Data Source: California Air Resources Board, California Greenhouse Gas Inventory - by Sector and Activity.
Analysis by CEC Economics
Highlight
- From 2022 to 2023, emissions from SODS fell by 4.3% in the transportation sector (from 3.68 MMTCO2e to 3.52 MMTCO2e), and by 0.6% in the industrial sector (from 2.70 MMTCO2e to 2.68 MMTCO2e). Emissions increased by 0.3% in the commercial sector (from 9.39 MMTCO2e to 9.42 MMTCO2e) and by 6.1% in the residential sector (from 5.13 MMTCO2e to 5.45 MMTCO2e). Since AB 32 became law in 2006, the residential and commercial sectors comprise increasingly larger shares of emissions from the use of SODS. From 2007 to 2023, the residential sector’s share of the use of SODs emissions has risen from 7.3% to 25.9%. Meanwhile, the commercial sector’s share of the use of SODs emissions have risen more slowly from 30.9% in 2007 to 44.7% in 2023.
Challenges
- Emissions from the use of substitutes for ozone-depleting substances (SODS),15 which emit high global warming potential (GWP) gases such as hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs), are the fastest-growing source of GHG emissions in California—especially within the commercial sector. In 2023, GHG emissions from SODS from all economic sectors accounted for 5.8% of total included statewide emissions, up from 2022 (5.6%) and the highest ever. GHG emissions from SODS in 2023 totaled 21.1 MMTCO2e and were considerably larger than in 2006 (9.6 MMTCO2e, 2.0%) when AB 32 was signed into law and 2016 (19.0 MMTCO2e, 4.6%) when the Kigali Amendment to the Montreal Protocol was signed.16, 17 Worldwide, emissions of high GWP gases from SODS are rising, as refrigeration and air conditioning, the main activities responsible for these emissions, become more commonplace worldwide.18, 19
- For the commercial and residential sectors, refrigeration and air conditioning activities are the main drivers of increase in GHG emissions from SODS, and there are four main refrigerants used that are hydrofluorocarbons (HFCs). For the commercial and industrial sectors, emissions from SODS are associated with aerosols, fire protection, foams, solvents, and refrigeration and air conditioning activities, of which refrigeration and air conditioning activities are the main drivers of increase in GHG emissions from SODS. The main refrigerants used for these sectors, which are hydrofluorocarbons (HFCs), that contribute to the majority of the increase in GHG emissions are refrigerants R-125, R-134a, and R-143a,20 which have global warming potentials of 3,500 times, 1,430 times, and 4,470 times, respectively, of the GWP of carbon dioxide.21 In the residential sector, R-32 (with a GWP of 675 times that of CO2) is commonly used alongside R-125 and R-134a (R-143a is not used in the residential sector).
- In 2023, GHG emissions from these four refrigerants across all economic sectors and activities totaled 19.8 MMTCO2e, an increase of 0.7% compared to 2022. These four refrigerants accounted for 94.1% of GHG emissions from all SODS in 2023, similar to the previous years. In recent years, California has attempted to rein in emissions from these HFCs, by maximizing recovery and reclamation of high-GWP HFCs and increasing the adoption of ultra-low-GWP and no-GWP alternatives and by prohibiting the use of high GWP refrigerants in air conditioning systems, ice rinks, and chillers, plus further restrictions in the next few years.22, 23, 24
15 Emissions occur when they are released into the atmosphere (e.g., from fire extinguishers or aerosol cans) or when they leak out of equipment such as refrigerators and air conditioning units.
16 The 1987 Montreal Protocol aimed to protect the Earth’s ozone layer by phasing out Ozone-Depleting Substances, but increased utilization of SODS have resulted in an unintentional growth of GHG emissions. See: United Nations Environmental Program (2016). Treaties—The Montreal Protocol on Substances that Deplete the Ozone Layer. Retrieved from: https://ozone.unep.org/treaties/montreal-protocol/amendments/kigali-amendment-2016-amendment-montreal-protocol-agreed
17 The Kigali Amendment (adopted in 2016 and entered into force in January 2019) to the Montreal Protocol aims to address the emissions problem that substitutes of ODS have presented by phasing down global production of these substances and creating market certainty to allow growth of more environmentally friendly alternatives.
18 Significant New Alternatives Policy, U.S. Environmental Protection Agency. Retrieved from: https://www.epa.gov/snap/global-emissions-substitutes-ozone-depleting-substances
19 While the Kigali agreement could help shape markets for these substances to reduce GHG emissions, at the state level, California has a number of programs aimed at reducing emissions from these substances, as outlined in the 2017 Short-Lived Climate Pollutant Reduction Strategy. See: Short-Lived Climate Pollutant Reduction Strategy. (March 2017.) California Environmental Protection Agency and California Air Resources Board. Retrieved from: https://ww2.arb.ca.gov/sites/default/files/2020-07/final_SLCP_strategy.pdf
20 The American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE) Standard 34 assign refrigerant designations. For more information, see: https://www.ashrae.org/technical-resources/standards-and-guidelines/ashrae-refrigerant-designations
21 GWP values are based on AR4 100-year GWP values. A list of refrigerants and the associated GWPs are available at California ARB’s webpage on High-GWP Refrigerants: https://ww2.arb.ca.gov/resources/documents/high-gwp-refrigerants
22 California Air Resources Board. Refrigerant Management Program. Accessed October 5, 2024. Available at: https://ww2.arb.ca.gov/our-work/programs/refrigerant-management-program
23 The Air Conditioning, Heating and Refrigeration NEWS. California Looks to Further Reduce HFC Emissions. September 28, 2023. Accessed October 7, 2024. Available at: https://www.achrnews.com/articles/153631-california-looks-to-further-reduce-hfc-emissions
24 ServiceChannel. What You Need to Know About CARB Refrigeration Regulations. August 11, 2024. Accessed October 7, 2024. Available at: https://servicechannel.com/blog/what-you-need-to-know-about-carb-refrigeration-regulations/
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