Graduated with a BSc (Hons) degree in Agriculture from Reading University and a PhD in Farm Management from Lincoln College, New Zealand.
He spent three years as a Post-Doc at the International Center for Tropical Agriculture (CIAT) in Colombia, working on bioeconomic modelling of livestock production systems in Latin America, and then was based at the University of Edinburgh for three years working on crop and household modelling projects in Central America and southern Africa.
In 1990, he joined the International Fertilizer Development Center (IFDC) in Alabama, and was involved in projects in various countries in Latin America, Africa, Asia and Eastern Europe.
He moved to the International Livestock Research Institute (ILRI) in 1996 and became Coordinator of the Systems Analysis and Impact Assessment Programme. From 2002 he was working for ILRI based in Edinburgh, involved with several integrated modelling and climate change impact projects in livestock systems in Africa.
He is an Honorary Research Fellow in the Institute of Atmospheric and Environmental Sciences at the University of Edinburgh. He has published widely on systems modelling and impact assessment.
He is on the Board of Directors of the International Consortium for Agricultural Systems Applications (ICASA), a member of the Scientific Advisory Committee of GECAFS (Global Environmental Change and Food Systems programme), and Editor-in Chief of the journal Agricultural Systems.