Today’s guest is Professor Mark Maslin, Professor of Climatology at University College London and Director of The London NERC Doctoral Training Partnership. Mark is a leading scientist with particular expertise in the causes of past and future global climate change and its effects on the global carbon cycle, biodiversity, rainforests and human evolution. He has published over 165 papers in journals such as Science, Nature, Journal of Human Evolution and The Lancet, with a current citation count according to Google Scholar over 17,500 (H=64 and i10 index=160). He has written 10 books, over 60 popular articles and appears regularly on radio and television. His books include the high successful ‘Climate Change: A Very Short Introduction’ (OUP, 2014 and 2021), ‘The Human Planet: How we created the Anthropocene’ co-authored with Simon Lewis (Penguin, 2018), and ‘The Cradle of Humanity’ (OUP, 2017 and 2019) which bring together the latest insights from hominin fossils, geology and palaeoclimatology to explore the evolution of our ultrasocial brains. He was included in Who’s Who for the first time in 2009 and was granted a Royal Society Wolfson Research Merit Scholarship in 2011 for his work on human evolution.
What are your research interests and your particular area of expertise?
My research interests are very wide, from human evolution to the development of the global green economy. I very much see myself as a natural scientist, using scientific methods to investigate important subjects such as human evolution, the Anthropocene, climate change and the other major challenges facing humanity in the 21st century. My areas of expertise can be summed up as understanding the fundamental causes of past and future climate change and their consequences for evolution, biodiversity, people and policy-making.
What originally drew you towards climatology?
I have always been fascinated about how the world works and took Geology and Geography at University. However I have a holistic view of the natural world and hence would describe myself as an Earth System scientist – because biology, climatology, ecology, biogeochemistry, oceanography, and geology are just some of the sciences we need to combine if we are to understanding how our planet works and our influence on it.
What was your PhD topic? How did you find your PhD experience?
My PhD was at Cambridge University and supervised by the late Professor Sir Nick Shackleton FRS and Professor Ellen Thomas who is now at Yale University – both brilliant in their own ways. My PhD topic was on the palaeoceanography of the North Atlantic Ocean trying to understand quasi-cyclic collapses of the North American ice sheet during the last ice age. These so called ‘Heinrich events’ sent huge armadas of icebergs crashing into North Atlantic Ocean disrupting the circulation of the deep ocean and affecting global climate.
The Cambridge PhD process was at that time very Darwinian – the survival of the fittest – there was a lack of regular supervision, no real official support, no one ever explained to me how one should approach a PhD or what were the expectations. But this experience was very valuable to me because when I become the Director of the London NERC Doctoral Training Partnership it meant I could develop a completely new way to training and supporting PhD students across the whole of London, simply by avoiding the failings of my own PhD training and empowering students.
After your PhD, what positions have you held and where?
After my PhD I was very luck to get a couple of post-doctoral positions in marine geology and palaeoclimatology at Kiel University in Germany under the mentorship of Prof. Michael Sarnthein who trained a whole generation of brilliant scientists. It is also where my friendship and collaboration with Prof. Martin Trauth started and has led us to some startling findings regarding the causes of human evolution. After Kiel University I was offered a position at UCL where I have stayed ever since. At UCL I have had the privilege of being Head of the Geography Department, Director of the UCL Environment Institute and now Director of the London NERC DTP.
What current projects are you working on? Where do you hope these go in the future?
This is probably the most difficult question to answer – as I have many different projects on the go in many different fields, from climate change health adaptation to the carbon footprint of coffee. One human evolution project I am very excited about is the work of one of my PhD student Cécile Porchier who is working on annually laminated diatom lake sediments from Kenya dated at 80 to 100 kyrs ago. She is co-supervised by colleagues at the Natural History Museum in London and if successful she will be able to understand past climate changes in East Africa at a yearly resolution to really understand what drove the evolution of modern humans and their dispersal out of Africa. I am also very excited as I am starting a new project called ‘Human Evolution in the Anthropocene’ with a friend and colleague Prof. Peter Kjærgaard, the Director of the Natural History Museum of Denmark and who knows where that project will take us.
What project or publication or discovery are you most proud of?
In the field of human evolution, I think the work I am most proud of is the synthesis of all the data from East Africa and the realisation that the exciting story our evolution could only be understand by bringing lots of different research areas together. Martin Trauth and I realised that a combination of tectonics and orbital cycles created periods of time when deep fresh water lakes appeared and then disappeared within the East African Rift Valley. The climate cycled from extremely wet and very dry and coincided with major period of human evolution and dispersal. For example the evolution of Homo erectus, Homo heidelbergensis and Homo sapiens and their dispersal out of Africa. We called this the ‘Pulsed Climate Variability hypothesis’ as it built on the work of Rick Potts and provided a temporal framework within which human evolution could be understood. The central idea that peaks in precession forcing are linked through lakes to human evolution was radical 15 years ago when Martin and I suggested it but now it is so accepted that many forget to attribute it to the original research.
What is your favourite memory from the field?
My favourite memory from fieldwork was the first time we took the helicopter from our camp on the Rift shoulder and swooped down into the Suguta valley in Northern Kenya. It was then for the first time I really understood how the geology and the tectonics had created this amazing landscape and how changes in the Earth orbits could fill or drain these massive lake basins. There is also a strange feeling when one is camped on the Rift shoulders as the climate is perfect for humans – not too hot, not too cold with ample vegetation and water – it feels like home.
If you were not an earth scientist, what would you be?
As an Earth System Scientist or a natural scientist, I do not really believe in the compartmentalism of science. I also do not believe in boundaries between science and social science and have worked on both. But as a second year undergraduate in the summer I did a six weeks internship with a leading international London Law firm – so I might have ended up being an environmental lawyer – now that is a scary thought.
What is the best thing about your job and what is one thing you would change if you could?
I have the best job in the world and people laugh when I say this – but I am serious. I am surrounded by some of the brightest people in the world both colleagues and students. It get to teach and training some of the most interesting students in the world at all levels from undergraduate to PhD. I get to choose exactly what subjects I want to research and no one worries when I stray far from my supposed areas of expertise to support students research the global green economy or food insecurity in Nicaragua or global health and climate change. My University is extremely supportive of public engagement and has allowed me to write 8 popular books (including “The Cradle of Humanity“) and many articles for New Scientist, Guardian, The Times and The Conversation. I also co-founded a company in 2012, Rezatec Ltd, which has grown to over 40 staff and a turnover of over £5 million per year. What other job would allow me to be teacher, trainer, mentor, researcher, author, presenter, explorer, and entrepreneur – and to work with the best of the best from every field of human endeavour.
Conversations in Human Evolution 