Chapter 2: A New Way of Living

Regaining Compassion for Humanity and Nature
by L. Charles Birch

Chapter 2: A New Way of Living

Unless we change we'll get where we’re going. Anon.

Because of the strain on resources it creates, materialism simply cannot survive the transition to a sustainable world. Lester R. Brown (1990, p. 190)

Religious pietism promotes a fallacious image of the relationship of the individual to the world. A jigsaw puzzle has a picture of a human being on one side. On the other side is a picture of the world. The puzzle is solved by putting the image of the human being together and, lo and behold, when you turn the picture over you find the world is put together also! The moral this purports to convey is that to save the world you save the individuals in it.

The image is fallacious because you can no more build a new world by planning to make everybody good than you can build a perfect house by collecting a pile of perfect bricks. You may have the best bricks in the world but they wont make a house unless a number of other conditions are fulfilled. The foundations have to be secured on rock or some other suitable base. There has to be a plan of the building. Engineers need to see that stresses are evenly placed so that the walls do not collapse. Beams have to be provided to support the roof, windows and doors. Good cement has to be prepared to stick the bricks together according to the plan.

The bricks are the people in society. The plans of the building, and everything else besides the bricks, are the structure of society -- its economics, its politics, its industries, educational institutions and so on. There are good structures of society and bad ones. Even the best people will not attain the best potential of their lives when they live in a very imperfect society; for example a society that does little about the way industry pollutes the air and water and whose transport system is inadequate.

Bricks that look perfect on the surface have defects within. None of us is unambiguously good. Even what appears to be the most altruistic act of a good person is alloyed with some degree of self-interest. Even amongst the most enlightened people, the will to live truly is transmuted into ‘the will to power’. The same person who is devoted to the common good may have desires and ambitions, hopes and fears, which set them at variance with their neighbor and the world

The will to power inevitably justifies itself in terms of the morally more acceptable will to realize our true nature. This means that corruption of universal ideals is a much more persistent factor in human affairs than any simple moralistic creed is inclined to admit. Reinhold Niebuhr (1944) held that ‘evil is done, not so much by evil men, but by good men who do not know themselves’. He refers to the ‘incorruptible’ Robespierre, the Jacobins of the French Revolution, Cromwell and Lenin (p. 93).

The distinction between justice and injustice, virtue and evil is not always sharp. In the parable of the ‘last judgment’, with the separation of the sheep and the goats, Jesus says that the righteous, who stood on the right hand of the judge, protested they were not really virtuous, while the unrighteous, who were on the left side of the judge, were equally unconscious of their deeds of omission and commission. The story prompted Blaise Pascal to say, ‘The world is divided between saints who know themselves to be sinners and sinners who imagine themselves to be saints’.

No society of perfect individuals has ever existed, so far as we know. Between the years 1500 and 1700, during the great period of the Renaissance, the Reformation and the Scientific Revolution, over 50,000 people were executed as witches. A similar number were tried on the charge of witchcraft and none was acquitted (Bartlett 1991). In our own time millions of innocent people died in gas chambers because they were of Jewish descent. The children of light and the children of darkness operate in the same society. Rules have to be made to help keep behavior within some sort of acceptable boundary. The problems of the world do indeed have to do with the problems of imperfect, ignorant and wicked people. They are always with us.

Just as you need a lot of information to build a house, so you need a lot of information to build a society that functions properly. Things don’t simply fall into place without a deliberate plan. The world’s problems have to do with management on a huge scale. To begin to see what the problems are we need a lot of information on ecology, science, technology, economics and politics. If we do not have this information, people with the best will and determination in the world will not be able to rectify mistakes. We need wisdom as well as righteousness.

In contemplating the revolution needed to move toward an ecologically sustainable society, global modelers speak of information as the key to the transformation. It will be information that flows in new ways and to new recipients. Secondly they recognize that major obstacles to any such transformation are the structures of society that resist changes in flows of information such, for example, as government bureaucracies (Meadows, Meadows & Randers 1992, p. 223).

We cannot save the Earth without a change in consciousness. Yet advances are made without converting the whole of the world’s people to some chosen norm. The fact of the matter is that the creative advance of any generation rests upon the responsiveness of a small margin of human consciousness. The pitifully few are called to be a leaven in the loaf.

The world is sick. Its healthy relationships have been broken and corrupted. It is groaning in agony to be saved. As theologian Joseph Sittler once said, the whole of Lake Michigan groans in agony waiting to be set free from its bondage of decay. For biblical and early Christianity salvation was a cosmic matter (see Chapter 6). Contemporary Christianity, with its emphasis on individual salvation, has lost sight of that.


Our generation has a litany of crimes against the world to its record. Topsoil disappears at the rate of one football field each second. Arable land is covered with concrete at the rate of three football fields each minute. Forests disappear at the rate of four football fields each minute. Species disappear at the rate of one hundred a day. Add to this the greenhouse effect and the hole in the ozone layer and it becomes obvious that our present treatment of the Earth cannot continue for ever.

The world is dying. We are on an unsustainable course. A flashing red light tells us that the scale and nature of human activity has grown out of proportion relative to the capacity of the Earth to sustain it. Half the world is poor, deprived, sick and dying of malnutrition and other preventable diseases. Our relations with other living creatures is that of a despot. We are fast destroying the environment on which all life depends.

From an emphasis on concern for individuals in the first two chapters we turn to the fate of the Earth as a whole. It is not only individuals who have to be saved, but the Earth as well. This will involve a change in tune in the sense that we will be dealing with more factual information in this chapter than in the previous ones. It is therefore a little technical, but not heavily so. I have attempted to put the issues in such a way that anyone who cares to read may understand.

A new consciousness leads to a new way of living. A new way of living leads to the concept of a new sort of society whose values are different from those of the consumer society designed around the factory.

The objective of that new society can be stated quite simply. Its end result is the opposite of sick people in a dying world. The new objective is for healthy (whole) people in a healthy environment, with healthy relations to that environment. The emphasis is on the quality of life or richness of experience of the inhabitants of the Earth, for this and future generations.

How then can we hope to move from the unhealthy world to a healthy one? We need first to recognize the tremendous tension between technological progress and the health of the environment, including all organisms in it. Secondly, we need to recognize the tremendous tension between social injustice in the world today and social justice. So destructive are these two tensions that many now wonder if what we call progress will eventually lead to our demise and that of the planet. The modern worldview and its conception of the future has dead-ended in wars, genocide, the exploitation of Third World countries, increasing pollution, the disappearance of resources and the specter of omnicide. The sort of progress we have become accustomed to is the forerunner to the clanging of a funeral bell.

Modernity has failed to point a way beyond injustice and destruction of the environment. Indeed it seems impossible to attain a vision of a viable future within the parameters of the modern mind. As Erwin Laszlo (1990) has commented: ‘Coping with mankind’s current predicament calls for inner changes, for a human and humanistic revolution mobilizing new values and aspirations, backed by new levels of personal commitment and political will’ (p. 12). He went on to say that humanity’s true limits relate to inner values and attitudes, not to outward resources. Yet so often technocrats and others believe that technology will provide the answers.

The economist Julian Simon says ‘the ultimate resource is human brains’, implying that human technical ingenuity and prowess will solve all problems of resources and pollution. Such technological optimists seem to think that the economy is a flow in a single direction between two infinities; infinite resources on one side, and an infinite hole on the other side into which we can dump all our wastes.

The life of nature has been maintained over aeons because life is based not on linear systems of resource use and production of pollution but on recycling of resources and the breaking down of pollutants. These are circular flows, not linear ones. The answer is not to be found in some technological fix. Indeed the technological perspective is largely the cause of the problem, not the cure.

There is an alternative vision. It requires different social goals from those the modern worldview demands. Its emphasis is on care and justice for all inhabitants of the Earth. The emphasis of the modern worldview has been on continuous and increasing production and consumption. The same aim is paramount in programs of development in the developing world. Yet there is increasing evidence that if the whole world were to become rich like the rich world, in the way the rich world became rich, the effect would be lethal for the planet.

The fundamental causes of environmental decline and poverty are inextricably linked. As Jose Lutzenberger when Minister of Environment in Brazil, said: ‘If development is to be the continuation of the present mode and we must help the developing countries to reach our level of affluence, while the developed countries must still continue developing to even higher levels of consumption, then what we are doing is suicidal’ (1991, p. 11).

The resolution of the problem of injustice requires a fundamental re-examination of the relationship between the one billion people, or 20 per cent of the world’s population, who live in industrialized countries and who use 80 per cent of the world’s resources and the majority of the world’s population in poor countries who have to make do with 20 per cent of the world’s resources.

How can we look after the needs of the poor and deprived and at the same time preserve the ecological integrity of the Earth? How can we achieve both a healthy people and a healthy environment? There is an increasing awareness that only a reversal in the direction of production and consumption and the economics and politics that determine that direction will save the future. The changed objective is for an ecologically sustainable society that is also a just society. As the quotation at the head of this chapter indicates, because of the strain on resources it creates, materialism simply cannot survive the transition to a sustainable world. In other words, materialism is dead-ended, not just because it fails to lead to a decent quality of life for all but because it destroys the Earth on which all life depends.

