Carrying Capacity Definition
Carrying capacity is the number of organisms that an ecosystem can sustainably support.
An ecosystem’s carrying capacity for a particular species may be influenced by factors as its ability to regenerate the food, water, atmosphere, and other necessities that the organisms need to survive.
Ecosystems cannot exceed their carrying capacity for a long period of time. In situations where the population density of a given species exceeds the ecosystem’s carrying capacity, the species will deplete its own source of food, water, or other necessities, and will soon begin die off. The species population can grow until it reaches that line, at which point resources will not be sufficient to allow it to continue to grow over the long-term:
An example of a situation in which the carrying capacity of an environment is exceeded is the example of deer in North America.
After the widespread elimination of wolves – the natural predator of North American deer – the deer reproduced until their need for food plant species exceeded the environment’s ability to regenerate their food plants. In many areas, this resulted in large numbers of deer starving until the deer population was severely reduced.
Humans have managed to increase the Earth’s carrying capacity for human life using technological inventions such as agriculture and genetically modified crops, which have a greater ability to produce food in some environments than natural crops.
Still, some scientists fear that humans may exceed the Earth’s carrying capacity for humans, and encourage the use of contraception to decrease birth rates in order to prevent human populations from exhausting their sources of food and other vital resources.
Examples of Carrying Capacity
The Daisyworld Model
The hypothetical “Daisyworld” model is a model developed by scientists to study how organisms chance their environment, and how ecosystems self-regulate.
In the original “Daisyworld” mathematical simulation, there were only two types of life forms: black daisies, which increase the environment’s temperature by absorbing heat from the Sun (this is a real property of black materials), and white daisies, which decrease the environment’s temperature by reflecting the Sun’s heat (this is also a real effect of white-colored materials).
Each species of daisies had to live in a proper balance with the other species. If the white daisies overpopulated, the world would become too cold. Daisies of both types would begin to die off, and the world would start to regain its pre-daisy equilibrium. The same held true for black daisies: if they overpopulated, the world would become warmer and warmer until the daisies began to die off again.
Real-life ecosystems are much more complicated than this, of course.
Each organism has many needs, and how well the environment can meet those needs might depend on what other organisms it shares the environment with. Such is the case for…
The North American Deer
Before Europeans colonized North America, one of its main forest herbivores were deer. Ordinarily existing in small groups, populations of deer were kept in check by wolves, the top predator of these forest ecosystems.
Deer, being fairly large as North American herbivores go, were capable of eating leaves off of trees and shrubs, as well as low-growing plants like flowers and grass. And they required a lot of leaves to keep them going, as members of different species of deer could weigh anywhere from 50 to 1,500 pounds!
But when European settlers severely depleted the population of wolves, who they found to be a danger to human children and livestock, an unexpected consequence resulted: deer began to multiply out of control, until they exceeded the carrying capacity of their environment.
As a result, deer began to starve. Plants species also began to suffer, some even being threatened with extinction as the starving deer ate all the green plants they could find.
When humans realized what was happening – and it began to affect their own food sources, after wild deer began to invade gardens and farms looking for crops to eat – they began to give nature a helping hand in reducing the deer population.
In modern times, some areas “cull” deer – a practice where deer are systematically hunted, not just for meat or sport, but to prevent deer starvation and damage to plants. Other areas have even begun to re-introduce wolves – humans’ old enemy – and have seen healthier ecosystems, gardens, and crops as a result.
The story of the North American wolves and deer has acted as a cautionary tale for people considering making changes of any kind to their natural environment, which might have unintended consequences.
Humans have become one of the world’s only global species my mastering technology. Time and time again, the human species has overcome a factor, such as availability of food or presence of natural predators, that limited our population.
The first major human population explosion happened after the invention of agriculture, in which humans learned that we could grow large numbers of our most nutritious food plants by saving seeds to plant in the ground, and making sure those seeds got enough water, were protected from competition from weeds and from being eaten by other animals, etc..
When agriculture was invented, the human population skyrocketed – scientists think that without agriculture, between 1 million and 15 million humans were able to live on Earth at a time. Today, there are about 1 million humans in the city of Chicago alone!
By the Middle Ages, when well-organized agriculture had emerged on every continent, there were about 450 million – or about half a billion – humans on earth.
A new revolution in Earth’s capacity to carry humans began in the 18th and 19th centuries, when humans began to apply advanced and automated technology to agriculture. The use of inventions such as the mechanical corn picker and crop rotation – a way of growing different crops in sequence that enriches the soil and leads to higher yields – allowed humans to produce even more food. As a result, the world population tripled from about half a billion to 1.5 billion people.
In the twentieth century, a third revolution occurred when humans began to learn how to rewrite the genomes of the plants, using viruses to insert new genes into seeds directly instead of relying on selective breeding and random mutation to increase crop yields. The result was another drastic increase in the Earth’s ability to produce food for humans.
During the 20th century, Earth’s human population more than quadrupled, from 1.5 billion to 6.1 billion. We’ve come a long way from the pre-agricultural days!
But some scientists worry that we may be well on our way to exceeding the Earth’s carrying capacity – or that we may have already done so.
Scientists point out that the practices currently used to grow genetically modified crops may not be sustainable, as they often require the use of chemicals that can harm other parts of our ecosystems.
Scientists point to the rapid decline of bee populations – which are necessary to pollinate some of our crops, and which many scientists believe are being killed by pesticides we use to protect those same crops – as evidence that our current food production practices may not be sustainable for much longer.
The proliferation of poisonous algae, which can poison our water supplies and which feeds on the same fertilizer we use to feed our crops, is another worrisome sign that we may be exceeding our carrying capacity, and may begin to cause problems for ourselves if our population continues to grow.
Some believe that humans will continue to invent newer, better ways to grow food and to make water safe to drink. Many scientists agree that this is true: however, they caution that we should not simply continue to grow our population and assume that advances in technology will be able to take care of everyone.
Instead, scientists urge us to consciously plan our birth rates and population growth to avoid humanitarian crises.
Related Biology Terms
- Climate change – A process by which the Earth’s weather changes significantly over time. Earth’s climate can be changed when organisms living on Earth alter its atmospheric chemistry, as humans have done by releasing large amounts of greenhouse gases through their activities.
- Ecosystem – A community of living things which interact with each other and their environment. Organisms in ecosystems compete with each other, but they also often rely on each other for long-term survival.
- Mass extinction – An event in which many species die off, often because environmental change occurred faster than they could adapt. Historical causes of mass extinction include asteroid impacts and climate change.
1. Which of the following is NOT true of carrying capacity?
A. An ecosystem’s carrying capacity depends on an interplay of many variables, such as weather, soil type, what food species are available, and how quickly they are able to regenerate.
B. When an organism exceeds the environment’s carrying capacity, it is instantly corrected.
C. Ecosystems are stable over time. Their carrying capacity does not change.
D. B and C.
Answer to Question #1
It is true that an ecosystem cannot sustain population over its carrying capacity – but sometimes it may take decades for resources like food species and water availability to become depleted, before the population that is over carrying capacity begins to fall back to sustainable levels.
Likewise, ecosystems are constantly changing and evolving. An ecosystem’s carrying capacity for a given organism might change, for example if a food species mutates to become more productive, or a change in the weather makes a food species less productive.
2. Which of the following is an example of carrying capacity being reached?
A. The peppered moth changing its camouflage colors in response to human pollution.
B. Bacteria in a petri dish multiplying until they run out of nutrients.
C. A leopard seal hunting a penguin for prey.
D. Deer multiplying until they deplete their food source and begin to starve.
E. B and D.
Answer to Question #2
E is correct. Both B and D are examples of a situation in which a population reached its maximum sustainable level, and then stopped growing or began to decline due to lack of resources.
