An excerpt from

The Middle Path

Avoiding Environmental Catastrophe

Eric Lambin


Observe the tightrope walker: always in motion, searching for the balance that he never quite achieves. Each momentary imbalance is corrected by assuming a new, unstable position: only by moving forward can he remain on the tightrope and avoid falling. He constantly modifies his movements, subtly, instantaneously, concentrating his attention on the next hint of danger, and reacting at once by a proportionate adjustment of posture.

Thus, too, the earth: constantly changing, forever far from equilibrium, adjusting by means of subtle mechanisms to every momentary reconfiguration of its physical and biogeochemical state in order to preserve its viability. The great climatic cycles, biological evolution, and the natural changes of the landscape are all part of the earth’s repertoire of balancing movements that keep it on its own tightrope.

Imagine now that our planetary tightrope walker carries on his shoulder a small, boisterous monkey that fidgets and turns in every direction without having the least notion of the difficulty of the task facing its host. So long as the monkey does not weigh very much, and so long as its movements are not too abrupt, the tightrope walker easily corrects for this additional source of instability. Over the course of the twentieth century, however, the monkey grew in size, until its weight was nearly equal to that of the tightrope walker himself. It acquired the ability to make sudden, highly destabilizing movements. Indeed, its impact on the chemical composition of the atmosphere, the earth’s plant cover, the structure of the landscape, and the abundance of animal and vegetable species increased to the point that human activity today exerts as much influence on the planet as natural forces do.

If the monkey continues to jump around as though it were on firm ground, the fall of the tightrope walker—and of the monkey—is inevitable. In that case a worldwide environmental catastrophe will occur, with grave, if unpredictable, consequences for humanity. But if the monkey learns to coordinate its movements with those of the tightrope walker, even helping him to anticipate and correct successive moments of disequilibrium, they will continue to advance along the tightrope without accident. The future of the monkey and the tightrope walker therefore depends on the monkey’s intelligence.

The Issues

From the beginning, mankind has been influenced by its natural environment and has acted upon it. The process of biological evolution that led to Homo sapiens is the result of successive adaptations to environmental conditions, often difficult ones. The earliest forms of social organization and mastery of the first tools were likewise a response to the challenges posed by the environment to our ancestors. The colonization of the planet by the human race was itself possible only by means of a series of adaptations to changing climatic conditions and to resources whose supply and availability varied over time and from one region to another.

The discovery by mankind that it was capable not only of adapting to nature, but also of transforming it, represents an important stage in the history of the planet. Fire was the first tool used to modify the earth’s plant cover on a large scale. The progressive domestication of animal and plant species increased the supply of food. Irrigation and drainage made it possible to control the supply of water, freeing agriculture at least to some extent from the vagaries of the weather.

Early on in human history, this new power proved to be a mixed blessing. The extinction of many species of large mammals in North America ten to twelve thousand years ago may have been caused in part by excessive hunting during the first human colonization of the New World (climatic changes at the end of the last ice age played a role as well). Similarly, some civilizations degraded the land they had placed under cultivation, either through excessive irrigation, which caused a salt layer to form that sterilized the soil (as in the case of Mesopotamia between 2400 and 1700 b.c.), or through excessive harvesting of wood for construction and cooking, which, by stripping away the plant cover, eroded the soil (as in the case of the Indus Valley around 1800 b.c., the loess plateaus of China from an even earlier period, in Ethiopia around 1000 b.c., in Greece around 600 b.c., and a few centuries later in Italy, as well as in the southwestern part of the North American continent, on the lands of the Anasazi and Hohokam societies, about 600û900 a.d. and 1100û1375 a.d., respectively).

Some civilizations, however, were able to avoid environmental degradation. Consider the extraordinary longevity—almost five thousand years—of ancient Egyptian civilization, whose agriculture was well adapted to the ecological conditions that prevailed along the Nile. The Egyptians managed to maintain an equilibrium between the seasonal rise and fall of the river, without disrupting the Nile’s deposit of sediments on cultivated land in the floodplain.

The question facing mankind today is whether it will be able to go on improving its standard of living while at the same time maintaining a delicate balance between human activities and the natural world. Recent data from the natural and social sciences, supported by careful observation of current developments, furnish us with a rigorous basis for deciding whether we should be pessimists or optimists concerning the future of our planet, and therefore of humanity, without regard for ideology, blind guesswork, existential anxiety, or regret at the loss of some part of the world’s original beauty. Our approach must be multidisciplinary and open to arguments on all sides, for whatever answer we finally arrive at, it cannot help but be a qualified one.

