Life cycle interpretation is the fourth and last phase of life cycle assessment (LCA). Being a “pivot” phase linking all other phases and the conclusions and recommendations from an LCA study, it represents a challenging task for practitioners, who miss harmonized guidelines that are sufficiently complete, detailed, and practical to conduct its different steps effectively. Here, we aim to bridge this gap. We review available literature describing the life cycle interpretation phase, including standards, LCA books, technical reports, and relevant scientific literature. On this basis, we evaluate and clarify the definition and purposes of the interpretation phase and propose an array of methods supporting its conduct in LCA practice. The five steps of interpretation defined in ISO 14040–44 are proposed to be reorganized around a framework that offers a more pragmatic approach to interpretation. It orders the steps as follows: (i) completeness check, (ii) consistency check, (iii) sensitivity check, (iv) identification of significant issues, and (v) conclusions, limitations, and recommendations. We provide toolboxes, consisting of methods and procedures supporting the analyses, computations, points to evaluate or check, and reflective processes for each of these steps. All methods are succinctly discussed with relevant referencing for further details of their applications. This proposed framework, substantiated with the large variety of methods, is envisioned to help LCA practitioners increase the relevance of their interpretation and the soundness of their conclusions and recommendations. It is a first step toward a more comprehensive and harmonized LCA practice to improve the reliability and credibility of LCA studies.

Carbon capture and utilization is a promising approach to reduce greenhouse gas emissions and fossil resource depletion in the chemical industry. However, since carbon capture and utilization is an energy and material intensive process, it is unclear whether it allows for a net reduction of environmental impacts from a life cycle perspective. Previous life cycle assessment studies on carbon capture and utilization focused on the production of one specific chemical or the comparison of C₁ basic chemicals and applied an attributional approach. This study assesses twelve CO₂-conversion technologies to provide decision support on the potential life-cycle environmental impacts of each technology. Consequential life cycle assessment was chosen as the modeling approach to better understand the system-wide environmental consequences of introducing carbon capture and utilization technologies in the chemical industry. This study has identified that in a near- and a long-term scenario the global warming impact for all CO₂ conversions technologies, besides dimethoxymethane, electrochemically produced formic acid, and Fischer–Tropsch production, is negative. Formic acid produced via hydrogenation and polyol production are the conversion technologies with the highest potential for reducing the global warming impact from a life cycle perspective. Holistically polyol production is the conversion technology with the highest potential for reducing environmental impacts. In general, it seems recommendable to introduce carbon capture and utilization within the chemical industry from an environmental perspective.