The co-creator of the Gaia theory reminds us of our possibilities and limits in living harmoniously with our planet.

   If we accept that humans have a finite individual lifespan, and no one can ever be immortal, then maybe we should keep in mind that our species also has a limit for its span on Earth. Instead, in our optimism we imagine that if we could manage ourselves and the Earth well enough we could, somehow, find ways to cope with a doubling lifespan, or a doubling of population. We assume the extra stress we would place on Earth's ecosystems could be prevented or alleviated by good stewardship or planetary management.

I think this is our greatest error. Consider how the well-intentioned application of the principles of human welfare and freedom that moved us in the... 20th century failed our bright expectations. Cruel tyrannies now reign in much of what we call the Developing World. In spite of modern medicine, in many places the quality and the length of life diminishes as the land dies under the weight of sacred cows and insupportable numbers of people.

Consider also yourself. You might suffer the misfortune of an accident that damaged your kidneys. Not fatally, but enough to cause those wonderful intelligent filters to fail in their task of regulating the electrolytes, the salts of your blood. You can survive, even live a normal life, but only by taking care to monitor your intakes of salt and water. Such a burden powerfully reinforces the wonder at how well our body manages itself when we are healthy.

But this example is a disablement of one system only. If several bodily systems were disabled simultaneously then you really would have little chance to do anything but consciously regulate your bodily functions. This is the kind of burden, slavery, I have in mind when I say there is no worse fate for humans than to so disable the Earth that to survive they must take on the task of running the planet. Just think of the task of managing even a developed nation, so that the emission of carbon dioxide from burning fuels and agriculture was balanced by the uptake from planted trees. A task that would require the meeting and matching of the conflicting interests of the individuals and groups that make up human society, the resisting of the powerful selfish pressures of their lobbies, and at the same time coping with the haphazard changes of the political, economic, and actual climate. That would be just the start of it, for then there would be the same and other problems involving the inputs and outputs of your nation with those of the numerous other national and tribal states of the world.

A planetary physician can only prescribe for your relationship with the Earth that kind of love and benign neglect that characterizes the relationship of good parents toward their children. There are no nostrums or simple remedies for the ills of the Earth.

This does not mean that there is nothing that you or your society can do about the health of the Earth. A good parent tries to provide an environment that is not damaging to their children and allows them to gain the strength to heal themselves. There are many simple things we can do to live better with Gaia. We cannot manage the Earth, but we can usefully regulate our own lives, and our human institutions. It is helpful as a start to keep in mind the three deadly C's: Cars, Cattle, and Chainsaws. We need not be fanatical and ask for them to be banned; it wouldn't work. But we can remember the physiological truth that the poison is in the dose, and be moderate in our use of these and other dangers to the health of Gaia.

The advantages of moderation in the use of cars and chainsaws are immediately self-evident. The damage wrought by excessive cattle farming, though less obvious, is equally severe: to produce food as beef or dairy products requires twenty times as much land as its vegetable equivalent. I do not propose that we all try to become vegetarian. Better first to think about Africa. We know that there is frequently famine there, yet few seem to realize that much of this distress comes as a direct result of land damage by primitive cattle farming. The human and natural ecosystems of that unhappy continent may soon disintegrate. In Africa, it is not overpopulation with people that is the problem but overpopulation with livestock.

There are other ways of living better with the Earth. Most of them are personal and I do not see this as the place to list them. These are for you to find for yourself, using your own judgement on how to moderate your demands on the Earth, and yet enjoy life. In the same way, you do not need me to tell you all the positive actions you could take-from planting trees wherever you can, to helping clean up the environment where you live and work. 

There is plenty of advice around, too, on how we could collectively, as governments and other institutions, act to solve the "environment crisis". Some of this advice is in principle good. We should, indeed, stop clearing the forest, reduce industrial and other pollutants, develop energy efficient solutions, cut back on fossil-fuel burning, seek less-damaging agricultural techniques, and try voluntarily to curb our numbers and consumption. But in practice, even if we find the will to act, the trouble with much of this advice is that, like some invasive medical approaches, it may do more harm than the disease. Our thinking is still deeply human-centred, based on short-term self-centred advantage, an overestimate of our powers, and a profound ignorance about the Earth.

I would particularly warn against imprudent planetary medication or surgery. There are, for example, proposals to "cure" the effect of greenhouse gas poisoning by applying medication to the oceans, to stimulate the algae there so they remove the excess carbon dioxide from the air. By irrigating the oceans with iron chloride solution, dispensed from super-tankers, we could, say the experts who dreamed up this idea, fertilize the algal blooms and remove enough carbon dioxide from the air to allow us to burn fossil fuels without restraint. By a fluke, this scheme might in the short term achieve its primary intention, of reducing carbon dioxide in the air. But it would still be foolish-as unwise an act as taking thyroid hormone to increase one's metabolic rate, so that a fancy for sugar, cakes and hamburgers could be indulged without the penalty of obesity. Both prescriptions-of iron chloride for the planet, or of thyroid hormone for the fat person-fail completely to recognize that the patients, whether Gaia or a human being, are self-regulating living systems. To attempt control from outside by increasing or decreasing one feedback loop only in these multiple feedback systems is rarely successful, and carries with it the risk of dangerous and unpredictable instability.