3. Which of the following is NOT a reason why scientists are concerned that humans may be pushing the limits of Earth’s carrying capacity?
A. Bee colonies dying off due to pesticide use.
B. Poisonous algae proliferating and excreting toxins into lakes and rivers.
C. Water sources that humans rely on in desert environments becoming depleted.
D. All of the above.
Answer to Question #3
D is correct. All of the above are indications that the current rate of human population growth may not be sustainable. Scientists fear that if population quadruples again in the coming century like it did in the 20th century, there may not be enough food to sustain human populations.
by Albert A. Bartlett, Department of Physics, University of Colorado
TABLE OF CONTENTS
The related terms, “sustainable” and “sustainability” have become popular and are used to describe a wide variety of activities which are generally ecologically laudable. At the same time, the term “compromise” is heard more frequently because the needs of the environment often are in conflict with the needs of humans. A brief examination of the question of compromise shows that a series of ten compromises, each of which saves 70% of the remaining environment, results in the saving of only 3% of the environment. Judging from the ways in which the terms “sustainable” and “sustainability” are used, their definitions are not very precise, especially when compromises are involved. An attempt is made here to give firm definition to these terms and to translate the definition into a series of laws and hypotheses which, it is hoped, will clarify the implications of their use. These are followed by a series of observations and predictions that relate to “sustainability.”
In the 1980s it became apparent to thoughtful individuals that populations, poverty, environmental degradation, and resource shortages were increasing at a rate that could not long be continued. Perhaps most prominent among the publications that identified these problems in hard quantitative terms and then provided extrapolations into the future as well as recommendations for corrective actions, was the book Limits to Growth (Meadows, et.al., 1972) which simultaneously evoked admiration and consternation. The consternation came from traditional “Growth is Good” groups all over the world. Their rush to rebuttal was immediate and urgent, prompted perhaps by the thought that the message of Limits was too terrible to be true. (Cole, et.al, 1973) As the message of Limits faded, the concept of limits became an increasing reality with which people had to deal. Perhaps, as an attempt to offset or deflect the message of Limits, the word “sustainable” began to appear as an adjective that modified common terms. It was drawn from the concept of “sustained yield” which had been used to describe agriculture and forestry when these enterprises were conducted in such a way that they could be continued indefinitely, i.e., they could be sustained. The use of the term “sustainable” provided comfort and reassurance to those who may momentarily have wondered if possibly there were limits. So the word was soon applied in many areas, and with less precise meaning, so that for example, “development” became “sustainable development,” etc. One would see political leaders using the term “sustainable” to describe their goals as they worked hard to create more jobs, to increase population, and to increase rates of consumption of energy and resources. These terms seem to have been redefined flexibly to suit a variety of objectives and conveniences.
A sincere concern for the future is certainly the factor that motivates many who make frequent use of the word, “sustainable.” But there are cases where one suspects that the word is used carelessly, perhaps as though the belief existed that the use of the adjective “sustainable” is all that is needed to create a sustainable society.
“Sustainability” has become big-time. University centers and professional organizations have sprung up using the word “Sustainable” as a prominent part of their names. In some cases, these may be illustrative of what might be called the “Willie Sutton school of research management.” (Sutton) For example, a governor recently appointed a state advisory committee on global warming. The charge to the committee was not to see what the state could do to reduce its contribution to global warming, but rather the committee was to work to attract to the state, companies and research grants dealing with the topic of global warming.
For many years, studies had been conducted on ways of improving the efficiency with which energy is used in our society. These studies have been given new luster by referring to them now as studies in the “sustainable use of energy.”
In the extreme case, one reads about “sustainable growth.”
“…the discussions have centered around the factors that will determine [a] level of sustainable growth of agricultural production.” (Abelson, 1990)
If we accept the idea that “sustainable” means for long indefinite periods of time, then we can see that “sustainable growth” implies “increasing endlessly,” which means that the growing quantity will tend to become infinite in size. The finite size of resources, ecosystems, the environment, and the Earth lead one to recognize that the term “sustainable growth” is an oxymoron. Yet the term is used by our leaders. In a recent report from the Environmental Protection Agency we read that
President Clinton and Vice President Gore wrote in Putting People First, “We will renew America’s commitment to leave our children a better nation – – a nation whose air, water, and land are unspoiled, whose natural beauty is undimmed, and whose leadership for sustainable global growth is unsurpassed.” (EPA, 1993)
And so we have a spectrum of uses of the term “sustainable.” At one end of the spectrum, the term is used with precision by people who are introducing new concepts as a consequence of thinking profoundly about the long-term future of the human race. In the middle of the spectrum, the term is simply added as a modifier to the names and titles of very beneficial studies in efficiency, etc. that have been in progress for years. Near the other end of the spectrum, the term is used as a placebo. In some cases the term may be used mindlessly (or possibly with the intent to deceive) in order to try to shed a favorable light on continuing activities that may or may not be capable of continuing for long periods of time. At the very far end of the spectrum, we see the term used in a way that is internally contradictory.
This wide spectrum of meanings is a source of confusion because people can ask, “Just exactly what is meant when the word ‘sustainable’ is used?” Is the use of the word “sustainable” sufficient to identify the user as one who is widely literate, numerate, and ecolate, in matters relating to the long-range problems of the human race?
Let us examine the use of the term “sustainable” in one of the major global reports to see if we can gain a better idea of the intended meaning of the word.
The terms “sustainable” and “sustainability” burst into the global lexicon in the 1980s as the electronic news media made people increasingly aware of the growing global problems of overpopulation, drought, famine, and environmental degradation that had been the subject of Limits to Growth in the early 1970s, (Meadows, et.al., 1972). A great burst of increased awareness came with the publication of the report of the United Nations World Commission on Environment and Development, the Bruntland Report, which is available in bookstores under the title Our Common Future. (Bruntland, 1987)
In graphic and heart-wrenching detail, this Report places before the reader the enormous problems and suffering that are being experienced with growing intensity every day throughout the underdeveloped world. In the foreword, before there was any definition of “sustainable,” there was the ringing call,
What is needed now is a new era of economic growth – growth that is forceful and at the same time socially and environmentally sustainable. (p.xii)
One should be struck by the fact that here is a call for “economic growth” that is “sustainable”. What is “economic growth?” Is it an increase in economic activity per capita, or is it an increase in total economic activity? Whatever the definition, one has to ask if it is possible to have an increase in ecomomic activity without having increases in the rates of consumption of non-renewable resources? If so, under what conditions can this happen? Are we moving toward those conditions today? As we have seen, these two concepts of “growth” and “sustainability” tend to conflict with one another, yet here we see the call for both. The use of the word “forceful” would seem to imply “rapid,” but if this is the intended meaning, it would just heighten the conflict. A few pages later in the Report we read,
Thus sustainable development can only be pursued if population size and growth are in harmony with the changing productive potential of the ecosystem.(p.9)
One begins to feel uneasy. What does the Commission mean by the phrase “in harmony with…?” It can mean anything. By page 11 the Commission acknowledges that population growth is a serious problem, but then
The issue is not just numbers of people, but how those numbers relate to available resources. Urgent steps are needed to limit extreme rates of population growth.
