He works on relations between society and nature, particularly on rural development and conservation with a focus on how social constructions of nature affect the way the environment is understood, transformed and managed. Much of his work focuses on Africa.

His books include a history of conservation, Against Extinction, and Future Nature, both with Earthscan and he has recently completed a paper on how the Transition to Sustainability can be achieved for the forthcoming Congress of the World Conservation Union in Barcelona.