier to be seized by China or India as there was for Britain, America, or even post–World War II Japan. Above all else, the climate is changing, and humanity’s most hard-wired mental map–the link between a place and its climate–is now contingent and uncertain.

These immense shifts underway across the globe make the task of environmentalism in the twenty-first century utterly unlike that which we undertook in the twentieth. For a hundred years, those who called themselves conservationists and then environmentalists defined our task as being to constrain, and clean up after, the existing industrial order. For the next hundred years, our task will be to design the very social and political contexts within which new technologies are deployed, so that the new economic order which will inevitably emerge is both sustainable and inclusive.