What Do the Optimists Say?

Optimists are convinced that technological progress will make it possible to go on coping indefinitely with the ecological challenges facing humanity. They base their conviction on the extraordinary success of technologies developed during the twentieth century, whose contribution to the health and welfare of mankind no one could have predicted a few centuries ago. They entertain no doubt that this progress will continue in the coming centuries, or that mankind’s mastery of nature will continually increase. Optimists are convinced, for example, that biotechnological research sponsored by large private companies will solve all future problems of food supply. They predict that, thanks to new production technologies, the demand for agricultural land will decline and the area occupied by forest will grow in the course of the twenty-first century. Mankind, they confidently assert, will manage to improve the environment while at the same time raising its standard of living. They do not fear unintended or unpredictable consequences, for they conceive of the earth as a robust system within which change is gradual, linear, and uncomplicated by major disruptions.

Optimists furthermore suppose that all change is reversible. If humanity should find itself heading down a dead-end street, it has only to turn around and explore other avenues of development. Underlying this view is the conviction that humanity has the ability, if not also the duty, to dominate nature, whose purpose is to assist mankind’s rise toward ever-higher levels of civilization. Natural resources are placed at our disposal, without constraint, obligation, or condition.

Optimists have unlimited faith in the mechanisms of the market, whose self-regulating power they believe is capable of correcting imbalances as they arise and of producing the most efficient possible use of resources. Each person is able to pursue his or her own personal interest, since competition for scarce resources within a market framework leads to a convergence between the individual good and the common good for both present and future generations: when a resource becomes less plentiful, its price rises, prompting users to search for substitutes before the resource is irremediably exhausted or degraded. Optimists are convinced that progress in the environmental domain is spontaneous and owes nothing to guidance by national or international bodies. They regard governmental intervention as a source of interference with the proper functioning of markets. Moreover, if a new technology poses risks for health or the environment, these risks are probably less serious than the ones that the technology makes it possible to avoid.

Optimists are fond of reminding pessimists that the population of the world today considerably exceeds the alarmist predictions of the past one hundred and fifty years, and that imminent famines (regularly forecast to occur until the 1970s) have failed to materialize: between 1960 and 1995, world food production almost doubled (197 percent) while total population increased by 188 percent. And if famines persist in certain parts of the world, they are due mainly to civil wars and the disastrous management of agriculture. Optimists find confirmation of their views in the continual decrease, for a century now, in the extraction cost and market price of many natural resources—proof, they contend, that these resources are becoming ever more abundant.

Looking back upon the extraordinary technological and economic development of the twentieth century, and its rapid diffusion from Western countries to the rest of the world, optimists are persuaded that the surest way to protect the environment in the future is to promote rapid economic growth by reducing the intervention of the state in the management of natural resources, thus freeing markets to a still greater degree. Some even advocate the privatization of resources such as water and wild fauna. Private ownership of these environmental goods, they maintain, would reveal their true value by subjecting them to market forces: if this value is high, the market will react by protecting them and by developing substitutes. Optimists note with satisfaction that every generation commits the error of underestimating the number of new ideas yet to be conceived.

The first great optimist was a Frenchman in the late eighteenth century, the Marquis de Condorcet, who firmly believed in the perfectibility of human nature. Imbued with the spirit of the Enlightenment, Condorcet placed his faith in the capacity of the human mind to overcome any and all obstacles that stand in the way of the progress of mankind.

What Do the Pessimists Say?

Pessimists are persuaded that there exist inherent limits to technological progress and that, because it cannot keep on growing at its current pace indefinitely, technology will never be able to free mankind entirely from its fundamental dependence on natural resources. It is therefore necessary in their view to preserve nature’s capacity to generate those goods and services that are indispensable for human development. They believe, moreover, that technological development obeys the law of diminishing returns: discovering new technologies that promise to substantially increase the supply of natural resources will become more and more difficult, with each discovery being more costly than the last, while yielding ever-smaller gains in productivity.

Pessimists are more concerned with changes in the stock of natural resources than with changes in the amount of goods produced using these resources. Whereas optimists see the continuous increase in the exploitation of natural resources as proof that these resources will go on being ever more abundant and ever less expensive, pessimists fear that an uncontrolled increase in the rate of extraction draws humanity nearer to the moment when these stocks will be exhausted, not only in the case of nonrenewable resources (such as oil) but also of renewable resources where the rate of exploitation exceeds the rate of natural regeneration.