I was present at the birth of the phrase the ‘ecologically sustainable society’ at a conference in Bucharest organized by the World Council of Churches in 1974 on Science and Technology and Human Development (World Council of Churches 1974). Jorgen Randers (an author of The Limits to Growth) and I were conducting a workshop at the conference on that subject. The objective of the workshop was to demonstrate that the Earth was finite in its resources, including its capacity to absorb the pollutants of industry. That being the case, we have to learn to live within limits if we and the Earth are to remain a home for people and its other inhabitants, many of whom are essential for our own lives. The workshop was getting nowhere with delegates from the developing world. Indeed, they were hostile to the idea. They argued that the rich countries had had their share of growth. Now it is their turn. Don’t talk to us about limits to growth, they said, when what we need is to grow as the rich countries have grown.

At a coffee break Jorgen Randers said to me: ‘We have to find some phrase other than limits to growth that is positive in its impact. Limits has a negative connotation. Other suggestions such as a stationary state, an equilibrium society and a steady state society are too static’. Then he suggested: ‘What about the ecologically sustainable society?’ meaning the society that could persist indefinitely into the future because it sustained the ecological base on which society is utterly dependent.

We went back to our workshop with this suggestion. Of course, they said, we want an ecologically sustainable society. How can we move toward that end? So we discussed requirements. All came to realize that the concept was radical indeed. Yet it was accepted by the plenary meeting of the conference. The phrase then spread around the world like wildfire. Its time had come. It became incorporated into the seven-year program of the World Council of Churches called the Just, Participatory and Sustainable Society.

The Worldwatch Institute in Washington was established in the 1970s to alert the world to increasing threats to human well-being and to the environment. Its director Lester Brown, caught on to the concept of the ecologically sustainable society and wrote Building a Sustainable Society (1981) in which he diagnosed the present state of global unsustainability and suggested paths to sustainability. In 1984 the Worldwatch Institute produced its first State of the World report with the subtitle ‘A Worldwatch Institute Report on Progress Toward a Sustainable Society’. Each year since then it has produced a State of the World report. In addition, it publishes Worldwatch papers and books on critical environmental issues.

The 1987 report of the World Commission on Environment and Development (WCED 1987), also known as the Brundtland report, dropped the phrase ‘sustainable society’ for ‘sustainable development’. As Herman Daly has argued, this is a contradiction in terms. For many it has come to mean sustainable economic growth. But sustainable growth is an impossibility. Sustainable development makes sense for the economy only if it is understood as development without growth, that is a qualitative improvement of the economic base without an ever-increasing throughput of energy and other resources (Daly 1991). Further landmarks in the recent history of moves toward an ecologically sustainable society are documented by Young (1991).

Concern for ecological sustainability and human justice for the poor and oppressed are, as I have already indicated, closely linked. Yet justice and ecological sustain-ability are sometimes seen as alternative human concerns. Those who emphasize human justice sometimes see ecological sustainability as the cry of those who benefit from the present structures of society and who want to distance themselves from the abuses of power within it. Yet justice and sustainability must ultimately be linked into a single vision of life-giving hope for a richness of experience of life for all people in the world (see Birch, Eakin & McDaniel 1990, pp. 2 - 4).

Ecologically Unsustainable Societies

There have been plenty of societies in history that proved to be ecologically unsustainable and perished. They give us clues to the sort of society that renders itself extinct. The decline of the Mayan civilization in the lowlands of Guatemala was almost certainly due to severe soil erosion and deforestation. For seventeen centuries the population doubled every 400 years, reaching a density by AD 900 comparable with that of agriculturally intensive societies of today. At this peak the civilization suddenly collapsed. Within decades the population fell to less than one-tenth of what it had been. They didn’t know how to look after the Earth.

The collapse of the civilization that occupied the Euphrates River basin of the Great Fertile Crescent was also probably a consequence of humanly induced environmental deterioration. Extensive irrigation without adequate drainage led to salinization and waterlogging of the soil. The ancient Chinese also recorded deforestation, followed by floods and droughts and other environmental changes in densely populated areas. They are still problems in China today.

It has been said that forests precede humanity, deserts follow. It is no accident that the fallen columns and broken statues of past civilizations often lie on devastated ground. The ruined cities of North Africa, once flowing with olive oil and honey, lie stagnant in the sand. The bare hills of Attica were mourned by Plato as ‘skeletons’ of what they had been. The Maowu desert of Inner Mongolia overtook the lush pasture land alive with deer that Genghis Khan chose for his tomb. All testify that when land is exploited by greedy and ignorant people, everything collapses.

No civilization, however, has set about devouring its own future with such enthusiasm as our own. The difference between us and the Mayans is that we know we are on an unsustainable path. We may not have seen the collapse of whole civilizations in our day in this way, but we have seen the disappearance of large areas of formerly habitable earth. Environmental degradation, resulting in desertification of once productive sub-Saharan Africa, has created millions of ‘environmental refugees’ in the decade of the 1980s alone. The United Nations Environmental Program warns that one-third of the entire land surface of the world is now in danger. In the world as a whole, topsoil disappears each year in an amount equivalent to the total topsoil of the entire vast wheat belt of Australia which covers 113,000 square kilometers.

Changing Direction Toward an Ecologically Sustainable Society

The first major effort to understand the needed changes was made by the Club of Rome in its report Limits to Growth (Meadows, et al. 1972). The report was based on a computer model for long-term global trends. It was not a prediction but a projection as to what would happen if the direction were not changed. It drew three main conclusions.

The first was that if existing trends in population, food production, industrialization, resource use and population were to continue unchanged, limits to growth would be reached within a century. Everything that has happened since then, including the greenhouse effect and the hole in the ozone layer, makes it clear that a future world could not sustain a population of even the present number at a higher level of industrial development without reaching environmental limits. This conclusion has become known as ‘the impossibility theorem’ -- the high rate of consumption and pollution of the rich would be impossible for the whole of the world. That immediately poses a problem of justice.

The second conclusion of the Club of Rome was that it is possible to alter present trends and establish conditions of economic and ecological stability that could be sustained indefinitely. We have a choice. We can either stabilize the number of people, and levels of use of resources and levels of pollution, or we carry on at the risk of overtaxing the environment.

The third conclusion was that if the people of the world wish to achieve an ecologically sustainable future, rather than pursuing the delusion that present levels of growth can be continued indefinitely, the chances of achieving that goal will be improved by starting sooner rather than later. The longer we delay, the more serious are the problems.

After surveying the debate, triggered twenty years ago by Limits to Growth, Eduard Pestel (1989), who was much involved in global modeling, said that the most important result was that it drove into the heads of more and more people the urgent need for long-term, anticipatory thinking and learning at a time of precipitous change and ‘opened our hearts and minds to the urgent necessity of a radical change of values, at present so dominated by material aspirations’ (p. 160).

There have been twenty or so projects of global modeling since the report of the Club of Rome on limits to growth in 1972. Ninety per cent of the conclusions are held in common, though the public perception from the media is that there is little agreement. Even the somewhat crude projections of the 1972 report have been borne out, to a greater or lesser degree (Van Ettinger 1989). ‘Twenty years after the publication of Limits to Growth three of the original four authors (Meadows, Meadows & Randers 1992) reworked all the models with the latest data, taking into account technological advances in efficiency in the use of resources and pollution control. After computing some dozen or more variants of the model they concluded that the present way of doing things in the world is unsustainable. Although in some twenty years some options for sustainability had narrowed, others had opened up as a result of technological advances. The three conclusions of the Limits to Growth referred to above are still valid and only needed strengthening (p. xv). We turn our attention now to the critical issues of a world at risk and how we might change direction.

The Life-Support Systems of Nature

For millions of years the thin envelope of life around the earth, which we call the biosphere, has sustained the resources necessary for life in a wonderful and complex way. We know only in part the complex relations involved. Some of them can be understood by considering what are called ‘the life-support systems of nature’ or ‘the cycles of nature.’

A life-support system is analogous to the engineering system that maintains the environment inside the space vehicle to support the life of the cosmonauts. They need an atmosphere to breathe, which means that the appropriate amount of oxygen and other gases have to be kept at a constant level, despite being constantly used up while carbon dioxide is constantly exhaled from breathing. They have other requirements that have to be provided, such as appropriate temperature, air pressure and food. Wastes have to be disposed of as they are produced.

It is appropriate to regard the Earth as a spaceship where the environment is maintained in such a way as to sustain life. Much of the science of ecology is concerned with finding out how this is done. Until recently we did not have to bother about this problem. The Earth looked after itself. But as the number of humans increased and their activities became industrialized we found we were disturbing the ecology of the Earth in disastrous ways. The lifesupport systems were being threatened.

Just six elements carbon, oxygen, hydrogen, nitrogen, phosphorus and sulfur -- constitute 95 per cent of the mass of all living matter on Earth. Since the supply of these elements is fixed, so life depends upon their efficient cycling through the rocks, soil, water the atmosphere and living organisms. These cycles are part of the life-support systems of nature. In recent years human activity has significantly disrupted these cycles, particularly those of carbon and nitrogen.

Atmospheric oxygen is essential for the life of all organisms except for a few microorganisms that are called anaerobic organisms. Yet the cycle of oxygen is one we do not need to worry about. The oxygen in the atmosphere comes from plants. It is carried by winds across the Earth. Every breath we take includes about a billion oxygen molecules that have been, at one time or another, in the lungs of every one of the fifty billion humans who have ever lived. The simple act of breathing links us in this curiously intimate way with every historical figure and the most obscure of our forebears in every epoch. Before there were plants there was probably no oxygen, or very little of it, in the atmosphere. That was about two billion years ago. The oxygen that is today removed by living organisms, including humans, is replenished by plants. The proportion of oxygen amongst the various gases of the atmosphere remains remarkably constant at 21 per cent. That means that oxygen is produced at about the same rate as it is removed from the atmosphere and all is well. Not so with the carbon cycle.

