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.

Forecasting future years

  • Driven by production fundamentals
    • Emissions are forecast based on mine plan and ore mineralogy which determine consumption intensities for combustibles and electricity.
  • Committed projects to reduce emissions are incorporated
    • Emission reductions are modelled based on company guidance and project scope.
    • Uncommitted reduction schemes are not included.
  • Grid emission factors are monitored and base case reductions are incorporated
    • Includes committed projects by electricity providers to reduce emissions.


Glossary

  • Scope 1 emissions include:
    • Fuel combusted on site (diesel, natural gas, HFO, propane, etc) including self-generated electricity.
    • Fugitive emissions which can be significant for roast / leach operations (copper, gold, nickel) and coal mines. Methane capture and flaring for coal mines are netted off Scope 1 emissions.
    • For benchmarked operations, emissions are estimated based on consumption intensities of fuel applied to mined material and processed ore.
  • Scope 2 emissions include:
    • Purchased electricity, heat and steam.
    • For benchmarked operations, emissions are estimated based on consumption intensities of electricity, heat and steam and grid emission factors deemed appropriate for the location or the mine / plant.
  • Scope 3 emissions include:
    • Freight and Distribution: Land freight (truck / rail) and ocean freight emissions are based on 2019 DEFRA emission factors and distances between mine site, port of export and port of import. Port emissions are also included.
    • Downstream processing: Emissions are modelled based on typical energy consumption intensities for technology type, and grid emission factor for the location of the plant.
  • Scope 3 currently excludes:
    • Upstream emissions and use of products sold by consumers (e.g. downstream emissions from the consumption of metallurgical coal or iron ore in steel manufacture or copper in the manufacture of wire). Skarn will be undertaking further analysis on downstream emissions in the near future.