Responsibility allocation to producers and users in the global industry and trade chain "energy-minerals-electric vehicles": An Emergy Accounting approach

Production of electric vehicles (EVs) is expected to promote sustainability by decreasing fossil fuel use in the mobility sector. However, the rapid development of a global industry chain for the production of electric engines and batteries has exacerbated the inequality of resource utilization. New environmental impacts linked to material flows associated with the industry chain (steel, lithium and other minerals) are a source of huge concern and upstream, midstream and downstream (extraction, production, trade and use) shared responsibility. This study developed a multi-layer trade network model of “steel-minerals-electric vehicles” industry chain and provided a scientific framework for resource flow and responsibility allocation based on Odum’s Emergy Accounting (EmA) approach. Results firstly show that the worldwide trade volume and the number of involved countries increased enormously from 2017 to 2021 and keep growing. Secondly, in spite of the aim of mobility decarbonization, non-renewable energies (mainly coal) are still used in upstream countries. Finally, trade patterns mostly flow from upstream to midstream steel and other minerals producing and refining countries, and then to downstream EVs' manufacturers and users, from which trade flows go back to midstreamand upstream countries. Environmental impacts can be differently allocated to these countries, among producers and users. This reflects the huge imbalance among production and use in the different stages of the worldwide “steel--minerals--electric vehicles” industry chain. By means of EmA-based indicators (Environmental Loading Ratio, Emergy Sustainability Index and other valuation indicators), we can quantify the sustainability of each stage of the industry chain, in so allocating both impacts and responsibility according to different types of production and patterns of electric vehicle use. Based on these results, our study proposes policy implications for promoting regional industrial ecological sustainability from the perspectives of industry chain, trading partners and countries.