James Lovelock: The man who changed the world

His theory of Gaia transformed our view of planet Earth - and made him a guru of the greens. But 30 years on, James Lovelock remains scornful of the movement that adopted him and would even welcome a supply of nuclear waste in his own back garden

"You're a champion of the chemical industry, a strong proponent of nuclear power and a supporter of MI5," I said to James Lovelock. "You're a pretty unlikely hero for the environment movement." He laughed. He giggled, actually. "Well, if you put it like that..." he said.

"You're a champion of the chemical industry, a strong proponent of nuclear power and a supporter of MI5," I said to James Lovelock. "You're a pretty unlikely hero for the environment movement." He laughed. He giggled, actually. "Well, if you put it like that..." he said.

He is 80 now, though he looks sixtysomething, and it is 30 years since he conceived perhaps the most radically new way of looking at life on our planet since Darwin: Gaia. Lovelock suggested that the Earth itself was alive. It was in effect a great super-organism, he said, that could regulate itself chemically and atmospherically to keep itself fit for life, and had done so for billions of years.

The complex mechanism he put forward for the Earth's self-regulation might have remained in The Journal of Geophysical Research had he called it "the biocybernetic universal system tendency". But his neighbour in the village of Bowerchalke, Wiltshire, the Nobel Prize-winning novelist William Golding, suggested he name it after the Greek goddess of the Earth; and when Lovelock did, he found it brought him a vast new audience.

In Gaia he had conceived more than a radical idea: suddenly he had created a new persona, a reinvented Mother Earth able to inspire reverence and awe besides scientific curiosity. It was an almost religious metaphor, seized on by the generation which had just seen the first wonderful pictures of the Earth taken by the Apollo astronauts, the shimmering pastel-blue sphere hanging in infinite black space. Gaia seemed to reach out to the burgeoning environmental movement: Gaia was benign, she kept the Earth favourable to life, but she was not necessarily pro-human, and if humans offended her, she might well readjust things to do without them.

The shock for Lovelock was that it was the metaphor which found instant acceptance and gave him world fame, not the scientific theory, which was at first ignored. "It was a great surprise," he says, sitting in his present home-cum-laboratory, an old mill in Devon. "I was astonished that two thirds of the letters came from philosophers, new age people, theologians and clerics. Only a third came from scientists."

This wasn't what he'd hoped to achieve; above all, it was the theory he wished to be taken seriously. As his new autobiography recounts, Lovelock was anything but a green dreamer: he had spent his life working as a practical scientist, achieving eminence as a researcher, first with the National Institute for Medical Research and later with NASA, where he worked on the American space programme. Along the way he produced a series of inventions, including one, the electron capture detector which made possible the detection of pollution in the environment in the most minute amounts, and thus underpinned the green movement. It was an invention which gave him enough money to free himself from research institutes and set up as an independent. He had very little time for anything that wasn't absolutely, rigorously scientific, and that is one of the points where he and the green movement part company. "Their hearts are very much in the right place," he says. "But they often get the science wrong, and you can't really be a green without being involved with science." He is exasperated, for example, by environmentalists' hostility to the chemical industry. "I find that side of the green movement that considers everything chemical as harmful, produced by a nasty organisation thinking only of its profits and never of the good of people or humankind, as rather absurd."

He feels the same about green hostility to nuclear power. "Fifty years ahead when the problems of the greenhouse effect really hit us hard, somebody is going to point a finger back at the greens and say, if we had nuclear power we wouldn't be in this mess now and whose fault was it? It was theirs."

Not even nuclear waste bothers him. "The waste is no problem at all. I made an offer to the British nuclear industry a long time ago that if they could arrange it, I would quite happily take a year's waste output of one of their major stations on this site here, and use it for heating. A year's output could be concentrated into a steel cylinder a metre long. It's not too difficult to build a concrete pit to shield you from any radiation. I wouldn't be frightened of it in the least. Furthermore, it would be very handy to have a porthole into which you could drop a chicken from the supermarket and wipe out all its salmonella - a marvellous way of sterilising food." By now Lovelock, who looks like a grey-haired imp, is not only warming to his theme, but there is a definite air of mischief about him. Yet he is totally serious.

And there are other aspects of his life which make him an unlikely fit for the label Green Guru. A socialist and conscientious objector during the Second World War, his sympathies slowly aligned with the Establishment, and when at the height of the Cold War the Security Service sought to draw on his expertise in inventing gadgets he responded enthusiastically. It would be an exaggeration to say he was the real-life equivalent of Q, James Bond's gadgeteer, but it is not an empty comparison. "I very much enjoyed my contact with MI5," he says.

It was with astonishment, therefore, that Lovelock found the Gaia hypothesis rejected by scientists but embraced by the alternative world. Yet perhaps it was his own doing: this most practical of men had been seduced by his own metaphor, speaking of Gaia as she, in highly personal terms, as if he were talking of a sentient being. He wryly recognises this now - "Who doesn't fall in love with a metaphor? Richard Dawkins fell in love with The Selfish Gene" - and over the last 30 years he has modified his language ("I've had to stop saying the Earth is alive") as the theory itself of the self-regulating planet has gradually been accepted by his scientific peers. "Yes, people have come round to the argument of Gaia, but they don't like the name. They call it Earth Systems Science."

Yet three decades on, Lovelock retains his twin vision of Gaia as Earth Goddess who should be respected and revered, as well as complex self-regulating mechanism. He fears that coming climate change may produce more drastic effects than people imagine as Gaia is perturbed, in the literal sense, by human actions; he can well contemplate the earth spinning on without people. Not that he is gloomy: he is serene at 80, hugely happy in a second marriage with an American 30 years his junior, Sandy Orchard. He simply sees through his unique metaphor, as the Greeks did, that the balance of things cannot be disturbed without consequences.

"Modern science has taken away from the authority of religion but has offered us nothing in the way of moral guidance in return," he says. "Gaia gives us something to which we are accountable. We're not here for ourselves alone."

'Homage to Gaia: the life of an independent scientist' by James Lovelock, is published today by Oxford University Press, £19.99