According to the late David Pearce, sustainable development means that each generation should pass on at least as much "capital" as it inherits, the Pearce approach defines capital in broad terms, to include physical capital (machinery and infrastructure); intellectual capital (knowledge and technology) and environmental capital (which includes quality and the stock of natural resources).

The Brundtland Commission on Environment and Development defined sustainable development as: "development that meets the needs of the present without compromising the ability of future generations to meet their own needs".