According to James Lovelock's Gaia Hypothesis, the planet Earth is a self-regulated living being. In this captivating theory, the planet, in all its parts, remains in suitable conditions for life thanks to the behavior and action of living organisms.
Lovelock is an independent scientist, environmentalist, inventor, author and researcher whose early interest in science fiction led him to Olaf Stapledon's idea that the Earth itself may have consciousness. From Erwin Schrödinger's What Is Life, he picked up the theory of “order-from-disorder,” based on the second law of thermodynamics, according to which “entropy only increases in a closed system (such as the universe)” and thus “living matter evades the decay to thermodynamical equilibrium by homeostatically maintaining negative entropy … in an open system.”
As a researcher at NASA, he worked on developing instruments for the analysis of extraterrestrial atmospheres. This led to an interest in potential life forms on Mars. He came up with the idea that to establish whether or not there is life on Mars, all one has to do is to measure the composition of the gases present in the atmosphere.
When I visited Lovelock last year in his home on Chesil Beach, he told me that it was in September 1965 that he had his epiphany. He was in the Jet Propulsion Lab with the astronomer Carl Sagan and the philosopher Diane Hitchcock, who was employed by NASA to look at the logical consistency of the experiments conducted there. Another astronomer entered the office with the results of an analysis of the atmosphere on Venus and Mars. In both cases, it was composed almost entirely from carbon dioxide, while Earth's atmosphere also contains oxygen and methane. Lovelock asked himself why the Earth's atmosphere was so different from its two sister planets. Where do the gases come from?
Reasoning that oxygen comes from plants and methane comes from bacteria—both living things—he suddenly understood that the Earth must be regulating its atmosphere. When Lovelock began to talk about his theory with Sagan, the astronomer's first response was, "Oh, Jim, its nonsense to think that the Earth can regulate itself. Astronomical objects don't do that." But then Sagan said, “Hold on a minute, there is one thing that's been puzzling us astronomers, and that's the cool sun problem: At the Earth's birth the sun was 30 percent cooler than it is now, so why aren't we boiling?”
This brought Lovelock to the realization that “If the animal and plant life regulate the CO2, they can control the temperature.” And that was when Gaia entered the building. While subject to criticism that it's a New Age idea, the first major scientist who took Lovelock's idea to heart was the hard-nosed, empirically-driven biologist and evolutionary theorist, Lynn Margulis. Because Lovelock was trained from the medical side, in bacteriology, he tended to think of bacteria as pathogens. He hadn’t previously thought of them as the great infrastructure that keeps the earth going. As he told me “It was Lynn who drove that home.” Margulis understood that contrary to so many interpretations, the Gaia hypothesis was not a vision of the earth as a single organism but as a jungle of inter-lacing and overlying entities each of which generates their own environment.
Lovelock has tried to persuade humans that they are unwittingly no more than Gaia's disease. The challenge this time is not to protect humans against microbes, but to protect Gaia against those tiny microbes called humans. “Just as bacteria ran the earth for two billion years and ran it very well, keeping it stabilized, " he said, "we are now running the Earth. We’re stumbling a bit, but the future of the Earth depends on us as much as it depended on the bacteria.”