I lead the oceans and atmospheres research group that undertake observations and modelling of atmospheric and ocean composition, physics and chemistry.
My research interest is “Earth Systems Science” — the processes that keep the Earth habitable for life today and over four billion years of Earth history. I’m particularly interested in the natural controls on atmospheric carbon dioxide, which is intimately connected with the climate of the planet and rapidly increasing due to human emissions. Understanding the natural system is very important, because if we don’t know how that works, we will be unable to predict how it may change in the future as we disturb it the climate.
I’m also fascinated by what sets concentrations of the life-critical atmospheric gases oxygen and nitrogen. This understanding of what maintains the strange composition of our atmosphere has implications for how common we think Earth-like planets, and life, might be around other stars.
A brief history: I studied BSc physics at Imperial College. My PhD at the University of Reading, supervised by James Lovelock, was on the history of oxygen in the Earth’s atmosphere. I then spent some years at the University of Michigan, researching the evolution of the Venus atmosphere as part of Nasa’s Pioneer Venus mission. Returning to the UK I turned to marine science, developing methods for using tracer experiments in the ocean. I used them to investigate a variety of questions, including the rate at which the oceans mix, and the hypothesis that iron was an important limiting nutrient in the oceans. I worked at Plymouth Marine Laboratory until 1996, and then at the University of East Anglia until 2013. I was elected a Fellow of the Royal Society in 2003.
Also, I play guitar.
After studying physics as an undergraduate at Imperial College, in 1975 Andy began a PhD supervised by James Lovelock, at that time just developing his Gaia theory. Together they experimented with lighting fires under different atmospheres, in order to place limits on past atmospheric oxygen concentrations. From there Andy moved to the United States and the University of Michigan, researching the evolution of the atmospheres of Earth and Venus as part of NASA’s Pioneer Venus mission. Returning to the UK and turning to marine science, he developed tracers that could be detected in the ocean at minute concentrations. He used these to solve diverse problems in oceanography, for example making the first direct measurements of vertical mixing rates over ocean-basin scales, directly measuring air-sea gas exchange, and enabling the iron release experiments that showed unequivocally that iron is an important limiting nutrient for marine life. He also developed methods automated instruments for measuring carbon dioxide in the surface ocean, which are now used worldwide on commercial ships. He retains a strong interest in Earth and other planetary histories, and the processes setting the concentrations of carbon dioxide and oxygen in the atmosphere, co-authoring the book “Revolutions that made the Earth” (OUP, 2011) with colleague (and former student) Tim Lenton.
Andy heads an observational group at Exeter that specializes in making and interpreting ocean and atmosphere measurements to high accuracy, particularly of carbon dioxide and other greenhouse gases, chlorofluorocarbons and other ocean tracers. They use these to research the uptake of atmospheric carbon dioxide by the oceans, ocean mixing and air-sea exchange processes. Andy was made a Fellow of the Royal Society in 2003. He is a recipient of the European Geophysical Union’s Nansen Medal for contributions to marine science (2003), and the Plymouth Marine Sciences medal (2009). Since 2009 he has been funded as a Royal Society Research Professor, which enables him to concentrate full time on research. He is currently a member of the Natural Environment Research Council, the Science Advisiory Board of the Centre for Climate Dynamics in Bergen, Norway and the Steering Committee of the National Oceanography Centre Association.