The suggestion that “The issue is not just numbers of people” is alarming. Neither “limit” nor “extreme” are defined, and so the sentence gives the impression that most population growth is acceptable and that only the “extreme rates of population growth” (“extreme” is not defined) need to be dealt with by some undefined process of limiting. By page 15 we read that
A safe, environmentally sound, and economically viable energy pathway that will sustain human progress into the distant future is clearly imperative.
Here we see the recognition that energy is a major long-term problem and we see the important acknowledgment that “sustainable” means “into the distant future.”
As the authors of the Report searched for solutions, they called for large efforts to support “sustainable development.” The most commonly quoted definition of “sustainable development” appears in the first sentence of Chapter 2,(p.43)
Sustainable development is development that meets the needs of the present without compromisingthe ability of future generations to meet their own needs.
This definition, coupled with the earlier statement of the need to “sustain human progress into the distant future,” should form the basis for our understanding of the use of the term, “sustainable development.”
Unfortunately, the definition gives no hint regarding the courses of action that could be followed to meet the needs of the present, but which would not limit the ability of generations, throughout the distant future, to meet their own needs.
The Commission’s recognizes that there is a conflict between population growth and development:(p.44)
An expansion in numbers [of people] can increase the pressure on resources and slow the rise in living standards in areas where deprivation is widespread. Though the issue is not merely one of population size, but of the distribution of resources, sustainable development can only be pursued if demographic developments are in harmony with the changing productive potential of the ecosystem.
Can the Commission mean that population growth slows the rise of living standards only “in areas where deprivation is widespread?” This statement again plays down the role of population size in exacerbating resource and environmental problems. The Commission repeats the denial that the problems relate to population size and it shifts the blame to the distribution of resources. The Commission then speaks of “demographic developments,” whatever that may mean, which must
be “in harmony with…”, whatever that means. If one accepts reports that the “global productive potential of ecosystems” is declining, due to deforestation, the loss of topsoil, pollution, etc., then the “in harmony with…” could mean that population also will have to decline. But the Commission is very careful not to say this.
These quotations (above) are thought to be representative of the vague and sometimes contradictory messages that are in this important report.
It seems that the Bruntland Commission Report’s definition of “sustainability” was, with reason, both optimistic and vague. The Commission probably felt that the definition had to be optimistic, but given the facts, it was necessary to be vague in order not to appear to be pessimistic. Straight talk about the meaning of “sustainability” is similarly avoided in a more recent report that came out of the 1992 Earth Summit in Rio de Janerio, which was
…the largest gathering of world leaders in history [which] endorsed the principle of sustainable development. (Committee for a National Institute for the Environment, 1993)
The report carries the impressive title, Agenda 21, The Earth Summit Strategy to Save Our Planet (Sitarz, 1993) The text discusses the relation between population growth and the health of the planet.
The spiraling growth of world population fuels the growth of global production and consumption.
Rapidly increasing demands for natural resources, employment, education and social services make
any attempts to protect natural resources and improve living standards very difficult. There is an
immediate need to develop strategies aimed at controlling world population growth.(p.44)
The first sentence is quite reasonable, but in the third sentence, what is meant by “controlling?” The dictionary suggests meanings such as, “To check or regulate; to keep within limits; to exercise directing, guiding or restraining power over..” “Controlling world population growth” could mean, “hold the annual population growth rate at its present value of approximately 1.7%,” which surely was not their intent. Why do they use the phrase “controlling world population growth” when one suspects that they know full well that the critical challenge is to “stop world population growth?” Having thus made a politically correct statement of the problem, the Report then lists, under the heading, “Programs and Activities”, the things that need to be done. Here we would expect that the authors would concentrate on the hard realities. Instead, it is all whipped cream. Perhaps their
strongest recommendation is
The results of all research into the impact of population growth on the Earth must be disseminated as widely as possible. Public awareness of this issue must be increased through distribution of population-related information in the media.(p.45)
How are we going to increase public awareness of the problem of population growth if the crucial report that purports to give guidelines for the future won’t talk frankly and honestly about the problem? How are we going to educate the public about the problem of population growth if we fail ourselves to give concrete details of “the impact of population growth on the Earth?”
Then, under the next heading of “National Population Policies” we read that
The long term consequences of human population growth must be fully grasped by all nations. They must rapidly formulate and implement appropriate programs to cope with the inevitable increase in population numbers. (p.45)
The authors indicate here that they know that there are serious “long term consequences of human population growth.” These consequences could have been explored in simple, concrete, and illuminating detail, and yet the authors fail to do the exploring. The authors could have educated us about the “long-term consequences of continued population growth” and then could have
identified for us the appropriate remedial courses of action which are necessary to achieve zero growth of population as rapidly as possible. By referring to the “inevitable increase in population numbers” the authors seem to say that there is nothing that can be done.
This book is loaded with admonitions suggesting that we all go out and embark on programs that are sustainable. In enumerating the things that the authors feel have to be done, the report has both the comprehensive scope and the literary style of the Yellow Pages. The book makes many references to sustainability, yet it artfully dodges the central issues relating to the meaning of “sustainability.”
Distribution, harmony, and “improvement in the capacity to assess the implications of population patterns” are important, but it seems clear that improvements in the human condition cannot be achieved without understanding and recognizing the importance of numbers, and in particular, numbers of people. As we look here in the United States, and around the world, we can see that the numbers of people are growing, and we can see places where the problems associated with the growth are so overwhelming as to make it practically impossible to address the vitally important issues of distribution, equity, and harmony.
The failure of writers to address the population problem was underscored recently by Robert M. May (May, 1993). May, who is Royal Society Research Professor at the University of Oxford and Imperial College, London, was reviewing a new book on biological diversity. He observes that the book says relatively little about the continuing growth of human populations. But this is the engine that drives everything. Patterns of accelerating resource use, and their variation among regions, are important but secondary: problems of wasteful consumption can be solved if population growth is halted, but such solutions are essentially irrelevant if populations continue to proliferate. Every day the planet sees a net increase (births less deaths) of about one quarter of a million people. Such numbers defy intuitive appreciation. Yet many religious leaders seem to welcome these trends, seemingly motivated by calculations about their market share. And governments, most notably that of the U.S., keep the issue off the international agenda; witness the Earth Summit meeting in Rio de Janerio. Until this changes, I see little hope.
THE ROLE OF COMPROMISE ON QUESTIONS OF THE ENVIRONMENT
Environmental conflicts are often portrayed in ways that pit the needs of humans against the needs of the environment, perhaps in the belief that most people feel that the environment is unlimited, and therefore how it is treated is irrelevant. This leads to calls for compromise. Humans will take a little of the environment, and some of the environment will be temporarily left untouched. It is urgent that we be aware that these compromises reduce the rate of destruction of the environment (which is good), but in most instances, the ultimate result of a succession of many compromises is the destruction of the environment. For example, instead of losing 60% of the local environment in some proposed development, a compromise might result in loss of only 30% of the environment, while 70% is saved. This is good; but one needs to know that a series of ten such compromises, each of which saves 70% of the remaining environment, will result in the loss of all but about 3% of the environment. (0.710 = 0.03) There have been situations where compromises have resulted in the preservation of large reserves in order to allow other critical areas to be set aside for human settlement and agriculture. It will be interesting to see how these compromises hold up in the face of the pressures of growing populations.
Preserving the environment can lead to frustrations. In contrast to the active promotion of population growth that is seen in most communities, a community can go to great effort and expense to purchase and to preserve open space for the benefit of generations yet to come. The result is predictable. People, industries, and businesses want to move to the communities that have preserved open space and have other environmentally sensitive programs and policies. Thus the effort to preserve a local environment helps to destroy the preservation that has been achieved.