Pessimists regard nature as a vast complex adaptive system whose evolution is not bound to follow a progressive and continuous trajectory. In their view, the possibility that surprises may occur, some with potentially catastrophic consequences, cannot be excluded. Consider, for example, the seasonal thinning of the ozone layer above the Antarctic. If bromofluorocarbons had been used, rather than chlorofluorocarbons, as refrigerant gases by industry from the 1930s onward, human health would have paid a heavy toll, for the destructive power of bromine on the ozone of the stratosphere is one hundred times greater than that of chlorine. It was only by chance—the relative properties of the two gases having been unknown when chlorofluorocarbons were first introduced for industrial purposes—that mankind escaped a major ecological catastrophe. The Dutch chemist Paul Crutzen, a Nobel laureate, points out that the use of bromofluorocarbons would have led not merely to a seasonal reduction in the concentration of stratospheric ozone (which filters out the dangerous ultraviolet rays of the sun) over an uninhabited part of the earth (the Antarctic), but to a permanent and worldwide reduction, with far-reaching consequences in the form of skin cancers and cataracts. The question arises whether such luck can reasonably be expected to continue indefinitely in the future.

Pessimists consider that certain changes caused by mankind to natural systems are irreversible. Humanity, they argue, cannot allow itself the luxury of conducting possibly fatal experiments with the earth, for it is the only one we have. Poor environmental management is liable to so profoundly degrade natural resources that the earth’s ability to provide services essential to human welfare would be permanently impaired. What would happen, for example, if excessive use of pesticides were to diminish insect populations to the point that the natural pollination of crops and fruit trees no longer occurred? Few countries in the world would be able to imitate the example of China, where peasants in Maoxian County pollinate every flower of every apple tree by hand. Pessimists therefore advocate what is known as the precautionary principle: if a risk of adverse effects on human health or the environment can plausibly be demonstrated, controls should be instituted even if the relevant cause-and-effect relationships are not fully understood.

Pessimists see progress as consisting not in economic growth and technological change, but rather in social development. In their view, humanity has a duty to promote cooperation among individuals, in order to maximize the common good, and to place technology in the service of humanity (rather than the other way around). It has an obligation to encourage innovation that favors development without degrading the natural environment and to regulate the behavior of the market in the interest of protecting the common good over the long term.

Pessimists point with particular alarm to the collapse of ancient civilizations that degraded their natural resources to the point that a critical threshold was irreversibly crossed, without anyone having perceived the scale or the immediacy of the danger in these societies beforehand, despite their often considerable technological sophistication.

The first great pessimist was the Reverend Thomas Malthus, who at the end of the eighteenth century predicted that famine, disease, and war would follow upon an increase in human population that outpaced the increase in food production. Pessimists are convinced that if the ecological disasters predicted over the last few centuries have not occurred, it is owing to their warnings and to advances in environmental science, which have led to better management of natural resources. The accuracy of such predictions is to be measured, then, by a society’s ability to prevent them from coming true.

Questions for the Future

Must we therefore listen to Cassandra, or can we go on believing the myth of the horn of plenty? The current environmental debate, in opposing the descendants of Malthus to those of Condorcet, bears upon three distinct issues: the magnitude of the changes to which the earth has been subjected; the causes of these changes; and the vulnerability of human societies as a result of these changes.

The first question is one of measurement and requires that objective data be assembled concerning physical, biological, and chemical changes. Substantial progress has been made in this connection. Although uncertainty persists with regard to the exact extent of certain changes (desertification, for example), only a biased and intellectually dishonest interpretation of the factual record would lead one to deny the existence of major environmental changes over the past three hundred years.

The second question is whether observed changes are to be attributed to human or natural factors, or to a combination of the two. The justice of ascribing most recent environmental changes to human activity, at least in part, can no longer be seriously disputed. However, the precise mechanisms that lead a society to degrade or improve its environment are not well understood in all cases, and simplistic notions continue to enjoy currency.

The third question, having to do with the vulnerability of human societies in the face of environmental change, is still more complicated than the two preceding ones, in part because it lends itself to arguments that are based on a great many assumptions and influenced by highly subjective assessments of the place of mankind in the world. These arguments are sometimes extremist, often ideologically motivated, and rarely supported by reliable scientific information. Much of the evidence adduced is anecdotal in character, fails to give an adequate picture of the global situation, and covers insufficiently long periods of time. Yet objective information is readily available. Since the early 1970s, for example, earth observation satellites have furnished data about the state of vegetation, soils, coastal areas, the atmosphere, oceans, and glaciers that, in combination with other findings, make it possible to detect specific environmental tendencies in each geographic zone.

