Among the small but highly influential group of scientists building on the Gaia theory of Lovelock and Margulis, Tim Lenton might have been the most unobtrusive - until now. At 49 he's quite young for the impressive quantity and quality of the work he has produced. For instance, he's the author of a very short but fundamental book on biogeochemical cycles, tracing the vast and intricate process whereby specific elements such as carbon circulate through the atmosphere, the oceans and the earth's crust - with important detours through living beings (1). He was also the lead author, with Rockstrom, Schellnhuber and others, of the inaugural 2008 paper on tipping elements capable of provoking phase changes in the earth system (2). You could further check out a recent article in The Anthropocene Review, co-authored with Bruno Latour, on the role of Life in the production and maintenance of habitable conditions on our planet (3). Lenton appears for Zoom talks in a spare, book-lined bedroom, as though he forgot he's no longer a graduate student and didn't notice whatever cascade of honors has ensued since then. He's concerned with other cascades.
Last summer Lenton was a co-author of a paper entitled "Climate Endgame: Exploring catastrophic climate change scenarios," which examines the existential risk to humanity posed by runaway global warming (4). The key concept is that of so-called "tipping cascades," which are likely to begin in earnest at only 1.5 degrees centigrade of global warming (we're currently around 1.2 degrees). In such cascades, one fundamental change in earth system dynamics sets off another, leading to consequences far beyond those outlined in the increasingly dire IPCC reports. The main difference between the IPCC consensus and Lenton's view concerns the rates of possible change, which are essentially linear for the former (more CO2, more warming), while for the latter, they necessarily pass accelerative thresholds affecting not only temperature, but also, the intricate dynamics of biogeochemical cycles.
A couple weeks ago I started watching a talk that Lenton gave a year ago to a group - or really, a movement - called Scientist Rebellion. It's got the most ungainly title: "Positive tipping points to avoid climate tipping points" (5). After recapping the various cascade scenarios of the current climate emergency, he goes on to discuss reinforcing feedbacks that could push global society out of the current business-as-usual trajectory. Basically he's talking about cheap power from renewables and rising sales of electric cars as the drivers for major transformations in the sectors of battery storage, hydrogen fuel-cell production and "green fertiliser" (nitrogen produced without the use of methane feedstocks). The video is extraordinary because of the intense questions asked by the rebellious young scientists, including how does he deal emotionally with his own knowledge and whether it would be important to examine negative social tipping cascades, like the effects of European colonization of the Americas.
I returned to the video last night, and finished watching it in parallel with my partner Claire. At some point near the end Lenton begins talking about coalitions between scientists, civil society, the financial sector and the media - in short, a concerted intervention in global political ecology, although he doesn't use the term. It was obvious that this was not a traditional egghead paper but an activist blueprint for global system change. According to Lenton it represents a possibly feasible pathway - a "fifty-fifty chance" - for avoiding the above-mentioned existential risk to the human species (and presumably, many many others).
As soon as she had finished the video, Claire began googling around and found an article in the Guardian, only hours old, about a proposal that had just been pitched to the World Economic Forum in Davos, Switzerland. It's an operationalized plan produced by the Systemiq consultancy in collaboration with the Global Systems Institute directed by Lenton at the University of Exeter, under the title "The Breakthrough Effect: How to Trigger a Cascade of Tipping Effects to Accelerate the Net-Zero Transition" (6). This is not about a revolution, and concerning the Scientist Rebellion question about negative social tipping cascades, it's clear Lenton does not want to go there. This is about a consensual transformation of the material basis underpinning the current form of the corporate state, whose representatives gather every year at this time, on top of a Swiss mountain.
Do you think it can be done? Will Davos Man finally answer the ecological question? Will you sign on too? Can a nudge in time save nine degrees of global warming?
Or maybe the initial prophecy holds...
cheers, Brian
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1. Lenton, *Earth System Science: A Very Short Introduction*, Oxford University Press, 2016.
2. Lenton et al., "Tipping elements in the Earth's climate system," PNAS 105(6), 2008,
https://www.pnas.org/doi/full/10.1073/pnas.07054141053. Lenton, Dutreuil and Latour, "Life on Earth is Hard to Spot," Anthropocene Review 7(3), 2020,
https://journals.sagepub.com/doi/full/10.1177/20530196209189394. Luke Kemp et al., "Climate Endgame: Exploring catastrophic climate change scenarios," PNAS 119(34), 2022,
https://www.pnas.org/doi/10.1073/pnas.21081461195. Scientist Rebellion Talk Series #1,
https://www.youtube.com/watch?v=KqpmE_FQwpI6. Meldrum, Pinnell, Brennan, Romani, Sharpe and Lenton, "The Breakthrough Effect: How to Trigger a Cascade of Tipping Effects to Accelerate the Net-Zero Transition," report by Sytemiq and the Global Systems Institute, 2023,
https://www.systemiq.earth/wp-content/uploads/2023/01/The-Breakthrough-Effect.pdf