Jerome B. Wiesner was President of M.I.T. (1971-1980) and was Special Assistant for Science and Technology for Presidents Kennedy and Johnson. He made a very sobering observation about the conflict between the needs of humans and the needs of the environment. (Wiesner, 1989)
There are no clear-cut ways to reconcile economic growth with the measures needed to curb
environmental degradation, stretch dwindling natural resources and solve health and economic
The term “carrying capacity,” long known to ecologists, has also recently become popular. It “refers to the limit to the number of humans the earth can support in the longterm without damage to the environment.” (Giampietro, et al, 1992) The troublesome phrase here is “without damage to the environment.” One damages the environment when one kills a mosquito, builds a fire, erects a house, develops a subdivision, builds a power plant, constructs a city, explodes a nuclear weapon, or wages nuclear war. Which, if any, of these things takes place “without damage to the environment?” Although it is not stated explicitly, the term “can support” must mean “for a very long time.”
There are two ways of viewing damage to the environment. At one extreme, one could hold the view that humans are apart from the environment, so that everything humans do damages the environment. At the other extreme, one could view humans as part of the environment, so that everything humans do is a part of the course of nature and hence, by definition, is not damaging
to the environment.
Human activities have already caused great change in the global environment. May observes that (May, 1993)
…the scale and scope of human activities have, for the first time, grown to rival the natural processes that built the biosphere and that maintain it as a place where life can flourish.
Many facts testify to this statement. It is estimated that somewhere between 20 and 40 percent of
the earth’s primary productivity, from plant photosynthesis on land and in the sea, is now
appropriated for human use. Perhaps the definition of carrying capacity means, “without further damage to the environment?” But then we note that growing populations need growing numbers of jobs and growing rates of consumption of resources. The satisfaction of these needs is almost always at the expense of the environment. So, if we do not want to do further damage to the environment, it seems logical that, as a minimum, we must stop population growth. When we talk about carrying capacity we must focus on population numbers and on the long term. This inevitably leads to a recognition of the need to stop population growth.
It is most probable that the term “carrying capacity” has to imply attaining a period of negative growth of populations, until populations and life styles reach a level that can be maintained indefinitely (sustained) by the world’s biological and physical resources. The widespread rejection of this conclusion leads one to be certain that every estimate of the number of people that constitutes the carrying capacity of a country or of the Earth will be a subject of controversy. In some cases different scientists will intrepret the data differently. In other cases the entire concept of carrying capacity will come under political and ideological attack. For example, when Jack Kemp, who was then the U.S. Secretary of Housing and Urban Development, was informed of a report from the United Nations that told of resource problems that would arise because of increasing populations, it was reported that he said, “Nonsense, people are not a drain on the resources of the planet.” (Kemp, 1992) Malcolm Forbes, Jr. Editor of Forbes Magazine had a similar response to the reports of global problems resulting from overpopulation in both the developed and underdeveloped parts of the world; “It’s all nonsense.” (Forbes, 1992) This helps make the concept of “carrying capacity” contentious and and hence an unpopular one for political leaders to embrace. None the less, carrying capacity is a vitally important concept, and it must become central to our thinking.
POPULATION AND THE ENVIRONMENTAL PROTECTION AGENCY
The U.S. Environmental Protection Agency has done many constructive and beneficial things. The policies, actions, and leadership of the Agency are crucial to any hope for a sustainable society. In a recent report we read,
In view of the increasing national and international interest in sustainable development, Congress has asked the Environmental Protection Agency (EPA) to report on its efforts to incorporate the concepts of sustainable development into the Agency’s operations.
The Report (EPA, 1993) is at once encouraging and distressing. It is encouraging to read of all of the many activities of the Agency which help protect the environment. It is distressing to search in vain through the Report for acknowledgment that population growth is at the root of most of the problems of the environment. Unlike the report of the Bruntland Commission, the EPA report avoids making the allegation that population growth is not the central problem. The EPA report makes only a very few minor references to the problems of urban population growth.
The Report speaks of an initiative to pursue sustainable development in the Central Valley of California where many areas are experiencing rapid urban growth and associated environmental problems….
A stronger emphasis on sustainable agricultural practices will be a key element in any long- tern
solutions to problems in the area.
“A stronger emphasis on sustainable agricultural practices” won’t stop “rapid urban growth and the associated environmental problems…” and hence, an emphasis on agriculture can not solve the problem. If the EPA is to address the “associated environmental problems”, it would seem to be more important to focus on stopping the “rapid urban growth” which causes the problems. Why focus on the development of “sustainable agricultural practices” when agriculture will be displaced by the “rapid urban growth.” However, if “A stronger emphasis on sustainable agricultural practices” means protect agricultural land from any further loss to developments, then perhaps there is logic to the statements quoted above.
In general, with our present social systems, agriculture, sustainable or otherwise, can’t be maintained in the face of urban population growth.
In speaking of the New Jersey Coastal Management Plan for the management of an environmentally sensitive tidal wetland, the Report says
The project involves balancing the intense development pressures in the area with wetlands wildlife protection, water quality, air quality, waste management, and other environmental considerations.
Here we are “balancing” again. In many ways, a series of balances is a way to “Sacrifice the environment in an environmentally sensitive way.”
In the Pacific Northwest
The EPA…is an active participant in these discussions, which focus on sustaining high quality natural resources and marine ecosystems in the face of rapid population and economic growth in the area.
These quotations of minor sections of the EPA report make it clear that the EPA understands the origin of environmental problems. Thus it is all the more puzzling that the Agency so carefully avoids serious discussion of the fundamental source of so many of the problems it is supposed to address.
In this report of approximately 30 pages on the Agency’s programs relating to sustainable development, the term “sustainable development” is mentioned hundreds of times, and population growth, the most important variable in the equation, is mentioned just these few times. It is as though one attempted to build a 100 story skyscraper from good materials, but one forgot to put in
A proposal for the establishment of a “National Institute for the Environment” (1993) is being advanced. If the proposed institute is to be effective, its mission and charge must include, “Studying the demographic causes and consequences of environmental problems.”
A PERIOD OF TIME
The pertinent definition of “sustain” is “to maintain, or to cause to continue…” The definition suggests that things can be sustained for long periods of time. Thus, when the Bruntland Report speaks of “Future generations” and “into the distant future,” it would seem to mean “for all future generations” or “forever.”
Let us be specific and state that both “Carrying Capacity” and “Sustainable” imply “for the period in which we hope humans will inhabit the earth.” This means “for many millenia.”
In what follows, “standard of living” is to be thought of in terms of the average annual per-capita consumption of goods; “carrying capacity” refers to the number of people that can be sustained. The term “resources” refers to virgin resources, while “goods” can include both virgin and recycled materials.
LAWS, HYPOTHESES, OBSERVATIONS AND PREDICTIONS
RELATING TO SUSTAINABILITY
The laws, hypotheses, observations, and predictions that follow are offered to define the term “sustainability” which must be understood to mean, “for many millenia.” In some cases these statements are accompanied by corollaries that are identified by capital letters. They all apply for populations and rates of consumption of goods and resources of the sizes and scales found in
the world in 1994, and may not be applicable for small numbers of people or to groups in primitive tribal situations.
These laws are believed to hold rigorously.
The hypotheses are less rigorous than the laws. There may be exceptions to some, and some may be proven to be wrong. Experience may show that some of the hypotheses should be elevated to the status of laws.
The observations may shed light on the problems and on mechanisms for finding solutions to the problems.
