Material flow analysis (MFA) is a mass balance approach used to quantify and characterize industrial metabolism. A sustainable (and ideal) industrial metabolism is “characterized by minimized and consistent physical exchanges between human society and the environment, with the internal material loops being driven by renewable energy flows.” Generally, the MFA methodology begins with a specified goal and consists of identifying an industrial system, defining the processes that make up that system, and then analyzing the material inputs and outputs of those processes and the system. In other words, MFA provides a snapshot of how a given industrial system functions within and in relation to the biogeosphere.
The snapshot of how a given industrial system operates provides insight into how the industrial system can be made more sustainable through 1) detoxification, or minimizing the toxicity of the system’s outputs, and 2) dematerialization, or minimizing the inputs needed for the system’s operation. There are more specific MFA methodological approaches that are defined based on the various goals, concepts, and target questions. For example, Bringezu and Moriguchi suggest that there are two main types of analysis: the first type is used to address environmental problems related to substances, materials, and products; and the second type is used to address environmental problems related to the activities of firms, sectors, and regions. MFA has specifically been used to support various management measures, for example in the crafting of public and environmental policies.
The MFA approach has been applied to national economies, and resultant indicators related to the inputs and outputs have been used for environmental and economic accounting. Inputs included resources extracted domestically and imports; exports include emissions, disposal, exports, and new infrastructure. Indicators calculated from GDP, inputs, and outputs provide estimates of the trade-off between economic performance and environmental material losses. The economy-wide MFA can be disaggregated and attributed to specific sectors, activities, and functions; the disaggregated MFA can be compared with bottom-up approaches for greater insight.
While detoxification and dematerialization were presented as the objectives of MFA, there seems to be a disconnect between the specific methodological types and the indicators generated by the MFA. For example, there are output indicators that quantify the material flows to nature vs. material that remains embedded in the industrial system, but neither reflect the toxic potential of these outputs. Why is there such a disconnect between the two paradigmatic strategies and the methodological types?
References:
Bringezu S, Moriguchi Y. Material flow analysis. In: Ayres RU, Ayres LW, editors. A Handbook of Industrial Ecology. Cheltenham: Edward Elgar, 2002:79-90.