can’t see the forest

Gaia Hypotheses: Is the Earth Smarter Than Us?

Posted in Ecosystems by Curtis on 8/20/06

Depiction of a small ecosystem

If you ask most people what they know about the Gaia Hypothesis or the Gaia Philosophy, it turns out that what you hear most often are things like:

“Oh, the Earth is alive. Right.” Or,

“Oh, yeah, the Earth is like a mother goddess or something and we’re killing her with nuclear war.”

Throughout much of popular consciousness, the predominating idea about Gaia seems to be that it is a personification of the Earth. This is at least partially due to the way in which James Lovelock, the independent researcher who formulated the original Gaia Hypothesis (I use the plural form in the title because there are now many interpretations of the original), worded his initial assertions. Even the name of the theory, taken from the name of a Greek goddess upon the suggestion of novelist William Golding (Lord of the Flies),invites the personification of Earth. Lovelock’s original paper was published in 1969 but was widely ignored until 1975, when it began to be addressed by the scientific community principally through open ridicule. Lovelock used fiery language and scientifically questionable terminology that opened the doors for much of this slander. But as planetary astronomers, geologists, biologists, and other scientists began to examine his core ideas on their own merit, the science of ecology—an understanding of our planet as a delicate, closed system in which each species of life has a small but indispensable part to play in maintaining and sustaining that system—began to flourish as never before.

Lovelock defined Gaia as “a complex entity involving the Earth’s biosphere, atmosphere, oceans, and soil; the totality constituting a feedback system which seeks an optimal physical and chemical environment for life on this planet.” Lovelock advocated the insight to be gained in thinking of Earth as a single living organism, which was perverted by the scientific community and by popular culture to mean that the Earth must be an intelligent, sentient being which self-regulates its ecology through purposeful machinations. The Gaia Hypothesis was accused of a teleological prejudice, meaning that it implies the existence of purposeful intelligence behind the ecology of Earth. It was regarded by many, but certainly not all, scientists as a sort of New Age mysticism, and, unfortunately, it is in this light that Gaia came to be championed by many environmentalists, usually with limited understanding of the science behind Lovelock’s ideas and thus sometimes to the detriment of those ideas. Even the brilliant Isaac Asimov chose to explore in his novel Gaia a teleological perspective of the theory instead of using his intelligence and creativity to demonstrate a constructive interpretation. This is not a discredit to Asimov, so much as an indication of prevailing attitudes and understandings in the wake of Lovelock’s publications. Later, microbiologist Lynn Margulis developed the theory with more focus on the ecological relationships involved in the concept rather than the view of the Earth as a single living organism.

Scientific basis for Gaia

Since the first appearances of life on Earth, the energy output of the Sun has increased by about 25 to 30 percent. Geologic records show that the Earth has maintained a high degree of homeostasis despite this not insignificant environmental change. The composition and temperature of the Earth’s atmosphere have remained remarkably stable, which is counterintuitive. Oxygen is a highly reactive element which tends to fuse with other elements, but the oxygen level has been holding steady at about 20 percent. Methane should not exist in trace amounts in our atmosphere as it does, because it is combustible in oxygen. The biological processes of living organisms, Lovelock asserted, evolve with and sometimes against one another to influence atmospheric and oceanic composition in such a way that homeostasis is maintained. This assertion was nothing new. But Lovelock’s focus was that, if these fundamental processes were sufficiently tampered with, multicellular life would not be able to exist.

The only major source of atmospheric carbon dioxide—keep in mind, we are not considering human emissions yet—is volcanic activity. The removal of carbon dioxide is handled through precipitation of sediment into carbonate rock (such as limestone) and through the respiration of plants. Plant root systems and soil bacteria force gaseous circulation of carbon dioxide, and certain kinds of oceanic microorganisms make their shells out of carbonate precipitate, which is returned to the ocean bottom when these organisms die. When there is too much carbon dioxide in the atmosphere, an increase in the quantity of these microorganisms can regulate the gas level by extracting more carbon dioxide from the atmosphere and depositing it at the ocean bottom. Not coincidentally, as human carbon dioxide emissions have skyrocketed throughout the last fifty to one hundred years, carbonaceous algal blooms have reciprocated. Unfortunately, there is only so much the algae can do to negate our carelessness.

Similarly, the salinity of ocean water does not exist in a state of equilibrium, yet has maintained constancy at around three and a half percent for as far back as the geologic record goes. Constancy of salinity is absolutely crucial to cellular life, because osmosis does not work properly when salinity exceeds about 5 percent. Rivers wash large amounts of salts and minerals into the ocean on a continuous basis, so the stability of seawater composition has long been a mystery to scientists. Lovelock’s idea suggests that ocean life exhibits built-in mechanisms which help to maintain this balance.


Daisyworld was a mathematical computer model which Lovelock and Andrew Watson developed to demonstrate two things. First, they wanted to show that the kinds of feedback mechanisms described above do in fact exist in planetary ecology. Secondly, they wanted to prove that the development of these feedback mechanisms and their aim of maintaining global homeostasis in the face of increased solar radiation did not require any sort of consciousness.

In Daisyworld, a planet orbits a star whose energy output is slowly and steadily increasing over time. This world has two life forms—white daisies and black daisies—which grow upon its surface. The black daisies absorb solar energy efficiently, being black, while the white daisies reflect solar energy efficiently. At the beginning of the simulation, the global temperature is so cold that only black daisies can absorb enough heat to survive. Increased numbers of black daisies cause the temperature to rise, at which point the reflective white daisies can survive and compete. At some point an equilibrium of temperature arises, wherein the shifting daisy populations are able to maintain a static temperature in spite of increasing solar energy. Eventually, near the end of the simulation, the heat overwhelms the entire population and life dies out. We can only hope that some of the daisies migrated to another, younger world, or at least to a daisy space colony.  

