Professor Tim Lenton
Chair in Climate Change/Earth Systems Science
I am working on three main areas with my research group:
- Revolutionary transformations of the Earth system, involving the coupled evolution of life and the planet
- Tipping points in the Earth system, especially the climate system, and early warning methods for them
- An evolutionary ecosystem model, with an initial focus on the marine microbial biosphere
We are actively developing and using process-based models, spanning spatial scales from the sub-cellular components of marine plankton up to the whole planet, and capturing timescales from days to millions of years, which demands a nested hierarchy of models. We are also applying methods of time-series analysis to deduce system properties directly from data.
Climate tipping points and early warning methods
You can find some videos where I describe the potential tipping elements in the climate system on a nifty spinning globe. The original paper was published in PNAS following a commentary on the policy implications, and it won the Times Higher Education Award for Research Project of the Year 2008. Our report for WWF and Allianz looked in more detail at the impacts of crossing various climate tipping points. Currently I am working with Valerie Livina on developing early warning methods for climate tipping points, and applying these to paleo-climate and observational data – see my recent review in Nature Climate Change. I am also co-editing a special issue on Arctic tipping points, and helped organise a joint British Academy-Royal Society meeting on tipping points, out of which we are producing a book.
Redefining dangerous climate change
My research on actual thresholds (tipping points) in the Earth’s climate system led me to re-examine how we define dangerous anthropogenic interference in the climate system. In particular, I question the policy ‘threshold’ of 2°C global warming and offer some alternative approaches to defining dangerous climate change. The detailed version is published in WIREs Climate Change with an op-ed piece in Nature.
My evaluation of the climate cooling potential of different geoengineering options, with my former PhD student Nem Vaughan, is published in Atmospheric Chemistry and Physics. There is also a brief piece for the Green Room explaining what roles geoengineering might play in avoiding dangerous climate change. My latest work assesses the potential for land plant-based carbon dioxide removal to lower future atmospheric CO2 concentrations and limit global warming.
The evolutionary ecosystem (EVE) model
Years of frustration at how inadequately we capture life within Earth system and ecosystem models, has led us to develop a new approach. Hywel Williams and I started with a generic, gene-based, individual-based model of an evolving microbial ecosystem, which James Clark developed to study the Earth’s early biosphere. Now we are developing a new model of the modern marine microbial biosphere, nested within the MIT ocean model. Stuart Daines is developing a process-based model of resource allocation within individual cells, James Clark is concentrating on interactions between individuals and coupling to the environment, and Hywel Williams is including viruses and their impact on marine biogeochemical cycles.
Revolutions that made the Earth
Having published a book that introduces the concept of a very few critical revolutions in Earth history, I am currently focusing on the ‘complexity revolution’: Between about 800 and 542 million years ago in the Neoproterozoic Era, the modern Earth system was born. Out of the turmoil of ‘snowball Earth’ glaciations and a rise in atmospheric oxygen, came the first animals forming familiar ecosystems. We are seeking to understand the causes and consequences of this revolution in Earth history, in a multi-disciplinary project involving Richard Boyle and colleagues at UCL, Cambridge, Newcastle, Edinburgh and UEA.
- ‘Re-inventing the planet: the Neoproterozoic revolution in oxygenation, biogeochemistry and biological complexity’ funded by NERC (NE/I005978/1): £297,320 and lead of overall consortium <£1M which also co-ordinates the ‘Long-term Co-evolution of Life and the Planet’ programme.
- ‘Detecting and classifying bifurcations in the climate system’ funded by NERC (NE/F005474/1): £275,896.
- ‘Modelling evolution, ecology and biogeochemistry of marine microbial ecosystems’ funded by the Leverhulme Trust (F/00 204/AP): £249,917.
- ‘Ocean circulation, nutrient cycling and atmospheric carbon dioxide’ funded by NERC (NE/G018332/1): £270,110.