During the week of 22 September 2025, States once again met in Vienna under Working Group III (WGIII)...
The global transition to renewable energy systems will be mineral intensive and, under the current linear economy conditions,...
Discussing specific areas in which industry groups and standards-setters should engage in dialogue to move towards harmonized GHG accounting and reporting not just for these two sectors, but also for the metals industry as a whole
Greenhouse gas (GHG) accounting methods for steel and aluminum products have begun converging towards common standards within their respective industries in recent years. However, accounting methods for steel products and aluminum products are still not fully comparable with each other. If emissions are measured and allocated differently for these products, then these accounting differences have the potential to influence materials choices for manufacturers concerned about reducing their reported GHG footprint. Companies could therefore be motivated to make a choice between aluminum and steel according to emissions benefits that materialize from differences in accounting frameworks, but which do not actually exist in practice. These incentives will materialize for any substitutable materials which do not use fully comparable GHG accounting frameworks. Bringing product-level accounting methods for substitutable materials such as steel and aluminum into alignment with each other is therefore necessary to eliminate this gap.
This study analyzes the major high-level differences between the International Aluminium Institute’s product-level guidance and cradle-to-gate product-level accounting in the steel industry, represented by a synthesis between the ResponsibleSteel International Standard and the Worldsteel Life Cycle Inventory Methodology. Differences in the following key areas were identified:
The methods examined do not apply consistent approaches to determining materiality constraints on the inclusion of emissions sources. The methods also differ by the definition of a final product.
Treatment of scrap is extremely inconsistent between the methods and reflective of an active debate taking place within both industries. Different categories of scrap are variously treated as waste products, co-products carrying their own emissions burdens to be allocated between producers, and sources of emissions credits estimated according to data on scrap recovery and recycling rates. Other co-products receive emissions treatments that are sometimes difficult to compare due to differences between industries, but they remain reflective of different philosophies around GHG accounting in general.
Lifecycle emissions factors from electricity consumption are generally required for aluminum, while location-based and market- based emissions factors generally suffice for steel. Steel methods do not explicitly detail how emissions from electricity exports associated with a combined heat and power facility should be allocated, while the aluminum industry does provide a method for doing so.
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