The use of Urban Metabolism to support decision making processes: The case of Gothenburg

Rapid urbanization in recent decades has placed huge pressure on the world’s natural resources, leading to threats of resource scarcity and degraded ecosystems. Decoupling economic growth from resource use and environmental... [ view full abstract ]

Rapid urbanization in recent decades has placed huge pressure on the world’s natural resources, leading to threats of resource scarcity and degraded ecosystems. Decoupling economic growth from resource use and environmental impact has been identified has the most promising strategy for ensuring future prosperity. The Urban Metabolism (UM) concept, based on insights from living systems, study resource consumption and environmental pressure of urban areas in a systemic way. The UM research field contains the characteristics to support decision making processes regarding resource use reduction in cities. In this paper, research developed by the UM group at Chalmers is presented with examples of different types of quantitative information that support decision making processes in Gothenburg, Sweden. The main idea is that by developing analytical methods and tools it is possible to provide more informed support to decision making at the municipal and metropolitan area level regarding established environmental and climate programs.

With the application of the UMAn model to the city of Gothenburg it was possible to account a 15 year time series urban Material Flow Accounting (MFA). This allowed for a quantified study of the flows disaggregated in 1000 product groups and 28 material types for the full set of MFA indicators and an identification of approximately 100 economic sectors that are the responsible for the resource use. Additionally, approximately 80 products were identified as representative products of the 1000 product types and their life cycle impact indicators were constructed in order to quantify not only the physical amounts, but also environmental impacts - climate change, acidification, eutrophication, photochemical ozone, and resource use. Accounting flows and environmental impacts provides opportunities for Gothenburg to identify hotspot products that should be properly managed. This will allow for minimizing the environmental impacts in multiple dimensions while keeping the compromises defined with the climate and environmental programs defined for the city. The establishment of priorities can support changes in public procurement processes and the establishment of targeted strategies for resource use. The accounting of the flows also allows for setting up proper monitoring schemes to track progress towards climate and environmental goals.  

Another area where support can be provided is on understanding existing material stocks providing detailed information about the material composition of buildings. The UM group at Chalmers is developing databases on Material Intensity coefficients and estimating the material stocks of Gothenburg. This allows for an efficient management of stocks of buildings.

Accounting for the flows and stocks of cities allows the design of strategies for resource use reduction. The UM group at Chalmers is supporting the identification of potential symbiosis partnerships in Gothenburg, using urban MFA data, by characterizing the needs of raw materials and the production of wastes in the region. This allows for the identification of convergence points where potential symbiosis can be established.

In summary, the UM field ensures complete accounting of materials and allows defining priorities for action, the establishment of quantified monitoring schemes and the identification of potential strategies to ensure a sustainable resource use in Gothenburg.