Unlike the more recent Product and Scope 3 standards, the Corporate standard does not currently include specifications or guidance related to the selection and use of GWPs in organizational GHG assessments. The proposed amendment would align the Corporate standard with the Product and Scope 3 standards in requiring the use of 100-year GWP values published by the IPCC.
Furthermore, the WBCSD/WRI has proposed recommending that any company conducting an assessment for the first time use GWP values published in the IPCC’s most recent Assessment Report, which at this time is the 4th Assessment Report (AR4). Companies that have previously conducted an assessment using GWP values in the 2nd Assessment Report could continue using these values, provided that they are 100-year figures. Lastly, the source of the GWP values must be reported in the company’s assessment.
It’s interesting to note that the change will have implications for Defra/DECC’s conversion factors for company reporting, which currently provide emission factors for CH4 and N2O in CO2e using the 2nd Assessment Report GWPs. Reporting companies will need to convert the kgCO2e factors into kgCH4 and kgN2O using the 2nd Assessment Report GWPs, and then convert back to kgCO2e using the 4th Assessment Report GWPs (assuming they opt to use latest GWPs). Alternatively, it would be helpful if Defra/DECC published base factors for kgCH4 and kgN2O rather than kgCO2e, allowing reporting companies to choose which GWPs they want to apply.
The open comment period enabling stakeholders to provide feedback on the proposed changes ended July 29th. If accepted, the amended standard should be used for all new GHG assessments prepared for the next year of reporting seeking compliance with the WBCSD/WRI Corporate Greenhouse Gas Protocol.