A decline in emissions of CFC-11 and related chemicals from eastern China

Journal Article
A decline in emissions of CFC-11 and related chemicals from eastern China
Park, S., ..., R.G. Prinn, ... and M. Rigby (2021)
Nature, Online first (doi: 10.1038/s41586-021-03277-w)

Abstract/Summary:

Abstract: Emissions of ozone-depleting substances, including trichlorofluoromethane (CFC11), have decreased since the mid-1980s in response to the Montreal Protocol. In recent years, an unexpected increase in CFC-11 emissions beginning in 2013 has been reported, with much of the global rise attributed to emissions from eastern China.

Here we use high-frequency atmospheric mole fraction observations from Gosan, South Korea and Hateruma, Japan, together with atmospheric chemical transport-model simulations, to investigate regional CFC-11 emissions from eastern China. We find that CFC-11 emissions returned to pre-2013 levels in 2019 (5.0 ± 1.0 gigagrams per year in 2019, compared to 7.2 ± 1.5 gigagrams per year for 2008–2012, ±1 standard deviation), decreasing by 10 ± 3 gigagrams per year since 2014–2017. Furthermore, we find that in this region, carbon tetrachloride (CCl4) and dichlorodifluoromethane (CFC-12) emissions—potentially associated with CFC-11 production—were higher than expected after 2013 and then declined one to two years before the CFC-11 emissions reduction.

This suggests that CFC-11 production occurred in eastern China after the mandated global phase-out, and that there was a subsequent decline in production during 2017–2018. We estimate that the amount of the CFC-11 bank (the amount of CFC-11 produced, but not yet emitted) in eastern China is up to 112 gigagrams larger in 2019 compared to pre-2013 levels, probably as a result of recent production. Nevertheless, it seems that any substantial delay in ozone-layer recovery has been avoided, perhaps owing to timely reporting and subsequent action by industry and government in China.

Citation:

Park, S., ..., R.G. Prinn, ... and M. Rigby (2021): A decline in emissions of CFC-11 and related chemicals from eastern China. Nature, Online first (doi: 10.1038/s41586-021-03277-w) (https://www.nature.com/articles/s41586-021-03277-w.epdf?sharing_token=OlAn8HL3CV56-6hQfa8YmtRgN0jAjWel9jnR3ZoTv0MVYPnV5MMliQMiPy3sHQiemQsC2NucHo6yPOkVlJx9Z0gf5hyN58HntWCnoJ2fbjsYElBCn7NGUkvulGJ0pMMYa_be_tigUftV2ygr0nhANRk9RxPbP4m1K1b_jZabiyg%3D)
  • Journal Article
A decline in emissions of CFC-11 and related chemicals from eastern China

Park, S., ..., R.G. Prinn, ... and M. Rigby

Online first (doi: 10.1038/s41586-021-03277-w)
2021

Abstract/Summary: 

Abstract: Emissions of ozone-depleting substances, including trichlorofluoromethane (CFC11), have decreased since the mid-1980s in response to the Montreal Protocol. In recent years, an unexpected increase in CFC-11 emissions beginning in 2013 has been reported, with much of the global rise attributed to emissions from eastern China.

Here we use high-frequency atmospheric mole fraction observations from Gosan, South Korea and Hateruma, Japan, together with atmospheric chemical transport-model simulations, to investigate regional CFC-11 emissions from eastern China. We find that CFC-11 emissions returned to pre-2013 levels in 2019 (5.0 ± 1.0 gigagrams per year in 2019, compared to 7.2 ± 1.5 gigagrams per year for 2008–2012, ±1 standard deviation), decreasing by 10 ± 3 gigagrams per year since 2014–2017. Furthermore, we find that in this region, carbon tetrachloride (CCl4) and dichlorodifluoromethane (CFC-12) emissions—potentially associated with CFC-11 production—were higher than expected after 2013 and then declined one to two years before the CFC-11 emissions reduction.

This suggests that CFC-11 production occurred in eastern China after the mandated global phase-out, and that there was a subsequent decline in production during 2017–2018. We estimate that the amount of the CFC-11 bank (the amount of CFC-11 produced, but not yet emitted) in eastern China is up to 112 gigagrams larger in 2019 compared to pre-2013 levels, probably as a result of recent production. Nevertheless, it seems that any substantial delay in ozone-layer recovery has been avoided, perhaps owing to timely reporting and subsequent action by industry and government in China.

Posted to public: 

Wednesday, February 10, 2021 - 14:28