Carbon dioxide is taken from the atmosphere by plants to make their plant tissues. It is returned to the atmosphere in the decomposition of plants and animals. A second smaller source is volcanoes. Some of the carbon dioxide in the atmosphere is absorbed by water in oceans and rivers. Not all animals and plants that die are decomposed. Some of them have in the past been converted into coal and oil. When we burn these fossil fuels, or for that matter the trees in forests, carbon dioxide is returned to the atmosphere.

The balance between what is taken out of the atmosphere and what is returned has been remarkably constant over the ages until recently. Since 1958, when measurements were first made, the carbon dioxide content of the atmosphere has been increasing. The combustion of fossil fuel now augments the atmospheric carbon dioxide by 0.7 per cent each year. A doubling of the concentration of carbon dioxide over its pre-industrial level may occur by the middle of the next century.

The increase in carbon dioxide that is now occurring is expected to have dramatic consequences for life on Earth as a result of the so-called greenhouse effect which will make the Earth hotter. Should the carbon dioxide level reach double pre-industrial levels, the Earth’s average temperature may rise between 1.5° and 4.5° C. Such a change could have profound effects on the climate of the world. (For details of the greenhouse effect see Henderson-Sellers and Blong 1989.)

That presents huge ecological problems for the future. Immediate and enormous steps need to be taken to reduce the amount of carbon dioxide we produce. Increases in the price of fossil fuels since 1979 have meant that less has been burned and less carbon dioxide has been added to the atmosphere. But the decrease is well below that required. Increasing the efficiency of production and use of energy would also be beneficial. The destruction of forests causes an increase in carbon dioxide in the atmosphere due to the decomposition and burning of the forest and the fact that there are fewer trees to remove carbon dioxide from the air,

A 1980 study by the World Bank of West African countries showed that the demand for wood for fuel exceeded the estimated sustainable yields of forests in eleven of the thirteen countries surveyed. In both Mauritania and the mountainous areas of Rwanda, the demand for firewood is ten times the sustainable yield of remaining forests. In Kenya the ratio is five to one; in Ethiopia Tanzania and Nigeria, demand is 2.5 times the sustainable yield and in the Sudan it is roughly double (Brown 1986, pp. 23-4).

Besides the burning of wood for fuel, forest fires add carbon dioxide to the atmosphere. Fires in the Amazon region are entirely man-made. For trees to burn in the wet tropical forest they have to be felled and left for two or three months to dry. They are then ignited by people who want to clear the land. Satellite surveys have shown that at the peak of the burning season, from the end of August to early September, there are as many as 8000 separate fires in a single day throughout the Amazon region. Deforestation is second only to fossil fuels as a human source of atmospheric carbon dioxide, almost all of which comes from the tropics and overwhelmingly from Brazil.

Reforestation is one way of helping to restore the balance in the carbon cycle. This is being done on a large scale in South Korea and China, where enormous areas of land have been denuded of forests. But the largest contribution to restoring the carbon balance will be a reduction in world population since every person who lives makes a contribution to the carbon dioxide in the atmosphere by his or her use of the products of industry or by burning wood for fuel. On the average each person contributes two metric tons of carbon dioxide a year of which one ton gets into the upper atmosphere to contribute to the greenhouse effect. Small increases per person can have an enormous effect when multiplied by huge numbers of people, as for example in China and India, if, as they propose, they increase their use of fossil fuels in the near future. There is probably no practical way to achieve the necessary reduction in greenhouse emissions (chiefly carbon dioxide and methane) without controlling the numbers of people in the world (Ehrlich & Ehrlich 1990).

Why does the carbon dioxide increase as a result of the burning of fossil fuels, yet the oxygen which is used up in this burning is not significantly depleted? The reason is that the proportion of oxygen in the atmosphere (21 per cent) is very much larger that the proportion of carbon dioxide (about 0.03 per cent). The combustion of fossil fuel that increases carbon dioxide by 0.7 per cent per year decreases the oxygen by only 0.001 per cent per year (Ehrlich, Ehrlich & Holdren 1977, p. 79).

Nitrogen constitutes 78.1 per cent of the atmosphere. It is also circulated in cycles in nature. It is removed by microorganisms which pass it on to plants. Some plants, notably the blue-green algae, ‘fix’ it directly from the atmosphere. Animals get their nitrogen for making proteins from plants. When animals and plants die and decompose, nitrogen is released back to the atmosphere. Some bacteria also return nitrogen directly to the atmosphere. Industry, which includes factories that make nitrogenous fertilizers, take nitrogen from the atmosphere and return it to the environment as nitrates. Automobiles, power plants and industries release oxides of nitrogen into the atmosphere. In the United States the quantity of nitrogen oxides released in this way doubled between 1950 and 1973 (Postel 1987).

This is a matter of much concern as nitrogen oxides are greenhouse gases. They now constitute quite a substantial proportion of the nitrogen that goes from the atmosphere into the soils and waters of the Earth. We do not know yet what the consequences of this are. Nor are we sure what the consequences would be if chemicals we add to the environment killed off important microorganisms in the nitrogen cycle.

All other elements that are necessary for life have their own cycles in nature such as, for example, the phosphorus cycle and the sulfur cycle. We intervene in the phosphorus cycle by mining rock phosphate and adding it to soil as fertilizer. Phosphorus is also used in detergents, animal feed supplements, pesticides and many industrial activities. The most critical aspect of our use of phosphorus is that the supplies will run out in the long run since we are doubling the amount used every fifteen years. In the meantime, excess phosphates from fertilizers get leached into rivers and lakes. There they provide nutrients for algae which increase in numbers in what is called algal blooms. The change is quite undesirable, as the bloom depletes oxygen in the waters, killing off fish and other animals. There are other cycles in nature, such as the water cycle, in which water circulates between the atmosphere and the soil and oceans and rivers. When forests are destroyed more water runs into rivers and is wasted and there may be less rain when trees are removed.

The greatest human influence on the sulfur cycle comes from industrial activity, mainly the combustion of coal and oil and the smelting of sulfur-bearing metallic ores. These sources produce sulfur dioxide. When sulfur dioxide gets into the atmosphere and meets nitrogen oxides, compounds are formed that lead to acid in the rain.

This has disastrous effects on forests, killing trees in many parts of the world. Likewise, nitrogen oxides and sulfur dioxide react with other chemicals in the atmosphere under the influence of intense sunshine to form ozone, which is a main ingredient of photochemical smog. Besides being hazardous to human health, smog is also disastrous to trees. Huge areas of pine forests in the mountains east of Los Angeles are dead because of smog from Los Angeles.

A cycle which incorporates all these cycles is the food cycle. In any community of plants and animals, the basis of the life of the community life is the plants that convert the energy from the sun, the minerals from the soil and the carbon dioxide from the air into plant tissue. Plants are called producers. Animals feed on plants and are known as herbivores or consumers. Then there are predatory animals that feed on the herbivores, known as carnivores. There may even be, in some cases, predators of predators. So in the plains of Africa the grass in the plain is eaten by herbivores, such as antelopes, and the antelopes are eaten by lions. But in this case the lions have no major predators other than parasites and other organisms that cause diseases. All organisms eventually die and are decomposed by microorganisms which return the mineral nutrients, that are broken down from their tissues, back to the soil or river or sea.

Ecologists investigate the amount of energy that exists at each food level, say over a hundred hectares. A rough rule of thumb is that if green plants capture 10,000 units of energy from the sun, only about 1000 units will be transformed into herbivores and only 100 units will have got into the carnivores. There is a loss of 90 per cent of energy at each step of the food cycle.

There are two important implications of this information. The first is that ten times as many people can survive eating a corn crop as can survive eating cattle that have been fed on the corn. It is not surprising therefore that peasant farmers in Brazil, for example, have a staple diet of rice and beans. Far more people could be fed with the food the world produces if less of it were not converted into pigs, sheep and cattle. It seems certain that in the future more and more people will, by necessity, become vegetarian if they are to survive. Human beings use up some 40 per cent of the planet’s potential plant production either by direct consumption or in indirect ways by suppression of plant production. This not only represents a huge impact on what is available for humans, but it is a disproportionate share for only one of 30 million or so species of animals! (Ehrlich & Ehrlich 1990, p. 36) As the Ehrlichs point out, this is a frightening figure for ecologists, yet they are even more concerned about the rising fraction of potential plant production that is being lost for all life, including ourselves. Humans have become a globally destructive force increasingly threatening the habitability of the Earth.

A second consequence of the features of the food cycle is that when toxins such as the insecticide DDT get absorbed by plants, they get concentrated at each successive food level. This is because the herbivores have to eat ten kilos of plants to produce one kilo of flesh. And the predators of herbivores have to eat ten kilos of herbivore to produce one kilo of their flesh. A consequence is that many predators throughout the world, particularly predatory birds, get lethal concentrations of toxins in their flesh. The problem applies particularly to the pesticides that are called persistent. They do not readily break down and so persist for long periods unchanged. Persistent pesticides, such as DDT, are a serious cause of disruption of food cycles even in places far removed from where they were used. Even the flesh of Antarctic penguins contains DDT.

