Sunday, 30 October 2016

The Limits to Growth, Part 5

In my last post we looked at The Limits to Growth, Chapter V—The State of Global Equilibrium. The post concludes my review of this book, with a look at the last two sections and some thoughts of my own.


This chapter is by the Executive Committee of the Club of Rome and contains their comments on the book. They make it clear that they did want a study on limits.

...we had two immediate objectives in mind. One was to gain insights into the limits of our world system and the constraints it puts on human numbers and activity....

A second objective was to help identify and study the dominant elements, and their interactions, that influence the long term behavior of world systems....

The report has served these purposes well. It represents a bold step toward a comprehensive and integrated analysis of the world situation, an approach that will now require years to refine, deepen, and extend. Nevertheless, this report is only a first step. The limits to growth it examines are only the known uppermost physical limits imposed by the finiteness of the world system. In reality, these limits are further reduced by political, social, and institutional constraints, by inequitable distribution of population and resources, and by our inability to manage very large intricate systems.

But the report serves further purposes. It advances tentative suggestions for the future state of the world and opens new perspectives for continual intellectual and practical endeavor to shape that future.

A preliminary draft was submitted to 40 people, mostly members of the Club of Rome, who responded with just the kind of weak criticisms that have become so familiar in the years since the book was published.

1. Since models can accommodate only a limited number of variables, the interactions studied are only partial. It was pointed out that in a global model such as the one used in this study the degree of aggregation is necessarily high as well. Nevertheless, it was generally recognized that, with a simple world model, it is possible to examine the effect of a change in basic assumptions or to simulate the effect of a change in policy to see how such changes influence the behavior of the system over time. Similar experimentation in the real world would be lengthy, costly, and in many cases impossible.

2. It was suggested that insufficient weight had been given to the possibilities of scientific and technological advances in solving certain problems, such as the development of foolproof contraceptive methods, the production of protein from fossil fuels, the generation or harnessing of virtually limitless energy (including pollution-free solar energy), and its subsequent use for synthesizing food from air and water and for extracting minerals from rocks. It was agreed, however, that such developments would probably come too late to avert demographic or environmental disaster. In any case they probably would only delay rather than avoid crisis, for the problematique consists of issues that require more than technical solutions.

3. Others felt that the possibility of discovering stocks of raw materials in areas as yet insufficiently explored was much greater than the model assumed. But, again, such discoveries would only postpone shortage rather than eliminate it. It must, however, be recognized that extension of resource availability by several decades might give man time to find remedies.

4. Some considered the model too "technocratic," observing that it did not include critical social factors, such as the effects of adoption of different value systems. The chairman of the Moscow meeting summed up this point when he said, "Man is no mere biocybernetic device." This criticism is readily admitted. The present model considers man only in his material system because valid social elements simply could not be devised and introduced in this first effort. Yet, despite the model's material orientation, the conclusions of the study point to the need for fundamental change in the values of society.

Overall, a majority of those who read this report concurred with its position. Furthermore, it is clear that, if the arguments submitted in the report (even after making allowance for justifiable criticism) are considered valid in principle, their significance can hardly be overestimated....

Although we can here express only our preliminary views, recognizing that they still require a great deal of reflection and ordering, we are in agreement on the following points:

1. We are convinced that realization of the quantitative restraints of the world environment and of the tragic consequences of an overshoot is essential to the initiation of new forms of thinking that will lead to a fundamental revision of human behavior and, by implication, of the entire fabric of present-day society.

2. We are further convinced that demographic pressure in the world has already attained such a high level, and is moreover so unequally distributed, that this alone must compel mankind to seek a state of equilibrium on our planet.

3. We recognize that world equilibrium can become a reality only if the lot of the so-called developing countries is substantially improved, both in absolute terms and relative to the economically developed nations, and we affirm that this improvement can be achieved only through a global strategy.

4. We affirm that the global issue of development is, however, so closely interlinked with other global issues that an overall strategy must be evolved to attack all major problems, including in particular those of man's relationship with his environment.

5. We recognize that the complex world problematique is to a great extent composed of elements that cannot be expressed in measurable terms. Nevertheless, we believe that the predominantly quantitative approach used in this report is an indispensable tool for understanding the operation of the problematique. And we hope that such knowledge can lead to a mastery of its elements.

6. We are unanimously convinced that rapid, radical redressment of the present unbalanced and dangerously deteriorating world situation is the primary task facing humanity.

7. This supreme effort is a challenge for our generation. It cannot be passed on to the next. The effort must be resolutely undertaken without delay, and significant redirection must be achieved during this decade.

8. We have no doubt that if mankind is to embark on a new course, concerted international measures and joint long-term planning will be necessary on a scale and scope without precedent.

9. We unequivocally support the contention that a brake imposed on world demographic and economic growth spirals must not lead to a freezing of the status quo of economic development of the world's nations.

10. We affirm finally that any deliberate attempt to reach a rational and enduring state of equilibrium by planned measures, rather than by chance or catastrophe, must ultimately be founded on a basic change of values and goals at individual, national, and world levels. This change is perhaps already in the air, however faintly.

