Aluminum GHG Emissions Reporting Guidance

The RMI Aluminum GHG Emissions Reporting Guidance establishes a framework for product-level emissions reporting in the aluminum sector. It defines fixed system boundaries—benchmarking and full—to ensure comparability regardless of a producer's vertical integration. The guidance emphasizes the use of primary data, provides specific calculation procedures for primary and recycled aluminum, and outlines a hierarchy for sourcing renewable energy to drive sectoral decarbonization.

• The aluminum sector is a major contributor to global emissions, accounting for over 1.1 gigatons of CO2 equivalent in 2018, which represents approximately 2% of global anthropogenic emissions.
• To ensure comparability across the industry, the guidance mandates reporting against two fixed system boundaries: a 'benchmarking boundary' covering processes from bauxite mining to the final cast house, and a 'full boundary' that adds semi-fabrication and further downstream processes to capture cradle-to-gate emissions.
• Recycled aluminum production is significantly less carbon-intensive than primary production, with emissions being approximately 6% of those from primary aluminum processes.
• Because scrap supply is limited and expected to meet only 50%–60% of total demand by 2050, the guidance requires the separate reporting of 'mine-to-smelter emissions intensity' for primary aluminum to incentivize the decarbonization of primary production technologies.
• The guidance requires the use of the 'cutoff approach' for benchmarking product carbon footprint (PCF) calculations, where pre-consumer scrap is treated as burden-free. However, it also recommends reporting using a 'co-product allocation approach' if reliable data on embodied emissions of pre-consumer scrap is available.
• To prevent greenwashing and drive actual decarbonization, the guidance establishes a hierarchy for sourcing renewable energy, prioritizing physical transitions of self-generation facilities and direct procurement (such as PPAs) over unbundled Energy Attribute Certificates (EACs).
• The framework mandates the reporting of the 'primary data share' to incentivize the use of first-hand information from supply chain partners over secondary or average emission factors, which can lead to inaccuracies.
• Specific guidance is provided for subtracting emissions from intermediate products not used in aluminum production, such as non-calcined hydrates from alumina refineries and surplus anodes from anode manufacturing facilities.

APA

RMI (2023). Aluminum GHG Emissions Reporting Guidance. https://rmi.org/app/uploads/2023/11/aluminum_guidance.pdf

Chicago

RMI. Aluminum GHG Emissions Reporting Guidance. 2023. https://rmi.org/app/uploads/2023/11/aluminum_guidance.pdf.

Wikipedia

{{cite report |author=RMI |title=Aluminum GHG Emissions Reporting Guidance |date=December 2023 |url=https://rmi.org/app/uploads/2023/11/aluminum_guidance.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{rmi2023aluminum, author = {{RMI}}, title = {{Aluminum GHG Emissions Reporting Guidance}}, institution = {RMI}, year = {2023}, month = dec, url = {https://rmi.org/app/uploads/2023/11/aluminum_guidance.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }