Professor in the Department of Earth Sciences, with a specialism in tectonics and geochemistry. His research combines field based, petrological and geochemical research projects with physical modelling in order to understand better the important processes which control global evolution. Most of the research has been related to tectonic processes within the solid Earth but most recently he has been working on solid earth-hydrosphere-atmosphere interactions. This work investigates the controls on long-term climate change through an understanding of river chemistry. The major long-term mechanism for removing carbon dioxide from the atmosphere is through weathering of silicates on the continents with the CO2 transported by rivers to the ocean where it is deposited as a carbonate. This research examines how much the erosive exhumation of the Himalayas is responsible for climatic cooling over the last 50 myr.