James Lovelock is the inventor of the idea of Gaia, which, in his own words, is "the hypothesis, the model, in which the earth's living matter, air, oceans and land surface form a complex system which can be seen as a single organism and which has the capacity to keep our planet a fit place for life".
Earth, then, is not just an inert lump on which we happen to have landed, an alien place for us to exploit and colonise. It is in some sense alive, a living system of which we are part. This is not just some weird Californian fancy: it is, despite its surprising shape, a concept that we badly need, a concept that can help to counteract the unrealistic and corrosive forms of social atomism that colour so much of our political and scientific thinking today. The Gaia theory breaks the unrealistic notion that we have of ourselves as detached, omnipotent minds. It points firmly to our place in a larger whole.
Lovelock first had this thought when, as a scientist working for Nasa in the 1960s, he noticed some of the dramatic ways in which the presence of life seemed to make the earth entirely different from neighbouring planets. He saw that the earth's atmosphere - a rich mixture of many gases constantly interacting and constantly renewed - was quite unlike the static stuff (mostly carbon dioxide) that envelops those dead planets Mars and Venus. Remarkably enough, this earthly mix - which is exactly what living things need - has been present in a fairly constant form all through the three and a half aeons that life has existed on earth. The earth's ambient temperature has been kind enough to stay within the narrow range that suits life through all that time, even though the sun's heat has increased by as much as 30 per cent. There are other factors - such as the proportion of oxygen present - which could, at any time, have put a stop to life if they had varied beyond certain narrow limits. Yet this never happened.
To Lovelock this was no coincidence. Something had been keeping our planet fit for life. Was it possible that living things themselves were responsible? He began to think of ways in which this might indeed have been so. For instance, there is the carbon cycle. Life continually takes carbon from the atmosphere for its own use - thus thinning down carbon dioxide, the greenhouse gas that would otherwise raise the temperature - and eventually buries this carbon, perhaps as chalk or coal, until it may be needed again. Other necessary stuffs such as water, sulphur and nitrogen revolve, too, in similar benign cycles. If we put all these systems together, it seems that life is not just a helpless passenger on an alien planet; rather, it is a crucial factor shaping its constitution.
What has official science to say about all this? When Lovelock first made these suggestions, most scientists rejected him. Since that time, however, the scene in the earth sciences has changed. Biology and geology, formerly hardly on speaking terms, are increasingly being brought together. Much of the Gaian story is now accepted - but not under that imaginative name.
Modern specialisation finds it hard to consider the earth as a whole. Scientists are not much interested in reading one another's journals. But more deeply, holistic explanation of this kind - explanation by looking outwards - is the reverse of the reductionist kind, which looks inward for causation by particles. It seems obvious that both kinds are needed. Yet recent fashion in science has leant strongly towards reductionism alone.
Gaia - the name was originally suggested by the novelist William Golding - is a bold, imaginative vision, requiring scientists, and the rest of us, to make as big a change from recently fashionable concepts as did Copernicus. It counters atomistic, individualistic reductionist models such as the Selfish Gene, which have dominated so much recent intellectual discussion. When Gaia theory first began to be discussed, Darwinian biologists were among its most excited opponents. They argued that the co-operation needed for a self-sustaining earth could never be combined with the competition needed for natural selection.
Gaian thinkers have replied that these processes do not clash because they occur at different levels. Life is not a zero-sum game at the biological level, any more than it is in human society. In both spheres, individualism and obsession with competition have forged an unbalanced, one-sided myth. Both Gaian science and Gaian symbolism work to correct that imbalance.
Lovelock is an independent scientist. Though fanatically accurate over details, he never isolates those details from a wider, more demanding vision of their background. He thinks big. Preferring, as Darwin did, to work outside the tramlines of an institution, he has supported himself since 1963 through inventions and consultancies. Reared in Quakerism, he remains, in his eighties, quiet, vigorous, amiable and intellectually explosive.
James Lovelock Born 1919 in Letchworth Garden City, UK. Graduated Manchester University as a chemist, and taught at Baylor University College of Medicine in the US from 1961-64. Leading environmental advocate and founder of Gaia theory. Has worked independently and been a visiting professor at numerous universities. Currently visiting fellow at Green College, Oxford. Books include Gaia: a new look at life on earth (1979), The Ages of Gaia (1988) and Gaia: the practical science of planetary medicine (1991)