But our tradition, education, current activities, and interests will make the transformation embattled and slow. Only real comprehension of the human condition at this turning point in history can provide sufficient motivation for people to accept the individual sacrifices and the changes in political and economic power structures required to reach an equilibrium state.

The question remains of course whether the world situation is in fact as serious as this book, and our comments, would indicate. We firmly believe that the warnings this book contains are amply justified, and that the aims and actions of our present civilization can only aggravate the problems of tomorrow. But we would be only too happy if our tentative assessments should prove too gloomy.

The commentary concludes with the following thoughts:

The last thought we wish to offer is that man must explore himself-his goals and values-as much as the world he seeks to change. The dedication to both tasks must be unending. The crux of the matter is not only whether the human species will survive, but even more whether it can survive without falling into a state of worthless existence.


Simply a list of related studies, and the last section in the book.

My thoughts

I think it is first and foremost important to understand that the idea of exponential growth leading to overshoot and collapse should not be a surprise to anyone. This is simply the way ecosystems behave. It is the height of hubris to believe that the human race is an exception to this. Of course, many people do believe exactly that—that because we are intelligent and can anticipate problems before they occur, we will always be able to solve them.

There is also a common misconception that there is "a balance of nature", that leads us not to expect ecosystems to undergo change. Of course our ecosystem has undergone drastic change during the last two centuries, but many people have become inured to this, see it as normal and expect that it can go on forever.

It may be that the authors of The Limits to Growth should have spent more time familiarizing their readers with these issues...

At any rate, once one has understood the implications of exponential growth, it also should be of no surprise that none of the proposed technological solutions in Chapter 4 provide more than temporary relief. Or any other technological solutions, really. The problem, after all, is the exponential growth, not the technology. If we could just get the growth under control (stopped, in other words), the judicious application of appropriate technologies might lead to a stable system, as discussed in Chapter 5.

Stopping that growth, though, would be a social, not a technological solution. And it seems that we don't have a very good grasp of how to engineer social change. For the most part it just happens in reaction to whatever is going on, rather than as part of any sort of plan.

I can't help observing that except for the Standard Run, all the other model runs in The limits to Growth involve ridiculously optimistic assumptions. Even the ones that still end in collapse. The "successful" ones shown in Figures 46 and 47 take that optimism even further, especially as regards social change. And while population and industrial activity are stabilized in those runs, resources are still being used in a non-sustainable way. If those runs were continued on into the twenty second century, at some point they too would run into a resource crisis.

A great many otherwise intelligent people were totally gobsmacked by this book, and reacted very negatively. They simply didn't believe in limits and it seems that The Limits to Growth only hardened that irrational disbelief.

But here we are 44 years after the book was published. Can't we just look at how things turned out to see if there was anything to the future they predicted? Yes, indeed we can—have a look at Is Global Collapse Imminent? An Updated Comparison of The Limits to Growth with Historical Data by Dr Graham M. Turner, who is a Principal Research Fellow at the Melbourne Sustainable Society Institute, University of Melbourne, Australia.

It turns out that the Limits to Growth standard model run is a pretty good match to how things have turned out since then. In the standard run, resource depletion started early in this century and required more capital to be diverted to the resource sector.

With significant capital subsequently going into resource extraction, there is insufficient capital available to fully replace degrading capital within the industrial sector itself. Consequently, despite heightened industrial activity attempting to satisfy multiple demands from all sectors and the population, actual industrial output (per capita) begins to fall precipitously from about 2015, while pollution from the industrial activity continues to grow. The reduction of inputs to agriculture from industry, combined with pollution impacts on agricultural land, leads to a fall in agricultural yields and food produced per capita. Similarly, services (e.g. health and education) are not maintained due to insufficient capital and inputs.

I'd say there is every indication that we have already seen the start of something very much like this in the past decade or two. As early as the 1990s real economic growth slowed due to resource depletion and surplus energy issues. The markets started blowing bubbles in an attempt keep growth going. First the dot com bubble and then the real estate and derivatives bubble in 2008. After that, higher prices for depleted resources (especially energy) slowed a faltering economic recovery, reduced the demand for those same resources and brought their prices down below what it costs to produce them, leaving the extraction industries in a very rough spot. I certainly expect a further down turn and eventually collapse during the next few decades—just what the standard run shows us.

But you can look at the same evidence, squint a little and hold your mouth just right, and conclude that what we are seeing is just a bump on the way to growth with no end in sight—the techno-optimist's wet dream. Are we already deep into overshoot or just nicely getting started on our way to the stars? Depending on who you ask, you can hear spirited arguments on either side of the issue.

Based on The Limits to Growth and the intervening years of history, during which essentially nothing was done to address our headlong approach to those limits (and lots of other evidence as well), I'd say you'd have to be pretty deep in denial not to see that we are already well into overshoot. Time will tell, but my nature is such that I want to be prepared for the worst. In the unlikely event that it doesn't happen, I'll be quite relieved.

I've just finished reading Nicole Foss's The Boundaries and Future of Solution Space. I mention this here because it deals mainly with defining things that are outside the set of feasible responses. And because most of what is suggested in The Limits to Growth is indeed outside of that set. She looks in detail at the kind of changing social conditions which will be brought on by collapse—the sort of thing that was anticipated but not explored in detail by the authors of The Limits to Growth.

