Facts and Interpretations in Environmental Assessments of Products
Doktorsavhandling, 2002

Contemporary environmental discourse increasingly emphasises environmental impacts associated with products. In response to this attention, methods for assessing the impacts of products over their life cycles, life cycle assessment (LCA), have been devised. Since LCAs generally involve judgements that cannot be science based, such as comparisons of environmental impacts (weighting), they leave room for differing interpretations. To facilitate weighting, various methods have been worked out; most research on such methods has been of an analytical and theoretical character. In contrast, this thesis, which is based on both empirical and theoretical investigations, concentrates on the function of weighting methods in assessments. Emphasis is laid on how such methods may contribute to learning processes and facilitate conclusions that can form the basis of acceptable decisions. A central theme explored is the role of science and scientific information in environmental assessments. The empirical part comprises both personal and group interviews with decision makers in industry, local and national authorities, and academics. The theoretical part analyses and compares methodology discussions among LCA researchers, as well as specialists in related areas such as risk assessment, ecological economics, systems analysis and policy analysis. Findings from these investigations are used for working out a more effective approach to handling environmental trade-offs in assessments. It is argued that useful assessments need be tailored to specific organisations and situations. Only in this way can assessments incorporate the concerns and beliefs of affected and interested parties. Assessment methods that aim at a high level of generality may fail in this respect, and thus produce outcomes of limited perceived relevance and usefulness. In addition to the research on LCA methods, the thesis includes two studies on environmental assessments of wastewater systems: an LCA study of projected systems with increased recycling of plant nutrients, and a study of the Swedish controversy over sewage sludge use in agriculture. Both of these studies reveal the need for greater awareness that some assessments and scientific investigations match specific problem definitions and beliefs better than others. For scientific input to be meaningful to concerned parties with different points of view, it is argued that broad-based deliberation is often a prerequisite.

wastewater systems



decision making


environmental trade-offs

sewage sludge

life cycle assessment (LCA)


environmental evaluation


Magnus Bengtsson

Institutionen för miljösystemanalys


Annan naturresursteknik



Report - Department of Environmental Systems Analysis, Chalmers University of Technology: 2002:8

Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 1877