Many of the environmental problems found in the developing countries are different from those characteristic of the industrial countries. Shrinking forests, eroding soils, more frequent flooding of river basins and plains, over-grazed pastures and expanding deserts: these are the special problems one encounters in the third world. In these cases there is a close link between the persistence of poverty and restricted economic opportunities for the poorest people in society and the processes that result in the deterioration of the physical environment. Deforestation, desertification and degradation of existing cultivated land are inevitable as long as inequality in the distribution of productive resources is great and the pressure of the poor upon the physical environment is high. If there are lots of people, if many of them are poor and if the poor are denied access to produced means of production, it is obvious that the poor will have no alternative but to earn living as best they can by extracting the maximum possible output from the natural resources available to them. This will unavoidably occur, the reduction of long-term growth notwithstanding.Some problems could be ameliorated if the poor were organized to protect common resources. This would help to avoid over-exploitation. If nothing else were done, however, a serious problem would still remain because of the high time rate of discount of the poor and the associated high optimal rate of extraction, as seen from the perspective of the poor. The only real or permanent solution is to alter the strategy of development, redistributing resources in favor of the poor, giving high priority to human development and adopting policies that ensure that the benefits of growth accrue directly to those most in need.