Figure 2. Alternative refrigerants used to calculate the low-GWP and medium-GWP scenarios. The low-GWP scenario assumed equipment using high-GWP refrigerants is replaced at end-of-life with equipment using alternative refrigerants with GWP<5. The medium-GWP calculations assumed GWP<800 (100-yr basis) and GWP<2,700 (20-yr basis) alternatives in applications where low-GWP replacements are currently less common (commercial refrigeration, transport refrigeration, stationary air conditioning) and assumed low-GWP replacements for the remaining applications where they are more developed technologies (residential refrigeration, industrial refrigeration, mobile air conditioning). The alternative refrigerants in the table are used for effectiveness and/or cost calculations.
| Application |
Scenario 1: Low-GWP only (low GWP: < 5, 100-year basis) |
Scenario 2: Medium-GWP when low-GWP alternatives are less common, otherwise low-GWP (medium GWP: < 800, 100-year basis) |
|---|---|---|
| Residential refrigeration | Isobutane | |
| Commercial refrigeration | Propane, CO₂ | Medium-GWP HFC and HFO blends |
| Industrial refrigeration | Ammonia, CO₂, propane | |
| Transport refrigeration | Propane, propene, ammonia, CO₂, low-GWP HFOs |
Medium-GWP HFC and HFO blends |
| Mobile air conditioning | CO₂, low-GWP HFOs | |
| Stationary air conditioning | Propane, CO₂, ammonia, low-GWP HFOs |
Medium-GWP HFC and HFO blends |
Sources:
Purohit, P., & Höglund-Isaksson, L. (2017). Global emissions of fluorinated greenhouse gases 2005–2050 with abatement potentials and costs. Atmospheric Chemistry and Physics, 17(4), 2795–2816.
Sustainable Purchasing Leadership Council Climate Friendly Refrigerant Action Team. (2021). Recommendations for climate friendly refrigerant management and procurement.
United Nations Environment Programme. (2023). Refrigeration, Air Conditioning and Heat Pumps Technical Options Committee: 2022 assessment report.
United Nations Framework Convention on Climate Change. (2023). National inventory submissions, Annex 1 parties [Data set].
U.S. Environmental Protection Agency. (2011). Transitioning to low-GWP alternatives in transport refrigeration.