Long-term temporal variations and source changes of halocarbons in the Greater Pearl River Delta region, China

Zeng, Lewei; Dang, Juan; Guo, Hai; Lyu, Xiaopu; Simpson, Isobel J.; Meinardi, Simone; Wang, Yu; Zhang, Luyao; Blake, Donald R.

doi:10.1016/j.atmosenv.2020.117550

Cited by 19 publications

(6 citation statements)

References 66 publications

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“…The most commonly used tracers in previous studies are CO − and HCFC-22. ,, The source of CO from fossil and biofuel combustion is broadly co-located with the emission sources of halogenated gases, which generally occurs in populated areas . Emissions of HCFC-22 from China have spatially extensive sources, and its atmospheric mole fraction has significant statistical correlations with those of other halogenated gases. , Owing to their generally good correlations of enhanced mole fractions (Figure ), both CO and HCFC-22 were used as tracers in this study.…”

Section: Experimental Methodsmentioning

confidence: 99%

In Situ Observations of Halogenated Gases at the Shangdianzi Background Station and Emission Estimates for Northern China

Yu³

et al. 2023

Environ. Sci. Technol.

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Halogenated gases include ozone-depleting substances and greenhouse gases, such as chlorofluorocarbons, halons, hydrochlorofluorocarbons, hydrofluorocarbons, and perfluorinated gases. In situ atmospheric observations of major halogenated gases were conducted at the Shangdianzi (SDZ) background station, China, from October 2020 to September 2021 using ODS5-pro, a newly developed measurement system. The measurement time series of 36 halogenated gases showed occasional pollution events, where background conditions represented 25% (CH2Cl2) to 81% (CF3Cl, CFC-13) of the measurements. The annual mean background mole fractions of most species at SDZ were consistent with those obtained at the Mace Head station in Ireland. The background conditions were distinguished from pollution events, and the enhanced mole fractions were used to estimate the emissions of four categories of fluorinated gases (F-gases) from northern China using a tracer ratio method. The CO2-equivalent (CO2-equiv) emission of F-gases from northern China reached 181 ± 18 Tg year–1 during 2020–2021. Among the four categories of F-gases estimated, SF6 accounted for the highest proportion of CO2-equiv emissions (24%), followed by HFC-23 (22%), HFC-125 (17%), HFC-134a (13%), NF3 (10%), CF4 (5.9%), HFC-143a (3.9%), HFC-32 (3.4%), and HFC-152a (0.2%).

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Section: Experimental Methodsmentioning

confidence: 99%

In Situ Observations of Halogenated Gases at the Shangdianzi Background Station and Emission Estimates for Northern China

Yu³

et al. 2023

Environ. Sci. Technol.

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“…18 It is worth noting that using the tracer ratios in Shandong province to estimate CFC-11 emissions from eastern mainland China will result in an overestimation because Shandong province is a major source region of CFC-11 in eastern China, and the ratios observed in Shandong province would be much higher than that in other regions of eastern China. As an example, the ΔCFC-11/ΔCO ratio of ∼0.08 ppt/ppb at MT was even higher than 0.05 ppt/ppb from surface monitoring in 2016 in the PRD region, 23 one of China's most densely populated and highly industrialized regions with stricter control of ODSs. 21,28 Therefore, the average emission estimate of 14.7 ± 4.3 Gg year −1 from this study based on observations in Shandong province may represent the upper limit of CFC-11 emissions in eastern China, which is quite in line with emission estimates based on measurement at the remote Pacific sites.…”

Section: ■ Introductionmentioning

confidence: 89%

“…CFC-11 had been used primarily as a refrigerant and foam blowing agent and was supposed to be released from banks such as air conditioners or foams only after its complete phase-out. , The emissions of CFC-11 that were far from what was expected from banks , were found to be largely or entirely attributed to the rigid polyurethane (PU) foam industry, , with CFC-11 emission either from the foaming process or from rigid polyurethane foams being a significant portion of the CFC-11 bank . Faced with the CFC-11 crisis in eastern China and the differences in emission estimates of CFC-11 based on observations outside mainland China, we thought it would be better to have local monitoring data to confirm and constrain the estimated emissions, yet data about ambient CFC-11 in mainland China in recent decades are quite sparse, − particularly after 2012 in eastern China. As Shandong and Hebei provinces of China are suggested to be major regions with increased emissions of CFC-11 in eastern mainland China, in this study we present field observation data from five campaigns carried out from 2012 to 2018 in Shandong province and estimate CFC-11 emissions in eastern mainland China on the basis of these observations.…”

Section: Introductionmentioning

confidence: 99%

Constraining Emission Estimates of CFC-11 in Eastern China Based on Local Observations at Surface Stations and Mount Tai

Huang

Zhang

Xue

et al. 2021

Environ. Sci. Technol. Lett.

