Carbon modelling beyond scientific production: a critical review of standards and European policies

Abstract Efforts to mitigate climate change in European policies increasingly emphasize accurate carbon accounting along supply chains. This interdisciplinary study conducts a comprehensive grey literature review, analysing standards, scientific publications, legislation and technical reports, to establish a framework for comparing carbon modelling standards. A preselection and screening process was developed based on criteria such as adherence to the life cycle assessment (LCA) approach, explicit carbon modelling content, alignment with EU legislative trends, and the binding nature of standards among others. The tools used for comparison are a set of LCA structures and LCA elements. These arise from the same grey literature review focusing on providing applied, harmonized and transversal insights of the different standards selected for comparison. The level of comprehensiveness within the whole LCA based standards comparison, and the interlinkage of concepts across standards are the key identifiers of this work. The findings include commonalities such as carbon bio-based content or electricity modelling. Nevertheless, notable discrepancies were observed in product scope, cut-off criteria, direct land-use change or carbon offsetting among others. The findings point towards harmonization without endorsing any single standard. In all, under a triple legislative mapping, scientific and standards analysis, a comprehensive methodology is suggested to backbone standards comparison thus reducing trade-offs while providing a potential tool for policy making. Keywords Grey literature; Carbon modelling; LCA element; standards harmonization; legislative mapping.