Several years ago a valued friend telephoned, full of enthusiasm, to pass on the news of James Lovelock’s “Gaia hypothesis.” She met a dismissive response; the idea of the earth as alive was just too close to “Oh, the wonder of it all!” to be taken seriously. On belatedly reading the book that reply turns out worse than unfriendly: plain wrong. Not in any way soft-headed, Lovelock’s hypothesis rests largely on chemistry, if not strictly a “hard” science at least a solid one. Although introducing a feminine personal name (from an old Greek word for the earth) he does not intend to suggest sentience. Lovelock dates the origin of his hypothesis to the time when spaceflight first made it possible to see the earth from outside, and from that viewpoint “earth” includes the life on earth the rock and magma standing to the biosphere much as the skeleton stands to the living flesh.
Formulating his hypothesis, Lovelock writes: “the earth’s living matter, air, oceans, and land surface form a complex system which can be seen as a single organism and which has the capacity to keep our planet a fit place for life.” Finding a place fitting its requirements, life creates a need for regulation by producing dis-equilibrium; the atmospheres of dead Mars and Venus remain stable, the reducible gases having combined with oxygen long ago; earth’s free oxygen and methane can only come from life. The delicacy of the needed balance appears when we note that an increase from 2l to 25 percent in atmospheric oxygen would create a danger of fire destroying the biosphere. Lovelock sets himself firmly against the crude simplicities of the single-principle approach: “a diverse chain of predators and prey is a more stable and stronger ecosystem than a single self-contained species, or a small group of very limited mix.”
The concept of Gaia arises when one extends the concept “earth” to include the surrounding atmosphere, for this both makes life possible and depends for continuance of its present condition upon life. Oxygen in the atmosphere provides the energy permitting life to function, and most of it arises from the burial each year, in sedimentary rocks, of some 0.1 per cent of the carbon fixed by green plants and algae in their tissues; each carbon atom thus removed leaves an additional molecule of oxygen in the air. Nor does life regulate only the oxygen level; the salinity of the oceans and many other regular features of earth, air and sea arise in this way, and the accumulating weight of limestone deposited by minute organisms depressed the continental shelves, starting the movement of tectonic plates. “The biosphere is a self-regulating entity with the capacity to keep our planet healthy by controlling the chemical and physical environment.”
Lovelock displays an attractive, if sometimes disconcerting, large-mindedness, reducing present pollution to a merely human concern, meaningless on the Gaian scale. We cannot claim the poisoning of the air as entirely our own achievement, for it comes as an inevitable consequence of life at work. The biggest-ever pollution incident took place long before humanity was even a gleam in a monkey’s eye, when (from the activity of aerobic microbial life) free oxygen emerged into the atmosphere, making the tidal seas and the surface of the earth lethal for anaerobic bacteria. Humanity ranks as no more than a factor in the life of the planet, and one of the more dispensable; “an infestation of intelligent fleas.” For the continuation of life unicellular creatures matter more than the large animals (including humans) and we have little reason to think that even the explosion of all nuclear weapons together would much affect the bacteria. The continuing radioactivity of the Bikini Atoll has had little effect on the normal ecology of the area wherever soil remains.
The Gaia hypothesis holds firmly to the concept of functional hierarchy, with numbers diminishing as complexity of organisation increases; the free-floating single-celled plans form the food of the zooplankton, these get cropped by larger creatures, these consumed by carnivores and so on, through a series “of ever-increasing size and rarity.”
Already in 1979 Lovelock had realised that human society does not go charging blindly ahead until it smashes fatally against planetary limitations: “the population no longer increases everywhere, industry is far more conscious of its effect on the environment, and there is above all growing public awareness of our situation. We might claim that the spread of information about our problems is leading to the development of new processes for controlling, if not solving, them.”
He suggests that the evolution of homo sapiens with their technology may constitute an increase of Gaia’s range of perception. “She is now through us awake and aware of herself.” If Gaia comprises not only the inorganic structure of the planet but also the biosphere then she incorporates every function of that biosphere, with society, industry and ideology among them. Not only “the earth’s living matter, air, ocean, and land surface” but also all human activities go to “form a complex system which can be seen as a single organism and which has the capacity to keep our planet a fit place for life;” the increasingly ingly self-conscious self-regulation of humanity, controlling its effects upon the environment, shows the ideologies engaged in that function.
Lovelock J. E. 1979 Gaia: a new look at life on Earth. Oxford: UP
– – 1988 The Ages of Gaia; a biography of our living Earth. Oxford: UP
from Ideological Commentary 54, Winter 1991.