The World Summit on Sustainable Development in Johannesburg that is currently in session, presents a two fold challenge to the comity of nations: (1) The conceptual challenge. Until now sustainable development meant that economic growth and technical change had to be made consistent with the conservation of the natural environment. The on going summit is discussing the possibility of enlarging this concept to include issues of poverty, human rights and governance within the rubric of sustainable development. (2) The second challenge is to make a political commitment to the new vision of sustainable development. Yet if the gulf between vision and reality is to be bridged then this political commitment has to be made not just in terms of abstract propositions of the kind contained in the draft political declaration (Agenda item 13).

The key to the success of the Summit would lie in: (1) concretizing the new vision of sustainable development into time bound targets for achieving its various component elements: For example the promotion of renewable energy, provision of water and sanitation to the world's poor; development aid, debt relief and access over the markets of developed countries to the exports of developing countries to enable them to get on to the path of sustainable development. (2) To put into place specific institutional mechanisms at the global and national levels for achieving these objectives. In this article we will first briefly examine the concept of sustainable development and then indicate the progress of the summit so far.

The concept of sustainable development was first defined in the 1980s by the World Commission on Environment and Development (led by Mrs. Brundtland), as follows: "Sustainable Development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs." It may be useful to deconstruct this definition in order to reveal its fundamental implications for the science of economics and international economic relations. This definition introduced three new concepts: The first was the idea that the present generation owes a responsibility to future generations. Further more, this responsibility implies that the present generation should exercise its right to fulfill its own needs in such a way that the right of future generations to fulfill their needs is not undermined. This brought a completely new dimension to mainstream economic theory which had propounded a concept of rationality in which each individual was required to maximize his/her own satisfaction regardless of the satisfaction of other individuals. (The concept of social responsibility much less the needs of future generations was absent from the paradigm of mainstream economics). The practical implications of this concept were: (a) Governments and institutions in civil society had to invest in protecting the natural environment. (b) Regulation of the market was required to induce technical change in a 'green' direction and to constrain private sector production units from damaging the physical environment in the pursuit of private profitability.

The second and related dimension implied in the Brundtland Commission definition of sustainable development, was the idea of limitations on the pursuit of need satisfaction by the present generation. These limitations were imposed by the state of technology and social organization on the environment's ability to meet both present and future needs. The fundamental implication of this was: The pattern and level of consumption and hence the market driven culture of greed would need to change i.e. sustainable development implied a new relationship between man, nature and goods.

The third concept contained in the original definition was that of the inter-dependence of human beings across the world not just in the future but also to-day. This arose out of the recognition that the natural environment exists as an integrated whole in a state of delicate balance. Therefore the actions of people in one part of the planet can affect the natural environment and hence the conditions of life of people in another part of the planet. Thus the idea of a global community with both local and global responsibilities, which in earlier times had been drawn from social theory now arose out of a recognition of the nature of the physical environment itself. The sociality of humankind was thus recognized within the discourse of natural science as simply a fact of our being in this world. The key implication of this concept was that the developed countries where 20% of the world's population was consuming over 80% of the world's resources and causing most of the damage to the global environment (green house gas emissions, as well as air and water pollution), were obliged to seek cleaner technologies. They were also obliged to provide the resources to the poor countries to overcome poverty as well as establish an infrastructure for protecting their environment. This transfer of resources logically has to be seen not as a paternal handout, but as a matter of right for the people of the developing countries. Equally important is the need to restructure multi lateral financial institutions which through the international terms of trade and operation of the debt servicing mechanisms constitute a framework for a net transfer of resources from the developing to the developed world.

On the basis of the above analysis we can suggest that the Brundtland Commission's definition of sustainable development had important implications for changing the global allocation and use of resources, the functioning of international markets for goods, the structure of multi lateral financial institutions and the prevalent culture of consumerism. It is clear that over the last two decades the commitment to sustainable development by the world community, has indeed resulted in significant positive changes in resource use, technologies and social institutions. It is equally clear that these changes have been far from adequate in meeting the requirements of sustainable development.

Let us now briefly indicate the successes and possible failures of the World Summit so far. Its success lies in further widening the concept of sustainable development to include issues of global poverty, human rights and good governance. This is reflective of recent social science research which shows that the provision of human rights, transparent and accountable governance and the establishment of an environment of trust are crucial factors in both economic growth and environmental conservation.

At the operational level two successes may have been achieved in the summit so far: (i) Governments of the world have agreed to provide basic sanitation to 50% of the world's population presently deprived of this service, by 2015. The poignance of this issue was perhaps brought home to the participants by the simple fact that during the ten days of the summit, 50,000 children would have died from illnesses relating to lack of sanitation. (ii) The European Union has proposed that countries aim to use renewable energy for 15% of their energy needs. However there is much debate and disagreement on this issue on profitability grounds, since the cost of renewable energy is still greater than conventional energy sources.

The major issue of setting a target for the use of renewable energy and the switching of subsidies for nuclear and fossil fuels to cleaner energy sources is not likely to be resolved in the summit. However several less contentious but significant proposals have been agreed. These are: (i) Promotion of energy-efficient technologies. (ii) Removal of lead from petrol (lead pollution of the air can damage the brains of children). (iii) Reduction in the practice of flaring and venting of gas during crude oil production. (iv) Improving the competitiveness of clean energy sources by creating a level playing field in the market.

On issues of human rights and governance there is a possibility that these may be marginalized or even bargained away as governments negotiate to extract concessions from each other for short and medium term gains. Finally the hope of fixing an adequate target for official development assistance to the poor countries is not likely to be realized given the politics of the summit.

While the Johannesburg summit may provide a richer vision of sustainable development yet the gulf between vision and reality will probably widen. Ever since the idea of sustainable development was adopted over two decades ago, progress in implementing it, has been significant but clearly inadequate. That is why the threat to the life support systems of the planet to-day is perhaps even greater than before. The World Summit on sustainable development is both timely and necessary. The question is, will it go beyond mere words and meet the challenge of survival that faces humankind to-day