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

Abstract

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. 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. 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. We put the elements discussed in a structure that provides a research agenda for dealing with comparative uncertainties in LCA.