Methodology: GHG Emissions
We currently offer Carbon Emission Curves for the mining industry with underlying mine-by-mine data for copper, nickel, iron ore (seaborne) and metallurgical coal (seaborne). Our analysis for covers global mine production excluding China.
This analysis quantifies carbon emissions along the supply chain at a granular (asset) level. We have defined supply chain system boundaries to facilitate like-for-like comparison of assets - essentially we cover emissions from mining activities, ore processing, transport and downstream processing, up to the first-use entry point.
Our methodology for each commodity is summarised below; please use the arrows to switch between copper, nickel, iron ore and metallurgical coal.
Copper : Normalised to finished metal
- All assets are normalised to finished metal (i.e. copper cathode)
- For SxEw operations, this includes all emissions to production of copper cathode on site.
- For concentrate producers, emissions from freight and downstream processing to cathode (smelting and refining processes) are added on1.
- For those mines with integrated downstream processing – these emissions are included in the mine’s Scope 1 & 2
- Examples include Kansanshi mine and smelter, Kennecott (Bingham Canyon mine, smelter and refinery), etc.
- For mines with partial integration, the portion of concentrate sold to third parties are treated in the same way as non-integrated mines.
- For the majority of mining operations that are not integrated with a smelter or refinery we have added on emissions associated with smelting and refining copper concentrates
- Smelter emission intensities are modelled, based on regional benchmarks
- Emissions at the smelter are driven by technology, electricity, and consumption of combustibles such as natural gas, diesel and coal.
- Concentrate shipments are modelled according to export destination based on reported statistics or Skarn’s industry expertise.
- Default reporting of emission intensities is on a recovered copper-equivalent basis
- CO2e emissions are divided by contained copper-equivalent production at the minesite. This allows for a like-for-like comparison between polymetallic mines producing multiple commodities with single product operations.
- Copper equivalent production is calculated as the volume of each metal multiplied by the average metal price divided by the average copper price for the year in question.
Nickel : Normalised to first saleable product
- All assets are normalised to first saleable product
- For concentrate producers, emissions from freight and downstream processing to class 1 Nickel is modelled and added on1.
- For other operations, analysis includes emissions to production of first intermediate product (mixed sulphides, hydroxides, FeNi and NPI).
- Mines integrated with downstream facilities – these emissions are included in Scope 1 & 2
- Examples include Norilsk, Nickel West, Eramet etc.
- For direct shipped ore (laterites), Scope 1 & 2 includes mining and washing of ore; all other emissions are included in freight and downstream processing unless integrated.
- Emission intensities are on a recovered nickel-equivalent basis
- The divisor is contained nickel-equivalent production at the minesite. Emissions are pro-rationed across all commodities based on their contribution to gross revenue.
Metallurgical Coal : Delivery to country of import
- Comprehensive coverage of seaborne metallurgical coal market
- Includes exports from Australia, USA, Canada, Brazil, Mozambique.
- Excludes production from Russia, Mongolia and China – this will be added to coverage during Q4 2020.
- All assets include emissions to port at final country of import1
- For mines in Australia, all metallurgical coal exports are to China.
- For other countries, a typical export split is assumed between Europe, Americas and Asia based on government / company export statistics.
- Fugitive emissions
- As reported, or benchmarked based on location of mine and mining method (surface / underground).
- Methane capture and flaring are netted off Scope 1 emissions.
- Carbon credits from methane capture and flaring are netted off from Scope 1 emissions.
- Emission intensities are on coal production basis.
- Intensities are calculated at each mine by dividing total Scope 1 & 2 emissions by total saleable coal production, both thermal and metallurgical coal.
Iron Ore : Delivery to country of import
- Comprehensive coverage of seaborne iron ore
- Includes exports from Australia, Mauritania, South Africa, Other Africa, USA, Canada, Sweden, Brazil.
- Excludes production from Russia and China.
- All assets are normalised to port at country of import1
- For mines in Australia, all iron ore exports are to China.
- For other countries, export destinations are based on a split between Asia, Europe and the Americas based on government / company export statistics.
- Emission intensities are on iron ore production basis
- Intensities are calculated at each mine by dividing total Scope 1 & 2 emissions by total iron ore production including all product types (fines and lumps).
- Emissions from pellet plants are pro-rated to applicable % of mine production for partially integrated assets and included in Scope 1 & 2.
- Emission intensities can be presented on a wet, dry or contained metal basis.