From Daisyworld to Crazy World – please do not blame Gaia
When he published The Revenge of Gaia in 2006, James Lovelock probably felt that he had finally been accepted back into the mainstream scientific community. If he was right to think so, then that is a major indictment of the scientific community.
In the book, Lovelock begins by trying to explain the complicated history of an idea – much misunderstood and maligned – that others named ‘the Gaia hypothesis’. It is a peculiar thing in science but, names that detractors devise in order to ridicule an idea often end up – when the idea later proves worthy – being adopted as the common name for it. The ‘Big Bang Theory’, the idea that the Universe had a definitive beginning some 13 billion years ago, being another case in point.
As such, the book is effectively a review of the history of environmental science. I say this as someone who is not quite old enough to remember watching – although I was deliberately made to watch – the live television coverage of Neil Armstrong being the first human to walk on the Moon. As I point out at the beginning of my own book, it is commonly accepted that the concept of ‘the Environment’ developed – just as Fred Hoyle had said it would – once humans had seen a photograph of the Earth taken from Space.
However, not long after the concept of the environment was born, Lovelock was challenging it: The concept of ‘Spaceship Earth’ – along with reductionist and mechanistic thinking in science as a whole – being something that Lovelock makes very clear he considers deeply unhelpful. In the book therefore, Lovelock begins by explaining what Gaia is; and what it is not.
As implied above, Gaia was not Lovelock’s name for his ‘hypothesis’ – it is just the name everyone else gave it. Furthermore, Lovelock uses the term hypothesis very reluctantly: Reading the book, it becomes quite clear that he does not see Gaia as a hypothesis or an idea; he sees it as an insight into the way Nature works. Therefore, despite using the word hypothesis, Lovelock defines Gaia as seeing the biosphere as… “an active, adaptive, control system” that has maintained the Earth as a place capable of supporting life for at least the last 3 billion years (i.e. page 29 in the paperback).
It is therefore tempting to see Lovelock’s insight as being of similar importance to science as that of Charles Darwin almost a century earlier. This would be ironic, however, as evolutionary biology was probably the biggest impediment to the Gaia hypothesis being accepted. This is because (as Lovelock also points out on p. 29) “…a self-regulating biosphere could never have evolved, since the organism was the unit of selection, not the biosphere.” Another possible reason that the Gaia hypothesis failed to catch on, one which is also ironic as it too was a problem that Darwin faced, is that Lovelock managed to upset both the British scientific community and Church leaders. This is because, far from seeing Gaia as evidence of Intelligent Design, the Church mainly saw the Gaia hypothesis as a piece of ‘New Age’ thinking masquerading as science. Indeed, it is entirely possible that disapproval of both groups was mutually-supportive; with both being strengthened in their prejudice towards the idea by the opposition of the other (i.e. both dismissing Gaia as ‘unscientific’).
However, although he may use labels like ‘hypothesis’ and metaphors like ‘the living Earth’, Lovelock warns his readers not to “…assume that I am thinking of the Earth as alive in a sentient way, or even alive as an animal or a bacterium.” (p.20)
So much, then, for what Gaia is not. What, however, is it? I think the best analogy that Lovelock produces is actually an anecdote from his own childhood: This is the account (on p.47) of an early visit to the Science Museum in London during which, for the first time, he saw a working model of a steam engine “complete with James Watts’ famous governor.” As Lovelock points out, Watts’ innovation was an early example of a control system using a negative feedback (i.e. a self-correcting rather than self-reinforcing mechanism) to govern the otherwise uncontrollable engine.
So, then, Lovelock’s insight was to see the biosphere as a self-regulating system, wherein changes that might otherwise make the planet uninhabitable for life tend to be eliminated in the same way that a gyroscope tends to self-stabilise. The latter being a consequence of the Law of conservation of angular momentum – the same thing that enables an ice dancer to change their speed of rotation just by moving their arms. The ice dancer may be intelligent but the gyroscope is not. Thus, there is nothing unscientific or hypothetical about the concept of Gaia.
However, The Revenge of Gaia is much more than the reminiscences of an old man whose idea took some time to be accepted. The Times newspaper described Lovelock’s book as, “Riveting… a stark warning to mankind” – and the BBC’s Andrew Marr described it as, “The most important decade for decades”. This is because it is; and buried within its pages is a very stark warning indeed…
‘Daisyworld’ is an early computer model that Lovelock created to prove that the biosphere could be self-regulating: This simplistic model biosphere contains only two types of flower; white daisies (that reflect heat) and black daisies (that absorb it). Running the Daisyworld model, Lovelock demonstrated that the changing populations of the two daisies had a similar effect to Watts’ governor on the steam engine; counteracting external factors that might otherwise alter the Earth’s temperature.
Nothing too scary in that, I agree. However, what makes the book almost impossible to put down, is the way in which Lovelock repeatedly emphasises two things: (1) that the Sun is now nearly 25% hotter than it was when life on Earth first emerged 3 billion years ago; and (2) that the biosphere is capable of supporting more life when colder than it is now. With regard to the latter, Lovelock points out that, with the exception of areas surrounding coral reefs, cold polar oceans support much greater biodiversity than warm tropical seas.
However, the really scary thing in the book is this: Lovelock and his colleagues did not stop with Daisyworld. In 1994, James Lovelock and Lee Kump produced a more sophisticated model in which the CO2 content of the atmosphere was gradually tripled from its pre-industrial level of 280 ppm over a 20 thousand year period. The results, subsequently supported by a variety of different and more complex models, suggest that our current biosphere is likely to collapse when atmospheric CO2 reaches 500 ppm and/or average atmospheric temperature rises above 20 Celsius (i.e. 3 Celsius above its pre-Industrial level) – because the surface layer of the oceans becomes too warm for oceanic algae producing cloud condensation nuclei (i.e. vital for the maintenance of the hydrological cycle).
At current rates of increasing CO2 emissions, the Earth will reach this state within the next 40 years. Furthermore, just phasing out the use of fossil fuels in the next couple of decades (something we seem reluctant to contemplate doing at present) will not be sufficient to prevent the 500 ppm target being reached later in this century. To do that, CO2 will have to be artificially removed from the atmosphere. It is time, I think, that we got serious about investing in carbon capture and storage.
In order to limit this blog post to a reasonable length, I have simplified a great deal and omitted an awful lot. Therefore, if you have never read The Revenge of Gaia, I would recommend that you do so (as I am doing). However, I reserve the right to return to this subject in the near future. In the interim, I would particularly welcome comments from anyone who has actually read the entire book.