With a PhD in Tropical Pathology from the University of the Witwatersrand, Johannesburg, John is a South African who has had several careers in different fields. His first one spanned 18 years at the South African Institute for Medical Research where he became Head of the Department of Medical Entomology. A life-long interest in the environment and conservation was fulfilled when he served as Director of the Endangered Wildlife Trust (EWT) for 17 years. His interest in energy led him towards academia, and he is a past Associate Professor of Energy Studies at the University of Johannesburg, as well as Visiting Associate Professor at the University of the Witwatersrand. Here he still teaches a module on Energy and the Environment for the MSC in Environmental Science, which commenced in 2002.

John served as a Consultant to the World Bank on the Lesotho Highlands Water Project for 21 years, and his interest in reconciling conflicts between birds and powerlines resulted in the establishment in 1977 of a strategic partnership between the EWT and Eskom (South Africa's national electrical utility) which endures to the present. He has worked all over southern Africa, including Namibia and Mozambique, and has presented papers at a number of international meetings on wildlife and energy. He has published extensively in his various fields of expertise, and is a writer, editor, teacher and consultant on energy and environmental issue. He is Consulting Editor of African Wildlife & Environment magazine and writes a conservation column for the African Hunting Gazette.