Blackwell Reference Online

Extract

The rapid urbanization of the world's population (accompanied by the rise of megacities) and the profound growth in the scale of impacts on the natural environment were two dominant trends of the twentieth century. Today over 3 billion people, nearly one-half the human population, live in urban areas ( United Nations 2004 ). Humans have altered the composition of the atmosphere, contributing to global climate change, have changed land cover over a large proportion of the earth's surface, and have contributed to a dramatic rise in the rate of species extinction. All signs point to a continuance of these trends in the twenty-first century. More than half the world's population will live in urban areas before 2010 and nearly two-thirds will be urban residents by 2030 ( United Nations 2004 ). It appears that environmental impacts will likely follow a similar pattern of growth. The parallelism of these trends points to the importance of assessing the connection between urbanization and environmental degradation. The causes and consequences of urbanization are highly complex as they are embedded in other global processes, such as modernization, population growth, trade liberalization, migration, and the expansion of global capitalism. Global environmental change is similarly embedded in a complex of transformative processes. Nevertheless, urbanization plays a dominant role in the mounting ... log in or subscribe to read full text