Data Source: California Air Resources Board, California Greenhouse Gas Inventory - by Sector and Activity
Analysis by CEC Economics
Challenges
- Emissions from the use of substitutes for ozone-depleting substances (substitutes for ODS),24 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 2022, GHG emissions from substitutes for ODS from all economic sectors accounted for 5.5% of total included statewide emissions, the same as in 2021 but up from the 2019 share of 5.0%. Total GHG emissions from substitutes for ODS in 2022 were considerably larger than in 2006 (2.0%) when AB 32 was signed into law and 2016 (4.6%) when the Kigali Amendment to the Montreal Protocol was signed.25, 26 Worldwide, emissions of high GWP gases from substitutes for ODS are rising, as refrigeration and air conditioning, the main activities responsible for these emissions, become more commonplace worldwide.27, 28
- In total, emissions from substitutes for ozone-depleting substances (ODS) across all sectors experienced a 0.6% year-over-year increase in 2021. However, the rate of increase appears to be slowing down, as the annual percentage increases since 2018 have been less than 3% year-over-year, compared to the 2010-2015 period, when annual percentage increases ranged from 5.2% to 10.3% year-over-year.
- For the commercial and industrial sectors, refrigeration and air conditioning activities are the main drivers of the increase in GHG emissions from substitutes for ODS, and there are four main refrigerants used that are hydrofluorocarbons (HFCs).29 In 2022, GHG emissions from these four refrigerants across all economic sectors and activities totaled 19.7 MMTCO2e, an increase of 0.6% compared to 2021. These four refrigerants accounted for 94.2% of GHG emissions from all substitutes for ODS in 2022, 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.30, 31, 32
- In 2022, emissions from substitutes for ODS fell in the transportation sector (-4.5%) and industrial sector (-0.8%) compared to 2021, but rose in the residential sector (+5.6%) and the commercial sector (+0.5%). Since AB 32 became law in 2006, the residential and commercial sectors comprise increasingly larger shares of emissions from substitutes for ODS. From 2007 to 2022, the residential sector’s share of substitutes for ODS emissions has risen from 7.8% to 24.6%, and from 28.5% to 44.9% for the commercial sector.
24 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.
25 The 1987 Montreal Protocol aimed to protect the Earth’s ozone layer by phasing out Ozone-Depleting Substances, but increased utilization of substitutes for ODS 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
26 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. President Biden had announced plans to ratify the Kigali agreement in April 2021.
27 Significant New Alternatives Policy, U.S. Environmental Protection Agency. Retrieved from: https://www.epa.gov/snap/global-emissions-substitutes-ozone-depleting-substances
28 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
29 For the commercial and industrial sectors, emissions from substitutes for ODS 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 substitutes for ODS. 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, which have global warming potentials of 3,500 times, 1,430 times, and 4,470 times, respectively, of the GWP of carbon dioxide. In the residential sector, R-32a (with a GWP of 675 times of that of CO2) is commonly used alongside R-125 and R-134a (R-143a is not used in the residential sector).
30 California Air Resources Board. Refrigerant Management Program. Accessed October 5, 2024. Available at: https://ww2.arb.ca.gov/our-work/programs/refrigerant-management-program
31 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
32 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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