All cycles of nature constitute part of what is called the life-support systems of nature. They have been going on for millions of years without much perturbation until humans began to alter the cycle through industrial activity. Nature’s global society has been kept sustainable because the molecules keep moving through these cycles. Indeed, in some cases the molecules are kept moving with very little loss along the way. A mature rainforest community of plants and animals recycles virtually all materials used as resources. Apart from water and carbon dioxide the only resource that comes in from outside is the energy of the sun.

Trees and other plants absorb minerals from the soil with great efficiency. They turn them into their own tissues. Their leaves and branches fall to the ground or are eaten by animals whose waste products fall to the ground as well. They die and decompose and produce waste products, all of which go back to the forest floor to be decomposed by bacteria and fungi that turn them into minerals. They are taken up by plants again with such efficiency that the water that runs from the undisturbed Amazonian rain-forest is virtually the same as distilled water in composition. The rivers are called black rivers because the water looks black compared to the white rivers which drain eroded areas and are full of clay and other minerals. A paradox of the great Amazon rainforests is that most of them live on impoverished soils, yet they sustain more than 500 tons of living material on each hectare. Moreover, the underlying rock is so far beneath the surface that roots of trees do not reach it to get minerals from there. For a long time this remained a mystery until the amazingly efficient recycling of minerals in the forest was discovered.

The Carrying Capacity of the Earth

A sheep farmer speaks of the carrying capacity of the farm for sheep in terms of one sheep per hectare or perhaps ten sheep per hectare. This means that the farm can sustain indefinitely up to that many sheep. Exceed the carrying capacity and the quality of the farm deteriorates. Every natural habitat has a carrying capacity for the sorts of organisms that live there, whether they be kangaroos or buffaloes or lions.

In many years the numbers of inhabitants of a region may be well below the carrying capacity because of unfavorable weather or other unfavorable features of the environment of the organism in the habitat. In a series of good years the carrying capacity may increase and so too may the number of inhabitants. When lean years return there may be too many inhabitants to be catered for. The carrying capacity will have been exceeded. The consequence is that many of the inhabitants will go short of resources and may perish.

Exactly the same situation applies to the human inhabitants of the Earth, which has a limited carrying capacity for people. Exceed that capacity and two things happen. The quality of the environment (its carrying capacity) deteriorates and human life is threatened along with that of other species.

A leading economist pronounced ‘no-one has ever died of overpopulation’. The American journal Science responded with an editorial under that title. Just at that time disastrous floods in the delta region of the river Ganges in Bangladesh had taken the lives of thousands of villagers and left countless others homeless. What killed these hapless people? The editorial argued quite correctly that they died from overpopulation. The region is prone to periodic disastrous flooding. It should not be populated at all. But it is populated because suitable living places in Bangladesh are already overcrowded. So the poor are forced to live in perilous places. After each flood they go back again because they are denied safe space elsewhere.

The semi-arid belt of the sub-Saharan countries known as the Sahel, which stretches from Mauritania in the west to Ethiopia in the east, was until recently inhabited largely by nomadic peoples. Their agricultural practices, learned over the centuries, conserved the soil and its vegetation for continued pastoral use. This changed in the 1950s and 1960s. Nomads were restricted in their movements and so stayed in areas longer than before. New strains of cotton and peanuts were introduced to increase production from the land. Attempts were made to boost this intensive agriculture by sinking wells to irrigate the land. Overgrazing followed. In drought years disaster ensued. The desert extended further south. The region was now overpopulated. Production of food per person declined. Its carrying capacity was lower than it had ever been. People either died on their farms or they joined huge numbers of ‘environmental refugees’ seeking some haven to the south.

This sort of thing is happening in many parts of the world to a lesser or greater extent. In the last decade productive land the size of the twelve countries of the European Community has been turned to dust because carrying capacity has been exceeded. One-third of the entire land surface of the Earth is now in danger. The foundations of civilization in these places crumble to sand.

A sustainable society will respect the limits of the Earth, which is finite, in three respects. It has a limited Capacity to produce renewable resources such as timber, food and water. It has a limited amount of non-renewable resources such as fossil fuels and minerals. And it has a limited capacity for providing its free services for the maintenance of the life-support systems such as its pollution absorption capacity. In the 1980s emphasis moved from limits of resources to the sort of limits which are referred to as ‘sink limits’. This was because of the serious threat of greenhouse gases and secondly of chlorofluorocarbons to the ozone layer.

These three limits determine the carrying capacity of the Earth for people. Growth in population coupled with industrial growth reduces the carrying capacity of the Earth because of the environmental impact on both renewable and non-renewable resources. Figure 3.1 illustrates this relationship. Suppose that today the human demand on the environment is equivalent to only 5 per cent of the carrying capacity of the Earth, which is surely an underestimate. Take into account the overall environmental impact, which, according to the American study SCEP (1970, p. 22) is growing at 5 per cent per year. The environmental demand would reach the saturation point in fifty-five years, even if the carrying capacity itself were not reduced by growth.

A group of twelve economists, including two Nobel prize economists, have issued a critically important working paper published by the World Bank in which they argue

Figure 3.1 p. 129

The generalized relationship between economic growth and the carrying capacity of the Earth. Growth results in environmental deterioration with consequent reduction in carrying capacity.

that the world’s economy cannot grow any more (Goodland, Daly & El Serafy 1991). If the poor are to be fed and housed and if the global environment is to be saved, the rich must reduce their economic growth. Ecologists have been saying this for years. But this has been anathema for traditional economists. They have held to the opposite view that the rich must grow richer if the poor are to become richer. Furthermore, economists have shown singularly little concern for the deterioration of the global environment. So why should economists, some of whom are on the staff of the World Bank, have produced such a document? After all, the bank is well known for financing huge projects in developing countries that have made it an accomplice in the pollution of rivers, the burning of forests, and the strip mining of huge areas. The basic argument of the twelve economists is that there are limits to growth which have now been reached on a global scale. They do not speak for the World Bank but to the World Bank. The critical issues they identify are as follows:

• The ‘sink restraints’ are now considered to be more stringent than the resource constraints. They have become of immediate critical concern for the global community. Global emissions of carbon dioxide from the use of fossil fuels are estimated to have to be reduced by 75 to 80 per cent. This means that the use of fossil fuels must be reduced by 75 per cent. That means the global industrial economy has to be reduced drastically.

• The WCED (1987) or Brundtland report argued that the poor world could only be helped if there were an increase in the world economy from between five to ten times the present world economy. This is not possible. All the resources used by humans, with the exception of minerals and petroleum, are dependent upon four ecological systems: grasslands, croplands, forests and fisheries.

Of all the plant material produced on land each year in the world, humans use 40 per cent. This has been a frightening figure for ecologists. It has now frightened the twelve economists who wrote the World Bank working paper. The critical question they ask is, how big can the human economy be relative to the total ecosystem? Two more doublings sees us using over 100 per cent of the world’s ecological production. So the World Bank paper argues that an increase of five to ten in the world economy recommended by the Brundtland report is ecologically impossible.

• The World Bank paper finds that the Brundtland growth plan fails also because it argues for a lifting of the bottom (the poor) rather than a lowering of the top (the rich). The poor cannot be lifted unless the top falls. The rich must live more simply that the poor may simply live. Yet that seems unacceptable to the rich world which considers that its difficulties, such as inflation and unemployment, can only be remedied by increasing economic growth.

It is neither helpful nor ethical to expect poor countries to cut their development, though we can expect them to drastically curb their population growth. Therefore the rich world, which is responsible for most of today’s environmental

 Figure 3.2 p. 131

The generalized ecological history of the world, past, present and future.

I. direct transition to High-level sustainable state;

II. belated transition to somewhat lower-level sustainable state;

III. reversion to a pre-modern agrarian way of life.

damage, must take the lead. More growth for the poor must be balanced by less growth for the rich. The cake of limited size must be carved up more equably. ‘We cannot grow our way into sustainability’ (Goodland, Daly & El Serafy 1991, p. 6). This conclusion was also reached by economists and ecologists in an international symposium on ecological economics edited by Robert Costanza (1991).

Both the World Bank paper and the 1991 report from the Club of Rome (King & Schneider 1991) argue that only a change in heart will suffice. Economic rationalism must fly out the window and let ecological realism in. The consequences would be a drop in living standards of the rich, though an increase in their quality of life. For example, to stop the contribution of the Netherlands to acidification of forests and lakes the Dutch would have to reduce the number of motor car kilometers and farm livestock by half. The quality of the rain would be better but the standard of living would be lower. The specter is also raised of increased unemployment when economic growth does not continue. However, this need not be the case, as is well argued by Renner (1991).

When to Grow and When not to Grow

The momentum of growth and the lag in social response to deterioration of the environment predispose the world system to overshoot the level that would be sustainable over a long period. The inevitable consequence of overshoot is collapse. The options open to us are shown in Figure 3.2. Throughout most of human history, growth in economic activity has been very low. It began to skyrocket after the Industrial Revolution and has continued ever since. Policy option I in Figure 3.2 is an early and direct transition to a sustainable steady state. Policy option I illustrates the literal meaning of ‘to grow’, namely to spring up and develop to maturity. Daly (1977 p. 99; 1991) makes the important point that the notion of growth therefore includes some concept of maturity beyond which physical accumulation gives way to physical maintenance. Growth gives way to a steady state.

