Optimizing carbon responsibility allocation in the steel supply chain: A cradle-to-cradle life cycle assessment approach

This study addresses the challenge of incentivizing carbon reductions in supply chains under carbon pricing mechanisms. Focusing on upstream raw materials, we propose a cradle-to-cradle life cycle assessment (LCA)-based carbon accounting model and a cooperative game model to optimize the fair allocation of carbon responsibility across a multi-level, multi-agent supply chain. Using a steel-construction supply chain case, we validate the model and uncover key insights: 1) High-performance products, with high production emissions but lower use-phase emissions, face unfair responsibility allocation when only production-stage emissions are considered; 2) Focusing on production-stage reductions leads to emission responsibility transfer from downstream to upstream and from larger to smaller companies; 3) Factors such as material-saving rates, product lifespan, and recycling have a greater impact on life cycle emissions than production-stage reductions alone. Based on these findings, we recommend enhancing the carbon labeling system and optimizing responsibility allocation to balance production and use-phase emissions.