Reference: Global warming potential values under the temporary measures

  1. The Executive Board of the clean development mechanism (the Board), at its 108th meeting, agreed on temporary measures [1], pending guidance from the Conference of the Parties serving as the meeting of the Parties to the Kyoto Protocol (CMP) at its sixteenth session, for processing:

    1. Requests for registration of project activities and programmes of activities (PoAs), renewal of crediting periods and PoA periods, and inclusion and renewal of crediting periods of component project activities that have a crediting period or PoA period starting on or after 1 January 2021;
    2. Requests for issuance of certified emission reductions (CERs) for emission reductions achieved on or after 1 January 2021.

  2. In this context, the Board agreed to inform project participants and coordinating/managing entities that, in converting emission reductions achieved on or after 1 January 2021 to carbon dioxide equivalents in project and programme design documents or in preparing monitoring reports for emission reductions achieved on or after 1 January 2021, they shall apply as global warming potential (GWP) values, the lowest value from the Intergovernmental Panel on Climate Change (IPCC) assessment reports for each greenhouse gas (GHG) for a 100-year time horizon.[2]

  3. For ease of reference, the table below lists the lowest of the GWP values from the second, fourth and fifth IPCC assessment reports for each GHG that is most relevant to CDM activities, to be applied to estimate emission reductions achieved on or after 1 January 2021 under the temporary measures referred above.

Greenhouse gas

GWP for 100-year time horizon

 Carbon dioxide (CO2)

 1*a,b,c

 Methane (CH4)

 21*a

 Nitrous oxide (N2O)

 265*c

 Hydrofluorocarbons (HFCs)*d

      HFC-23

 11,700*a

      HFC-134a

 1,300*a,c

 Perfluorocarbons (PFCs)*d

      CF4

 6,500*a

      C2F6

 9,200*a

 Sulfur hexafluoride (SF6)

 22,800*b

 Nitrogen trifluoride (NF3)

 16,100*c
    1. From the IPCC second assessment report (AR2).
    2. From the IPCC fourth assessment report (AR4).
    3. From the IPCC fifth assessment report (AR5).
    4. For other HFCs and PFCs that are not listed in this table, see the following second, fourth and fifth IPCC Working Group I report:
      • Climate Change 1995: The Science of Climate Change - Contribution of Working Group I to the second assessment report of the Intergovernmental Panel on Climate Change”, Table 4 (page 22)[3]
      • Climate Change 2007: Physical Science Basis - Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change”, Table 2.14 (pages 212-213)[4]
      • Climate Change 2015: Physical Science Basis - Working Group I Contribution to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change”, Table 8.A.1 (pages 731−738)[5]
  1. It should be noted that the Board also agreed to inform designated operational entities that validation reports and verification reports for the requests and other submissions referred to in paragraph 1 above shall contain a forward action request that requires the project participants and the coordinating/managing entities to apply any GWP values that may be adopted by the CMP for the period from 1 January 2021.[6]