Not everything is held constant in the sustainable society. As a sustainable society develops, its development is not dependent upon quantitative growth. The sustainable society differs from a growth economy in aiming at maturity. It will have plenty of scope for development in services such as education, health and welfare, to improve the quality of life. But the services will be such as to reduce the use of energy by, for example, promoting rail over motor cars. A significant degree of decoupling economic growth from energy throughput appears substantially achievable. Witness the 81 per cent increase in Japan’s output since 1973 using the same amount of energy.

There is a phase of growth in the life of every organism. This is followed by a phase of no further growth in size in which resources are used for the maintenance of maturity. This rule of healthy life is disobeyed in cancerous growth in which parts of the body continue to grow at the expense of the organism as a whole. The organism dies from overgrowth.

The global human society has been in a growth phase all its history. Parts of the body, namely the rich countries, have cancerous growth which is destructive to other parts of the body, namely the poor countries, which still need to grow in material goods. This concept was developed in the second report of the Club of Rome (Mesarovic & Pestel 1974), where it is called organic growth as distinct from undifferentiated growth. In undifferentiated growth every nation has as its goal continued growth. A global society that promoted organic growth would eventually conform to option I in Figure 3.2. Indeed it would be similar in its pattern of growth to that of the trees in the Amazonian rain-forest. There is a growth phase as young trees approach maturity. That is followed by a no-growth phase in a mature forest where the total mass of living trees remains much the same from year to year at about 500 tons per hectare.

The Earth can be visualized as a hollow vessel with an inlet and an outlet. For population the inlet is the birthrate. The outlet is the deathrate. For a steady state no-growth population, birthrate and deathrate are equal. Both should be as low as possible, perhaps around 11 per 1000 people per year.

Similarly with goods or material wealth in the world. The inlet is the production of goods. The outlet is the consumption of goods. One should equal the other, giving a constant level of material wealth. The level at which people and wealth stabilize is largely an ecological problem. Traditional economic systems that encourage growth, aim to maximize throughput of goods and materials, whereas in a sustainable state it would be minimized.

If option I in Figure 3.2 is not taken, overshoot will occasion a fall to a lower sustainable state (option II). This is the situation in a run-down farm. It is probably characteristic of many countries in Africa, where population still grows at a phenomenal rate. The production of necessities, such as food, does not keep pace with a growing population. Other renewable resources, especially timber, become unrenewable and agricultural land deteriorates. Option III indicates what happens when the overshoot is even greater than in option II. This could be tantamount to a pre-agrarian way of life as seems to be happening in much of sub-Saharan Africa. It is the way of those societies like the Mayans whose civilization became extinct.

Meadows, Meadows & Randers (1992) give detailed examples of the three options in Figure 3.1. On their global model they set finite limits to non-renewable resources of 200 years at 1990 rates of extraction. They also set optimistic limits to land that could be brought under cultivation for agriculture and to the pollution absorption capacity of the environment (p. 117). In models represented by options II and III in Figure 3.2, overshooting the sustainable capacity of the Earth occurs soon after the year 2000 with collapse occurring 100 years or so before resources run out. One lesson from these models is that in a finite world, if you remove or raise one limit and go on growing, you encounter another limit. The next limit occurs surprisingly soon. You do not of course have to resort to a computer model to come to the conclusion that in a finite world exponential economic growth in use of resources will sooner or later lead to collapse. What the models tell is something about the rate of collapse and what has to be done if we are to move to option I in Figure 3.2.

The Environmental Impact of Humans

The impact of human beings on the environment probably began 10,000 years ago with the Agricultural Revolution in Asia Minor and the Near East. At a slightly later time similar events happened in Central America and perhaps in the Andes, in South-East Asia and in China. From these centers the new way of life, the farm, spread to the rest of the world. As a consequence the human population grew from about 15 million before the invention of agriculture to 200-300 million, some 2000 years ago. During this period forests were cut down for fuel, land was cleared for farming and irrigation began to be practiced by diverting water from rivers to the fields. As farmers produced more food than they needed for their own families, cities came into existence. The first were in Mesopotamia. The growth of cities in the Middle East culminated about 2500 BC in the Sumerian city-state of the Tigris and Euphrates valleys in what is now Iraq. The Sumerian culture was based on irrigation. One cause of its demise is believed to have been the result of centuries of irrigation with consequent salinization of the soil and silting of rivers.

The next major impact of human beings on the environment came with the Industrial Revolution from about 1850. There had been increased growth in human populations in the 200 years prior to the Industrial Revolution which was due to improved hygiene. But the Industrial Revolution had an even greater impact. Death rates fell in countries undergoing industrialization and the numbers of people in the world began to soar. It was not until the nineteenth century that birthrates began to fall in industrialized countries.

The Industrial Revolution improved the standard of living for many people. However, it began a new phase of environmental deterioration with its great and increasing dependence upon non-renewable resources such as fossil fuels and on renewable resources such as timber and food. The question of what are the limits to the use of these resources became a critical one, while the whole time industry increased pollution of the atmosphere, the soils and waters of the Earth. Add to that the threat of war and the possibility of a nuclear holocaust and it is now widely recognized that humans have in their hands the instruments of vast environmental devastation.

Instead of thinking of the environmental impact of humans as a long list of components, we get a much better picture from a synoptic approach. By far the best proposal is that of Ehrlich, Ehrlich and Holdren (1977, p. 720), which was used as a basis for their later book on the population explosion (Ehrlich & Ehrlich 1990, p. 58). The impact of humans on the environment is viewed as a product of three components: (a) the number of people; (b) a measure of the average person’s consumption of resources (which is also an index of affluence); and (c) an index of environmental disruptiveness of the technologies that provide the goods consumed. This component can also be viewed as the environmental impact per quantity of consumption. Hence:

Impact = Population x Affluence x Technology



Each of these components can in principle be measured. For example, resource use could be measured in terms of units of energy used per person. The T factor is difficult to measure, but one index might be the grams of sulfur produced per kilowatt hour of electricity generated.

The equation shows that the components are multiplicative in their effect. Suppose that population, consumption of some commodity and the impact of technology per unit of consumption each increase threefold. The total impact increases twenty-seven fold. The contributing components in this example are equally important, but each seems quite small compared to the total. Slowly growing components, when they multiply each other, lead to rapidly growing totals. Suppose we want to know whether population growth or rising consumption per person played the greater role in the growth of total energy consumption in the United States between 1880 and 1966. In this period, total energy consumption increased about twelvefold while the population increased fourfold. It may therefore appear that consumption per person was a more important component than population growth. It was not. Consumption per person increased threefold, versus a fourfold increase in the population. The twelvefold increase in the consumption of energy arose as the product, not the sum, of the fourfold increase in population and the threefold increase in consumption (Ehrlich, Ehrlich & Holdren 1977, p. 720).

In poor countries P is large and A and T are small. In rich countries A and T are large and P is much smaller. The total impact can be reduced by reducing one or more of these components. In the case of the attack on the ozone layer by chlorofluorocarbons, the impact could be made negligible by operating on the T factor alone, that is, ban the offending chemical. This might result in a slight decrease in affluence if substitutes were more expensive. On the other hand, the injection of the major greenhouse gases, carbon dioxide and methane, into the atmosphere is not so easily corrected.

The concentration of greenhouse gases in the atmosphere is tightly tied to the size of the population. Small per person changes can have enormous effects when multiplied by enormous numbers of people. There is probably no practical way to achieve the necessary reduction in greenhouse emissions without population control. Ehrlich and Ehrlich (1990, p. 113) have calculated an interesting example that illustrates this principle.

Suppose the United States decided to cut its contribution to the carbon dioxide emissions by terminating all burning of coal. Suppose also that China’s population remained at 1.1 billion. Suppose secondly that China scaled back its development plans so that it only doubled its per person consumption of coal. That would raise China’s per person use of energy to some 14 per cent of that in the United States. This modest advance in development by China would more than offset the reduction of carbon dioxide emissions achieved by the total abandonment of coal by the United States.

The P component of the PAT equation is critical here. Poor nations are at present relatively minor contributors to the carbon dioxide generated by burning fossil fuels. Industrialized countries with less than a quarter of the world’s population are responsible for about three-quarters of the carbon dioxide released by burning fossil fuels. But that could change when China and India, for example, increase their energy consumption by using their vast reserves of coal.

When people in Brazil are persuaded by their government to migrate away from the coastal areas to take up farming on a plot of land in Amazonia, they cause great destruction. The land is made available by cutting down forests and burning the trees, and in many cases only one crop is obtained from the land. The native Indians have been doing this for centuries without any serious environmental impact. In each case the plot of forest destroyed is quite small per person. But whereas the P component is small in the case of the Indians, it is very large in the case of overpopulated modern Brazil. The situation is more complex than that because of the combination of technology with so-called development in modern Brazil. Small farms in remote areas need access. That is provided by building huge highways through the forests. Also dams are built across streams for the farmers. The total effect is an enormous increase in soil erosion and in some cases the farms have to be abandoned, so great is the environmental impact.

The amount of firewood burnt by a single family in India or in Africa is quite small. But the P factor in both continents is so high that forests are disappearing at an unsustainable rate in many places. One could also argue that the number of cardboard boxes each one of us uses in a year is not that great, but multiply it by the population of Japan and its customers and we get huge areas of forest in Australia destroyed by the wood-chip industry. Attempts are made by the forest industry to regenerate the forests, which is to their advantage. However it is not the original forest, with its varied inhabitants, that is re-grown any more than is the case in Brazil when rainforests are cut down.

