Towards effective carbon accounting for the global steel industry within the EU carbon border adjustment mechanism

The steel industry accounts for approximately 9% of global greenhouse gas (GHG) emissions, making it a key sector for decarbonization. In this study, we quantify (i) current and prospective location-specific GHG emissions from crude steel production facilities worldwide and (ii) the effectiveness of the European carbon border adjustment mechanism (CBAM) using a comprehensive life cycle assessment (LCA) framework. Based on our LCA approach, GHG emissions of global crude steel production are around 4.0 GtCO ₂ -eq. year ^-1 , highly concentrated in Asia. To support decarbonization of the European industry and create a level playing field, effective carbon accounting frameworks are important. The current CBAM accounts for roughly 68% of the life cycle-based GHG emissions associated with steel imported to the European Union, leaving significant emissions (19 MtCO ₂ -eq. year ^-1 ) unaccounted for. Depending on the future 2 ^◦ C scenario in 2040, global steel production-related GHG emissions could be reduced by up to 63%, i.e., to 1.5–3.7 GtCO ₂ -eq. year ^-1 . However, this may require substantial amounts of hydrogen (up to 96 MtH ₂ year ^-1 ) and/or CO ₂ storage volumes (up to 1.06 GtCO ₂ year ^-1 ). To effectively decarbonize the steel industry, (i) policy measures are needed that build on facility-specific LCA results, and those (ii) must be supported by consistent (carbon) accounting frameworks with broad emissions coverage to support the global deployment of low-carbon steel production technologies.