Life cycle assessment (LCA) is a key tool to assess the environmental impact of product systems. Two prominent types are attributional (ALCA; the global impact share of a product life cycle) and consequential LCA (CLCA; the consequential impact of a decision). We analysed to which extent they are of relevance for society and can support decision-making, building further on literature, this based on two ideological and three pragmatic criteria. First, when it comes to realistic modelling as desired in the context of sustainable development, in theory, CLCA attempts to project these realistically, whereas ALCA falls short to a certain degree because of conceptual constraints, e.g., artificial splitting of co-product processes. Concerning the second criterion of alignment with ethics, CLCA aligns completely with consequential ethics, making it undoubtedly of relevance in a world where time moves forward and we aim to fulfil goals in the future, e.g., sustainability goals. ALCA is only partially consequential, as it is restricted by rules relating with deontological ethics, and for example even covers the relative past of the product. Since deontological ethics are in general of relevance for our modern human society, there is room for complementarity in ethical relevance between ALCA and CLCA. However, the rules of ALCA (e.g., additivity) and their relevance have not been society-wide accepted, leaving ALCA still in need of ethical acceptance. In the context of decision-support, CLCA would evaluate the consequences of decisions and ALCA covers the approval & sharing of potential responsibility of the life cycle environmental impact of the product associated with the decision. We also point out a unique valorisation for Organisational ALCA, covering the latter for the organizations behind a product. Concerning the three practical criteria, following conclusions were drawn. Although ALCA has been the most considered in standards, only a CLCA can currently be performed consistently in a certain manner, because current life cycle impact assessment methods applied in ALCA do not partition environmental multi-input processes yet. CLCA should get put more forward in standards. Furthermore, modelling complexity and uncertainty may often be only slightly higher for CLCA than for ALCA due to a consideration of change caused by a decision, but both ALCA and CLCA modelling may be similarly complex and have evenly high uncertainties as both methods cover past and/or future projections (e.g., prediction of future background processes). Finally, ALCA modelling may be seen as a practical approximation of CLCA, but current CLCA models are more adequate to study consequential effects, and the further CLCA modelling and databases improve, the more this will be the case