I think looking at things to avoid is a very good place to start. Here's Nicole's list:

  • Given that the cost of capital will be very high, and there will be little purchasing power, proposed solutions which are capital-intensive will lie outside solution space.
  • Proposed solutions to our predicament that depend on the functioning of large-scale organizations operating in a top-down manner do not lie within viable solution space.
  • If proposed solutions depend on a cooperative social context at large scale, they will not be part of solution space.
  • Given that the energy supply will be falling, and that there will, over time, be competition for increasingly scarce energy resources that we can no longer take for granted, proposed solutions which are energy-intensive will lie outside of solution space.
  • Proposed solutions dependent on the current level of socioeconomic complexity do not lie within solution space.

In the early 1970s, The Club of Rome was advocating the sort of top down, co-operative response that needed to be started almost immediately if it was to be successful in moving towards a "equilibrium state". None of this happened, and the model run illustrated in Figure 48, where stabilizing policies are not put into effect until the year 2000 and which leads to another collapse, serves as a cautionary tale. All the more so in 2016 with no move toward stabilizing policies anywhere in sight.

Ms. Foss believes there is little hope of ever achieving a worldwide steady state economy. The fact that there is no such thing as a "balance of nature" would tend to support that. It is a new concept for me, but one worth considering. I definitely agree with her that our efforts need to be focused at the family and local community level. And that reliance on government and high level activism to convince governments to change course, would be foolhardy in the extreme.

I should add at this point my usual comments about the shape of the collapse I am expecting. First of all, I am not talking about sudden, apocalyptic change. The collapse I expect, and indeed am already seeing, will take place very unevenly both geographically, chronological and across the various social classes. It will take place over decades—a slow, step-wise descent to a level of economic activity that can be support by our remaining energy resources.

For many people it will be detectable only after it has happened. If you are a member of the elite, moderately lucky and perhaps a bit dense, you may not be aware that it is happening until it is pretty much over. On the other hand, if you are a refugee in a war zone or starving in the middle of a famine, collapse has already happened for you. And if your investments have turned out to be worthless and you've just lost your job and your house, then collapse will very real for you, even if most of the people around you are oblivious.

Already, even for those of us that collapse hasn't quite caught up with yet, it is easy to see what Ms. Foss is talking about. Most of us don't have access to much in the way of capital, or much influence in large scale organizations or government. So what shape should our preparations take?

In the early days of this blog, I talked about that quite a bit and I think most of what I said still applies. You might have a look at the following posts:

Well, this concludes my first attempt at a book review. I still have several shelves full of books I'd like to talk about, but I clearly need to find a way to do this that doesn't take more than one post per book!

As an aid to those who are reading this whole series of "Limits to Growth" posts, here is a complete set of links.

The Limits to Growth

Sunday, 23 October 2016

The Limits to Growth, Part 4

This posts continues looking through the book The Limits to Growth, summarizing it and offering my thoughts on what it has to say. In my last post (insert link) we finished with Chapter IV, Technology And The Limits To Growth.

Chapter V—The State of Global Equilibrium

In real world finite systems there are negative feedback loops which stop positive feedback loops from generating exponential growth and collapse. The delays in the negative feedback loops allow overshoot to occur, which is wasteful of resources and actually reduces the carrying capacity of the environment, leading to a deeper collapse and making recovery more difficult. Technological solutions work by weakening the negative loops and allowing growth to continue for a while, but in the long run the result is the same.

Instead we need to stop growth and level out into a steady state system before we encounter limits.

We are searching for a model output that represents a world system that is: 1. sustainable without sudden and uncontrollable collapse; and 2. capable of satisfying the basic material requirements of all of its people.

How to do this? Well, we could strengthen the negative feedback loops. But most people would take a dim view of increasing the death rate in order to stop population growth or increasing the rate at which industrial equipment wears out in order to stop industrial growth.

What if we weakened the positive feedback loop instead? This has never been tried or even seriously suggested, but within a system dynamic model we can easily change a few numbers to see what happens if we reduce positive feedbacks, and see if it is worth trying in the real world.

In Figure 44 the positive feedback loop of population growth is effectively balanced, and population remains constant. At first the birth and death rates are low. But there is still one unchecked positive feedback loop operating in the model—the one governing the growth of industrial capital. The gain around that loop increases when population is stabilized, resulting in a very rapid growth of income, food, and services per capita. That growth is soon stopped, however, by depletion of nonrenewable resources. The death rate then rises, but total population does not decline because of our requirement that birth rate equal death rate (clearly unrealistic here).

What happens if we bring both positive feedback loops under control simultaneously?

The result of stopping population growth in 1975 and industrial capital growth in 1985 with no other changes is shown in Figure 45. (Capital was allowed to grow until 1985 to raise slightly the average material standard of living.) In this run the severe overshoot and collapse of Figure 44 are prevented. Population and capital reach constant values at a relatively high level of food, industrial output, and services per person. Eventually, however, resource shortages reduce industrial output and the temporarily stable state degenerates.

What if we combine controlling both positive loops with technological changes? One example of such an output is shown in Figure 46.