The predictions are those of a retired nuclear physicist who has been watching these problems for several decades.
The lists are but a single compilation, and hence may be incomplete. Readers are invited to communicate with the author in regard to items that should or should not be in these lists.
In many cases, these laws and statements have been recognized, set forth, and elaborated on by others.
GARRETT HARDIN’S THREE LAWS OF HUMAN ECOLOGY
We start by repeating three laws of human ecology that are given by Garrett Hardin. (Hardin, 1993) These are fundamental, and need to be known and recognized by all who would speak of sustainability.
First Law: “We can never do merely one thing.”
This is a profound and eloquent observation of the interconnectedness of nature.
Second Law: “There’s no away to throw to.”
This is a compact statement of one of the major problems of the “effluent society.”
Third Law: The impact (I) of any group or nation on the environment is represented qualitatively by the relation
I = P A T
where P is the size of the population, A is the per-capita affluence, measured by per-capita consumption, and T is a measure of the damage done by the technologies that are used in supplying the consumption. Hardin attributes this law to Ehrlich and Holdren. (Ehrlich and Holdren, 1971)
The suggestion may be made that the Third Law is too conservative. The Third Law suggests that I varies as Pn where n = 1. There are situations where the impact of humans increases more rapidly than linearly with the size of the population P so that n > 1.
BOULDING’S THREE THEOREMS
These theorems are from the work of the eminent economist Kenneth Boulding. (Boulding, 1971)
First Theorem: “The Dismal Theorem” “If the only ultimate check on the growth of population is misery, then the population will grow until it is miserable enough to stop its growth.”
Second Theorem: “The Utterly Dismal Theorem” This theorem “states that any technical improvement can only relieve misery for a while, for so long as misery is the only check on population, the [technical] improvement will enable population to grow, and will soon enable more people to live in misery than before. The final result of [technical] improvements, therefore, is
to increase the equilibrium population which is to increase the total sum of human misery.”
Third Theorem: (“The moderately cheerful form of the Dismal Theorem”) “Fortunately, it is not too difficult to restate the Dismal Theorem in a moderately cheerful form, which states that if something else, other then misery and starvation, can be found which will keep a prosperous population in check, the population does not have to grow until it is miserable and starves, and it can be stably prosperous.”
Boulding continues, “Until we know more, the Cheerful Theorem remains a question mark. Misery we know will do the trick. This is the only sure-fire automatic method of bringing population to an equilibrium. Other things may do it.”
LAWS RELATING TO SUSTAINABILITY
First Law: Population growth and/or growth in the rates of consumption of resources cannot be sustained.
A) A population growth rate less than or equal to zero and declining rates of consumption of resources are necessary, but are not sufficient, conditions for a sustainable society.
B) Unsustainability will be the certain result of any program of “development,” whether or not it is said to “sustainable,” that ignores the problem of population growth and that does not plan the achievement of zero or a period of negative growth of populations and of rates of consumption of resources.
C) The research and regulation programs of governmental agencies that are charged with protecting the environment and promoting “sustainability” are, in the long run, irrelevant unless these programs address vigorously and quantitatively the determination of carrying capacities and unless the programs study in depth the demographic causes and consequences of environmental problems.
D) Societies, or sectors of a society, that depend on population growth or growth in their rates of consumption of resources, are unsustainable.
E) Persons who advocate population growth and/or growth in the rates of consumption of resources are advocating unsustainability.
F) Persons whose actions directly or indirectly cause increases in population or in the rates of consumption of resources are moving society away from sustainability. (Advertising your city or state as an ideal site in which to locate new factories indicates a desire to increase the population of your city or state.)
G) The term “Sustainable Growth” is an oxymoron.
Second Law: In a society with a growing population and/or growing rates of consumption of resources, the larger the population, and/or the larger the rates of consumption of resources, the more difficult it will be to transform the society to thecondition of sustainability.
Third Law: The response time of populations to changes in the total fertility rate is the length of time people live from their child-bearing years to the end of life, or approximately fifty years. (This is called “population momentum.”)
A) If we want the population sizes to be reduced or at least stabilized by the mid-21st century, we must make the necessary changes in the total fertility rates before the end of the 20th century.
B) The time horizon of political leaders is of the order of two to eight years.
C) It will be difficult to convince political leaders to act now to change course, when the full results of the change may not be apparent in those leaders’ lifetimes.
Fourth Law: The size of population that can be sustained (the carrying capacity) and the sustainable average standard of living of the population are inversely related to one another.
A) The higher the standard of living one wishes to sustain, the more urgent it is to stop population growth.
B) Reductions in the rates of consumption of resources and reductions in the rates of production of
pollution can shift the carrying capacity in the direction of sustaining a larger population.
Fifth Law: Sustainability requires that the size of the population be less than or equal to the carrying capacity of the ecosystem for the desired standard of living.
A) Sustainability requires an equilibrium between human society and dynamic but stable ecosystems.
B) Destruction of ecosystems tends to reduce the carrying capacity and/or the sustainable standard of living.
C) The rate of destruction of ecosystems increases as the rate of growth of the population increases.
D) Population growth rates less than or equal to zero are necessary, but are not sufficient, conditions for halting the destruction of the environment.
Sixth Law: (The lesson of “The Tragedy of the Commons”) (Hardin,1968):
The benefits of population growth and of growth in the rates of consumption of resources accrue to individuals; the costs of population growth and growth in the rates of consumption of resources are borne by all of society.
A) Individuals who benefit from growth will continue to exert strong pressures supporting and encouraging both population growth and growth in rates of consumption of resources.
B) The individuals who promote growth are motivated by the recognition that growth is good for them. In order to gain public support for their goals, they must convince people that population growth and growth in the rates of consumption of resources, are also good for society. This is the Charles Wilson argument: if it is good for General Motors, it is good for the United States. (Yates, 1983)
Seventh Law: Growth in the rate of consumption of a non-renewable resource, such as a fossil fuel, causes a dramatic decrease in the life-expectancy of the resource.
A) In a world of growing rates of consumption of resources, it is seriously misleading to state the life-expectancy of a non-renewable resource “at present rates of consumption,” i.e., with no growth.
B) It is intellectually dishonest to advocate growth in the rate of consumption of a non- renewable resource while, at the same time, reassuring people about how long the resource will last “at present rates of consumption.”
Eighth Law: The time of expiration of non-renewable resources can be postponed, possibly for a very long time, by
i) technological improvements in the efficiency with which the resources are recovered and used
ii) using the resources in accord with a program of “Sustained Availability,” (Bartlett, 1986)
iv) the use of substitute resources.
Ninth Law: When large efforts are made to improve the efficiency with which resources are used, the resulting savings are easily and completely wiped out by the added resource needs that arise as a consequence of modest increases in population.
A) When resources are used more efficiently, the consequence often is that the “saved” resources are not put aside for the use of future generations, but instead are used immediately to encourage and support larger populations.
B) Humans have an enormous compulsion to find an immediate use for all available resources.
Tenth Law: The benefits of large efforts to preserve the environment are easily canceled by the added demands on the environment that result from small increases in human population.
Eleventh Law: (Second Law of Thermodynamics) When rates of pollution exceed the natural cleansing capacity of the environment, it is easier to pollute than it is to clean up the environment.
Twelfth Law: (Eric Sevareid’s Law); The chief cause of problems is solutions. (Sevareid, 1970)
A) This law should be a central part of higher education, especially in engineering.
B) Solutions of neighborhood problems cause city problems:
Solutions of city problems cause county problems:
Solutions of county problems cause regional problems:
Solutions of regional problems cause statewide problems:
Thirteenth Law: Humans will always be dependent on agriculture.
