 He moved to the University of Edinburgh where he was awarded a PhD in 1990 for research on the regulation on mitochondrial function in "Cucumis sativus L." seedlings supervised by Chris Leaver.After various postdoctoral research appointments, Hill served as a Lecturer in the Department of Plant Sciences at the University of Oxford for eight years.He moved into science policy, with two roles at the Department for Environment, Food and Rural Affairs (DEFRA), focussing on bringing science and research into policy-making.