Continuous increase in East Asia HFC-23 emissions inferred from high-frequency atmospheric observations from 2008 to 2019
Hyeri Park1,Jooil Kim2,Haklim Choi3,Sohyeon Geum1,Yeaseul Kim3,Rona L. Thompson4,Jens Mühle2,Peter K. Salameh2,Christina M. Harth2,Keran M. Stanley5,Simon O'Doherty5,Paul J. Fraser6,Peter G. Simmonds5,Paul B. Krummel6,Ray F. Weiss2,Ronald G. Prinn7,and Sunyoung Park1,3Hyeri Park et al.Hyeri Park1,Jooil Kim2,Haklim Choi3,Sohyeon Geum1,Yeaseul Kim3,Rona L. Thompson4,Jens Mühle2,Peter K. Salameh2,Christina M. Harth2,Keran M. Stanley5,Simon O'Doherty5,Paul J. Fraser6,Peter G. Simmonds5,Paul B. Krummel6,Ray F. Weiss2,Ronald G. Prinn7,and Sunyoung Park1,3
Received: 03 Jan 2023 – Discussion started: 10 Jan 2023
Abstract. Trifluoromethane (CHF3, HFC-23), one of the most potent greenhouse gases among HFCs, is mainly emitted to the atmosphere as a by-product in the production of the ozone depleting legacy refrigerant and chemical feedstock chlorodifluoromethane (CHClF2, HCFC-22). A recent study on global HFC-23 emissions (Stanley et al., 2020) showed significant discrepancies over 2014–2017 between the increase in the observation-derived (top-down) emissions and the 87 % emission reduction expected from capture and destruction processes of HFC-23 at HCFC-22 production facilities mandated by national phase-out plans (bottom-up). However, the actual sources of the increased emissions were not identified. Here, we estimate the regional top-down emissions of HFC-23 for East Asia based on in situ measurements at Gosan, South Korea, and show that the HFC-23 emissions from eastern China have increased from 5.0 ± 0.4 Gg yr-1 in 2008 to 9.5 ± 1.0 Gg yr-1 in 2019. The continuous rise was contrary to the large emissions reduction reported since 2015 under the Chinese hydrochlorofluorocarbons production phase-out management plan (HPPMP). The magnitude of the mismatch between top-down and bottom-up estimates for 2015–2019 in eastern China was ~23.7 ± 3.6 Gg, which accounts for 47 ± 11 % of the global mismatch.
Given the location of HCFC-22 production plants in eastern China and the fraction of regional to global HCFC-22 production capacities, the HFC-23 emissions rise in eastern China is most likely associated with known HCFC-22 production facilities and thus, observed discrepancies between top-down and bottom-up emissions could be attributed to unsuccessful factory level HFC-23 abatement and inaccurate quantification of emission reductions.
This study quantifying East Asia HFC-23 emissions reveals that there have been significant discrepancies between continuous increase in the observation-derived emissions and emission reductions anticipated under national phase-out plans and implies that unaccounted emissions in eastern China and probably elsewhere associated with HCFC-22 production have driven the observed growth in global HFC-23 emissions.
This study quantifying East Asia HFC-23 emissions reveals that there have been significant...