Research Fellows Directory
Professor Andrew Watson FRS
University of Exeter
My research area is the carbon cycle and its interactions with climate, particularly sources and sinks of atmospheric CO2 and how it they are changing as we emit more carbon dioxide to the atmosphere. I'm also interested in what caused atmospheric CO2 to vary naturally in the past, both relatively recently (the last million years or so, where we know from ice cores how CO2 varied) and much further back in time. We know less about the variations the further into the past we go, but we have reason to think that atmospheric CO2 is one of the most important variables controlling past climate variations.
Humans release close to 10 billion tons of carbon into the atmosphere annually, about half of which is taken up by vegetation on land and by absorption into the ocean. These natural "sinks" are very important for us, because they slow the build-up of CO2 in the atmosphere and the rate of climate change. However, it is difficult to measure accurately how much is going into a given region of land or ocean. Though we know that the natural sinks are variable from year to year, we don't know precisely why, or how they may change in the future.
My research encompasses observational studies, especially in the oceans, of the uptake and release of CO2 to the atmosphere and experiments to investigate the processes responsible for it, be they physical, chemical or biological. We also perform modelling of the Earth system, aimed at synthesising our knowledge of both the modern and ancient carbon cycles.
The research involves understanding the cycles of carbon, oxygen, and the nutrient elements important to life, how we are changing them now, but also how they have changed over the 4.5 billion year history of the Earth. It leads naturally to big questions: what processes have kept Earth habitable over such a long period, are they likely to be frequently replicated on other planets round nearby stars, or is the Earth very unusual?
Interests and expertise (Subject groups)