The terms sustainability and sustainable development mean different things to different people. In general, sustainability involves some notion of respect for the interests of our descendants. Ecologists have taken this to include preserving the status and functions of entire ecological systems. Economists have stressed the maintenance and improvement of overall human living standards. There is also disagreement about the prospects for achieving sustainability. Some scholars argue that in the past humankind, through resource substitution and technological progress, has avoided the specter of Malthusian scarcity. Yet others believe that the human pressure on natural systems has already passed sustainable levels. They argue that it is likely that the world’s population will at least double before it stabilizes, and they cannot conceive of ecological systems tolerating the consequences of the economic growth that will be needed to support a decent living standard for this increased population. It is difficult to determine where the truth lies and what the appropriate strategies are. Progress is hampered by disagreements about basic concepts and terms of reference.