The policies that produced the behavior shown in Figure 46 are:

1. Population is stabilized by setting the birth rate equal to the death rate in 1975. Industrial capital is allowed to increase naturally until 1990, after which it, too, is stabilized, by setting the investment rate equal to the depreciation rate.

2. To avoid a nonrenewable resource shortage such as that shown in Figure 45, resource consumption per unit of industrial output is reduced to one-fourth of its 1970 value. (This and the following five policies are introduced in 1975.)

3. To further reduce resource depletion and pollution, the economic preferences of society are shifted more toward services such as education and health facilities and less toward factory-produced material goods. (This change is made through the relationship giving "indicated" or "desired" services per capita as a function of rising income.)

4. Pollution generation per unit of industrial and agricultural output is reduced to one-fourth of its 1970 value.

5. Since the above policies alone would result in a rather low value of food per capita, some people would still be malnourished if the traditional inequalities of distribution persist. To avoid this situation, high value is placed on producing sufficient food for all people. Capital is therefore diverted to food production even if such an investment would be considered "uneconomic." (This change is carried out through the "indicated" food per capita relationship.)

6. This emphasis on highly capitalized agriculture, while necessary to produce enough food, would lead to rapid soil erosion and depletion of soil fertility, destroying long-term stability in the agricultural sector. Therefore the use of agricultural capital has been altered to make soil enrichment and preservation a high priority. This policy implies, for example, use of capital to compost urban organic wastes and return them to the land (a practice that also reduces pollution).

7. The drains on industrial capital for higher services and food production and for resource recycling and pollution control under the above six conditions would lead to a low final level of industrial capital stock. To counteract this effect, the average lifetime of industrial capital is increased, implying better design for durability and repair and less discarding because of obsolescence. This policy also tends to reduce resource depletion and pollution.

In Figure 46 the stable world population is only slightly larger than the population today. There is more than twice as much food per person as the average value in 1970, and world average lifetime is nearly 70 years. The average industrial output per capita is well above today's level, and services per capita have tripled. Total average income per capita (industrial output, food, and services combined) is about $1,800. This value 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.

We might choose to make different tradeoffs in setting up a stable system, but this example does show the levels of population and capital that are physically maintainable on the earth, under the most optimistic assumptions. What if we go back a little in the direction of the real world and relax some of the restrictions imposed in Figure 46?

Suppose we retain the last six of the seven policy changes that produced Figure 46, but replace the first policy, beginning in 1975, with the following:

1. The population has access to 100 percent effective birth control.
2. The average desired family size is two children.
3. The economic system endeavors to maintain average industrial output per capita at about the 1975 level. Excess industrial capability is employed for producing consumption goods rather than increasing the industrial capital investment rate above the depreciation rate.

The model behavior that results from this change is shown in Figure 47. Now the delays in the system allow population to grow much larger than it did in Figure 46. As a consequence, material goods, food, and services per capita remain lower than in previous runs (but still higher than they are on a world average today).

We do not suppose that any single one of the policies necessary to attain system stability in the model can or should be suddenly introduced in the world by 1975. A society choosing stability as a goal certainly must approach that goal gradually. It is important to realize, however, that the longer exponential growth is allowed to continue, the fewer possibilities remain for the final stable state. Figure 48 shows the result of waiting until the year 2000 to institute the same policies that were instituted in 1975 in Figure 47.

In Figure 48, both population and industrial output per capita reach much higher values than in Figure 47. As a result pollution builds to a higher level and resources are severely depleted, in spite of the resource-saving policies finally introduced. In fact, during the 25-year delay (from 1975 to 2000) in instituting the stabilizing policies, resource consumption is about equal to the total 125-year consumption from 1975 to 2100 of Figure 47.

From my viewpoint in 2016, this is not encouraging. Yet it bears out much of what I have been saying is this blog all along—that resource depletion is already causing a collapse and it is too late for a solution that enables those of us in the western world to maintain our current lifestyles.

The rest of the chapter is spent considering the many obstacles to setting up a steady state system and arguing the value of doing so. Here are a few typical paragraphs that will give you the flavour of this:

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.

Achieving a self-imposed limitation to growth would require much effort. It would involve learning to do many things in new ways. It would tax the ingenuity, the flexibility, and the self-discipline of the human race. Bringing a deliberate, controlled end to growth is a tremendous challenge, not easily met.

By choosing a fairly long time horizon for its existence, and a long average lifetime as a desirable goal, we have now arrived at a minimum set of requirements for the state of global equilibrium. They are:

1. The capital plant and the population are constant in size. The birth rate equals the death rate and the capital investment rate equals the depreciation rate.
2. All input and output rates—births, deaths, investment and depreciation are all kept to a minimum.
3. The levels of capital and population and the ratio of the two are set in accordance with the values of the society. They may be deliberately revised and slowly adjusted as the advance of technology creates new options.

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.

Technological advance would be both necessary and welcome in the equilibrium state. A few obvious examples of the kinds of practical discoveries that would enhance the workings of a steady state society include:

  • new methods of waste collection, to decrease pollution and make discarded material available for recycling;
  • more efficient techniques of recycling, to reduce rates of resource depletion;
  • better product design to increase product lifetime and promote easy repair, so that the capital depreciation rate would be minimized;
  • harnessing of incident solar energy, the most pollution-free power source;
  • methods of natural pest control, based on more complete understanding of ecological interrelationships;
  • medical advances that would decrease the death rate;
  • contraceptive advances that would facilitate the equalization of the birth rate with the decreasing death rate.