The really interesting thing about Daisyworld is that, in later, more complex, and more realistic models, when higher-level species such as foxes and rabbits were introduced to create elementary food chains, the ability of Daisyworld to maintain equilibrium increased. In fact, the more species that were added to the world, the better Daisyworld seemed to be able to regulate its temperature! These findings were very important in the development of an understanding that biodiversity is important to planetary ecology. Species compete brutally at an individual level, but nevertheless all share a very real interest in the proliferation of new species which will in turn have to compete with them.

The implications of Gaia for mankind

So what do we make of all of this?

The really urgent idea behind the Gaia theories is not that the Earth is “smart.” This kind of metaphysical mumbo-jumbo only serves to pit the theologians against the scientists again and again. To appreciate what Gaia means for mankind, one does not have to view the Earth as a living being…the Earth’s corporality or sentience is really of no consequence to the most compelling implications of Lovelock’s theory.

Whether or not the Earth is alive, there are moral implications to the Gaia Hypothesis—namely, in terms of biodiversity, that the short-term gain of a species over its competitors may not be as important as the long-term gain offered by increased competition and biodiversity. As the only species smart enough to realize this, humanity has a special role in the ecosystem that is unprecedented in its history.

The idea is that humanity has undertaken all of its industrial progress without due consideration for the possibility that the byproducts of our activities may be influencing a delicate ecological balance that is responsible for our ability to exist in the first place.

It’s not just that the toll of our civilization on its environment is morally wrong in some way—I would argue that it certainly is wrong, as wrong as anything could be—but that it is circumstantially upsetting to an extremely long-running and well developed mechanism of homeostasis that life on Earth has created for itself as a function of its own existence.

It’s the idea that global warming is not just a phenomenon created by humans—it happens naturally, because a star gets brighter and hotter as it matures, before it enters the final cooling stage of its life. In about a billion years, the Sun will have become too hot to allow the Earth to support life as we know it. The truth is that life on Earth has developed ways to deal with a certain degree of global warming, but that human activities are aggravating global warming and restricting the inherent ability of ecology to deal with the phenomenon.

In fact, one implication of the theory is that it is of importance that the global ecosystem is not intelligent. It doesn’t know that humans are causing this problem, and this may result in unnatural bio-evolution in attempts to deal with a problem that is manmade (and thus self-corrigible by a single species) rather than “starmade” (requiring ecological cooperation.)

This means that it is our responsibility as intelligent creatures capable of affecting our surroundings for better or for ill to responsibly take the helm of ecological control. This, more often than not, appears to simply mean letting good enough alone. Unfortunately, that idea is total anathema to the tenets of industrial society. But it doesn’t have to be. In a future post I will be discussing the moving leadership of Ray Anderson, CEO of the world’s largest carpeting conglomerate, which singlehandedly transformed the carpet industry from one of the world’s most environmentally hostile enterprises into a pinnacle of sustainability and ecological responsibility.

It is my conviction that the lure behind the tendency for scientists and persons of all persuasions to view Gaia as some sort of weird mystical philosophy while ignoring its real-world implications is merely a psychological projection–if we think of the Earth as “alive” or “smart,” the responsibilities we must shoulder as the intelligent life form within our ecosystem can be relegated, consciously or subconsciously, to “Mother Earth” who will “take care of her own.”

A differentiation was drawn early on between what is called “strong” and “weak” Gaia theory. In the strong theory, life makes the environment stable so that more complex life can flourish. The weak theory is simply a (more viable) observation that lifeforms have co-evolved on this planet from their beginnings and that this co-evolution led to an ecological homeostasis that allowed the continued evolution of life. There is an important but subtle distinction between these two versions of the theory. The strong theory insists that the co-evolution of life purposefully precipitated the conditions ideal for more extensive evolution. The weak theory says that it may all be happenstance just as easily as a “plan,” but that the observation of these mechanisms is important regardless of the presence or absence of a teleological interpretation.  

The bottom line is that humanity is becoming, in ecological terms, a destructive parasite rather than a part of the existing symbiosis which makes life possible. Whether or not this symbiosis developed as a function of some kind of intelligence is nowhere near as important as the fact that, as the only species around with the ability to impact the world at our level, we can change more readily than the life around us and we must reduce our net impact at all costs if we and all other life forms are to survive.



4 Responses

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  1. […] More on the Gaia hypothesis The really urgent idea behind the Gaia theories is not that the Earth is “smart.” This kind of metaphysical mumbo-jumbo only serves to pit the theologians against the scientists again and again. To appreciate what Gaia means for mankind, one does not have to view the Earth as a living being…the Earth’s corporality or sentience is really of no consequence to the most compelling implications of Lovelock’s theory. […]

  2. Jack Frenson said, on 4/16/07 at 6:55 am

    How do you pronounce gaia ? says it GAY-ah. Isn’t it rather GUY-ah ?

  3. Curtis said, on 4/18/07 at 5:23 pm

    The word comes to us from Greek, in which case it would be pronounced “GUY-ah.”

  4. rough-hewn fellow said, on 10/22/07 at 3:15 am

    The worst crimes were dared by a few, willed by more and tolerated by all — Tacitus

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