The World Commission on Environment and Development (the Brundtland Commission) brought the concept of sustainable development to geopolitical significance. Today the term sustainable development is a catch phrase meaning different things to different people. To some it is a truism, to others a contradiction in terms. Sustainable development is often identified with sustainable growth. Questions about the trade-offs and links between economic development, economic welfare and the environment remain unanswered. As the Brundtland Commission and others have defined it, the primary implication of sustainable development is that future generations should inherit an undiminished stock of “quality of life” assets. This is, however, a political concept, and this capital stock can be measured or interpreted in three ways: 1) as comprising man-made and environmental assets; 2) as comprising only environmental assets; or 3) as comprising man-made, environmental and “human capital” assets. The notion of intergenerational equity lies at the core of the concept of sustainable development. While there is no solid definition to go by, development that does not meet the criteria of intergenerational equity must be bad development. Barbier (1987) has attempted to reconcile different views in a working definition of sustainable development. He identified three systems that are basic to any development process: biological, economic and social. Society applies sub-goals and targets to be achieved within each of these systems. The objective of sustainable development will be to maximize goal achievement simultaneously across these three systems, through an adaptive process of trade-offs. An unsustainable process would seek to maximize goals for each of the systems separately, without regard for the trade-offs. The choices and trade-offs made in a sustainable development strategy will depend on priorities, time, and scale (local, regional, national or global).
