If we found environmentalists and their opponents scattered randomly along the conventional spectrum of political ideologies running from left to right, there would be little point in asking how the two realms of beliefs—call them earthviews and worldviews—are related. But the question does arise, for support for green causes and measures today is far from being randomly distributed; it clusters on the left and resistance to it on the right. The American members of Congress rated most highly by environmental organizations enjoy equally high ratings from liberal watchdog groups and low ones from their conservative counterparts. Green parties in Europe have gained most of their support, formed most of their alliances, and staked out most of their positions on the left; they have incurred the most animosity from the right.1 The rule has its exceptions and anomalies, to be sure, which include a certain number of avowed conservative environmentalists, Marxist, and populist critiques of a neo-Malthusianism focused on the dangers of population growth, and challenges to some of the priorities of mainstream green organizations by the environmental justice movement.2 It holds generally true nonetheless. “Environmental and natural-resource doomsayers,” the conservative American jurist Richard Posner wrote in 2001, “are invariably leftists.” “Ever since the environment was put on the global agenda some four decades ago,” two Canadian political scientists have summed up the matter, “the left has attributed more importance to this issue than the right … the main cleavage places environmentalists on the left and their opponents on the right.”3
No one, I suppose, would argue that the pattern exists by mere chance. There must, then, be reasons for it. Evidently, something about the political ideologies of the contemporary left and right makes the former more sympathetic to environmental concerns than the latter. That such a difference exists may seem to be cause for dismay. Why, it might be asked, should one’s beliefs about politics or society affect what—or whom—one believes about the relation of the physical, chemical, and biological processes of the earth’s surface to the survival and well-being of its human population? How could they do anything but confuse and distort it? But in practice, however things ought to be in principle, they appear not to be irrelevant after all. In some way or another, most people’s environmental beliefs are not merely scientific but political. Why they display the politics that they do is worth trying to clarify.
One can approach this question in several ways. One, with which I begin, is to inquire into the logic of today’s divide and ask why concern about human impact on the earth should be so much greater on the left than on the right. Another, to which I devote the rest of the book, is to see whether the same alignments existed in earlier times as well. Answering the second question may help in arriving at or verifying an answer to the first. If there is some necessary and inherent logic to today’s pattern, one would expect to find it stable over the course of history. If one did not find it so, substantially different explanations would be in order.
Some key terms require definition at the outset. First of all, what is environmentalism? I use the word to denote a commitment to several core beliefs: the irreplaceability of the natural world, in its basic contours, as a human home and the danger that excessive human pressures will disrupt its essential functions. The French ecologist and green activist Antoine Waechter spoke of the need for humankind “to place limits on its own expansion and on its own power” rather than suicidally seek to “push ever farther the bounds of human mastery.” The American ecologist and green activist Barry Commoner wrote that the “ecosphere,” “the home that life has built for itself on the planet’s outer surface,” “sustains people and everything that they do,” but that human activities disharmonious with its workings have left it “so heavily strained that its continued stability is threatened” and it “is being driven towards collapse.” More succinctly still, he proposed the axiom “nature knows best” as a basic statement of the essential green position. Aldo Leopold likewise proposed that an act is good if it helps to maintain, and bad if it undermines, the existing ecosystem: the assemblages of plant and animal life and the conditions of climate, water, terrain, soil, and material and energy flow on which they—and ultimately we—depend. In the formulation of the French green philosopher Michel Serres, “we have become so much and so little masters of the Earth that it once again threatens to master us in turn,” human dominance of the environment being a mirage and a dangerous one. Serres proposed a “natural contract” by analogy to the “social contract,” replacing human efforts to subordinate the earth with a relation of harmonious coexistence as essential to society’s own survival.4
On this view, the structure and processes of the environment as it is and as it has been possess a logic that may not always be evident but that should always be presumed. Human action that substantially alters them, whether on purpose or not, therefore carries a strong potential for harm, not least to human beings themselves. Environmentalists see the biophysical world as an immensely complex network of complex ecosystems, one whose present state reflects a long process of development through their internal and mutual adjustment. Any component of the environment may play key roles, some of them far from obvious, in maintaining the narrow range of conditions that make the earth’s surface a livable habitat for human beings. Therefore, further alterations in the environment or further increases in society’s demands (enormous already in their magnitude and scope) are apt to disrupt it, and the more dangerously the more novel, sudden, drastic, profound, and far-reaching they are. What I call environmentalism corresponds closely to what the American political scientist Paul Wapner has described as “naturalism” or “the dream of naturalism,” which, in his words, “recommends that we align ourselves with, rather than impose ourselves on, the natural world”—and as much for our own good as for its.5
A statement like Commoner’s “nature knows best” is an extreme one, and meant to provoke. No one follows it as if it were absolutely and literally true. And as many writers have emphasized, environmentalists have often exaggerated the balance and equilibrium of earth systems even when largely undisturbed by human actions and ignored the fact that there is no single stable natural condition that we can use as a standard and seek to maintain or return to.6 Those who assert nature’s wisdom are, rather, issuing admonitions to stop and think before acting. They are warning that there is much about the environment that even scientific experts do not know—and, in a phrasing that has lately come into currency, cannot ever fully know—save only for a few general truths: that it is complex in its workings, though finite in its bounty, and that we cannot survive as a species if we change it too much. To suppose that “people know best,” they imply, is dangerous hubris too easily indulged in, for many changes that seem obviously improvements may well turn out to be the opposite. We should, therefore, restrain and limit our impacts, deliberate as well as inadvertent, as much as we can. What some now call “the end of nature” and others the advent of the “Anthropocene” does not fatally undermine the environmentalist credo. That human action has now profoundly altered much of the face and functioning of the planet, leaving little that can be called “nature” in the strictest senses of the word, is not, to environmentalists, any reason why still further and deeper change from the present state of the earth should be accepted. Indeed, it is a strong reason why such change is more than ever to be feared.7 That rational management and domestication of the earth can make the era of human domination the “good Anthropocene” that some writers now envision, environmentalists regard as a dangerous delusion.