The current debate must go beyond a simple discussion of recent environmental trends, however, and seek to analyze their implications for the future of humanity. Ultimately, the issue is whether mankind can continue pursuing its current mode of development indefinitely. The various parties to the debate defend radically opposed points of view depending on the place they occupy in society, whether they see themselves as winners or losers, and whether the consequences are short term or long term. It is hardly surprising, for example, that representatives of the petroleum industry should not hold the same view of global warming—caused in part by emissions of carbon dioxide that their own activities generate—than an inhabitant of an island in the Pacific Ocean who fears seeing his home submerged as a consequence of a rise in the level of the sea. Similarly, the perspective of business executives and political leaders who pursue short-term economic and social agendas is apt to differ from that of environmental activists who are committed to the defense of certain threatened animal species, indigenous cultures, or the welfare of future generations.

In the pages that follow, I shall try to examine the main issues of this debate in a clear and evenhanded manner. I begin by presenting a summary of data regarding the impact of human activity on the natural environment in recent centuries that cannot easily be challenged. I then go on, in the second chapter, to review the ways in which interactions between human activity and the environment have been conceived in the history of Western scientific thought.

The third chapter presents a few simple models that make it possible to identify the key factors shaping the environmental impact of human societies. The fourth chapter seeks to go beyond the somewhat unrealistic simplicity of these models by inquiring into the fundamental causes of the environmental changes caused by mankind. The fifth chapter looks at two contrasting historical situations: an ancient society that collapsed as a result of degrading its environment (the Maya of the classic period) and several modern societies that have succeeded in improving their natural environment after a period of rapid environmental degradation (certain European countries during the eighteenth and nineteenth centuries). The sixth chapter considers the desertification of Sahelian Africa in order to illustrate the importance of having a thorough understanding of the nature of environmental changes and the need to be able to properly characterize them in all their complexity. The final chapter reviews contemporary developments in Western societies with regard to the direction of technological, institutional, and cultural changes that suggest a reversal of current environmental tendencies is not impossible.

By way of conclusion, I lay out my own views regarding the mode of economic development that will need to be followed if a major ecological crisis is to be avoided, and I propose a number of things that individuals can do in their daily lives that would make a difference.

A Mixed Outlook

This work is the bearer of both good and bad news. The bad news is that mankind has so profoundly transformed the earth that nature’s ability to produce the goods and services that are essential for human life (fertile soils protected against erosion; potable water; clean air; a diversity of genetic resources permitting the development of pharmaceutical and agricultural products; ample supplies of fish, game, and fuel; protection against flood; climatic stability; the natural beauty that nourishes the spiritual, aesthetic, and symbolic life of human societies; and so on) is gravely threatened—to the point that the response of the natural environment to further escalation of human pressures upon it has become unpredictable. Humanity is no longer immune to bad environmental surprises. The pessimists are right, then, in insisting that humanity is following a trajectory of development today that cannot long be sustained.

The good news is that mankind has given proof throughout its history of a great capacity to adapt to changes in its environment. Human creativity is, it is true, a powerful source of innovation. By modifying technologies, institutions, and attitudes toward nature, it holds out hope that the pressures exerted by human activity on the environment can be eased before it is too late. The optimists are therefore also right in claiming that innovation makes it possible to prevent changes in the natural environment from threatening the future of humanity.

But innovation on the scale necessary to redress the balance of human activity and natural processes will not occur spontaneously. It will require major social and economic reforms over a period of several decades.

In the past, human adaptation to natural changes occurred only when societies perceived no other choice. Today, given the global extent of environmental change, the inertia of natural and social systems, and the growing complexity of the international economic system, human activity must be adjusted in a deliberate and planned manner before critical thresholds are reached. A general awareness of the risks we face, leading to a rapid and effective response by means of appropriate policies, is indispensable if we are to regain a sustainable course of development. Looking to the long term, we can be optimistic only on the condition that pessimism helps us in the short term to change the world in which we presently live.


Eric Lambin
The Middle Path: Avoiding Environmental Catastrophe
Translated by M. B. DeBevoise
©2007, 208 pages, 7 line drawings
Cloth $25.00 ISBN: 978-0-226-46853-2 (ISBN-10: 0-226-46853-4)

For information on purchasing the book—from bookstores or here online—please go to the webpage for The Middle Path.

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