must be understood here is that human economic activity is far less independent of the natural world than too many economists try to pretend. The scale of this dependence is as rarely recognized as it is hard to overstate. One of the few attempts to quantify it, an attempt to work out the replacement costs for natural services carried out a few years back by a team headed by heretical economist Robert Costanza, came up with a midrange figure equal to around three times the gross domestic product of all human economic activity on earth.7 In other words, out of every dollar of value circulating in the world’s human economies something like 75 cents were provided by natural processes rather than human labor. What’s more, most if not all of that 75 cents of value had to be there in advance for the production of the other 25 cents to be possible at all. Before you can begin farming, for example, you need to have arable soil, water and an adequate growing season, as well as more specialized natural services such as pollination. These are nonnegotiable requirements; if you don’t have them, you can’t farm. The same is true of every other kind of productive work in the human economy: Nature’s contribution comes first, and generally determines how much the human economy can produce.
The Power of Paradigms
Unfortunately, these reflections unfold from a way of thinking about the Nature of economic activity that is not shared by most people in the industrial world. The core of that way of thinking, and the focal point of the disagreements that surround it, is the issue of environmental limits. It’s no exaggeration to say that either you believe in these limits or you don’t. If you do, it seems glaringly obvious that modern industrial civilization, which depends on ever-increasing exploitation of finite and nonrenewable resources, is in deep trouble, and the only viable options are those that jettison the fantasy of perpetual growth and aim at a controlled descent to a level of energy and resource use per capita that can be sustained over the long run.
If you don’t believe in limits, by contrast, such notions are the height of folly. Since, according to this way of thinking, progress can always overcome any limit Nature might impose on human beings, it seems glaringly obvious that modern industrial civilization needs to push progress into overdrive so that it can find and deploy the innovations that will get us past today’s problems and launch our species onward toward its glorious future, whatever that happens to be.
Disbelief in environmental limits, as it happens, is far more common these days than belief in them. That’s a fascinating twist of fate, because the evidence for the power of environmental limits over human life is overwhelming. Ecologists have documented the myriad ways that environmental limits play a dominant role in shaping the destiny of every species, ours included. Historians have chronicled the fate of many civilizations that believed themselves to be destiny’s darlings, and proceeded to pave the road to collapse with their own ecological mistakes.8 From a perspective informed by these facts, the insistence that limits don’t apply to humanity is as good a case study as one might wish of that useful Greek word hubris, defined as the overweening pride of the doomed. Still, this makes it all the more intriguing that the power and relevance of environmental limits are anything but self-evident–to most people in the industrial world today.
The power of nonrational assumptions in shaping human thought was mapped out decades ago by Thomas Kuhn, whose book The Structure of Scientific Revolutions is as famous as it is rarely read. Kuhn was among the first historians of science to put the popular image of scientific progress to the test, and he found it wanting. In place of the notion that science advances toward objective truth by the accumulation of proven facts — a notion that still shapes histories of science written for popular consumption — he showed that scientific beliefs are profoundly shaped by social and cultural forces, and that the relation between scientific theory and the facts on the ground is a great deal more complex than conventional ideas allow.
Kuhn’s take on things has been misstated often enough that it probably needs a summary here. During a period of what he calls “normal science,” scientists model their work on a paradigm. This isn’t some sort of vague worldview, in the sense too often given to the word; rather, it’s a specific example of science at work, an investigation in a given field by an exemplary scientist and the successful theory resulting from that research. In bacteriology, for example, Louis Pasteur’s research program in the 1870s and 1880s, which led to the first artificial vaccines, became the paradigm that later researchers followed; good bacteriological research — in Kuhn’s terms, normal science — was research that followed Pasteur’s lead, fine-tuned his theories and asked the same kinds of questions about the same kinds of phenomena that he did.
Sooner or later, though, a mismatch opens up between the paradigm and the facts on the ground: the research methods drawn from the paradigm stop yielding good answers, and the paradigmatic theory no longer allows for successful prediction of phenomena. Scientists normally respond by pursuing the research methods with redoubled energy while making the theory more elaborate, the way that Ptolemy’s earth-centered cosmology was padded out with epicycle after epicycle to make it fit the vagaries of planetary motion. Crisis comes when the theory becomes so cumbersome that even its stoutest believers come to realize that something is irreducibly wrong, or when data emerges that no reworking of the paradigmatic theory can explain. The crisis resolves when a researcher propounds a new theory that makes sense of the confusion. That theory, and the research program that created it, then becomes the new paradigm in the field.
So far, so good. Kuhn pointed out, though, that while the new paradigm solves questions the old one could not, the reverse is often true as well: the old paradigm does things the new paradigm cannot. It’s standard practice for the new paradigm to include the value judgment that the questions the new paradigm answers are the ones that matter, and the questions the old paradigm answered better no longer count. Nor is this judgment pure propaganda; since the questions the new paradigm answers are generally the ones that researchers have been wrestling with for decades or centuries, they look more important than details that have been comfortably settled since time out of mind. They may also be more important, in every meaningful sense, if they allow practical problems to be solved that the old paradigm left insoluble.
Yet the result of that value judgment, Kuhn argued, is the false impression that science progresses by replacing false beliefs with more true ones, and thus gradually advances on the truth. He argued that different paradigms are not attempts to answer the same questions, differing in their level of accuracy, but attempts to answer entirely different questions — or, to put it another way, they are models that highlight different features of a complex reality, and cannot be reduced to one another. Thus, for example, Ptolemaic astronomy isn’t wrong, just useful for different purposes than Copernican astronomy; if you want to know how the movements of the planets appear when seen from Earth — for the purposes of navigating a boat by the stars, for example — the Ptolemaic approach is still a better way to go about things.
These same considerations sprawl outside the limits of the sciences to define the rise and fall of paradigms in the entire range of human social phenomena. The difference between the believers and the disbelievers in limits is a difference in paradigms. Those who believe that modern industrial society is destined for, or capable of, unlimited economic expansion have drawn their paradigm from the Industrial Revolution and its three-century aftermath, with James Watt and his steam engine playing roughly the same role that Louis Pasteur played in the old paradigm of bacteriology. Like any other paradigm, the Industrial Revolution defines certain questions and issues as important and dismisses others from serious consideration.
This is where the problems arise, because a solid case can be made that some of the questions dismissed from consideration by the “normal culture” of industrial expansion are those our species most needs to face just now, as the depletion of fossil fuel reserves and the soaring costs of environmental damage become central facts of our contemporary experience. The industrial paradigm can only interpret running out of one resource as a call to begin exploiting some even richer one. If there is no richer one, and even the poorer ones are rapidly being depleted as well, what then? From within the industrial paradigm, that question cannot even be formulated; the assumption that there is always some new and better resource to be had is hardwired into it.
Thus the current predicament of industrial society demands a change of paradigms. The belief in limits