Linking Urbanization and the Environment: Conceptual and Empirical Advances

Urbanization is one of the biggest social transformations of modern time, driving and driven by multiple social, economic, and environmental processes. The impacts of urbanization on the environment are profound, multifaceted and are manifested at the local, regional, and global scale. This article reviews recent advances in conceptual and empirical knowledge linking urbanization and the environment, focusing on six core aspects: air pollution, ecosystems, land use, biogeochemical cycles and water pollution, solid waste management, and the climate. We identify several emerging trends and remaining questions in urban environmental research, including (a) increasing evidence on the amplified or accelerated environmental impacts of urbanization; (b) varying distribution patterns of impacts along geographical and other socio-economic gradients; (c) shifting focus from understanding and quantifying the impacts of urbanization toward understanding the processes and underlying mechanisms; (d) increasing focus on understanding complex interactions and interlinkages among different environmental, social, economic, and cultural processes; and (e) conceptual advances that call for articulating and using a systems approach in cities. In terms of governing the urban environment, there is an increasing focus on public participation and coproduction of knowledge with stakeholders. Cities are actively experimenting toward sustainability under a plethora of guiding concepts that manifests their aspirational goals, with varying levels of implementation and effectiveness.