from PropagandaMatrix Website
Abstract established by Eduard Pestel
Our world model was built specifically to investigate five major trends of global concern - accelerating industrialization, rapid population growth, widespread malnutrition, depletion of nonrenewable resources, and a deteriorating environment.
The model we have constructed is, like every model, imperfect, oversimplified, and unfinished.
Furthermore, the basic behavior modes we have already observed in this model appear to be so fundamental and general that we do not expect our broad conclusions to be substantially altered by further revisions.
If the world’s people decide to strive for this second outcome rather than the first, the sooner they begin working to attain it, the greater will be their chances of success.
The method is called System Dynamics. The basis of the method is the recognition that the structure of any system - the many circular, interlocking, sometimes time-delayed relationships among its components - is often just as important in determining its behavior as the individual components themselves.
The world model described in this book is a System Dynamics model Extrapolation of present trends is a time-honored way of looking into the future, especially the very near future, and especially if the quantity being considered is not much influenced by other trends that are occurring elsewhere in the system. Of course, none of the five factors we are examining here is independent.
Furthermore, over long time periods each of these factors also feeds back to influence itself.
In this first simple world model, we
are interested only in the broad behavior modes of the
population-capital system. By behavior modes we mean the tendencies
of the variables in the system (population or pollution, for
example) to change as time progresses.
A major purpose in constructing the world model has been to determine which, if any, of these behavior modes will be most characteristic of the world system as it reaches the limits to growth. This process of determining behavior modes is “prediction” only in the most limited sense of the word.
We include only one class of pollutants - the long-lived, globally distributed family of pollutants, such as lead, mercury, asbestos, and stable pesticides and radioisotopes - whose dynamic behavior in the ecosystem we are beginning to understand.
We plot one generalized resource that represents the combined reserves of all nonrenewable resources, although we know that each separate resource will follow the general dynamic pattern at its own specific level and rate.
From 1900 to 1970 the variables agree generally with their historical value to the extent that we know them. Population rises from 1.6 billion in 1900 to 3.5 billion in 1970. Although the birth rate declines gradually, the death rate falls more quickly, especially after 1940, and the rate of population growth increases. Industrial output, food and services per capita increase exponentially.
The resource base in 1970 is still about 95 percent of its 1900 value, but it declines dramatically thereafter, as population and industrial output continue to grow.
In this run the collapse occurs because of nonrenewable resource depletion.
Population finally decreases when the death rate is driven upward by lack of food and health services.
The exact timing of these events is not meaningful, given the great aggregation and many uncertainties in the model. It is significant, however, that growth is stopped well before the year 2100.
We have tried in every doubtful case to make the most optimistic estimate of unknown quantities, and we have also ignored discontinuous events such as wars or epidemics, which might act to bring an end to growth even sooner than our model would indicate.
In other words, the model is biased to allow growth to continue longer than it probably can continue in the real world. We can thus say with some confidence that, under the assumption of no major change in the present system, population and industrial growth will certainly stop within the next century, at the latest.
The larger industrial plant releases pollution at such a rate, however, that the environmental pollution absorption mechanisms become saturated. Pollution rises very rapidly, causing an immediate increase in the death rate and a decline in food production. At the end of the run resources are severely depleted in spite of the doubled amount initially available.
Only if we make the initial assumption that our present way of doing things will not change. We have ample evidence of mankind’s ingenuity and social flexibility. There are, of course, many likely changes in the system, some of which are already taking place. The Green Revolution is raising agricultural yields in non industrialized countries.
Knowledge about modern methods of birth control is spreading rapidly.
Over the past three hundred years, mankind has compiled an impressive record of pushing back the apparent limits to population and economic growth by a series of spectacular technological advances.
Since the recent history of a large part of human society has been so continuously successful, it is quite natural that many people expect technological breakthrough to go on raising physical ceilings indefinitely.
All this means we are utilizing a technological policy in every sector of the world model to circumvent in some way the various limits to growth.
The model system is producing nuclear power, recycling resources, and mining the most remote reserves; withholding as many pollutants as possible; pushing yields from the land to undreamed-of heights; and producing only children who are actively wanted by their parents.
The result is still an end to growth before the year 2100.
The application of technological solutions alone has prolonged the period of population and industrial growth, but it has not removed the ultimate limits to that growth.
