System Boundary

  • Full life cycle (cradle-to-gate) greenhouse gas (GHG) emissions (as CO2e);
  • All processes including mining, refining, anode production, electrolysis and casting;
  • All sources including GHG emissions from electricity, direct emissions (CO2 and Non-CO2 GHG emissions), GHG emissions from thermal energy, transport and ancillary materials;
  • Global coverage including informed estimates for non-reporting plants.

Greenhouse Gas Emissions

The International Aluminium Institute (IAI) has published three life cycle inventory (LCI) reports of the global primary aluminium industry for the reporting years 2005, 2010 and 2015.

The 2015 LCI report was used for the 2015 numbers and is using GaBi-Software (v8, 2018). Please note, that the dataset for alumina refining reflects a change in modelling assumptions for the process.

For 2005 and 2010, the direct and electricity-related indirect emissions of reporting production were calculated, using GHG Protocol tools. These two datasets are used as reference to calculate the global average carbon footprint of one tonne of cast primary aluminium.

For the years with no LCI publication, data from the previous LCI report is used, updated with annually collected energy data for smelting (intensity and source) and refining (intensity and source) as well as perfluorocarbon (PFC) emissions data. These three datasets collectively constitute over 80% of total global aluminium sector emissions.

To convert electricity data (kWh/tonne) for smelting to tonnes of CO2e, national/regional electricity emission factors published by the International Energy Agency (IEA) and Gabi Database are applied to the appropriate regional electricity mix. The emissions factors include CO2, CH4 and N2O. Upstream emissions are calculated based on UK data.

To convert the energy data (MJ/tonne) for refining to CO2e emissions, global fuel emission factors published in the Gabi Database are used.

Historical primary production is based on IAI statistics. Primary aluminium is defined in the IAI production statistics as liquid aluminium tapped from electrolytic cells or pots during the electrolytic reduction of metallurgical alumina (aluminium oxide). It thus excludes alloying and scraps additions in cast metal production. While this data does not fully represent a primary ingot (i.e., excluding alloying elements and metal losses), it is a proxy for primary aluminium ingot production.

DISCLAIMER

The IAI own the intellectual property rights to these datasets. Use of this data in any written or online form must credit the International Aluminium Institute as the rightful owner. The IAI reserves the right to revise the data based on improved modelling assumptions and updated external datasets. The IAI shall not have any liability, duty or obligation for or relating to the data contained herein, any errors, inaccuracies, omissions in the data, or any actions taken in reliance thereon.

© International Aluminium Institute