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Emissions of HCFC-22 and HCFC-142b in China during 2018-2021 Inferred from Inverse Modeling
Yahui Sun1, Bo Yao2,3,4, Mengyue Ma1
1College of Environmental & Resource Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, P. R. China.
Environmental Science & Technology
|July 22, 2024
Summary
China
Area of Science:
- Atmospheric Chemistry and Physics
- Environmental Science
- Climate Change Research
Background:
- Hydrochlorofluorocarbons (HCFCs) are ozone-depleting substances (ODSs) and transitional replacements for CFCs.
- China is scheduled to phase out HCFCs by 2030 under the Montreal Protocol.
- Post-2017 emission data for HCFC-22 and HCFC-142b in China were lacking, hindering assessment of phase-out effectiveness.
Purpose of the Study:
- To estimate HCFC-22 and HCFC-142b emissions in China from 2018-2021.
- To analyze emission trends of these HCFCs during their phase-out period.
- To identify global emission uncertainties for HCFCs.
Main Methods:
- Utilized flask and in situ atmospheric measurements of HCFC-22 and HCFC-142b.
- Employed inverse modeling techniques to determine emission magnitudes.
- Analyzed emission data from 2018 to 2021.
Main Results:
- China's HCFC-22 emissions remained stable between 2018-2021 (154-172 Gg yr⁻¹).
- HCFC-142b emissions in China showed a decreasing trend from 2013-2021 (7.4-8.3 Gg yr⁻¹).
- Significant global HCFC emissions (46% for HCFC-22, 39% for HCFC-142b) were untraced in 2020.
Conclusions:
- China's HCFC phase-out appears to have stabilized HCFC-22 emissions while reducing HCFC-142b emissions.
- Substantial untraced global HCFC emissions highlight the need for enhanced monitoring.
- Further global HCFC emission studies are crucial for effective ozone layer recovery and climate mitigation.
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