One of the most commonly accepted myths in our present society is the promise that a continuation of our present patterns of growth will lead to human equality. We have demonstrated in various parts of this book that present patterns of population and capital growth are actually increasing the gap between the rich and the poor on a worldwide basis, and that the ultimate result of a continued attempt to grow according to the present pattern will be a disastrous collapse.

The greatest possible impediment to more equal distribution of the world's resources is population growth. It seems to be a universal observation, regrettable but understandable, that, as the number of people over whom a fixed resource must be distributed increases, the equality of distribution decreases. Equal sharing becomes social suicide if the average amount available per person is not enough to maintain life.

And they conclude with the following:

If there is cause for deep concern, there is also cause for hope. 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 equilibrium.

Forty plus years later we are no closer to having the goal they speak of. Our politicians still see "economic recovery"—the resumption of "robust" growth—as their main goal. Even though growth is the very thing that is causing most of our problems.

In my next post we'll (finally) wrap up this review.

As an aid to those who are reading this whole series of "Limits to Growth" posts, here is a complete set of links.

The Limits to Growth

Tuesday, 18 October 2016

The Limits to Growth, Part 3

This posts continues looking through the book The Limits to Growth one chapter at a time, summarizing it and offering my thoughts on what it has to say.

In my last post we stopped part way through Chapter IV, Technology And The Limits To Growth, having just looked at several runs of the World 3.0 model, each of which ended with a collapse of the world system as one sort of limit or another was reached. The rest of this chapter is spent discussing the implications of those model runs and some of the limitations of the model.

One limitation is that once collapse starts, there will be significant social change and the model's structure will no longer match the structure of the world's systems. So the models "predictions" are valid only up until things start to fall apart.

The model runs in this chapter make it clear that the basic behaviour mode of the world's system is exponential growth of population and capital followed by overshoot and collapse. This is so if we assume no change from the current system or numerous technological changes. All the model runs to this point assume that population and capital growth are allowed to continue until they reach some natural limit, since this seems to be a basic part of the current human value system.

Using the most optimistic estimates of the effect of technology in the model did not prevent the ultimate decline of population and industry, nor even delay it past the year 2100.

Delays are built into many of the feedback loops in the system, so that the effect of a change in one value is not felt immediately in other areas. The result of this is that a value which is approaching a limit will often actually overshoot that limit before collapsing.

I'd like to point out that during the first part of an occurrence of overshoot, when population and industry are still growing, it is difficult to tell that overshoot is actually occurring. Only after they peak and start to decline does it become obvious that the system has actually been in overshoot for some time. This leads us to what is for me the essential question that comes out of The Limits to Growth: are we already in overshoot or are we just starting to do really well as the techno-optimists and cornucopians would have us believe. It should be no surprise that I believe we are well into overshoot and heading merrily along toward collapse.

The authors go on to say that technological change has social effects that are not included in the model and that these effects often manifest themselves after a delay as well. This is unfortunate since we may commit to a technology and become dependent on it, only to find out too late that it has some negative social consequences, which we now have to live with since we have become dependent on the technology.

As an example they point to the Green Revolution, which was intended to be a technological solution to the world's food problems. They claim it was also intended to be labour intensive so as to provide more jobs and not require large amounts of capital so as to be accessible to the poor in developing nations. In areas like the East Punjab in India this worked well—the number of agricultural jobs increasing faster than the rate of growth of the total population, with real wage increases of 16 percent from 1963 to 1968.

The principal, or intended, effect of the Green Revolution—increased food production—seems to have been achieved. Unfortunately the social side-effects have not been entirely beneficial in most regions where the new seed varieties have been introduced. The Indian Punjab had, before the Green Revolution, a remarkably equitable system of land distribution. The more common pattern in the non-industrialized world is a wide range in land ownership, with most people working very small farms and a few people in possession of the vast majority of the land.

Where these conditions of economic inequality already exist, the Green Revolution tends to cause widening inequality. Large farmers generally adopt the new methods first. They have the capital to do so and can afford to take the risk. Although the new seed varieties do not require tractor mechanization, they provide much economic incentive for mechanization, especially where multiple cropping requires a quick harvest and replanting. On large farms, simple economic considerations lead almost inevitably to the use of labor-displacing machinery and to the purchase of still more land! The ultimate effects of this socio-economic positive feedback loop are agricultural unemployment, increased migration to the city, and perhaps even increased malnutrition, since the poor and unemployed do not have the means to buy the newly produced food.

I would add that the Green Revolution was intended not as a final solution, but rather to give us a breathing space while we got population growth under control. That hasn't yet happened, and the social problems caused by the Green Revolution haven't been solved, either. It is also becoming evident that the Green Revolution and conventional agriculture in general is pushing up against resource limits such as arable land, fresh water, fossil fuels and mineral resources like phosphorous. That is exactly what the model runs earlier in this chapter should lead us to expect—that the application of technology to apparent problems of resource depletion, pollution or food shortage has no impact on the essential problem, which is exponential growth in a finite and complex system.