A) Supermarkets alone are not sufficient.
B) The central task in sustainable agriculture is to preserve agricultural land. The agricultural land must be protected from losses due to things such as
i) Urbanization and development
iii) Poisioning by chemicals
Fourteenth Law: If, for whatever reason, humans fail to stop population growth and growth in the rates of consumption of resources, nature will stop these growths.
A) Nature’s method of stopping growth is cruel and inhumane.
B) Glimpses of nature’s method of dealing with population that have exceeded the carrying capacity of their lands can be seen each night on the television news reports from places where large populations are experiencing starvation and misery.
Fifteenth Law: Starving people don’t care about sustainability.
A) If sustainability is to be achieved, the necessary leadership and resources must be supplied by people who are not starving.
Sixteenth Law: The addition of the word “sustainable” to our vocabulary, to our reports, programs, and papers, and to the names of our academic institutes and research programs, is not sufficient to ensure that our society becomes sustainable.
Seventeenth Law: Extinction is forever.
HYPOTHESES RELATING TO SUSTAINABILITY
1) For the 1994 average global standard of living, the 1994 population of the Earth exceeds the carrying capacity of the Earth.
2) For the 1994 average standard of living in the United States, the 1994 population of the United States exceeds the carrying capacity of the United States. (Abernethy, 1993), (Giampietro and Pimentel, 1993)
3) The increasing sizes of populations that result from population growth are the single greatest and most insidious threat to representative democracy.
4) The costs of programs to stop population growth are small compared to the costs of population increases.
5) For society as a whole, population growth never pays for itself. (This is a consequence of the Tragedy of the Commons.)
A) In the U.S. in general, the larger the population of a city, the higher are the municipal per-capita annual taxes.
6) The time required for a society to make a planned transition to sustainability on its own terms, so it can live within the carrying capacity of its ecosystem, increases with increases in
i) the size of its population
ii) the rate of growth of its population
iii) the society’s average per-capita rate of consumption of new resources.
7) The rate (S) at which a society can improve the average standard of living of its people is directly related to the rate of application of new technologies (T) and is inversely related to the rate of growth (R) of the size of the population (the fractional increase per unit time), by a relation with the general properties of the equation,
S = T – A R + B
where A and B are positive constants.
A) In places in the world in 1994, the value of R (the rate of growth of population) is so large that it is causing S to be negative. Said in other words,
a) Population growth competes with and slows down the rate of improvement of the average standard of living and may cause the average standard of living to decline. In other words,
b) Population growth interferes with economic growth.
8) Social stability is a necessary, but not a sufficient, condition for sustainability.
A) Human freedoms depend on social stability.
B) Armed conflict (war) cannot be a part of a sustainable society.
9) In some cases, social stability tends to be inversely related to population density.
10) The per-capita burden of the lowered standard of living that generally results from population growth and from the decline of resources falls most heavily on the poor.
11) When populations are growing, the rate of growth of the fraction of the population that is poor exceeds the rate of growth of the fraction of the population that is wealthy.
12) Environmental problems cannot be solved or ameliorated by increases in population or by increases in the rates of consumption of resources.
A) Probably all environmental problems would be easier to solve if the population were smaller and/or if the rates of consumption of resources were smaller.
13) Problems of shortages of non-renewable resources cannot be solved or ameliorated by population growth.
14) In general, the environment cannot be enhanced or even preserved through compromises.
A) Compromises and accommodations between the immediate needs of people and the long-term needs of the environment will generally be resolved in favor of people. For the most part, compromises only reduce the rate of destruction of the environment or they increase the elegance with which the environment is destroyed.
15) The fractional rate of destruction of the environment that results from human activities will always exceed the fractional rate of increase of our knowledge and understanding of the environment.
A) Every decision affecting the environment will have to be made with less than full knowledge of the risks and consequences of the decision.
B) Much of our knowledge of the environment has come from the study of past mistakes.
C) It will always be possible for persons to delay the implementation of corrective measures, claiming that our information about the problems is incomplete.
16) By the time overpopulation and shortages of resources are obvious to most people, the carrying capacity has been exceeded. It is then almost too late to think about sustainability.
A) It is difficult to know what to do once one realizes that the population is too large.
B) Long-range thinking, planning, and leadership, carried out with a full recognition of the laws of nature, is most urgently needed.
17) Importing non-renewable natural resources demonstrates unsustainability; exporting non- renewable natural resources reduces the ultimate sustainable standard of living and/or the carrying capacity of the exporting country.
18) Because of the universal nature of world trade, the concept of “carrying capacity” is difficult to apply to a nation or region.
A) Sustainability is a global problem.
B) The approach to stainability must be sought on the local and national levels.
C) If a local official speaks of his/her community being sustainable, it probably is not true.
19) Sustainable agriculture cannot be based on large annual energy inputs from fossil fuels, and in particular from petroleum.
i) “The food system consumes ten times more energy than it provides to society in food energy.” (Giampietro and Pimentel, 1993)
20) Irrigation of farmland, as it has been practiced throughout history and up to the present time, cannot be sustained. (Abernethy, 1993, p.136)
i) The lands become poisoned with salts.
21) Hydroelectric power generated from reservoirs created by construction of large dams, cannot be sustained.
i) The reservoirs fill with silt.
OBSERVATIONS RELATING TO SUSTAINABILITY
1) The first and most important effort that must be made in order to move toward a sustainable society is to stop population growth. This will require the initiation of major comprehensive educational, technical, and outreach programs in the areas of social responsibility, contraception, family planning, and immigration control. The greater the degree to which themcarrying capacity has been exceeded, the more probable it is that coercion will become a factor in these programs.
2) The food chain is nature’s equilibrium mechanism. It functions to prevent unlimited expansion of populations of flora and fauna. Primitive human societies were able to maintain approximately constant populations and to live within the carrying capacity of their ecosystems. The methods used were often cruel and inhumane. Technology has given many people the feeling that humans are exempt from the constraint of limited carrying capacities.
3) Ancient civilizations have vanished, in part because they grew too large and their size exceeded the carrying capacity of the ecosystems on which they depended for support.
a) Civilizations today show considerable tendency to repeat the mistakes of earlier civilizations, but on a much larger scale.
4) The complete era of the use of fossil fuels by humans will be a vanishingly short fraction of the span of human existence on the Earth.
5) The supplies of all non-renewable resources will effectively expire when the costs (in cash, in energy, in ecological and societal disruption) of making available a quantity of the resource exceed the value of the quantity of the resource.
6) Comprehensive educational, technical, and outreach programs in the areas of efficient use of resources will be needed in order to help achieve sustainability.
7) A major use of technology is, and has been, to accommodate the growth of populations, and to remove the recognition of the importance of living within the carrying capacity of the environment. (See Boulding’s Utterly Dismal Theorem and Eric Sevareid’s Law)
A) This use of technology has had the effect of encouraging population growth.
B) This use of technology inhibits an approach to sustainability.
C) An essential condition for sustainability is that technology be redirected toward the improvement of the quality of life and away from its use to increase the quantity of life.
8) Creating jobs increases the number of people out of work.
In a city or state, creating jobs increases the population, of which 5% to 7% are always unemployed. It follows that the increase in population that is the result of the creation of jobs is always reflected as an increase in the number of people out of work. This is the direct consequence of the ease with which people can move from places with high unemployment to places with low unemployment. In this regard, the movement of people is like the movement of molecules of an ideal gas, that tend to move until they achieve a constant pressure throughout a closed vessel.
