Everything is relative and nothing is certain. Toward a theory and practice of comparative probabilistic LCA

Abstract

Introduction: It is widely recognized that LCA is in most cases relative and contains uncertainties due to choices and data. This paper analyses the combination of the two comparative uncertainties. Basic concepts: We carefully define the idea of relativity and uncertainty within LCA. We finish off by giving an example of case where inappropriate handling of comparative uncertainties will lead to a misleading result for a decision-maker. Correlations: We develop a generic framework for probabilistic comparative LCA and analyse at which places correlations may be present. We also discuss the most convenient approaches for handling such correlated uncertainties. Conclusion: We put the elements discussed in a structure that provides a research agenda for dealing with comparative uncertainties in LCA.