Piping sewage into the sea is a cheap way of disposing of it. It worked in the case of the city of Sydney without causing much environmental impact while the city had relatively few inhabitants. But when the population of Sydney grew to 3 million the P factor results in an unacceptable environmental impact as Sydney-siders have discovered to their chagrin. Acceptable alternatives are very expensive.


Population is the P factor in the PAT equation of environ-mental impact. Some people claim there is no global problem of overpopulation, only problems of mal-distribution and faulty technology. Examples above illustrate how population in our day is always a component of total environmental impact. The people who think that population is no longer important point to the growth of population in Western countries which has slowed, with zero growth in thirteen countries. And some Asian countries have managed to reduce their rate of population growth in recent years.

What these people fail to appreciate is that, despite this, the annual global increment in population in 1990 was an all-time high of 95 more million people added to the planet. The fact remains that the 1990s will see the greatest increase in human numbers of any decade in history. If by some way humanity were able to reduce the environmental impact of all its technologies by 10 per cent and there were no increase in per-person affluence, world population growth would return the collective impact of humans to the previous level in about five years. Just about every step forward in the A and T items of the PAT equation is negated by population growth.

The world’s population in 1992 was estimated to be 5.4 billion. It is likely to reach 6.3 billion by the end of this century, nearly the equivalent of adding another China. More than 90 per cent of the increase is in poor countries. That poses an immense problem for the rich and poor world alike.

The average birthrate in industrial countries of 1.9 children per woman is below replacement level. But this does not mean the industrial countries have not a population problem. Indeed it can be argued that because of their high level of A and T in the PAT equation, their impact is enormous. Perhaps the impact of one person in the rich world is 50 times that of one person in the poor world.

The 1980s saw a slight slackening in the rate of growth of the population of the world. But this does not herald an end of the population explosion as some have proclaimed. The slowdown has been from a peak annual rate of 2.1 per cent a year in the early 1960s to 1.7 per cent in 1992. To put this in perspective, the doubling time of the human population has been extended from thirty-three years to thirty-seven years from 1950 to 1987. The largest jump in population numbers from 5 to 10 billion in well under a century is still ahead of us.

If every woman in the world from this year on had no more than 2.2 surviving children, which is replacement reproduction, the world’s population would still grow. This is because population growth has a momentum such that it takes about two generations before curbs applied now have a major effect. Some European countries have expressed a concern at having reached replacement reproduction. Yet these same countries cannot avoid a 20 to 30 per cent increase in numbers, even if they maintain replacement reproduction. To achieve zero population growth in the twentieth century, even in the most developed countries, birthrates would have to fall well below replacement levels. This seems unlikely. If replacement reproduction for the developed world as a whole had begun in the 1980s, the population would still increase by more than a quarter, adding some 300 million more people.

The reason for the population momentum is the relative youth of the growing population. It is young people who have most of the children and deaths occur primarily in old people. So if a population has a high proportion of young people, one has to wait for the average age of the population to increase before deathrates catch up with birthrates. That takes about sixty years in poor countries. That is why it is so important to reduce birthrates as soon as possible, if population growth is to be curbed. A reduction in the birthrate now takes many years to be reflected in numbers of people. The concept of population momentum may be a difficult ecological concept to grasp, but it is not difficult to understand its effects. That understanding should be far more widespread than it is. Precisely because population growth is slow to be controlled, it is the issue to tackle now,

A sustainable world will have a population whose size is commensurate with global carrying capacity and which size does not increase unless carrying capacity increases. Zero population growth is an inevitable component of the sustainable world of the future. If we do not deliberately work for a smooth transition we shall arrive there through overshoot and catastrophe. What then is a sustainable population for the world as a whole? The question is a complex one with no simple answer. Any assessment must depend upon an estimate of the environmental impact of people on the planet. Indeed some would argue that the world is already overpopulated, that the existing 5.4 billion people are causing such a deterioration of the environment that this cannot continue for much longer without a severe lowering of the carrying capacity of the Earth. For example, Ehrlich and Ehrlich (1990) conclude that ‘Earth cannot long sustain even [the 1990s figure of] 5.3 billion people with foreseeable technologies and patterns of human behavior’ (p. 238).

If civilization is to survive, population shrinkage below today’s size eventually will be necessary. Population shrinkage would require below replacement reproduction to be continued beyond the point when zero population growth had been reached. Below replacement reproduction would not be unprecedented. It prevails in most European countries and the United States today. China has for some time recognized that all its problems become more intractable the larger the population grows. The gradual reduction of the population after reaching zero population growth has been an explicit part of China’s policy. Thirteen countries have already achieved zero population growth, so it is not utopian to expect others to follow.

When is an area overpopulated? That depends upon the carrying capacity of the area. When a population cannot be maintained without rapidly depleting its nonrenewable resources and without degrading the capacity of the environment to support the population, that area is overpopulated. Africa is overpopulated because its soils and forests are rapidly being depleted such that its carrying capacity for humans in the future will be lower than now. The United States is overpopulated because it is depleting its soils and water resources and contributing greatly to the greenhouse effect. Europe, Japan, and the republics that used to constitute the Soviet Union are overpopulated along with other rich nations because of their massive contributions to the greenhouse effect and the deterioration of their soils and waters.

The population of the People’s Republic of China increased 64 per cent between 1949 and 1973. In the late 1970s China’s leaders were jolted to discover that there were almost 100 million more people living in China than had been thought. The Deng regime claimed that high rates of population growth, lower deathrates caused by modern medicine and a generally poor and badly educated population had forced China to spend too much on housing, food and employment, and fresh water was becoming a limiting factor. The resources drained for these purposes could be used, so Chinese officials argued, to develop and ‘modernize’ the country. The government concluded that China could support no more than 800 million people on a sustainable basis at a decent standard of living. China’s population had already reached one billion when this conclusion was reached.

To arrest population growth the Chinese regime created a program of mass ‘ideological education’ and a system of economic incentives to encourage people to have fewer children. According to the guidelines set by the Ministry of Health, the number of children should not exceed one per family. The government set targets for each province. China became the only nation in the world with the goal of not only ending population growth as soon as possible but also of reducing its population by a substantial amount. The number of children per family is approaching replacement level, slightly more than two per family. But the momentum of population growth caused by high birthrates in the recent past means that the population will grow to a peak of about 1.2 billion or more before it begins to fall.

Australia, by contrast with China is now almost unique among developed Western nations in its continued commitment to population expansion. The only evidence of a sustainable population in Australia is the population of Aborigines which lived there for 40,000 years or more. Modern Australia is overpopulated because of the very high levels of A and T in the PAT equation. People who do not know better think of Australia as a vast land waiting to be populated far and wide. But Australia is mostly desert. It is the second driest continent on earth after Antarctica.

Water the Australian desert as the Israelis do, people say. But there is a catch. There is no permanent water in the vast deserts other than artesian water in some places which is fast being used up. So-called development of vast inland spaces is limited by shortage of water. That is the main limiting resource of Australia. It is the reason why most Australians live on the coastal fringe. The population of Australia in 1992 was 17.8 million. If we make the reasonable assumption that one Australian has an environmental impact equivalent to fifty Indonesians, the total environmental impact of Australians would be the equivalent of about one billion Indonesians!

The present rate of growth of the population in Australia of 1.6 per cent a year is the highest in the industrial world. Almost half of this comes from immigration. At this rate the population will reach 30 million by about the year 2025. And what is good about that? It is quite ridiculous to have an immigration policy without a population policy.

As Paul Ehrlich commented on a visit to Australia it is like someone asking you to design an aircraft that can take sixty people on board a minute but not telling you how many passengers it is going to fly with! Senator John Coulter has made a humane proposal that he believes could lead to a sustainable population in Australia. Immigration would be restricted to compassionate grounds; migrants for family reunion would amount to 50,000 per year, refugees would amount to 20,000 per year. Migration on the grounds of skill, wealth and business ability would be eliminated for the most part. Such a program would result in the Australian population gradually rising to a plateau of about 25 million people by the year 2055 (Coulter 1990). It is a better prospect than continuation of the trend of the 1980s, but many of us think it is still too large and will extend the damage to the already beleagured Australian environment, unless Australians discover ways of making a smaller environmental impact than they do at present.

Overpopulation is deleterious because:

• It reduces the chance that all the people in the world can be adequately fed and housed. The increase in production of food in the world following the Green Revolution has hardly done more than maintain the existing amount of food per person because of the continuous increment in population.

• It increases the pressure on most other resources many of which are difficult to obtain.

• It accentuates the problem of urbanization. Increased population means more people migrate to already overcrowded cities such as Sao Paulo and Calcutta.

• It negates the effect of economic development in poor countries and in rich countries it exaggerates still further their disproportionate consumption of the world’s resources and their disproportionate contribution to pollution. Overpopulation in rich countries presents a much greater present threat to the health of the environment than does population growth in poor nations. The rich countries, for example, are responsible for about 80 per cent of the carbon dioxide injected into the atmosphere.

• Population growth in the poor countries increases the misery of the poor. According to a study of the Food and Agriculture Organization about 700 million people in the rural areas of the poor countries live in absolute poverty and their lot is not improving.

