New Paradigm or Old Distance to Target?

摘要

In the Viewpoint Do we need a paradigm shift in life cycle impact assessment?" by Huijbregts, Hellweg, and Hertwich (Environ. Sci. Technol. 2011,45,3833-3834) Huijbregts, Hellweg, and Hertwich (HHH) question whether the marginal approach typically applied in life cycle impact assessment (LC1A) "is truly representing what we are looking for in LCA" and "advocate to further explore the benefits of following an average approach in the derivation of characterization factors". What HHH propose is using characterization factors per unit of emission, which "represents the average distance between the current and the preferred state of the environment." This is in fact not a new paradigm for impact assessment, but a simple normalization relative to a target, as we know it from some of the early LCIA methods such as EDIP (Hauschild & Wenzel 1998, ref 2) and the Swiss ecoscarcity method (Frischknecht et al. 2006, ref 1).