Environmental News, 78 – Impact categories, normalisation and weighting in LCA

Impact categories, normalisation and weighting in LCA

Authors' preface

This guideline focusing on normalisation and weighing is a result of an LCA methodology and consensus-making project. The project has involved a large part of the LCA practitioners and interested parties in Denmark. The guideline gives a presentation of normalisation references with the reference year 1994 and weighting factors with 2004 as the target year. Along with the guideline a technical report (Stranddorf et al., 2003) has been developed.

During the project two workshops were held. At the first workshop the data intended to form the basis of the updated and extended normalisation reference and the weighting factors were presented and at the second, the collected data were presented and discussed. This gave valuable input to the project group regarding data to the normalisation references and the weighting factors. Further, at the second of the workshops background and recommendations for choice of impact category and normalisation reference were presented and discussed.

This guideline is based on the technical report mentioned above. However, the approach in the guideline is more practical than theoretical. The guideline provides a short presentation of the impact categories described in detail in the technical report. The guideline includes a common example on how to apply normalisation references and weighting factor for the included impact categories. In addition to the presented normalisation reference and weighting factors, the guideline presents recommendations regarding choice of impact categories and choice of normalisation references.

The following persons have been responsible for the chapters regarding the different impact categories in the technical report and should be specially acknowledged for their contributions that forms the basis for the chapters regarding impact categories in this guideline:

Chapter 4: Global warming: M.Sc (Chem. Eng) Leif Hoffmann
Chapter 5: Ozone depletion: M.Sc (Chem. Eng) Leif Hoffmann
Chapter 6: Photochemical ozone formation: B.Sc (Chem. Eng)
Karsten Fuglsang
Chapter 7: Acidification: M.Sc (Chem. Eng) Leif Hoffmann
Chapter 8: Nutrient enrichment: Ph.D. (Biology) Jørgen Larsen
Chapter 9: Ecotoxicity: Ph.D. (Ecotoxicology) Jens Tørsløv
Chapter 10:Human toxicity: M.Sc (Eng) Frans Møller Christensen & M.Sc
(Chem. Eng) Leif Hoffmann
Chapter 11:Weighting: M.Sc (Eng) Niels Juul Busch

The expertise was provided by the following Danish research and consultancy institutions which are acknowledged for their contribution to this work:

FORCE Technology (editing, global warming, ozone depletion,
photochemical ozone formation, acidification, human toxicity, noise (not included in the technical report and the guideline))
Danish Technological Institute (nutrient enrichment)
DHI - Water & Environment (ecotoxicity)
Danish Toxicology Centre (human toxicity)
Ramboll (weighting)