'The Vanishing Face of Gaia' by James Lovelock

Late this year, if all goes as planned, a 90-year-old James Lovelock will rocket into suborbital space as Virgin Galactic's premier spaceflight tourist. It's a two-hour-plus trip that includes several minutes of weightlessness, during which Lovelock will be able to take an affectionate look at his first love, Gaia -- our blue planet. Lovelock, a British scientist without portfolio but with many admirers, is a friend of Virgin's gleaming entrepreneur, Richard Branson, who enlisted him as a judge in the Virgin Group's $25-million challenge to devise a way to reduce atmospheric greenhouse gases to an acceptable level. Lovelock does not really think this is possible. There are too many of us -- closing on 7 billion at last count.

"It is not simply too much carbon dioxide in the air . . . ," he writes in "The Vanishing Face of Gaia," "the root cause is too many people, their pets, and their livestock -- more than the Earth can carry. No voluntary human act can reduce our numbers fast enough even to slow climate change." Just the breathing those billions of people do, he writes, "is a potent source of carbon dioxide. . . . Like it or not, we are the problem." Because of our numbers and our depredations, the Earth is in a state of positive feedback: "deviations of the climate are amplified, not suppressed, so that greater heat leads to even greater heat."

Earth's atmosphere is "entirely the product of living organisms at the surface." This is a central tenet of Lovelock's Gaia hypothesis, which he conceived in the 1960s, as the environmental movement booted up and the New Age arrived. Because of that unfortunate timing, his hypothesis had for a long time a tie-dyed aura. Gaia, he recalls, was "the science that dare not speak its name." (The name, that of the Greek goddess of the Earth, was suggested to him by his neighbor, novelist William Golding.)

Today it has become a respectable discipline and is called Earth system science by geophysicists and geochemists who can't bring themselves to call it Gaia theory. But it is Lovelock's science -- a study of Earth's physiological responses to its biota. Lovelock has contributed to its respectability by speaking of Earth now as "self-regulating" rather than, as he originally put it, "alive." He still calls it Gaia theory, though ("[W]ould you have read this book if it had the title "The Vanishing Face of Earth System Science"?)