1. INTRODUCTION
The world is now experiencing severe problems of natural resource depletion and environmental degradation. This deterioration has been justified by the so-called “development process”. In this context, developed countries have set the standard of material comfort to which the growing population of developing countries are now aspiring. At the same time, those who have enriched themselves from exploiting resources and the environment have not ceased to acquire more. With the limits of natural resources and the Earth’s finite carrying capacity, this situation is of global concern.