The 1990s is now regarded as the crucial decade which will determine population trends over the next century. Immediate action is required on a number of fronts. Rapid population growth is now widely recognized as a hindrance to development in poor countries. In the 1970s there was a widespread notion that ‘development is the best contraceptive’. We now know that this is an oversimplification. Such traditional measures of development as GNP per person and urbanization seem to have little or no relation to birthrates and therefore population growth.

On the other hand, certain kinds of development do foster reduction in the birthrate. ‘Social development’, as opposed to ‘economic development’, seems to hold the key here. For example, adequate nutrition is important. Some people in the past have argued that the more food the poor get the larger will be their families, that extra food is converted into extra babies. The fact is that denying people food will not lower birthrates. It increases deathrates. Providing food in conjunction with the improvement of socio-economic conditions actually lowers birthrate. Improved socio-economic conditions can be identified that motivate parents to have fewer children. These conditions are: parental confidence about the future, improved status of women, literacy, better health and sanitation. These are measures that lead to a sense of greater security and they are effective in lowering birthrates. Increased economic equality greatly accelerates the process as does land reform. It is not necessary that per capita GNP be very high, certainly not as high as that of the rich countries during their gradual demographic transition from high rates of growth to low rates. In other words, lower birthrates in poor countries can be achieved long before the conditions exist that were present in the rich countries in the late nineteenth and early twentieth centuries. At the same time vigorous family planning programs become effective when they were ineffective before these measures were taken (Murdoch 1980; Murdoch & Oaten 1975).

At least thirteen developing countries have managed to reduce their birthrates by an average of more than one birth per 1000 population per year for periods of five to sixteen years. Such a reduction would bring birthrates in poor countries to replacement level by the turn of the century. These countries include Taiwan, Singapore, Costa Rica, South Korea, Egypt, Chile, China, Cuba and Sri Lanka. To stop population growth worldwide, birth control would have to grow from about 50 per cent to 70 per cent of couples, and average family size would have to decrease from about four to two children.

Affluence: The Consumption of Resources

This is the A factor in the PAT equation. It is little appreciated that four biological systems -- croplands, forests, grasslands, and fisheries provide all the resources for the economy, except for fossil fuels, minerals and water. Crop-lands supply food, fiber, vegetable oils and such like. Grasslands provide meat, milk, leather and wool. Forests provide timber, lumber and paper.

The share of the land planted to crops increased from the time agriculture began until 1981. Since then the area of newly reclaimed land has been offset by that lost to degradation and conversion to non-farm uses. The area of grassland has shrunk since the mid-seventies, as overgrazing converts it into desert. Forests have shrunk for centuries, but the losses accelerated in the middle of this century and even more from 1980 onwards. The combined area of the three biologically productive systems on land is shrinking, while what is left, wasteland and areas covered with human settlements, are expanding (Brown 1990).

Until world population reached 3 billion in 1960 the yields of the four biological systems expanded more rapidly than population. By the time the population had reached 4 billion in 1976 the per capita production of forest wood and the products of grasslands (beef, mutton and wool) began to decline and have continued that trend ever since. The fish catch had been growing at a record rate for two decades prior to 1970, but since 1970 the fish catch per person fell by 13 per cent or over 1 per cent per year Then fifteen years later in the mid-1980s there was an upturn of nearly 20 per cent due largely to the recovery of the depleted Peruvian anchoveta fishery.

Turning from per capita production to total global production, the total production from forests has been declining for several years (Brown 1991). There was an enormous growth in grain production from croplands between 1950 and 1984. But it fell sharply in 1987 and that fall has continued. Per capita grain production varied from region to region. During the 1950s and 1960s, grain production exceeded population growth on every continent, diets improved almost everywhere. Beginning in the 1970s, however, production in Africa fell behind population growth, leading to a fall in production per person of about one-tenth. During the 1980s, Africa has been joined by Latin America, whose decline dates from 1982, the year the debt crisis began. In Japan, Taiwan and South Korea, production of grain has been declining since 1967. Japan’s historically excellent, productive and sustainable agricultural system is being destroyed by deforestation, development, pollution and pesticides. From a peak production in 1967, Japan’s production of grain fell by more than one-quarter in ten years (Brown 1988).

It is clear that human demand is now outstripping the sustainable yield of the natural biological systems that support the world economy. The concept of sustainable yield is an ecological one. It refers to the yield that can be sustained without causing a deterioration of the carrying capacity of the resource and therefore a reduction in the yield. For example, intensive studies of the effect of fish catch on yield led to the conclusion in the early 1970s that the total global fish yield could be sustained at around 100 million tons a year. That projection may have to be reduced (Brown 1981, p. 53).

The principal determinant of whether food production per person is rising or falling in various regions is the rate of population growth. Where population growth is slowest, Western Europe, per capita food production is rising most rapidly. In the two regions where population growth is fastest, Africa and Latin America, it is declining. In these latter areas and throughout the poor world increasing population is pushing farmers onto lands too steep to sustain cultivation or too arid to protect them from winds when cultivated.

The deterioration of land in Third World countries often starts with growing demand for firewood. Forests are destroyed and villages start to use crop residues and animal dung for fuel. This sets in motion two processes of degradation. The land is deprived of nutrients and organic matter which is essential for maintaining productive soil-structure. Second, as soils become more compact more rain runs off, soil erosion accelerates, less water is absorbed into the soil and soil moisture for crops diminishes. Water tables fall and wells dry up. Eventually not enough soil is left to support even subsistence-level agriculture. At that point villagers become environmental refugees, migrating to cities and relief camps. In India about 40 per cent of the nation’s land is now degraded. It is losing some 5 billion tons of topsoil each year (Brown 1988).

The deterioration of soil on agricultural lands is worldwide. The world as a whole loses 113, 000 square kilometers of topsoil each year which is equivalent to the topsoil of the entire wheat belt of Australia being lost each year. The United States is in the midst of a program to convert at least 16 million hectares of eroded cropland, II per cent of the total, to grassland or woodland before it loses more. Much agriculture in the United States is unsustainable, that is to say present practices are causing soil deterioration with reduction in crop yields. The causes are manifold including overuse of chemical fertilizers that tend to destroy soil structure, salting from irrigation and wind erosion.

Likewise, much of existing agriculture in Australia is unsustainable. The Center for Farm Planning and Land Management in the University of Melbourne estimates that 60 per cent of Australian agricultural land requires treatment for land degradation, salinity, erosion and tree decline. For every hectare of land used for cropping, between 50 and 300 tons of topsoil is lost each year. The cost is at least $600 million each year. Former Prime Minister Bob Hawke said that ‘none of Australia’s environmental problems is more serious than the soil degradation . . . over nearly two-thirds of our continent’s arable land’ (Brown 1990, p. 60).

Soil erosion in Australia has been called the quiet crisis because it creeps upon a farmer often unnoticed. It has increased in recent years because of the pressure for the farmer to produce more from each hectare. Another problem is that short-term costs of combating soil deterioration often exceed the short-term benefit in some places by three times. Rangelands provided about a quarter of Australia’s grazing country for sheep. Overstocking and subsequent invasion by inedible shrubs, such as hopbush, and inedible annual grasses has resulted in nearly 3 million hectares being completely ‘shrubbed out’.

Deserts are expanding as a result of inappropriate human activity in Africa, south-central Asia, Australia, the western United States and southern South America. In China between 1949, when the Communist government came into powei; and the year 2000 it is estimated that the total area of desert will have doubled (Ehrlich & Ehrlich 1990, p. 129).

The deterioration of natural productive systems in the many ways so far discussed exemplifies the ecological principle that over-use converts renewable resources into nonrenewable ones. It uses them faster than they can be renewed. When this happens soil becomes unsustainable for cropping and forests do not regenerate. Another example of this principle is the extent to which water is being taken out of underground stores (aquifers) many times faster than it is being replaced by nature. This is happening to the aquifer underlying the great plains of the United States, to the artesian basin of Central Australia and possibly also to the great underground stores of water in the Sahara desert fed from the Atlas Saharile mountains in north western Algeria. Likewise the rate of net withdrawal of water from the Colorado River is now about equal to its flow.

Most irrigated land in the Soviet Union gets its water from two great rivers, the Syr-Darya and the Amu-Darya, that flow into the land-locked Aral Sea. As a result of excessive withdrawal of water from the diversion of these rivers the water in the Aral Sea has fallen some twelve meters. The sea has shrunk to half its size. Its port city of Muniak is now fifty kilometers from the shoreline. The dry bottom is becoming a desert, the site of sand storms that may drop up to half a ton per hectare of a mixture of sand and salt on the surrounding fields to damage the cotton crops. In addition the irrigated fields have severe problems of salination due to evaporation of surface waters that leave salt behind in the soil. Restoration of the irrigated lands might be possible by using crops that need less water and by using drip irrigation which is so expertly used in Israel. The Aral Sea used to support a fishing industry and had fourteen species of fish. Now only one species survives and is not commercially useful (Brown 1988, p. 27; UNEP 1991, p. 10).

A major biological resource that is being drastically depleted as a consequence of human activity is the diversity of life of microorganisms, plants and animals. The depletion of the diversity of species is referred to as the reduction of bio-diversity. We do not really know how many species there are possibly over 30 million (Wolf 1987). We do know that the tropics provide the richest array of plants, insects, birds and mammals. More than a third of all known species of flowering plants are native to tropical America. Tropical rainforests that cover just 7 per cent of the Earth’s land surface may contain more than 40 per cent of all living species of plants and animals. A single hectare of Peruvian rainforest has 41,000 species of insects in the forest canopy. One isolated ridge-top in the Andean foothills of western Ecuador, only twenty square kilo-meters in area, lost as many as ninety unique plant species when the last of its forest was cleared to plant subsistence crops (Wolf 1987).