In any case as the world changes, we have to adapt by making social changes, which take place quite slowly. The authors comment:

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. The world population grew from 1 billion to 2 billion over a period of more than one hundred years. The third billion was added in 30 years and the world's population has had less than 20 years to prepare for its fourth billion. The fifth, sixth, and perhaps even seventh billions may arrive before the year 2000, less than 30 years from now. 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.

They go on to discuss that there is a whole range of problems that cannot be solved by technological advances. Problems which yield only to social solutions.

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. This culture has been reinforced by the apparent immensity of the earth and its resources and by the relative smallness of man and his activities.

The basic choice... is the same one that faces any society trying to overcome a natural limit with a new technology. Is it better to try to live within that limit by accepting a self-imposed restriction on growth? Or is it preferable to go on growing until some other natural limit arises, in the hope that at that time another technological leap will allow growth to continue still longer? 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.

The chapter ends with this:

Perhaps the best summary of our position is the motto of the Sierra Club: "Not blind opposition to progress, but opposition to blind progress."

We would hope that society will receive each new technological advance by establishing the answers to three questions before the technology is widely adopted. The questions are:

1. What will be the side-effects, both physical and social, if this development is introduced on a large scale?
2. What social changes will be necessary before this development can be implemented properly, and how long will it take to achieve them ?
3. If the development is fully successful and removes some natural limit to growth, what limit will the growing system meet next? Will society prefer its pressures to the ones this development is designed to remove?

Let us go on now to investigate nontechnical approaches for dealing with growth in a finite world.

Answering those questions is likely to be difficult and such answers as we can get will not be terribly clear. But unfortunately, choosing not to adopt technology can also have severe consequences, as we'll see in the next chapter.

This is a rather short post, but including Chapter 5 would make it too long, so I'll break off here and be back in just a few days with my review of Chapter 5, which is already written.

As an aid to those who are reading this whole series of "Limits to Growth" posts, here is a complete set of links.

The Limits to Growth

Sunday, 2 October 2016

The Limits to Growth, Part 2

This posts continues on directly from my last post, working through the book The Limits to Growth one chapter at a time, summarizing it and offering my thoughts on what it has to say.

The graphic to the right is the "standard" run of the World 3.0 model, for which it is most famous. More on this soon—the graphic is just here so that when I post links to Facebook a graphic other than my ugly mug shows up.

Chapter III — Growth in the World System

In this chapter, the authors describe the formal model that they used in an attempt to understand the complex world system. The purpose of the model is to aid in study of the behaviour modes of the system, that is the tendencies of the variable in the system (population, capital, food, resources and pollution) to change in certain characteristic ways as time passes.

For example, it is well known that a population growing in a limited environment can behave in several different ways. It can adjust smoothly to an equilibrium below the environmental limit by means of a gradual decrease in growth rate, as shown in A below. It can over shoot the limit and then die back again in either a smooth or an oscillatory way, also as shown in B and C. Or it can overshoot the limit and in the process decrease the ultimate carrying capacity by consuming some necessary nonrenewable resource, as in D. This behavior has been noted in many natural systems. For instance, deer or goats, when natural enemies are absent, often overgraze their range and cause erosion or destruction of the vegetation.
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. The output graphs reproduced later in this book show values for caveats about the system dynamic model world population, capital, and other variables on a time scale that begins in the year 1900 and continues until 2100. These graphs are not exact predictions of the values of the variables at any particular year in the future. They are indications of the system's behavioral tendencies only.

Please note that the authors are claiming only "the most limited" predictive capabilities for their dynamic system model. They go on at some length about this and acknowledge that the model is extremely simplified. The whole world represented by a single general population, a single class of long lived globally distributed pollutants and a single generalized resource—this is necessary to keep the model understandable. They admit that this limits the information that can be gained from the model.

National boundaries are not recognized. Distribution inequalities of food, resources, and capital are included implicitly in the data but they are not calculated explicitly nor graphed in the output. World trade balances, migration patterns, climatic determinants, and political processes are not specifically treated. Other models can, and we hope will, be built to clarify the behavior of these important subsystems.

The authors describe 4 steps they took in building the model.

1. We first listed the important causal relationships among the five levels and traced the feedback loop structure. To do so we consulted literature and professionals in many fields of study dealing with the areas of concern-demography, economics, agronomy, nutrition, geology, and ecology, for example. Our goal in this first step was to find the most basic structure that would reflect the major interactions between the five levels. We reasoned that elaborations on this basic structure, reflecting more detailed knowledge, could be added after the simple system was understood.
2. We then quantified each relationship as accurately as possible, using global data where it was available and characteristic local data where global measurements had not been made.
3. With the computer, we calculated the simultaneous operation of all these relationships over time. We then tested the effect of numerical changes in the basic assumptions to find the most critical determinants of the system's behavior.
4. Finally, we tested the effect on our global system of the various policies that are currently being proposed to enhance or change the behavior of the system.

