The complex challenges of environmental governance depend in no small part on issues of spatial scale, whether the problem being addressed is local environmental health burdens typically associated with urban poverty, urban-regional pollution and resource depletion typically associated with motorization and industrialization, or the global ecological footprints typically associated with affluence. Marcotullio (research fellow, United Nations U. Institute of Advanced Studies, Japan) and McGranaham (director of the Human Settlements Programme at the International Institute for Environment and Development, UK) present 13 papers examining these complexities of scale by addressing trends in the spatial characteristics of urban environmental burdens, socio-economic and political causes and consequences of these trends, and implication for urban environmental policy. Specific topics include Asian-Pacific urban environmental transitions, improving urban water and sanitation services, poverty and environmental health in urban Ghana, dynamics of growth and degenerated peripheralization in urban India, and comparative analysis of urban transport and emerging environmental problems in middle-income countries.