City-Level Decoupling-Full Report

City-Level Decoupling: Urban resource flows and the governance of infrastructure transitions

4 Urban material flows in cities in the developed and developing world

4.1 A pplying material flow analysis to cities The negative consequences of unsustainable global material flows make decoupling an urgent priority. Most of these flows are converted into buildings and physical urban infrastructures or they are transported through cities by these infrastructures. Decoupling can, therefore, be achieved by retrofitting cities or building new ones. The second urbanisation wave creates new opportunities for reconfiguring the urban infrastructures that must still be designed and built in the rapidly expanding cities of the developing world, through the application of material flow analysis to urban systems. Although this is a new approach, it confirms that this kind of analysis is both viable and strategically important from a policy perspective. The application of material flow analysis (MFA) to the global economy and national economies is now quite well established. 54 This section reviews the application of MFA to the city- region, based on two approaches: industrial ecology; and urban political economy (led by the 'urbanists'). The systematic application of MFA from an industrial ecology perspective to the city-region has generated some sophisticated frameworks for assessing the empirical dynamics of resource flows through mainly developed world cities. 55 Many cases also demonstrate the robustness of the urban metabolism methodology. 56 Urbanists interested in

sustainability have in recent years integrated the general concept of resource flows into their analyses of urban infrastructures and economies. 57 While industrial ecologists are interested in empirical quantifications of resource flows, the urbanists are more interested in the socio- technical systems (and related governance arrangements) that conduct these flows through urban systems. From a policy perspective, the two approaches are complementary. Whereas the empirical analysis of flows highlights the dependence of cities on specific sources and sinks for the resources and wastes they require, the analysis of socio-technical systems addresses the regulatory, institutional and knowledge systems that conduct these flows. This research enables policy makers who want to promote more sustainable cities, to make decisions about the building of new - or retrofitting of existing - urban infrastructures that take into account the long-term flows of strategic resources into and out of the city. The most significant outcome of the application of MFA to the city-region is that it facilitates the re-embedding of urban systems within the wider nexus of local-regional ecosystem services (e.g. water supplies, soils, air quality, landfill space) and natural resource extraction (such as fossil fuels or building materials that can be drawn from local, regional, national and/or global sources). This effectively recognises that decoupling urban growth from increasing resource use will depend on a conceptual 'recoupling' of urban systems to their 'bioregions' in a way that accepts that it is

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