Megacities

Megacities are generally recognized as metropolitan areas whose populations exceed 10 million people. Their sheer size and density make them major engines of economic growth and opportunity, but at the same time their complexity, burden on natural ecosystems, and dramatic socioeconomic disparities make them increasingly vulnerable to natural and anthropogenic hazards. As of 2004, it was estimated by the United Nations that there were 20 megacities in the world, most concentrated in Asia and the global South. Although megacities are significant generators of economic activity, most are not considered globally significant “global cities” capable of influencing markets and political events on that scale.

It is not so much the size of these cities that is the cause of their social and environmental impacts but rather their ...