A considerable proportion of industrial greenhouse gas emissions are attributable to indirect Scope 3 sources present within supply chains, frequently accounting for more than two-thirds of the total emissions. As many manufacturers commit to net-zero targets by 2050, this paper investigates how firms can systematically decarbonise their supply chains by embedding emission reduction into procurement strategies. A conceptual framework has been developed to categorise internal and external levers for upstream decarbonisation, including strategic alignment, operational practices, supplier engagement, and regulatory mechanisms. The framework was validated through ten expert interviews with procurement and sustainability professionals from German OEMs and suppliers. The findings of the study indicate significant implementation gaps in data transparency, accountability, and the integration of sustainability in procurement. In order to address these issues, a four-stage maturity model is proposed with a view to guiding companies in assessing and advancing their decarbonisation readiness. The model provides actionable guidance to align procurement with climate goals and enhance supplier collaboration across complex industrial networks.
Steinmeier et al. (2026) studied this question.