While those of us in the developed countries of the world tend to think of environmental deterioration as the consequence of our heavily industrialized economies, in fact the worst examples of current environmental degradation are found within the world's less developed regions. There, high population growth rates and economies limited primarily to farming have forced the increasing use of more marginal (less suited to cultivation) land. In the world's grassland and arid environments, which occupy approximately 40 percent of the world's total land area, increasing cultivation pressures are turning vulnerable areas into deserts incapable of sustaining agricultural productivity.

In the world's forested regions, particularly in the tropical forests of Middle and South America, Africa, and Asia, a similar process is occurring: increasing pressure for more farmland is creating a process of deforestation or forest clearing that destroys the soil, reduces the biological diversity of the forest regions, and ultimately may have the capacity to alter the global climate by contributing to an increase in carbon dioxide in the atmosphere. This increases the heat trapped in the atmosphere and enhances the greenhouse effect.