Global Warming Potential
What does it mean? The Global Warming Potential (GWP) of a refrigerant is its global warming impact relative to the impact of the same quantity of carbon dioxide over a time period (typically 100 years). All effects beyond this time period are disregarded.
What GWPs are used for compliance in F-gas Regulation 2024/573
- HFCs (Annex I): 100 year (GWP-100) Fourth Assessment Report (AR4) values adopted by the IPCC. These are the same AR4 values that are used for reporting and compliance with the Kigali Amendment to the Montreal Protocol and were also used in the previous F-gas Regulation 2014/517.
- HFOs and HCFOs (Annex II): Where available, 100 year (GWP-100) Sixth Assessment Report (AR6) are used. The HFOs and HCFOs are not covered by the Kigali Amendment, which is for HFCs, and the F-gas Regulation uses the most recent IPCC GWP-100 values.
The F-gas Regulation Review Article 35 empowers the Commission to:
- adopt delegated acts in accordance with Article 32 to amend Annexes I, II, III and VI as regards the global warming potential of the gases listed therein, where it is necessary in the light of new Assessment Reports adopted by the IPCC or new reports of the Scientific Assessment Panel (SAP) of the Protocol.
- adopt delegated acts in accordance with Article 32 to amend the lists of gases in Annexes I, II and III, where it has been found by the SAP or by another authority of equivalent stature that such gases have a significant impact on the climate and where such gases are exported, imported, produced or placed on the market in significant quantities.
GWP-100 values for HFCs/HFOs/HCFOs
Download a table containing the AR4, AR5, AR6 GWPs, atmospheric lifetimes and applications for all the main HFCs, HFOs and HCFOs. This F-gas Regulation 2024/573 uses a combination of AR4 and AR6 GWP-100 values. The UNFCCC for reporting emissions under the Paris Agreement, adopted AR5 values for the purposes of national reporting of greenhouse gas emissions (national “Greenhouse Gas Inventories”).
Refrigerant blends subject to the F-gas Regulation 2024/573
The GWP Classification Scale
| 100-year GWP | Classification |
|---|---|
| < 30 | Ultralow |
| < 100 | Very low |
| < 300 | Low |
| 300-1000 | Medium |
| > 1000 | High |
| > 3000 | Very high |
| > 10000 | Ultrahigh |
The differences between GWP-100 and GWP-20 values
The use of 100 year time horizons (GWP-100) are referenced in the Montreal Protocol (Kigali Amendment) and F-gas Regulation 2024/573 for compliance and reporting purposes. The UNFCCC for reporting emissions under the Paris Agreement, adopted AR5 GWP-100 values for the purposes of national reporting of greenhouse gas emissions (national “Greenhouse Gas Inventories”). GWP-100 provides a balance between short and long term effects.
IPCC AR6 explains the use of GWP-100 values
The global surface temperature response following a climate change mitigation measure that affects emissions of both short- and long lived climate forcers depends on their lifetimes, their ERFs (effective radiative forcing), how fast and for how long the emissions are reduced, and the thermal inertia in the climate system. Pulse-based emissions metrics for short-lived GHGs with lifetimes less than 20 years are very sensitive to the choice of time horizon. Global warming potentials (GWP) give the relative effect of pulse emissions, that is, how much more energy is trapped (GWP) when unit emissions of different compounds are compared. Consequently, this metric provides information on how much energy accumulation (GWP) could be avoided (over a given time period, or at a given future point in time) by avoiding the emission of a unit of a short-lived greenhouse gas compared to avoiding a unit of CO2.
There is high confidence that achieving net zero CO2 emissions and declining non-CO2 radiative forcing would halt human-induced warming. There is also high confidence that reaching net zero GHG emissions as quantified by GWP-100 typically leads to reductions from peak global surface temperature after net zero GHGs emissions are achieved, depending on the relative sequencing of mitigation of short-lived and long-lived species. If both short- and long-lived species are mitigated together, then temperatures peak and decline. If mitigation of short-lived species occurs much earlier than that of long-lived species, then temperatures stabilize very near peak values, rather than decline. Temperature targets can be met even with positive net GHG emissions based on GWP-100.
Definition of Short-lived climate forcers (SLCFs)
Global Warming Potential (GWP) – how is it defined and applied
Simple Definition
The GWP of a refrigerant is its global warming impact relative to the impact of the same quantity of carbon dioxide over a time period (e.g 100 years).
Complete Definition
The Global Warming Potential of a refrigerant is defined as the integrated radiative forcing over a “time horizon” (e.g. 100 years) following an assumed release of 1kg, divided by the integrated radiative forcing over the same period from release of 1 kg of carbon dioxide. Radiative forcing is the specific increase in infrared absorption in Wm-2ppb-1 (Watts per square metre at the Earth’s surface per part per billion concentration of the material). All effects beyond the specified time period are disregarded; Even using GWP100, the Global Warming Potentials capture all of the effect of commonly used HFCs, such as HFC-134a and HFC-32, but less than about 40% of the total effect from CO2.
Why are GWPs used?
Basically, the intention is to put all greenhouse gas emissions onto a common scale and GWP, however imperfect, it remains the recommended metric to compare future climate impacts of emissions of long-lived gases.
The F-gas Regulation (EU) 2024/573 uses the Fourth Assessment Report by the Intergovernmental Panel on Climate Change (AR4) for HFCs (Annex I) and the Sixth Assessment Report (AR6) for HFOs and HCFOs (Annex II).