As the world enters the last decade of the 20th century, the environmental problems facing human societies have been given increased emphasis in world policy debates. The goal of the Worldwatch Institute is to help raise the level of public understanding of global environmental threats to the point where the public will support policies needed to…

Aside from the growth of world population itself, urbanization is the dominant demographic trend of the late twentieth century. The number of people living in cities increased from six hundred million in 1950 to over two billion in 1986. If this growth continues unabated, more than half of humanity will reside in urban areas shortly after the turn…