We would not expect the real world to behave like the world model in any of the graphs we have shown, especially in the collapse modes.
The model contains dynamic statements about only the physical aspects of man’s activities. It assumes that social variables - income distribution, attitudes about family size, choices among goods, services, and food - will continue to follow the same patterns they have followed throughout the world in recent history.
These patterns, and the human value they represent, were all established in the growth phase of our civilization.
They would certainly be greatly revised as population and income began to decrease. Since we find it difficult to imagine what new forms of human societal behavior might emerge and how quickly they would emerge under collapse conditions, we have not attempted to model such social changes. What validity our model has holds up only to the point in each output graph at which growth comes to an end and collapse begins.
Given that first assumption, that population and capital growth should not be deliberately limited but should be left to “seek their own levels”, we have not been able to find a set of policies that avoids the collapse mode of behavior.
Our attempts to use even the most optimistic estimates of the benefits of technology in the model did not prevent the ultimate decline of population and industry, and in fact did not in any case postpone the collapse beyond the year 2100.
Furthermore, they almost never change in anticipation of social need, but only in response to one. We must also keep in mind the presence of social delays - the delays necessary to allow society to absorb or to prepare for a change. Most delays, physical or social reduce the stability of the world system and increase the likelihood of the overshoot mode.
The social delays, like the physical ones, are becoming increasingly more critical because the processes of exponential growth are creating additional pressures at a faster and faster rate. Although the rate of technological change has so far managed to keep up with this accelerated pace, mankind has made virtually no new discoveries to increase the rate of social, political, ethical, and cultural change.
Applying technology to the natural pressures that the environment exerts against any growth process has been so successful in the past that a whole culture has evolved around the principle of fighting against limits rather than learning to live with them.
For the last several hundred years human society has followed the second course so consistently and successfully that the first choice has been all but forgotten.
At this point in man’s history, the choice posed above is still available in almost every sphere of human activity. Man can still choose his limits and stops when he pleases by weakening some of the strong pressures that cause capital and population growth, or by instituting counter-pressures, or both. Such counter-pressures will probably not be entirely pleasant.
They will certainly involve profound changes in the social and economic structures that have been deeply impressed into human culture by centuries of growth. The alternative is to wait until the price of technology becomes more than society can pay, or until the side-effects of technology suppress growth themselves, or until problems arise that have no technical solutions. At any of those points the choice of limits will be gone.
We strongly believe that many of the technological developments mentioned here - recycling, pollution-control devices, contraceptives - will be absolutely vital to the future of human society if they are combined with deliberate checks on growth. We would deplore an unreasoned rejection of the benefit of technology as strongly as we argue here against an unreasoned acceptance of them.
Perhaps the best summary of our position is the motto of the Sierra Club :
We would hope that society will receive each technological advance by establishing the answers to three questions before the technology is widely adopted.
The questions are:
We are searching for a model that represents a world system that is:
The overwhelming growth in world population caused by the positive birth-rate loop is a recent phenomenon, a result of mankind’s very successful reduction of worldwide mortality.
The controlling negative feedback loop has been weakened, allowing the positive loop to operate virtually without constraint.
We can stabilize the capital stock in the model by requiring that the investment rate equal the depreciation rate, with an additional model link exactly analogous to the population-stabilizing one.
Eventually, however, resource shortages reduce industrial output and the temporally stable state degenerates. However, we can improve the model behavior greatly by combining technological changes with value changes that reduce the growth tendencies of the system.
Total average income per capita (industrial output, food, and services combined) is about half the present average US income, equal to the present average European income, and three times the present average world income.
Resources are still being gradually depleted, as they must be under any realistic assumption, but the rate of depletion is so slow that there is time for technology and industry to adjust to changes in resource availability.
Excess industrial capability is employed for producing consumption goods rather than increasing the industrial capital investment rate above the depreciation rate.
Such policies as reducing the birth rate and diverting capital from production of material goods, by whatever means they might be implemented, seem unnatural and unimaginable, because they have not, in most people’s experience, been tried, or even seriously suggested.
Indeed there would be little point even in discussing such fundamental changes in the functioning of modern society if we felt that the present pattern of unrestricted growth were sustainable into the future.
