Integrating emergy into LCA: Potential added value and lingering obstacles

Emergy attempts to measure the environmental work required to generate (ecosystem) goods and services that can be used by humans. It is claimed that the use of inventory modelling principles behind the Life Cycle Assessment (LCA) method (European Commission, 2010a) may improve the Emergy Synthesis method, which has been criticized for its low accuracy and lack of standardization in the accounting procedure. LCA has become a standard procedure to investigate the environmental performance of human-dominated products and processes. Where LCA fundamentally differs from Emergy Synthesis is in that the former draws the boundary around the life cycle of the system under study, and looks at impacts that happen as direct consequences of it; conversely, Emergy Synthesis always looks at a system as embedded in the larger natural system that underpins it, and includes all direct and indirect inputs that converged to support it over much larger time and space scales, including ‘freely available’ ones which are typically neglected or only partly accounted for in LCA (e.g. rainfall, soil organic matter, etc.). Emergy arguably offers the added value of a comprehensive donor-side perspective, an approximation of the work of the environment that would be needed to replace what is used, and presents a unified measure of the provision of environmental support. We maintain that it may be viewed as a valuable complement, rather than an alternative, to existing life cycle impact assessment metrics. The lingering obstacles to such integration are enumerated and discussed.