They then go into some detail about the structure of the model, which I find very interesting. There simply isn't room to go into detail here and I can only encourage you to get a copy of the book and have a look. It is available as a pdf on line free of charge. (insert link here)

For those who have objected that the model is pulled out of thin air or question the numbers it is based on, I would point to the following statement by the authors:

The current state of knowledge about casual relationships in the world ranges from complete ignorance to extreme accuracy. The relationships in the world model generally fall in the middle ground of certainty. We do know something about the direction and magnitude of the causal effects, but we rarely have fully accurate information about them. To illustrate how we operate on this intermediate ground of knowledge, we present here three examples of quantitative relationships from the world model. One is a relationship between economic variables that is relatively well understood; another involves sociopsychological variables that are well studied but difficult to quantify; and the third one relates biological variables that are, as yet, almost totally unknown. Although these three examples by no means constitute a complete description of the world model, they illustrate the reasoning we have used to construct and quantify it.

They go on to discuss the three examples: per capita resource use (well understood), desired birth rate (well studied but difficult to quantify) and pollution effect on lifetime (almost totally unknown), describe the assumption they have made. They then discuss the usefulness of the model, given its limitations.

First, we hope that by posing each relationship as a hypothesis, and emphasizing its importance in the total world system, we may generate discussion and research that will eventually improve the data we have to work with. This emphasis is especially important in the areas in which different sectors of the model interact (such as pollution and human lifetime), where interdisciplinary research will be necessary. Second, even in the absence of improved data, information now available is sufficient to generate valid basic behavior modes for the world system. This is true because the model's feedback loop structure is a much more important determinant of overall behavior than the exact numbers used to quantify the feedback loops. Even rather large changes in input data do not generally alter the mode of behavior, as we shall see in the following pages. Numerical changes may well affect the period of an oscillation or the rate of growth or the time of a collapse, but they will not affect the fact that the basic mode is oscillation or growth or collapse.
Since we intend to use the world model only to answer questions about behavior modes, not to make exact predictions, we are primarily concerned with the correctness of the feedback loop structure and only secondarily with the accuracy of the data. Of course when we do begin to seek more detailed, short-term knowledge, exact numbers will become much more important. Third, if decision-makers at any level had access to precise predictions and scientifically correct analyses of alternate policies, we would certainly not bother to construct or publish a simulation model based on partial knowledge. Unfortunately, there is no perfect model available for use in evaluating today's important policy issues. At the moment, our only alternatives to a model like this, based on partial knowledge, are mental models, based on the mixture of incomplete information and intuition that currently lies behind most political decisions. A dynamic model deals with the same incomplete information available to an intuitive model, but it allows the organization of information from many different sources into a feedback loop structure that can be exactly analyzed. Once all the assumptions are together and written down, they can be exposed to criticism, and the system's response to alternative policies can be tested.

And now, at last, we get to actual behaviour of the world model, represented in a series of graphs based on varying assumptions. I can hardly avoid commenting that the graphs say a great deal about the primitive state of graphics software in the early 1970s.

The horizontal scale in each of the figures shows time in years from 1900 to 2100.
With the computer they plotted the progress over time of eight quantities:
solid heavy line—population, total number of persons
dashed line— industrial output per capita, dollar equivalent per person per year
solid light line—food per capita (kilogram-grain equivalent per person per year)
....... pollution (multiple of 1970 level)
-•-•- nonrenewable resources, fraction of 1900 reserves remaining
B — crude birth rate (births per 1000 persons per year)
D — crude death rate (deaths per 1000 persons per year)
S — services per capita (dollar equivalent per person per year)

Each of these variables is plotted on a different vertical scale. they deliberately omitted the vertical scales and made the horizontal time scale somewhat vague because they wanted to emphasize the general behavior modes of these computer outputs, not the numerical values, which are only approximately known. The scales are, however, exactly equal in all the computer runs presented here, so results of different runs may be easily compared.

The first is the famous (infamous?) "standard run", Figure 35, which is based on the assumption that there will be in the future no great changes in human values nor in the functioning of the global population-capital system as it has operated for the last one hundred years.

The behavior mode of the system shown in figure 35 is clearly that of overshoot and collapse. In this run the collapse occurs because of nonrenewable resource depletion. The industrial capital stock grows to a level that requires an enormous input of resources. In the very process of that growth it depletes a large fraction of the resource reserves available. As resource prices rise and mines are depleted, more and more capital must be used for obtaining resources, leaving less to be invested for future growth. Finally investment cannot keep up with depreciation, and the industrial base collapses, taking with it the service and agricultural systems, which have become dependent on industrial inputs (such as fertilizers, pesticides, hospital laboratories, computers, and especially energy for mechanization). For a short time the situation is especially serious because population, with the delays inherent in the age structure and the process of social adjustment, keeps rising. 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 with the next century, at the latest.

The collapse in Figure 35 is the result of a resource crisis, even though it is based on the optimistic assumption of a static resource reserve of 250 years. But let's be even more optimistic and assume that new discoveries or advances in technology can double the amount of resources economically available. A computer run under that assumption is shown in figure 36.