I have tried to show that the carbon dioxide and climate balance for Gaia is unstable and that carbon dioxide is oscillating at a level only just above the lower limit for the growth of plants. For a system near the limits of stable regulation the effects of adding or subtracting carbon dioxide are unpredictable. The only wise course would be to cut back the emissions of greenhouse gases.

What do we know of the Earth?

I have made a strong statement rejecting the idea of planetary management, or stewardship, in so far as it implies taking charge of the Earth. I propose instead that we learn to live with the Earth as a part of it; by managing ourselves, and by humbly taking and giving the gifts that sustain all of us on this planet.

Some of you may regard my proposal as irresponsible. As the only organized intelligence, surely we have the duty, if not the right, to take charge of the Earth and govern it responsibly? Maybe so, but how can we manage it if we do not know what it is? It may seem everyone knows what the Earth is, but unfortunately there seems to be no common view. Because we take the Earth for granted we tend to act like bacteria, never noticing the consequences of our unchecked growth. Even scientists differ about what the Earth is, although now more scientists see the Earth as a whole. But many, even if they give lip service to either Gaia or co-evolution, still act as if the Earth were a ball of white hot, partially melted rock with just a cool crust moistened by the oceans. They see life as a thinly spread layer of organisms that have adapted to the material conditions of the planet. With such a view go metaphors like "Space Ship Earth". As if humans were the crew and the passengers of a rocky ship forever travelling an inner circle around the Sun. As if the 3.8 billion years of life on Earth were just a prelude to the evolution of humans and to serve as their life-support system when they chanced to come aboard. Seen this way, obviously the Earth might appear fragile. 

This is the conventional wisdom about the Earth, still taught in most schools and universities. It is almost certainly wrong and has arisen as an accidental consequence of the fragmentation of science, into a growing collection of independent scientific specialities. There are a few geographers and Earth system scientists who teach or research the Earth as a whole. But the majority of practising Earth and life scientists are specialists and even though they know that the conventional wisdom is wrong, they continue to take their views of the Earth from it. If we want to know about life, the universe, and the Earth, we read about them in New Scientist or Scientific American. Back in the laboratory, scientists continue in their own speciality without concern for either the general wisdom or the intricate details of the specialities of their close colleagues.
Of course, no single approach can lead to a complete understanding of the Earth; all are needed. We need the reductionist model of the Earth to understand details at the molecular level. A key example is the chemistry of the stratosphere. It was only through the application of classical atmospheric chemistry and physics that Rowland and Molina first made known the threat to ozone from the CFCs. From biogeochemistry there came, through the work of G E Hutchinson, the recognition of the role of micro-organisms in the soil and the oceans as the source of methane and nitrous oxide. From geophysiology came the recognition that atmospheric gases, such as carbon dioxide, methane and dimethyl sulphide, may be part of a physiological climate regulation.

We are at a time when many scientists as professionals seem to have lost sight of the Earth as a planet, in the intricacies of detail. As a result they may often be more concerned about specific dangers to people, than about the looming threats to the planetary environment. The foremost personal and public fear is that of cancer. Consequently, any environmental chemical or radiation thought to cause cancer is given attention out of all proportion to the real risk it poses. Nuclear power, ozone depletion, and toxic chemicals such as dioxin and PCBs are regarded as the most serious of environmental hazards because of this fear (and also because nuclear radiation and halocarbons are so easy to measure). I think that the potential hazards of the gaseous greenhouse and land abuse have, until recently, been ignored because they perturb the planet, not individual people, and because they are much more difficult to quantify.
The art and science of model building has matured in the [last] ten years. Global climate models now exist in the world's climate centres that take account of greenhouse gases, and include land-based plants and ocean algae. Clouds are still a difficult problem and I am not yet convinced that more than a few models are tight coupled, geophysiological and include the oceans properly, but we have come a long way towards predicting future climates. We have made progress but we are still far from understanding the Earth as a system.

So how can we govern it if science is still unable to tell us what it is? Should we wait for the deliberations of the plenary session of the all-science interdisciplinary congress? Or should we listen to thoughtful environmentalists such as Jonathon Porritt, who ask: can we afford to wait for scientific certainty before taking the obvious sensible action on environmental affairs?

James Lovelock, with Lynn Margulis, developed the Gaia theory. He is a Fellow of the Royal Society, an author, consultant and inventor. His invention of the electron capture detector (ECD) led to the discovery of the global build-up of pesticides, which inspired Rachel Carson‘s Silent Spring, itself the start of environmental awareness.

This is excerpted from the book, Gaia: The Practical Science of Planetary Medicine by James Lovelock, © 2000 by the author. Thanks to Gaia Books Limited, 66 Charlotte Street, London W1P 1LR, for permission to use this text.