How quickly words lose their meaning in our times. Take the case of ‘sustainability’. It is derived from ‘sustain’, which means support, bear the weight of, hold up, enable to last out, give strength to, endure without giving way. Sustainability is a term that became significant in development discourse in the 1980s because four decades of the development experience had established that ‘development’ and its synonym ‘economic growth’, which were used to refer to a sustained increase in per capita income, were unsustainable processes. Development was unsustainable because it undermined ecological stability, and it destroyed people’s livelihoods. ‘Growth with equity’ and ‘growth with sustainability’ were attempts to legitimize and perpetuate economic growth in a period of doubt. Economic growth had promised to create abundance. It had promised to remove poverty. Instead, by causing the destruction of livelihoods and life-support systems in the Third World, growth itself became a source of poverty and scarcity. While the 1970s focused on the growing polarization and inequality that went hand in hand with economic growth, in the 1980s the focus shifted to the issue of ‘sustainability’. For ecology movements in the Third World, the two issues are usually non-separable-justice and sustainability, equity and ecology are inherently linked in a situation in which the majority of people are excluded by the market economy and continue to draw sustenance from nature’s economy. Development had been based on the growth of the market economy. The invisible costs of this development have been the destruction of two other economies, of nature’s processes and people’s survival. The ignorance or neglect of these two vital economies of nature’s processes and people’s survival has been the reason why development has posed a threat of ecological destruction and a threat to human survival which have, however, remained ‘hidden negative externalities’ of the development process.