James Lovelock, the famous scientist, environmentalist, and futurist, is probably best remembered for the Gaia hypothesis. This is the notion that the Earth is a giant self-regulating system that maintains conditions suitable for life on the planet. In the process of reviewing his first book, Gaia: A New Look at Life on Earth, it became clear that that book was a time capsule, its text not updated from the 1979 original. However, Gaia stimulated much criticism, response, and further research. This resulted in The Ages of Gaia, a second book aimed at a more scientific audience. Will it answer some of the questions I was left with after reviewing Gaia? Join me for this second of a four-part review series as I delve deeper into Lovelock’s ideas and how they developed (see also part 1, part 3, and part 4).

The Ages of Gaia: A Biography of Our Living Earth, written by James Lovelock, published by Oxford University Press in September 2000 (paperback, 255 pages)

The publication history of The Ages of Gaia is only slightly less convoluted than Gaia, so I will disentangle this first. The Ages of Gaia was first published in 1988 and then published in a second edition in 1995 in which Lovelock thoroughly updated the book to address some of the criticism voiced by scientists. This second edition was subsequently reissued in 2000 with corrections and a new preface which is the version I am reviewing here. As opposed to Gaia, The Ages of Gaia has not been included in the Oxford Landmark Science series, and the book is now out of print, so I tracked down a second-hand copy.

The Ages of Gaia contains ten chapters that can be divided into three parts. First is an introduction to, and exploration of, the Daisyworld model. This is followed by a palaeoclimatological history of our planet as seen through the lens of the Gaia hypothesis. Lastly, there is a miscellany of three chapters that touches on terraforming Mars, an interesting digression into the response of the faith community to Gaia, and a chapter discussing how the idea has developed since this book was first published in 1988. One convention adopted throughout this book is to designate the scientific study of Gaia as geophysiology, which I admit is a neat neologism. Lovelock also clarifies that his initial choice of words, that Gaia “is maintained by the organisms at the Earth’s surface” (p. 19), was wrong. “We had not then, and neither had our critics, envisaged the larger system, the superorganism that could regulate climate and chemistry” (p. 19). Whether the superorganism metaphor is appropriate can be questioned, but I am getting ahead of myself here; this is something that will be addressed in On Gaia.

“Lovelock convincingly counters the objection that Gaia is teleological. The Daisyworld models show that it is an emergent property, requiring no planning. “

The Daisyworld model was developed by Lovelock to show how Gaia might function. It models a simplified version of Earth warmed by a star just like our Sun on which black and white daisies^[1] compete for territory. In the process, an accurate regulation of planetary temperature comes about that is optimal for the daisies. This model was developed to address two main objections to Gaia.

Objection #1: Gaia is teleological, requiring foresight on the part of the organisms. I think Lovelock counters this criticism convincingly. His models show how, given certain assumptions, “a global regulatory system can develop from the local activity of organisms” (p. 97). In other words, Gaia is an emergent property, requiring no planning. However, having dismantled this objection, he later seemingly reinserts it. One misinterpretation of his ideas is that Gaia’s feedback mechanisms would protect the environment from harm inflicted by humans. Not so. To him, Gaia is neither a “doting mother tolerant of misdemeanors, nor [some] delicate damsel in danger from brutal mankind. She is stern and tough, always keeping the world warm and comfortable to those who obey the rules, but ruthless in her destruction of those who transgress” (p. 199). Phrasing like this reinserts agency into the concept. If Gaia is an emergent property, it does not destroy the transgressor and spare the innocent, it just destroys. And this is exactly what we see with the current biodiversity crisis: many species are threatened with extinction, none of whom contributed to climate change.

Objection #2: “biological regulation is only partial [and] the real world is a “coevolution” of life and the inorganic” (p. 33). I was also left with this objection after reading Gaia, and Lovelock agrees this is the harder one to counter. He adds that the purpose of this book is to answer it, but he never explicitly returns to this to summarize how he has dealt with it. Thus, I consider this first part a mixed bag.

“Lovelock’s description of palaeoclimatology is considered unconventional and speculative. there are developments that he ignores that you would expect him to be aware of by now.”

In the second part (chapters 4–6), Lovelock describes how the planet’s climate developed and interacted with life’s evolution during the last 3.6 billion years. In particular, he discusses changes in oceanic, atmospheric, and geochemistry. He admits that some of his ideas are considered unconventional and speculative by his scientific peers and much of what he presents here is indeed at odds with what I have read elsewhere. Given that this text was revisited in 2000, there are developments that he ignores that you would expect him to be aware of by now.