We do not know which are all the critical species involved in the life-support systems of the planet, nor those that might be useful in the future for creating new crops and new medicines. A probable estimate is that about one hundred species are becoming extinct each day. This is a tremendous loss in the diversity of life of the planet. Most of this loss is due to the destruction of habitats such as forests, especially those in the tropics. The rate of tropical deforestation in 1989 was almost double that in 1979, with roughly 1.8 per cent of the remaining forests disappearing each year (Ehrlich 1990).

Wolf (1985, p. 124) makes the pertinent comment that if Charles Darwin were writing today his subject would not be The Origin of Species but The Disappearance of Species. Paul and Anne Ehrlich (1981) have written that book with a one-word title, Extinction. They commence their account with their now famous parable of ‘The Rivet Poppers’. You are walking toward your airliner from the terminal and notice a man on a ladder prying rivets out of its wing. You inquire why he is doing this. He replies that he is working for the airline Growthmania Intercontinental which has discovered that it can sell these rivets for a couple of dollars apiece. But you ask, won’t that fatally weaken the wing? The rivet popper tells you not to worry as he has taken out lots of rivets so far and the wing hasn’t fallen off yet. You realize that you are not compelled to fly on that airliner. So you go back to the terminal to find another airline with its planes intact. But unfortunately all of us are passengers on a very large spacecraft on which we have no option but to fly. And it is swarming with rivet poppers behaving in ways analogous to the rivet popper of Growthmania Intercontinental. These rivet poppers are not consciously malign. They are just uninformed.

Rivet popping on spaceship Earth consists of doing things that cause the extermination of populations of nonhuman organisms and even whole species. The Tasmanian tiger, the pig-footed bandicoot, the brown hare wallaby and the Darling Downs hopping mouse are some of the mammals that became extinct in Australia following European settlement. On the endangered list are twenty-three Australian mammals, eighteen birds and two reptiles (Ovington 1978) as well as very many other animals and plants. Elsewhere there are current threats to the continued existence of the chimpanzee, mountain gorilla, right whale and Californian condor, to mention but a few. Added to these lists are about 20,000 species of threatened plants and over 400 invertebrates (Wolf 1985, p. 143).

It is possible that a dozen or so rivets lost from spaceship Earth might never be missed. On the other hand the thirteenth rivet popped from a wing, or the extinction of a key species in the cycling of nitrogen, for example could lead to a serious malfunctioning of the nitrogen cycle. In most cases an ecologist can no more predict the consequences of the extinction of a given species than an airline passenger can assess the effects of the loss of a single rivet. But no sensible policy could condone the continuous loss of either rivets or species. Acknowledging the limits of our understanding may be the first step toward conserving the diversity of life.

The parable of the rivet popper is particularly applicable to the threat of human activity to the cycles of nature such as the nitrogen cycle or the carbon cycle, which are part of the life-support systems of nature. Much more ecological research needs to be done before we are in a position to know the nature of the real threats to these cycles.

The loss of diversity of life has additional serious consequences. Agriculture has been greatly dependent upon wild varieties for genes that increase productivity, give resistance to disease and enable varieties to be produced that can withstand drought, cold and other extremes of weather. The wild relatives of commercial varieties, ranging from tomatoes to wheat, have provided genes worth billions of dollars in higher crop yields.

Recognition of this had earned these wild relatives the label ‘the newest resource’. They become increasingly important as advances in biotechnology make possible the transfer of genes, not just from one variety to another but, from one species to another. Genes of known existing varieties are now being preserved in ‘gene banks’ set up in thirteen international centers. The seeds and cuttings of a wide range of crops are stored at low temperature. The idea is also being explored of establishing ‘gene parks’ where crop species can be kept under cultivation (Wolf 1985, p. 134). In addition to the preservation of wild strains of crop plants there is the possibility of discovering altogether new crops. Only a few of the more than a quarter of a million kinds of plants that exist have been investigated for this purpose (Ehrlich & Ehrlich 1990).

Since most of the loss of species is a consequence of destruction of habitats it is clear that the prevention of further losses means that this sort of activity has to be severely restricted. Instead, reserves for the preservation of habitats need be created such as the two hundred and fifty-two reserves established in sixty-six countries under UNESCO’s Biosphere program. Acts of parliament need to be passed, as in the state of Victoria in Australia, that provide for the preservation of species by preserving critical habitats. The size of the preserved habitat is critical because of the ecological principle that increasing habitat size increases the chance of survival. There is a direct relation between the area of a natural habitat and the number of species it can sustain. One of the tragedies of clearing the Amazon rainforest in Brazil is that the forest in many places has been reduced to a series of islands too small to act as reservoirs of species that were at one time common.

In addition to habitat destruction, the disappearance of species is associated with other forms of deterioration of the environment. There is evidence that species of amphibians (frogs and the like) are becoming rarer throughout the world. In some cases this is due to local destruction of their habitat. But declines are occurring in the absence of destruction of habitats, suggesting other causes such as pollution from pesticides, acid rain and increases in ultraviolet exposure or even change in climate (Blaustein & Wake 1990). The possible effect of future change in climate is one of the big unknowns in the future of the diversity of life on the planet.

An indispensable strategy for saving our fellow living creatures is to diminish the scale of human activities. Both the size of the human population and the environmental impact of the average individual must eventually be reduced well below what it is today. Unless we can move in that direction, all other efforts will eventually be for naught.

In addition to biological resources discussed above, the life of human society is at present dependent upon non-renewable resources, notably fossil fuels and minerals. These are appropriately discussed in the next section on the impact of technology on the environment.

Technology: Its Environmental Impact

The environmental disruptiveness of technologies used to produce the goods consumed by society is the T factor in the PAT equation. They include the production of toxic substances both from the normal operation of industry such as ionizing radiation and from disasters such as the Chernobyl nuclear explosion, and products of industry such as pesticides and chlorofluorocarbons. By far the most important source of disruption of the environment comes from the use of fossil fuels for energy. Coal was the main offender soon after the Industrial Revolution began. In the middle of the nineteenth century coal began to be displaced by oil and later oil has been complemented with natural gas.

At its peak in the 1970s oil and natural gas accounted for nearly 70 per cent of the world’s use of commercial energy. The World Energy Conference in 1989 concluded that by the year 2020 the world, on present trends, would be using 75 per cent more energy, and that most of it would be supplied by coal oil and nuclear power. At present rates of use the accessible reserves of both coal and oil will be consumed within a single generation. Ours is essentially a petroleum culture. But it is not the exhaustion of fossil fuels that is the primary concern. It now seems certain that we shall have to phase out the use of these sources of energy well before the reserves are gone if we are to make the transition to the ecologically sustainable society. The reason is their disruption of the environment.

This began to be appreciated worldwide with the realization that carbon dioxide from the burning of fossil fuels was disrupting the carbon cycle and leading to the greenhouse effect. This is potentially so disastrous that a number of nations have agreed to drastically cut their emission of carbon dioxide. Some have already done so. Between 1973 and 1984 energy efficiency in the United States rose by 23 per cent despite economic growth. This saved 10 million barrels of oil a day. Western Europe, starting with substantially more efficient economies, realized a 16 per cent increase in energy efficiency. Japan was even better. On the other hand, in Greece and Australia the use of energy was less efficient during this period (Brown 1986, p. 84). In addition to carbon dioxide there are other disruptive products from the use of fossil fuels such as the nitrogen oxides that have already been referred to.

The energy component of the transition to a sustainable society has two dimensions -- a shift to renewable sources of energy such as solar energy and wind and increase in the efficient use of energy. Energy conservation is the way to increase energy efficiency. It should now top the list of all efforts to prevent further environmental disruption in the rich nations. Even quite small changes in technology can have dramatic effects in reducing environmental impact. In the United States the Reagan administration relaxed the efficiency standards of automobiles that had already been met by Chrysler. If these regulations had been kept in place, within a decade or so the amount of petrol saved would have been equivalent to the entire amount of oil estimated to underlie the Arctic National Wildlife Refuge. That single step could have both removed a threat to one of the last really wild places on Earth and would have reduced pollution in cities (Ehrlich & Ehrlich 1990, p. 320). Likewise, simple steps such as better insulation and more efficient heating and cooling systems in houses, are effective ways of conserving energy.


The world needs to be saved because it is moving in an ecologically unsustainable path. The global economy cannot continue to grow indefinitely. Even a twofold increase is likely to be perilous for the biosphere. There is no such thing as sustainable growth any more.

The transition to an ecologically sustainable society involves many steps that run counter to present trends; an emphasis on the health of the environment and the health of people instead of an emphasis on economic growth. That requires reduced consumption of goods, the efficient recycling of materials, a move away from the use of fossil fuels to the use of renewable sources of energy, zero global population growth, a reduced standard of living for the rich, an increased standard of living for the poor and an appeal to quality of life instead of materialism. It is the road not yet taken by the world. To move along that road we need to invent a new economic system that puts the priorities right -- people and the environment before growth in material goods. This is the subject of Chapter 4.