A) If it is desired to maintain an “island” of low unemployment, in a nation, a state, or a community, one must erect barriers to prevent the in-migration of unemployed people.
TECHNICAL PREDICTIONS RELATING TO SUSTAINABILITY
1) Coal and/or oil shale, may last 200 years. Other fossil fuels probably will not be available in globally significant quantities for more than a few decades into the 21st century.
2) If replacements can be found for fossil fuels, especially for petroleum, it will require major technological breakthroughs.
3) Technological progress in the future is much more likely to be characterized by incremental advances than by breakthroughs, especially in the field of sources of energy.
4) The probability is very small that technological developments will produce new sources of energy in the next century, sources not already known in 1994, that will have the potential of supplying a significant fraction of the world’s energy needs for any appreciable period of time.
5) The larger the global total daily demand for energy, the smaller is the probability that a new energy source or technology will be found that will have the potential of being developed sufficiently to meet an appreciable fraction of the global daily energy demand for any extended period of time.
6) The larger the global total daily demand for energy, the longer is the period of time that will be required for a new energy technology to be developed to the point where it will have the capacity of meeting an appreciable fraction of the global daily energy demand.
7) In the event that science and technology find a new source of large quantities of energy, the probability is high that the new source will be technologically very complex, with the result that it will be extremely costly to bring globally significant quantities of the new energy to the marketplace.
8) Children born in 1990 will not live to see 10% of the energy consumed in the U.S. generated by terrestrial nuclear fusion.
9) There will always be popular and persuasive technological optimists who believe that population increases are good, and who believe that the human mind has unlimited capacity to find technological solutions to all problems of crowding, environmental destruction, and resource shortages.
A) These technological optimists are usually not biological or physical scientists.
B) Politicians and business people tend to be eager disciples of the technological optimists.
10) Because population growth is only one of the factors that drives up the cost of living, the rate of increase of the cost of living will probably be larger than the rate of increase of population.
POLITICAL PREDICTIONS RELATING TO SUSTAINABILITY
1) Local and regional business and political leaders will continue to spend much of their time trying to attract new industries and populations to their areas, and to spend a prominent few minutes a week complaining and wondering what to do about the increasing pollution, congestion, crime, costs, etc.
2) Local and regional political and business leaders will continue to use the circular arguments of self- fulfilling predictions in order to generate local population growth. These are the steps in the cycle.
i) Quantitative projections of future population growth in the area are made.
ii) Plans are made to expand the municipal or regional infrastructure to accomodate the predicted growth.
iii) Bonds are issued to raise money to pay for the planned expansions of the infrastructure, and the infrastructure is expanded.
iv) The bonds must be paid off on a schedule that is based on the projections of population growth.
v) The political and business leaders will do everything in their power to make certain that the projected population growth takes place, so that the bonds can be paid off on schedule.
vi) When this results in the needed population growth, the leaders will speak loudly of their foresight.
vii) Go back to i) and repeat.
3) Some political and business leaders will continue to want to throw away all manner of toxic waste by dumping it on the lands of low-income or underdeveloped people, in the U.S. or abroad.
4) Some business leaders will want to continue to manufacture hazardous materials whose sale in the U.S. is prohibited, so that these materials can be sold abroad.
5) Business and political leaders will continue to find it more attractive to promote growth than to promote sustainability.
A) It is easy to talk about sustainability.
B) It is difficult to make realistic constructive progress toward sustainability
C) Business and political leaders are not attracted to the concept of a “carrying capacity.”
6) In the U.S., political “conservatives” will continue to be liberal in their policy recommendations in regard to rapid exploitation and use of the earth’s renewable and non-renewable resources, with complete confidence that technology will be able to solve all of the consequent problems of shortages, pollution, and environmental degradation. Political “liberals” will continue to urge people to be conservative, to conserve and to protect the environment, to recycle, to use energy more efficiently, etc.
7) Entrepreneurs and politicians will continue to use the term “sustainable” for their own personal advantage in promotion of enterprises and programs, whether or not these enterprises and programs are sustainable or contribute to the creation of a sustainable society.
SO WHERE DO WE GO FROM HERE?
The challenge of making the transition to a sustainable society is enormous, in part because there are so many aspects of the problem. If one glances through Agenda 21, The Earth Summit Strategy to Save Our Planet, one is overwhelmed by the sheer number of pages of recommendations, “We must do this,” “We must do that,” etc. The book does avoids the population problem, even though the authors have to know that population growth is the central and most fundamental human problem. Agenda 21 seems to be a diversion to keep people from recognizing the centrality of population growth to the enormous problems of the U.S. and the world. The immediate task is to get the population program back at the top of the national and global agendas.
The year 1992 was the year of the United Nations Conference on Environment and Development, the Earth Summit, that was held in Rio de Janerio. The year also marked the end of a long period of dangerous withdrawal of the U.S. from its active support of family planning programs throughout the world. This long period was characterized by the belief that the human mind could use technology to overcome all limits, so that carrying capacity was not an issue, and population increases should be welcomed rather than avoided. (Bartlett, 1985)
There are signs now that things have changed for the better and that there is a recognition in the top echelons of governments that population is the problem. The Mid-Atlantic Preparatory Consultation meeting in Airlie, Virginia urged the 1994 International Conference on Population and Development in Cairo, Egypt to focus on a number of important topics, including
A clear statement of the linkages between population, environment, economic growth and
sustainable development. (Popline, 1993)
President Fidel Ramos of the Phillipines delivered the keynote address at a workshop for implementing the Rio Earth Summit’s Agenda 21 in the Phillipines. (Ramos, 1993)
I believe that…the serious imbalance that today threatens the sustainability of both our economy and our environment has arisen primarily from our pervasive and proliferating population growth.
There are many encouraging signs from communities around the U.S. that indicate a growing awareness of the local problems of continued unrestrained growth of populations. It has been noted that creating jobs increases the number of people out of work, and that population growth in our communities never pays for itself. Taxes and utility costs must escalate in order to pay for the growth. For example, in the U.S., it costs the order of $15,000 per pupil to build a new school building. If each new home has, on the average, 0.4 school-age children, then each new house that is built creates the need for about $6000 of tax money for school construction. In addition, growth brings increased demands on all municipal utilities and brings increased levels of congestion, frustration, and air pollution.
In recent years, several states have seen taxpayer revolts in the form of ballot questions that were adopted to limit the allowed tax increases. These revolts were not in decaying rust-belt states, the revolts have been in the states that claimed to be the most prosperous because they had the largest rates of population growth. Unfortunately, these limitations on taxation, that were made necessary by population growth, and that were intended to stop or slow the increase of taxes, have not stopped the population growth which was the root cause of much of the increase in taxes.
At the local or state levels, there is an interesting parallel between the promotion of growth and the promotion of war. The waging of war is the sole enterprise of large military establishments. Even the lowest mind knows what has to be done to win a war; “One has to beat the opponent,” after which one can have a large party to celebrate the victory, and then one starts preparing for the next war. Promoting community growth is quite similar. The promotion of growth is the sole enterprise of large
municipal and state establishments. It does not take much of a mind to know that growth requires that you beat some competing community in the effort get new factories to come to your community. Campaigns and battles are planned, and, when a factory comes, you can have a large party to celebrate the victory, after which, you start looking for new factories.
