Principles of sustainability The concept of (environmental)
sustainability arose out of the growing recognition that human
activity is affecting many of the Earth’s critical resources not
only locally but now also at global scale, and with potential
effects on human as well as ecological health. Among the many
problems, there has been depletion of ocean fisheries, over-
exploitation of the great aquifers, an unprecedented rate of
species loss, increasing problems of waste disposal, and changes
to the gaseous composition of the lower and middle atmosphere.
Recognition of such problems led to the notion of
sustainability, which implies development that meets the needs
of the present without compromising the ability of future
generations to meet their own needs. In the 1980s a major
initiative was established under the aegis of the United Nations
to address issues of environmental sustainability. Its Agenda 21
is a comprehensive plan of action to be taken globally,
nationally and locally. Principles of sustainabl