This work examines 9 critical environmental regions: Amazonia, the Aral Sea basin, the middle mountains of Nepal, Kenya's Ukambani region, the US Southern High Plains, the Mexico Basin, the North Sea, the Ordos Plateau of China, and the eastern Sundaland region of South-East Asia. The case-studies make available an up-to-date synthesis of vast amounts of inaccessible data. The volume forms part of the UNU's work - as a response to the Rio Earth Summit - on improving environmental monitoring, and attempts to link the notion of environmental criticality with that of social vulnerability: in effect, research on human ecology in critical zones around the globe.