Half a century ago, James Lovelock came up with the ‘Gaia’ hypothesis, named after the Greek goddess of Earth by his then neighbour and novelist William Golding, which has provided a unique lens by which to view how life has thrived on Earth.
Gaia, which has become a powerful organising principle, portrays Earth as a superorganism, ‘a self-regulating system able to keep the climate and chemical composition comfortable for organisms.’
The Origins of Gaia
Gaia began to take shape in the mid-1960s while Lovelock was helping NASA search for life on Mars. He realised that the Martian atmosphere would be pushed out of chemical equilibrium by living processes that produced reactive gases such as methane and oxygen and that, by the same token, evidence of atmospheric chemical equilibrium would be tantamount to death and the absence of life.
This powerful concept of ‘disequilibrium’ as a marker of life began the journey towards Lovelock’s Gaia hypothesis – where Earth is as a self-regulating system – which provided an intellectual framework for understanding the only planet known to harbour life: Earth.
Lovelock articulated the theory in August 1972, with his first paper with ‘Gaia’ in the title, suggesting that living organisms and their inorganic surroundings evolved together as a single, self-regulating system that has kept the planet habitable for life – despite challenges such as a brightening Sun, erupting volcanoes, and meteorite strikes.
By the same token, Gaia can take ‘revenge’, for instance with pandemics, in response to the pressure put on ecosystems and the planet by its burgeoning human population as the Earth enters what some call the Anthropocene, as people and their technologies exert a significant impact on the planet.
Lovelock, who was inspired as a child by a visit to the Science Museum in 1925, occupies an unusual and influential niche in 20th century science as a truly independent researcher.
Having dealt with him since 1991, I can concur that Lovelock is a maverick who relishes being outside of the establishment.
Lovelock treats health and safety regulations with disdain (he once told me he was happy to have nuclear waste buried in his garden), is suspicious of consensus-led science and formal education, dislikes peer review, and is convinced that the main purpose of committees is to organise meetings.
Describing himself as ‘half a scientist, half an inventor,’ Lovelock believes that necessity is the mother of invention. He told me ‘the main advances in the world have not been driven by science but by invention.’
Indeed, the path to Gaia was opened up by his electron capture detector, ECD, a remarkably sensitive instrument which he began to develop in the early 1950s.
In the summer of 1967, Lovelock used his ECD to screen the supposedly clean air blowing off the Atlantic onto Ireland’s west coast and found that it contained traces of chlorofluorocarbons, CFCs, later found to cause ozone depletion and which are also potent greenhouse gases.
The ECD also helped to hone his thinking about the Earth as a living thing, a super-organism, to ensure the environment remains stable. In the 1970s, Lovelock would develop his theory with the American biologist Lynn Margulis, outlining their ideas in the scientific literature.
Gaia would come under attack, however.
The Oxford zoologist Richard Dawkins criticised the hypothesis as being teleological (that is, as having a predetermined purpose, as if designed by God) and against Darwinian principles. Lovelock responded in the early 1980s by developing a simple computer model to show how Gaia could regulate the Earth’s temperature.
Called Daisyworld, and developed with his student, Andrew Watson, the model was published in 1983 and proved inspirational because it showed how life could evolve to help Earth to keep its cool, even if the sun was warming.
The model was populated with black daisies that absorb heat and white ones to reflect it. These light and dark coloured daisies evolved within Lovelock’s idealised Daisyworld, waxing and waning to balance the way they absorbed and reflected sunlight to regulate Daisyworld’s temperature, so that it was optimum for plant growth.
His simple model gives a flavour of the complex feedback loops that abound in sophisticated computer models that are used today by supercomputers to forecast climate change.
Bolstering Lovelock’s Gaian vision came experimental evidence – the discovery that sulphur from ocean algae circulated in the form of a gas, DMS -that has since been linked with the formation of clouds that help to cool the world by reflecting sunlight back into space.
Lovelock would popularise his ideas with a series of books, starting in 1979 with Gaia: A New Look at Life on Earth, Homage to Gaia (2000), The Revenge of Gaia (2006), The Vanishing Face of Gaia (2009), and A Rough Ride to the Future (2014).
In his latest book, Novacene: The Coming Age of Hyperintelligence (2019), Lovelock argues that machines will evolve to outperform human beings by the end of this century but, adopting a Gaian perspective, will depend on humans just as we need plants.
Lovelock’s vision has been extended by Prof Tim Lenton from the University of Exeter, who is best known for his work on tipping points, where a small change can irreversibly alter the global climate, so that rainforest can turn into savanna, savanna can quickly change into desert, or the gulf stream current that warms our climate grinds to a halt.
Working with the French sociologist of science Prof Bruno Latour, Prof Lenton believes humans have the potential to ‘upgrade’ this planetary operating system to create what they call ‘Gaia 2.0‘.
As humans become more aware of the global consequences of their actions, most notably extreme weather caused by climate change, deliberate self-regulation becomes possible where we limit our impacts on the planet – if you like Gaia is becoming ‘self-aware’ and this could help humanity to achieve greater global sustainability in the future.
One powerful example of self-awareness, suggested by Prof Lenton, is that of positive tipping points, where collective action by people – to switch away from meat, adopt electric vehicles or whatever – can curb harmful climate change.
In September this year, Prof Lenton is organising a meeting at the university, ‘Tipping Points: From Climate Crisis to Positive Transformation’, to discuss the risks of catastrophic tipping points, and how to accelerate positive tipping points to avert the crisis.
Prof Lenton, who is the Director of Exeter’s Global Systems Institute, added: ‘If we are to create a better world for the growing human population this century then we need to regulate our impacts on our planetary life support-system, and deliberately create a more circular economy that relies – like the biosphere – on the recycling of materials powered by sustainable energy.’
He concluded: ‘Lovelock’s remarkable longevity mirrors that of Gaia (and both are reasons to celebrate) – but as Jim would say “she is an old lady now” – and that is all the more reason why we need to stop perturbing her.’
In 2012, the Science Museum Group acquired the archive of James Lovelock, 84 boxes of notebooks, manuscripts photographs and correspondence. Two years later, the museum celebrated his life with an exhibition, Unlocking Lovelock, curated by Alex Rose.
Explore the Science Museum Group’s Lovelock objects and archive.
Editor’s note: James Lovelock passed away on 26 July 2022, we pay tribute to him and his life in this blog post.