In contrast, winning the peace is quite different. Even the best minds don’t know for sure what is the best way to “win the peace.” There is no large public establishment that is devoted to or has a vested interest in maintaining the peace. There is noterminal point at which a party is in order where we can celebrate the fact that, “We won the peace!” Winning the peace takes eternal vigilance. Protecting the community environment is quite parallel. The best minds don’t know for sure the best way to do it. There are few public establishments whose sole role is to preserve the environment. One can postpone assaults on the environment, but by and large, it takes eternal vigilance of concerned citizens, who, at best, can only reduce the rate of loss of the environment. There is no terminal time at which one can have a party to celebrate that, “We have saved the environment!”
How do we work on the local problem? Many years ago I was discussing population growth of Boulder with a prominent member of the Colorado Legislature. At one point he said,
“Al, we could not stop Boulder’s growth if we wanted to!”
“I agree, therefore let’s put a tax on the growth so that, as a minimum, it pays for itself, instead of having to be paid for by the existing taxpayers.”
His response was quick and emphatic.
“You can’t do that, you’d slow down our growth!”
His answer showed the way. On the community level in the U.S., we should work to make growth pay for itself. The Tragedy of the Commons makes it clear that there will always be large opposition to programs of making population growth pay for itself. The promoters of growth will use their considerable resources to convince the community that the community should pay the costs of growth. In our communities, making growth pay for itself could be a major factor in slowing and
possibly stopping the population growth.
On the local and national levels, we need to work to improve social justice and equity. The series of big city riots of the recent decades are symptoms of a deep-seated illness that we have ignored too long. The illness is certainly made worse by the rapid population growth that consumes public and private resources in order to give minimal accomodation to the growth. The resources that are used to support the growth are taken away from all manner of community programs that are essential for improving education, justice, and equity. Injustice and inequity breed unrest and discontent. When a condition of instability is reached, things can happen with surprising speed. We were all stunned by the swiftness of the fall of the Soviet Union.
On the national scale, we can hope for leaders who will recognize that population growth is a major problem in the U.S. With a lot of work at the grassroots, our system of representative government will respond.
As we enter an era of expanded global trade, we need to know that the ease of international trade serves to block out our recognition of the concept of “carrying capacity.” These other countries with which we trade with such ease seem to provide an “away” from which we can get resources and to which we can later throw things made from those resources. International trade interferes with our understanding of the concept of limits.
On the global scale, we need to support family planning throughout the world, and we should restrict our foreign aid and send it only to those countries that make continued demonstrated progress in reducing population growth rates. Kenneth Boulding observed that, “The economic analysis I presented earlier indicates that the major priority, and one in which the United Nations
can be of great utility, is a world campaign for the reduction of birth rates. This, I suggest, is more important than any program of foreign aid and investments. Indeed, if it is neglected, all programs of aid and investment will, I believe, be ultimately self-defeating and will simply increase the amount of human misery.” (Boulding, 1971, p.361)
If we work on the problem of population growth in our communities, counties, and states, it is possible that our leaders in Washington, D.C. will get the message and follow the people. There is reason to be optimistic.
In writing about the essay of Malthus on population, Boulding observes that the essay, “punctures the easy optimism of the utopians of any generation. But by revealing the nature of at least one dragon that must be slain before misery can be abolished, its ultimate message is one of hope, and the truth, however unpleasant, tends ‘not to create despair, but activity’ of the right
kind.” (Boulding, 1971, p.142)
A THOUGHT FOR THE FUTURE
When competing “experts” recommend diametrically opposing paths of action regarding resources, carrying capacity, sustainability, and the future, we serve the cause of sustainability by choosing the conservative path. This is the path that would leave society in the less precarious position if the path we choose turns out to be the wrong path.
I am greatly indebted to Profs. Robert Ristinen and Charles Southwick for their critical reading of this manuscript and to Prof. Ulrich Muller-Herold, and Juliet Serenyi for their very helpful suggestions.
Abelson, P.H.,(1990). Dialog on the Future of Agriculture (Editorial), Science, Vol.249, p.457
Abernethy, V.D., Population Politics, (Insight Books, Plenum Press, New York City, 1993), pp.245- 257
Bartlett, A.A., (1986). Sustained Availability, A Management Program for Non-Renewable Resources, American Journal of Physics, Vol.54, p.398-402.
“Sustained Availability” involves having the rate of use of a finite non-renewable resource decline steadily at a rate that guarantees that the resource will last forever.
Bartlett, A.A., (1985) Book Review, American Journal of Physics, Vol.53, March 1985, pgs.282-285
Bartlett, A.A., (1990) The Future of Fusion, Physics and Society, Vol.19, April 1990, p.2
Boulding, Kenneth, Collected Papers, Vol.II, Foreword to T.R. Malthus, Population, The First Essay, (Colorado Associated University Press, Boulder, 1971), pp.137-142
Bruntland, G.H., , Our Common Future, World Commission on Environment and Development, (Oxford University Press, 1987)
Cole, H.S.D., Freeman, C, Jahoda, M, and Pavitt, K.L.R., eds. Models of Doom: A Critique of Limits to Growth, (Universe Books, New York City, 1973)
Committee for the National Institute for the Environment., Proposal for a National Institute for the Environment. Washington, D.C., Sept.1993
EPA, Sustainable Development and the Environmental Protection Agency, Report to the Congress, EPA 230-R-93-005, June 1993, p.2. The EPA report attributed this statement to Governor Bill Clinton and Senator Al Gore, Putting People First: How We Can All Change America,
(Times Books, New York City, 1992), p.94-95
Ehrlich, P., Holdren, J., The impact of Population Growth, Science, Vol.171, (1971), 1212-1217
Forbes, M.S.,Jr. Fact and Comment, Forbes Magazine, June 8, 1992, p.25
Giampietro, M., Bukkens, S.G.F., Pimentel, D.,(1992). Limits to Population Size: Three Scenarios of Energy Interaction Between Human Society and Ecosystem., Population and Environment. Vol.14, p.109-131.
Giampietro, M, Pimentel, D. The Tightening Conflict: Population, Energy Use, and the Ecology of Agriculture. N.P.G. Forum, (Negative Population Growth),
October 1993, pp.1-8
Hardin, G., (1968). The tragedy of the commons. Science, Vol.162, p.1243-1248
Hardin, G., Living Within Limits, 1993, (Oxford University Press, New York City, 1993), p.199-203
Kemp, J., quoted in High Country News, (Paonia, CO)
Jan. 27, 1992, p.4
May, R.M., The End of Biological History?, a book review in Scientific American, March 1993, p.146- 149.
Meadows, D.H., Meadows, D.L., Randers, J., Behrens, W.W., The Limits to Growth: A Report for the Club of Rome’s Project on the Predicament of Mankind. (Universe Books, New York City, 1972)
Popline, World Population News Service, Nov./Dec., 1993, p.4
Ramos, F., Popline , World Population News Service, Nov./Dec. 1993, p.1
Sevareid, E., CBS News, December 29, 1970,
Quoted in Martin, T.L.,Malice in Blunderland,
(McGraw-Hill Book Co., New York City, 1973)
Sitarz, D., Editor, Agenda 21; The Earth Summit Strategy to Save our Planet, (EarthPress, Boulder, CO, 1993)
Sutton, Willie, was a legendary bank robber. When asked why he robbed banks, he is said to have responded, “That’s where the money is!”
Wiesner, J.B., Scientific American, Jan. 1989, p.39
Yates, B., The Decline and Fall of the American Automobile Industry, (Empire Books, New York City, 1983), p.123.
Charles E. Wilson was president of General Motors who “would outrage many with his aphorism: ‘What is good for the country is good for General Motors and vice versa.”