‘If we take David Harvey’s dictum that ‘there is nothing unnatural about New York City’ seriously, this impels interrogating the failure of twentieth-century urban social theory to take account of physical or ecological processes. While late-nineteenth-century urban perspectives were acutely sensitive to the ecological imperatives of urbanization, these considerations disappeared almost completely in the decades that followed (with the exception of a thoroughly ‘de-natured’ Chicago school of urban social ecology). Re-naturing urban theory is, therefore, vital to urban analysis as well as to urban political activism.’ See Maria Kaika and Erik Swyngedouw, ‘Urban Political Ecology, Politicizing the Production of Urban Natures’, in In the Nature of Cities: Urban Political Ecology and the Politics of Urban Metabolism, ed. Nik Heynen, Maria Kaika and Erik Swyngedouw (Routledge, 2006), 2.