Let me give you some examples. First, Lovelock doubles down on his claim that Earth’s temperature was basically constant. Despite evidence for a series of glaciations 2.5–2.2 billion years ago, now collectively called the Huronian glaciation, he manages to both deny this and contradict himself in the same sentence: “There is no evidence of unusual temperature change during the Archean, and there was a cold glacial period 2.3 eons ago” (p. 78). So which is it? There is still no mention of the later Snowball Earth episode during the Cryogenian.

Second, Lovelock states that atmospheric oxygen levels have been constant at 21% for several hundred million years and points to fossil charcoal as evidence. Contrast this with Burning Planet, a book on fossil charcoal, which discussed various attempts at reconstructing historic oxygen levels, all of which show drastic fluctuations with time.

Third, Lovelock argues that we do not know what caused the most recent ice ages, ignoring evidence from plate tectonics. Land of Wondrous Cold explained how Australia and South America drifting away from Antarctica led to the formation of an uninterrupted oceanic current, the Antarctic Circumpolar Current, starting a new episode of global cooling some 33 million years ago.

Fourth, Lovelock still barely mentions mass extinctions. Asteroid impacts interest him only in the context of the recovery phase afterwards: “from their record we can learn a great deal about how the system works and the way that homeostasis is fully restored” (p. 42). The appearance of atmospheric oxygen is the only example given of a non-external catastrophe, but there is no mention of the big five mass extinctions, volcanism, ocean acidification, etc. It was instructive to return to my review of The Oceans, a book that covers the long history of ocean temperature, acidity, and oxygen content. It presents a picture that contrasts sharply with Lovelock’s claims, showing numerous instances when the planet was inhospitable to life. This second part, too, then, did little to quell my concerns. It shows him obstinately holding on to his ideas and ignoring evidence at odds with the Gaia hypothesis.

“there are passages here where Lovelock starts sounding a bit like a crank. […] The reason I hesitate to outright dismiss him is that elsewhere he shows himself to be well-spoken and thoughtful.”

What does not help is Lovelock’s attitude. I hesitate to write this, but there are passages here where he starts sounding a bit like a crank. For example, whereas in the 2000 preface to Gaia, he characterised himself as a scientist, “deeply committed to science as a way of life” (p. xviii therein), in the 2000 preface to The Ages of Gaia he sounds more rebellious. Though he has revised this book to remove terminology offensive to scientists, he hopes that “we will find that the tyranny of scientific orthodoxy is transient” (p. xvi). He rails against modern academia in which there is no place for the amateur scientist. After all, painters, poets, and composers are allowed to be independent, “but where are the independent scientists?” (p. xvii). This ignores the fact that you can call anything art, but you cannot call anything science. He opens chapter 1 by highlighting that one of the joys of living beyond fifty “is the freedom to be eccentric […] without bothering whether I look or sound foolish” (p. 3). And when W. Ford Doolittle criticized his ideas in a 1979 article, Lovelock was initially shocked but after a while realised that it “could be taken not so much as an attack on Gaia but as a criticism of the inadequacy of its presentation” (p. 31), which is a deft manoeuvre to avoid having to admit that you might be wrong. The reason I hesitate to outright dismiss him is that elsewhere he shows himself to be well-spoken and thoughtful. In Gaia, he impressed me with his criticism of the environmental movement; here he impresses me with his chapter on religion and Gaia, and the digression therein on holism versus reductionism in science.

Overall then, though Lovelock clarifies his Gaia hypothesis and phrases it more carefully in this book, much of his evidence is at odds with the work of numerous other scientists. In no fewer than three places (pp. 60, 120, and 213), he writes that it matters little whether his ideas are right or wrong because they have stimulated a new way of looking at Earth. Though the latter is undoubtedly true (he discusses examples of this in chapter 10, Gaia Since 1988), I disagree with the former half of that claim. I have outlined some of my gripes in this and the previous review but also recognize that many other people, far more knowledgeable than me, have worked on this idea for years, both to support and to challenge it. So, how relevant is my criticism? Fortunately, Toby Tyrrell wrote a thorough overview of the arguments for and against in his 2013 book On Gaia to which I will turn next.

1. ↑ When Oxford University Press reissued Gaia and The Ages of Gaia in 2000, their covers pictured, respectively, a white and a black daisy. Props to the designers for that subtle but clever nod.

The Ages of Gaia

Other recommended books mentioned in this review:

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