All the evidence available to us, however, suggests that of the three alternatives - unrestricted growth, a self-imposed limitation to growth, or a nature-imposed limitation to growth - only the last two are actually possible.
Bringing a deliberate, controlled end to growth is a tremendous challenge, not easily met.
Let us consider in more detail what a world of non-growth might be like.
Equilibrium means a state of balance or equality between opposing forces. In the dynamic terms of the world model, the opposing forces are those causing population and capital stock to increase (high desired family size, low birth control effectiveness, high rate of capital investment) and those causing population and capital stock to decrease (lack of food, pollution, high rate of depreciation or obsolescence).
We have only specified that the stocks of capital and population remain constant, but they might theoretically be constant at a high level or a low level - or one might be high and the other low. The longer a society prefers to maintain the state of equilibrium, the lower the rates and levels must be.
An equilibrium defined in this way does not mean stagnation.
Within the first two guidelines above, corporations could expand or fail, local populations could increase or decrease income could become more or less evenly distributed. Technological advance would permit the services provided by a constant stock of capital to increase slowly.
Within the third guideline, any country could change its average standard of living by altering the balance between its population and its capital.
Furthermore, a society could adjust to changing internal or external factors by raising or lowering the population or capital stocks, or both, slowly and in a controlled fashion, with a predetermined goal in mind.
The three points above define a dynamic equilibrium, which need not and probably would not “freeze” the world into the population Capital configuration that happens to exist at present time. The object in accepting the above three statements is to create freedom for society, not to impose a straitjacket.
No one can predict what sort of institutions mankind might develop under these new conditions.
In fact, we believe, that the evolution of a society that favors innovation and technological development, a society based on equality and justice, is far more likely to evolve in a state of global equilibrium than it is in the state of growth we are experiencing today
Population and capital are the only quantities that need be constant in the equilibrium state.
Any human activity that does not require a large flow of irreplaceable resources or produce severe environmental degradation might continue to grow indefinitely. In particular, those pursuits that many people would list as the most desirable and satisfying activities of man - education, art, music, religion, basic scientific research, athletics, and social interactions - could flourish.
Since the amount of material production would be essentially fixed, every improvement in production methods could result in increased leisure for the population - leisure that could be devoted to any activity that is relatively non-consuming and nonpolluting, such as those listed above
Technological advance would be both necessary and welcome in the equilibrium state.
The picture of the equilibrium state we have drawn here is idealized, to be sure. It may be impossible to achieve in the form described here, and it may not be the form most people on earth would choose.
The only purpose in describing it at all is to emphasize that global equilibrium need not mean an end to progress or human development. The possibilities within an equilibrium state are almost endless.
Equilibrium would require trading certain human freedoms, such as producing unlimited numbers of children or consuming uncontrolled amounts of resources, for other freedoms, such as relief from pollution and crowding and the threat of collapse of the world system.
Is possible that new freedoms might also arise - universal and unlimited education, leisure for creativity and inventiveness, and, most important of all, the freedom from hunger and poverty enjoyed by such a small fraction of the world’s people today.
The equilibrium society will have to weigh the trade-offs engendered by a finite earth not only with consideration of present human values but also with consideration of future generations. Long-term goals must be specified and short term goals made consistent with them.
During that time the population would grow from 50 million to 130 million.
We cannot say with certainty how much longer mankind can postpone initiating deliberate control of its growth before it will have lost the chance for control. We suspect on the basis of present knowledge of the physical constraints of the planet that the growth phase cannot continue for another one hundred years.
Again, because of the delays in the system, if the global society waits until those constraints are unmistakably apparent, it will have waited too long.
Deliberately limiting growth would be difficult, but not impossible. The way to proceed is clear, and the necessary steps, although they are new ones for human society, are well within human capabilities.
Man possesses, for a small moment in his history, the most powerful combination of knowledge, tools, and resources the world has ever known. He has all that is physically necessary to create a totally new form of human society - one that would be built to last for generations.
The two missing ingredients are a realistic, long-term goal that can guide mankind to the equilibrium society and the human will to achieve that goal.
Without such a goal and a commitment to it, short-term concerns will generate the exponential growth that drives the world system toward the limits of the earth and ultimate collapse.
With that goal and that commitment, mankind would be ready
now to begin a controlled, orderly transition from growth to global