The overall behavior mode in figure 36—growth and collapse—is very similar to that in the standard run. In this case the primary force that stops growth is a sudden increase in the level of pollution, caused by an overloading of the natural absorptive capacity of the environment. The death rate rises abruptly from pollution and from lack of food. At the same time resources are severely depleted, in spite of the doubled amount available, simply because a few more years of exponential growth in industry are sufficient to consume those extra resources.
Is the future of the world system bound to be growth and then collapse into a dismal, depleted existence? 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 nonindustrialized countries. Knowledge about modern methods of birth control is spreading rapidly. Let us use the world model as a tool to test the possible consequences of the new technologies that promise to raise the limits to growth.

Chapter IV — Technology and the Limits to Growth

Of course, there are always technological optimists eager to explain how we can overcome the limits to growth. In this chapter, several additional runs of the world model are presented, each an attempt to overcome one or more of the limits which cause collapse in Figures 35 and 36.

Let us assume, however, that the technological optimists are correct and that nuclear energy will solve the resource problems of the world. The result of including that assumption in the world model is shown in figure 37. To express the possibility of utilizing lower grade ore or mining the seabed, we have doubled the total amount of resources available, as in figure 36. We have also assumed that, starting in 1975, programs of reclamation and recycling will reduce the input of virgin resources needed per unit of industrial output to only one-fourth of the amount used today. Both of these assumptions are, admittedly, more optimistic than realistic.
In figure 37 resource shortages indeed do not occur. Growth is stopped by rising pollution, as it was in figure 36. The absence of any constraint from resources allows industrial output, food, and services to rise slightly higher than in figure 36 before they fall. Population reaches about the same peak level as it did in figure 36, but it falls more suddenly and to a lower final value.

"Unlimited" resources thus do not appear to be the key to sustaining growth in the world system. Apparently the economic impetus such resource availability provides must be accompanied by curbs on pollution if a collapse of the world system is to be avoided.

OK, if pollution is the problem, what if we use technology to control pollution?

As figure 39 shows, the pollution control policy is indeed successful in averting the pollution crisis of the previous run. Both population and industrial output per person rise well beyond their peak values in figure 37, and yet resource depletion and pollution never become problems. The overshoot mode is still operative, however, and the collapse comes about this time from food shortage.
As long as industrial output is rising in figure 39, the yield from each hectare of land continues to rise (up to a maximum of seven times the average yield in 1900) and new land is developed. At the same time, however, some arable land is taken for urban-industrial use, and some land is eroded, especially by highly capitalized agricultural practices. Eventually the limit of arable land is reached. After that point, as population continues to rise, food per capita decreases. As the food shortage becomes apparent, industrial output is diverted into agricultural capital to increase land yields. Less capital is available for investment, and finally the industrial output per capita begins to fall. When food per capita sinks to the subsistence level, the death rate begins to increase, bringing an end to population growth.

OK, if too little food is the problem, what if we increase agricultural yields?

In figure 40 we assume that the normal yield per hectare of all the world's land can be further increased by a factor of two. The result is an enormous increase in food, industrial output, and services per capita. Average industrial output per person for all the world's people becomes nearly equal to the 1970 US level, but only briefly. Although a strict pollution control policy is still in effect, so that pollution per unit of output is reduced by a factor of four, industry grows so quickly that soon it is producing four times as much output. Thus the level of pollution rises in spite of the pollution control policy, and a pollution crisis stops further growth, as it did in figure 37.

OK, if that doesn't work, what if we had perfect birth control?

Figure 41 shows the alternate technological policy-perfect birth control, practiced voluntarily, starting in 1975. The result is not to stop population growth entirely because such a policy prevents only the births of unwanted children. The birth rate does decrease markedly, however, and the population grows more slowly than it did in figures 39 and 40. In this run growth is stopped by a food crisis occurring about 20 years later than in figure 39.

Or, what if we had both increased agricultural yield and perfect birth control?

In figure 42 we apply increased land yield and perfect birth control simultaneously. Here 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. In this case growth is stopped by three simultaneous crises. Overuse of land leads to erosion, and food production drops. Resources are severely depleted by a prosperous world•population (but not as prosperous as the present US population). Pollution rises, drops, and then rises again dramatically, causing a further decrease in food production and a sudden rise in the death rate. 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.

I have discussed this with many techo-optimists who point out that, with enough energy and technology, the problems in Figure 42 (and many others) can be overcome, allowing prosperity to spread worldwide and increase indefinitely. Of course, I happen to doubt that we can find enough energy and develop enough technology, but even if we do there is still a problem. All the energy that we use ends up as waste heat. This isn't something we are doing wrong—it's just how the world works.

Tom Murphy discusses this in detail in a post at his blog "Do The Math". This a framed as a discussion between a physicist and an economist and I find it quite entertaining.

The gist of it, though, is that while currently the amount of waste heat is small enough that it isn't much of a problem, as it increases it will become an even worse problem than the climate change we are experiencing because of the greenhouse effect. Yes, there are ways to minimize (but not eliminate) temperature increases due to waste heat. Ultimately though, as growth continues, if we are clever enough to find ways around all the other limits this will be the limit that gets us.

But I digress—time to get back to The Limits to Growth. The rest of this chapter is spent discussing the implications of the model runs we've been looking at. But I've gone on long enough already, so we'll continue with that in my next post.

As an aid to those who are reading this whole series of "Limits to Growth" posts, here is a complete set of links.

The Limits to Growth