Review by Tim Radford of 1979 book Gaia by James Lovelock

27/8/2010 Guardian How James Lovelock introduced Gaia to an unsuspecting world.We have learned so much about our home planet in the three decades since James Lovelock wrote Gaia: A New Look at Life on Earth (Oxford, 1979). Has the book stood the test of time?
   Lovelock’s Gaia hypothesis proposed that life regulates the Earth’s systems to provide the optimum conditions for itself. Photograph: Corbis
Once in a generation, perhaps, you get to read a book that will change the world. But it might take a whole generation or so to realise how much it changed the way we see the world.
My copy of Gaia is a first edition from 1979: hardback price £4.95 (and there were no discounts in those days). To re-read the original text is to be reminded, in all sorts of unexpected ways, how far we have come. Its author has since then morphed from J E, an “independent scientist”, to James Lovelock,[] the world-famous author and speaker. The once-tentative Gaia hypothesis has since become part of scientific orthodoxy and formally enshrined as the Gaia Theory, although in the US it has been dubbed Earth System Science. A new generation of telescopes will soon be sweeping the nearby stars for evidence of oxygen and methane in the atmospheres of the planets that orbit them: a simple idea proposed by Lovelock 40 years ago during the hunt for life on Mars and at the time no doubt dismissed as a bit too simple.
The Gaia hypothesis, as it then was, is simply put. Life may be the product of blind chance and opportune circumstance, but once life has established itself on a planet, it takes over. It manages the planet in ways that continue to sustain life in more or less optimum circumstances. That is why it may be a mistake to call Earth the Goldilocks planet: not too hot, not too cold, but just right. In fact, Earth’s average temperature may be just right because life, by unconsciously manipulating the planet’s oceanic and atmospheric chemistry, sets the thermostat and keeps its Earthly home within a temperature range that is comfortable for life.
At the time, this idea seemed either thrilling or preposterously New Age, and sometimes both. Biologists in particular were annoyed because they see evolutionary forms as things that have adapted to their environments through natural selection, blindly and without purpose or direction. This remains true, but it is also true that having found an ecological niche, all creatures – elephants, ants, orchids and economists – tend to maintain their environments to their own advantage, and it now looks as though collectively, the whole assortment that we call life has got a good grip on Earth, has dug in, so to speak, and made itself at home.
Lovelock won over first his readers and then his fellow scientists by asking questions that might not have been obvious to any of us at the time. Where did the nitrogen in the atmosphere come from? Why was the proportion of atmospheric oxygen just within the safety zone? Why wasn’t the sea far more salty? Why hasn’t all that water boiled off into space? From such questions, he patiently built up an argument that began to sound increasingly interesting: that life is an agent in its own survival. At the time, some of us admired the book enormously, and still do, for its provocation, for its daring, for the huge sweep of the ideas that unfold.
Only now, on rereading, have I realised how tentatively Lovelock put his argument. Of course it depended on reasoning, but good evidence had still to be established. The other thing is how well written it is. Having invested a few paragraphs in rehearsing the improbability behind the assembly of sentient, self-replicating life from a chemical soup, in turbulent conditions, over immense timescales, Lovelock cheerfully resolves it all on page 14 by concluding, “Life on Earth was thus an almost utterly improbable event with almost infinite opportunities of happening. So it did.”

I don’t think I’ve ever seen a neater or more graceful summation.
The green movement gleefully embraced the metaphor of Gaia, but sometimes found Lovelock himself stubbornly unaccommodating: a chemist perfectly comfortable with the judicious release of pesticides, chlorofluorocarbons and atmospheric pollutants; a proselytiser for nuclear energy; a man who when he encountered a bandwagon, instinctively wanted to take its wheels off. He cheerfully points out that the first great toxic pollution crisis for Gaia was the emergence of free oxygen in the atmosphere: those microbial life forms that could not adapt thereafter survived only as anaerobic bacteria in swamps and in the intestines of animals.
He makes a case for the planet as a vast chemical apparatus. The natural oxidation of atmospheric methane produces a billion tonnes of carbon monoxide gas each year. Nature bubbles with sulphur dioxide, dimethyl mercury and a host of carcinogens, all part of Gaia’s planetary management chemical kit.
On page 113 Lovelock reports, expressionlessly, “It has been predicted that the increase in carbon dioxide will act as a sort of gaseous blanket to keep the Earth warmer.” On page 41 he addresses a different bubbling atmospheric anxiety by conceding: “There was of course at the time of the report a strange and disproportionate concern in America about stratospheric ozone. It might in the end prove to be prescient, but then as now it was a speculation based on very tenuous evidence.”
It would be another six years before a British scientist identified the alarming hole in the ozone layer, and it was Lovelock himself who devised the instruments sensitive enough to detect levels of CFCs in the atmosphere. So at the time of writing the book he was right: ozone destruction was speculation, and the evidence was tenuous.
Similarly, it would be another nine years before global warming exploded as a political concern. In fact, on page 149, Lovelock is rather more concerned about the fate of the next ice age, suggesting that the presence of “a large quantity of chlorofluorocarbons” might entirely reverse the onset of glaciation, “or at least greatly diminish its severity”.
To reread Gaia is to be reminded about how little we knew about our own planet in 1979, and how much of what we now know began to emerge as Lovelock and other scientists addressed some of the questions raised in this remarkable book: the first of a series of books that have developed, propagated and defended a remarkable and enduring idea.
Next month we will start to review, in no particular order, all six books shortlisted for the prestigious Royal Society Prize for Science Books.[
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