Global warming potential (GWP) of HFC refrigerants

Global warming potential (GWP) definition

The Global warming potential (GWP) is the metric most commonly used to indicate the climate impact potential of a refrigerant emission. ^[1] According to UNEP, GWP can be defined as a measure of the relative global warming effects of different gases (in this case, refrigerants). It assigns a value to the amount of heat trapped by a certain mass of a refrigerant relative to the amount of heat trapped by the same mass of carbon dioxide over a specific period of time.^[2] Carbon dioxide was chosen by the Intergovernmental Panel on Climate Change (IPCC) as the reference gas and its GWP is equal to 1.

Consistent with the Kigali Amendment, the IIR uses GWP values for the 100-year timeframe in its publications.^[3] The 100-year GWP is more commonly used in scientific articles, standards, and regulations, which is helpful for an efficient discussion of the climate impact.^[1] Some experts advocate the use of GWP values with shorter integration time horizons, particularly in the case of HFCs which often have relatively short lifetimes. Indeed, a 20-year time horizon is more relevant when discussing climate change during the next few decades, where it may also be better in differentiating between substances with shorter lifetimes.^[1]

100-year and 20-year GWP values of HFC-based refrigerants

The table below presents 100-year GWP and 20-year GWP values for HFC refrigerants. We listed blends that include at least one HFC in their composition. This means that our table also include HFC/HFO blends or HFC/hydrocarbons blends.

The values were extracted from UNEP’s RTOC 2022 report, in which GWP values have been updated according to the World Meteorological Organization (WMO, 2022). In previous reports, namely UNEP’s RTOC 2018 report and UNEP’s TEAP 2021 report, GWP values were sourced from WMO 2019 and the Intergovernmental Panel on Climate Change (IPCC) sixth assessment report, 2021 (AR6).

Useful links for further information

Acknowledgements

This document was prepared by Monique Baha (IIR Scientific and Technical Information Department) and proofread by Maud Grasmenil, under the supervision of Jean-Luc Dupont (Head of the Scientific and Technical Information Department).

References

[1] UNEP. (2023). Refrigeration, Air Conditioning and Heat Pumps Technical Options Committee (RTOC) 2022 Assessment Report (Montreal Protocol on Substances That Deplete the Ozone Layer.). https://ozone.unep.org/system/files/documents/RTOC-assessment%20-report-2022.pdf

[2] UNEP. (2016). Global Warming Potential (GWP) of Refrigerants: Why are Particular Values Used? https://wedocs.unep.org/xmlui/handle/20.500.11822/28246

[3] Domanski, P., & Motta, S. Y. (2022). Low-GWP Refrigerants: Status and Outlook. 48th Informatory Note on Refrigeration Technologies. IIF-IIR. https://doi.org/10.18462/iif.NItec48.06.2022