Professor Tim Lenton

Published on: 21 January 2016

Timothy Lenton is a Professor of Earth System Science and Chair in Climate Change at the University of Exeter.

Tim Lenton is a Professor of Earth System Science and Chair in Climate Change at the University of Exeter. On February 2 he will be talking part in a #UoEGlobalConvo event looking at what a warmer world could be like and the impact it could have. He is also is teaching a Massive Open Online Course (MOOC) in climate change that starts on 25 January. We spoke to him about his career so far and what global warming means for the world…

What is your current research about?

One of the things I am currently working on is the impact of passing tipping points in the climate system.
This work is focusing on the economic impact of passing these points, what it would mean for policy makers and what the optimal response should be.
We are analysing tipping points and the interactions between them using a model of the climate and economy. This model has shown that we need to work extremely hard to reduce the risk of reaching tipping points. The model recommends limiting warming to 1.5 degrees - which is exactly what the COP21 discussions ended up talking about - however it is phenomenally difficult to achieve this now – we have left it too late!

I also run a climate change MOOC (free online course) which provides a general and holistic introduction to climate change. It aims to encourage people to engage with the topic. I’m not telling people what to think - hopefully the MOOC creates a space where people can learn and assess the evidence for themselves.

How does this affect the general population?

As we suffer another winter of eternal rainfall and floods, that used to be one in 100 or 200 year events, the public realise that the climate is changing. Especially as this winter has been exactly the kind projected for the UK in a changed climate - milder and wetter.

What do you do to mitigate your impact on the climate?

I restrict my long distance travel, I cycle and walk a lot and try not to drive a car.
As an academic you are invited to international conferences and meetings. I do some of those talks virtually, which can annoy people. They don’t understand that it isn’t logical to give a talk about climate tipping points by adding to the problem by travelling thousands of miles.

What would a four degree warmer world be like?

If we don’t change from business as usual we can expect to see four degrees of warming later this century. In the longer term this will mean: Major ice sheets will be melting resulting in a rise in sea level that will ultimately reach around 10 metres. Eventually this will mean losing several small island nations, several large cities near sea-level and a long-term reorganisation of where people live.

In the shorter term: We’ll see intolerable heatwaves across the world. Agriculture will get difficult; mammals, including those we farm and eat, will suffer heatwave mortality. Changes in extremes in the weather will result in failed harvests. Changes in the amplitude of El Nino Southern Oscillation ( will mean more extreme El Nino events resulting in more droughts and flooding in around the world.

Some of the Artic summer sea ice will have been lost which means the circulation of the atmosphere and ocean in the northern hemisphere will change. This could change the patterns of seasonality in the UK. We could have triggered the loss of some big areas of ecosystems - the Amazon might be under threat and large areas of coral reefs will be seriously compromised.

The list goes on...

Is it inevitable that we will see warming beyond two degrees?

To restrict warming to two degrees will require decisive and immediate global action. It is already almost impossible to achieve 1.5 degrees of global warming. You could exceed it then try and come back to 1.5 degrees using carbon dioxide removal – this is a mostly unproven set of technologies, but a very interesting area I do some work on.

What does the future hold for research in these areas?

Research needs to become more action orientated. We need to: Give people a portfolio of climate change options; demonstrate the easy wins; and, develop some of the technologies, such as carbon dioxide removal, that give us flexibility.

Research needs to shift from further emphasis on the negative to doing something constructive.
We need to get away from the idea that we can indefinitely take from our surroundings, dump waste into the environment and not expect that to come back and bite us. We’ve got to shift to a more sustainable-energy powered, material-recycling based economy - what is sometimes called a circular economy. This is broader than just tackling climate change but it is fundamental.

What have been your major academic achievements?

I have won prizes and some of my work has had lots of citations and interest, especially the work on climate tipping points and planetary boundaries.
It’s nice to get prizes but that isn’t what motivates me. I would get a greater sense of achievement if I felt my work helped change people’s perception of the Earth. That people saw it as a system they depend upon, and realised their part in this extraordinary system and what a miracle their own existence is in the first place.

How has your background shaped the research you are currently doing?

My background is multi-disciplinary I have done lots of work on how life has shaped our planet over its four billion year history. For me it’s natural to think about life as a force that can alter the whole planet, and humans are just the latest example of that. I have also studied what stabilises and destabilised the atmosphere composition over geological time - what I would call an Earth system view of how our planet works.

Who or what is your inspiration?

My scientific inspiration was James Lovelock and his books on the Gaia hypothesis and the Earth as a self-regulating system.
My personal inspiration comes from the natural world; climbing mountains, running on Dartmoor, walking the coast path and appreciating this extraordinary planet.

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