Gaia: A New Look at Life on Earth

"Yes, this was a really quite radical notion that he developed of seeing the planet not as a dead entity on which life lives, but something that lives in the largest sense: that the biosphere, if you like, actively manages the atmosphere. The atmosphere is not something that would exist in anything like its chemical form without bacteria, phytoplankton in the oceans, plants on the land. It’s a very dynamic chemical entity, which is constantly topped-up or changed chemically by living things. So he developed this idea of ‘Gaia’—that the biosphere has evolved to manipulate the environment in ways that is conducive to it. Gaia was a Greek earth goddess. He used her name to try to sum up his idea. It does sound, almost, like a mystical notion, and I think for some people it is a spiritual thing: this sense of harmony within nature, or potential harmony. Jim Lovelock wasn’t quite like that. He was an old-school scientist, looking at this from a very scientific perspective. I reported on it at New Scientist magazine as a piece of science, as much as anything else. But he undoubtedly also captured the imagination of a lot of environmental scientists who are, in many ways, quite driven by environmental concerns. An awful lot of research has been developed to test his ideas. Can we measure how life is actively moderating, optimising, the amount of oxygen in the atmosphere? The amount of carbon dioxide in the atmosphere? The temperature? And some excellent results has come out of that. So whether you regard it as a literal truth or some kind of elaborate metaphor, it does seem to hold great power. This book was James Lovelock’s first attempt at that. He wrote several other books in a similar vein, and only died a couple of years ago, having reached 100 years of age. I interviewed him quite a few times. He was a kind of mentor for me, I suppose, in my environmental thinking. And certainly the book has been hugely powerful for many people. He had an interesting path. The ideas for the Gaia hypothesis arose out of his work for NASA. He was a top-line scientists working for industrialists, for NASA. NASA was trying to work out how they could find life on Mars. He said, well, yes, okay, you could send satellites and touch down and look for signs of life. Or you could look to the atmosphere: look for what we see on Earth, which is the gas methane, or perhaps other gasses that only living forms could have produced. That was a whole new way of thinking: that you didn’t have to physically go to find a green man in order to demonstrate there was life on Mars. You could look for indirect things. Having thought up that idea, he and a number of collaborators were pushed to think about the Earth and how the Earth functions. It’s been a hugely influential idea, certainly for me, but I think also more widely for the environmental science movement."