Thus one of the major themes of modern environmentalism is that of the unexpected and usually unwelcome consequences of human actions. (I am speaking here, and from now on, of anthropocentric environmentalism, or that form that frankly aims to secure the survival and well-being of human beings and of elements of their surroundings that they value; ecocentric forms of environmentalism add the rights of non-human entities.) In the language of systems theory, the environment is pervaded by feedback loops. In meddling with it at one point, we may unwittingly set some of them in motion and produce results quite unlike those that we expected. Simple prudence, then, should make us limit the extent, depth, and speed of our interference as much as we reasonably can and undertake novel kinds of changes only with great reluctance. By no accident, “ecology,” strictly speaking the name of a branch of natural science, has in ordinary usage become a synonym for environmentalism, which sees the interactions and complexities that it studies as crucially important. The Great Books of modern environmentalism rest much of their case on the unintended-consequences argument. Rachel Carson’s Silent Spring (1962) painted a horrific picture of the side effects on non-targeted species, people among them, produced by the unfettered spraying of long-lived synthetic chemical pesticides. Those who used so powerful a tool so extensively for the single purpose of destroying unwanted insects, Carson wrote, ignored the reality that the natural world was one “of ecology, of interrelationships, of interdependence.” “We are accustomed to look for the gross and immediate effect and to ignore all else,” she observed, but in such a complex world much else would always occur. She approvingly quoted a Dutch scientist to the effect that in our careless use of new technologies “we are walking in nature like an elephant in a china closet.” Aldo Leopold warned to similar effect that “all land-use technologies … are encountering unexpected and baffling obstacles which show clearly that despite the superficial advances in technique, we do not yet understand and cannot yet control the long-time interrelations of animals, plants, and mother earth” (emphasis in the original).7 The German green philosopher Hans Jonas decried a technological hubris that increasingly risked “setting the whole system of countless and delicate balances adrift toward catastrophe” by ignorantly disturbing ever more of them. “So long as we have not attained certainty of prediction,” he continued, “and especially in view of the likely irreversibility of some of the initiated processes … caution is the better part of bravery.”8 Such reasoning underlies the “precautionary principle,” which has been particularly influential in western Europe, calling for curbs on possibly harmful human actions even when proof that they will cause harm is not yet available.
A second and related theme of modern environmentalism is one of scale: the unsustainable magnitude of human demands on the earth’s finite resources and the urgent need to restrain and eventually to reduce them. Thomas Robert Malthus remains an intellectual hero to many environmentalists for having emphasized, as early as 1798, the physical limits to the land’s capacity for producing food.9 His successors have extended his argument to other natural resources and to the “natural services” provided by the processes that maintain such background conditions as a stable climate and atmospheric composition necessary for life to continue. Humankind, the ecologists Paul and Anne Ehrlich warned, “is living largely on capital,” the accumulated and exhaustible stocks of material, energy, and life-support that its actions are dissipating. The lesson they drew was the need “to reduce the scale of human activity.”10 The biosphere, neo-Malthusian environmentalists argue, the zone of the earth’s surface within which alone human beings can live, is a system of a given size, capable of tolerating only certain levels of stress and alteration and subject to abrupt change—which would be catastrophic for civilization—if our demands exceed its limits. Its sustainable “carrying capacity” for human numbers and demands may be transgressed in the short run, but only at the price of disaster to follow. If Carson’s book effectively dramatized the danger of unintended consequences, the collaborative study The Limits to Growth (1972) did as much, not least in its very title, to disseminate concerns about the finite capacity of the planet’s systems to support consumption by rising human numbers and absorb and assimilate the wastes emitted by their activities. Modeling a number of possible pathways for world society under continued rapid growth, The Limits to Growth painted bleak pictures of overshoot and collapse, differing only in the immediate cause of catastrophe. Sometimes it was the exhaustion of nonrenewable resources, sometimes excessive pollution, sometimes the failure of agriculture to keep up with the demand for food. In the same year that The Limits to Growth saw print, a team of British ecologists published a similar manifesto entitled A Blueprint for Survival. Society’s large and rising resource demands, pollution emissions, and conversion of land for direct human use, it warned, menaced humankind’s very existence by overloading the capacity of earth systems to continue their essential functioning.11 These concerns find expression in the present-day currency of such terms as sustainability and ecological footprints.
Some environmentalists offer a third argument for restraining the human alteration of the earth’s surface. As well as being the only habitat in which we can biologically exist, they argue, it is the only one in which we can psychologically flourish, as the one in which we ourselves developed as a species. Human beings have deep-rooted needs, whether affective, aesthetic, cognitive, or spiritual, that an environment too much tamed and transformed from its natural state can no longer satisfy. The ecologist Hugh Iltis in 1974 reacted vehemently to the suggestion by an urban planner that plastic trees might more effectively provide many of the benefits of live ones. “There can never be a healthy humanity, both physically and socially,” Iltis wrote, “without its ancient evolutionary and ecological basis.” Edward O. Wilson’s suggestion that “biophilia,” or an affini...