New Methods for Circular Economy Design Based on Urban Metabolism Modeling

An overview of the Circular Economy (CE) design and implementation on an urban level shows that the current approaches select a few sectors or products as the subject of CE based on local features. As a consequence, neither... [ view full abstract ]

An overview of the Circular Economy (CE) design and implementation on an urban level shows that the current approaches select a few sectors or products as the subject of CE based on local features. As a consequence, neither methodologies nor the insights can always be transferred to a different city. A more standardized and comprehensive method for CE design would enable a more streamlined CE implementation and allow replication in different cities.

Such a standardized approach has been developed based on Urban Metabolism modeling. Urban Metabolism (UM) studies resource consumption and environmental pressure of urban areas in a systemic way. The methods are sufficiently consolidated and standard, and many cities have had their UM profiles described. The UM profiles often contain the data necessary to support the design of CE in cities, such as comprehensive accounting of material flows at different life stages (raw materials, intermediate products, final products and waste) and relevant to the material flows economic activities and stakeholders. In addition, UM modeling provides monitoring tools for CE implementation and effects.

The two methods based on UM modeling are suggested:

• A method based on material consumption by an economic sector - identifying materials and products that can be influenced, and the relevant actors;

• A method based on a particular product or a material - identifying economic sectors that are relevant for management of this product’s flow, and involved actors.

The methods’ architecture, input data, advantages and limitations are described. The methods are illustrated for an economic sector and a particular product, respectively.

Both methods benefit from the established link between the economic classifications: for the products (the Combined Nomenclature) and for the economic activities (“Nomenclature Générale des Activités Économiques dans les Communautés Européennes” (NACE)). Through the cross-reference of these classifications, the resource flows and economic activities can be interrelated. This connection is used by material flow analysis (MFA) models for describing the economic sectors inputs and outputs and for tracing the resource flows through the sectors. In this study, the output of the urban MFA model UMAn for a Swedish city are used in the application of the methods (Kalmykova et. al. 2015).

The developed methods are suitable for different agendas and actors of CE. They contribute in several ways to development of the CE applications:

• They provide accurate quantitative studies

• They enable comprehensive studies of the economies, where all product flows and connections between the sectors are apparent

• The actors responsible for the flows and therefore in power for CE interventions can be identified

• Due to the use of the international economic classifications, their application is straightforward in Europe and, with some modification, in other regions

• The methods’ outputs provide information on the products’ value chain stage (extraction, manufacture, sales as a product or a service, consumption and disposal), which allows selection of the suitable CE strategies.

References 

Kalmykova, Y., L. Rosado and J. Patricio (2015). "Urban Economies Resource Productivity and Decoupling: Metabolism Trends of 1996-2011 in Sweden, Stockholm, and Gothenburg." Environmental Science & Technology 49(14): 8815-8823.