Urban metabolism profiles. An empirical analysis of the material flow characteristics of three metropolitan areas in Sweden

Knowledge about the characteristics and driving forces of material flows in urban areas is crucial, as the pathways towards sustainability depend on local conditions. Currently, Urban Metabolism research focuses on the analysis of trends and transitions in different stages of city development, on developing classification systems and identification of metabolism profiles for urban areas. A novel framework for characterizing cities metabolism is provided using Urban Material Flow Accounting indicators as the basis. A Material Flow Accounting study is conducted for three cities in Sweden, from 1996 until 2011: Stockholm, Gothenburg and Malmo. Based on the urban metabolism characteristics framework, three distinct profiles are proposed: consumer-service; industrial; and transitioning. Stockholm's material needs are mainly for final consumption. When compared with the other two cities, material flows follow a more stable trend and have lower dependency on external systems due to the marginal production and export of goods. Gothenburg has the most resource intensive metabolism. It requires several times larger material inputs than the other two cities and produces much larger outputs, for benefit of the rest of the country and the world. Consequently, CO2 emissions are higher in Gothenburg. Malmo characteristics are more complex than Stockholm's with higher material needs in particular construction minerals. Its dependency on external flows is low, due to the fact that the economy and exports are based on domestically extracted Non-Metallic Minerals and Biomass.