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While observations at global background sites in east Asia suggested unexpectedly increased emissions of trichlorofluoromethane (CFC-11) after 2012 in eastern China, particularly in Shandong province, there is a lack of local monitoring data to constrain the emission estimates. Here we report observations of ambient CFC-11 during 2012–2018 in Shandong province at five sites, including three rural sites and two background sites [one at Tuoji Island (TJI) in the Bohai Sea and the other at Mount Tai (MT), 1534 m above sea level]. The mixing ratios of CFC-11 at rural sites were 17–23% above the global background levels at Mauna Loa, Hawaii, and observations at MT and TJI revealed larger enhancements occurring in air masses traveling through the polyurethane foam industry region of the Shandong Peninsula. On the basis of the ratios of CFC-11 to tracers such as carbon monoxide (CO), chloroform (CHCl3), and carbon tetrachloride (CCl4) at the MT and TJI sites, the estimated emissions of CFC-11 in eastern China ranged from 12.0 ± 1.6 to 20.8 ± 3.9 Gg year–1 with an average of 14.7 ± 4.3 Gg year–1 in 2014 and 2017–2018. These tracer-based estimates may represent the upper limits due to relatively higher ratios of CFC-11 to tracers in the hot spot province.

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“…Nevertheless, regions such as Latin America and the Caribbean (LAC), Africa, and India suffer from a dearth of observation stations and top-down estimation studies. In eastern Asia, which contributes significantly to global HFC emissions, top-down and bottom-up studies targeting the whole of China (Yao et al, 2019 andFang et al, 2016) as well as specific regions in China such as the Yangtze River Delta (Pu et al, 2020), Greater Pearl River Delta (Zeng et al, 2020), North China Plain (Ding et al, 2023), and big cities (Yi et al, 2023) have been conducted. Until the early 2010s, many studies estimated HFC emissions for a limited period of time in the eastern Asia region (Japan, South Korea, North Korea, and Taiwan), excluding China (Fortems-Cheiney et al, 2015;Li et al, 2011;Lunt et al, 2015;Stohl et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Revealing the significant acceleration of Hydrofluorocarbon (HFCs) emissions in eastern Asia through long-term atmospheric observations

Choi,

Redington,

Park

et al. 2024

Preprint

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Abstract. Hydrofluorocarbons (HFCs) are powerful anthropogenic greenhouse gases (GHGs) with high global warming potentials (GWPs). They have been widely used as refrigerants, insulation foam blowing agents, aerosol propellants, and fire suppression agents. Since the mid-1990s, emissions of HFCs have been increasing rapidly as they are used in many applications to replace ozone depleting chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) whose consumption and production have been phased out under the Montreal Protocol (MP). Due to the high GWP of HFCs, the Kigali amendment to the MP requires the phase-down of production and consumption of HFCs to gradually achieve an 80–85 % reduction by 2047 starting in 2019 for non-Article 5 (developed) countries with a 10 % reduction against each defined baseline and later schedules for Article 5 (developing) countries. In this study, we have examined long-term high precision measurements of atmospheric abundances of 5 major HFCs (HFC-134a, HFC-143a, HFC-32, HFC-125, and HFC-152a) at Gosan station, Jeju Island, South Korea from 2008 to 2020. Background abundances of HFCs gradually increased, and the inflow of polluted air masses with elevated abundances from surrounding source regions were detected over the entire period. From these pollution events, we inferred regional and country-specific HFC emission estimates using two independent Lagrangian particle dispersion models and Bayesian inversion frameworks (FLEXPART-FLEXINVERT+ and NAME-InTEM). The spatial distribution of the derived “top-down” (measurement based) emissions for all HFCs shows large fluxes from megacities and industrial areas in the region. Our most important finding is that HFC emissions in eastern China and Japan have sharply increased since 2016. The contribution of East Asian HFC emissions to the global total increased from 9 % (2008–2015) to 15 % (2016–2020). In particular, HFCs emissions in Japan (Annex 1 country) rose rapidly from 2016 onward, with accumulated total inferred HFCs emissions being ~76 Gg/yr higher for 2016–2020 than the “bottom-up” (i.e., based on activity data and emission factors) emissions reported to the United Nations Framework Convention on Climate Change (UNFCCC). This is likely related to the increase in domestic demand in Japan for refrigerants and air-conditioning system-related products and incomplete accounting. A downward trend of HFCs emissions that started in 2019 reflects the effectiveness of the F-gas policy in Japan. Eastern China and South Korea, though not obligated to report to UNFCCC, voluntarily reported emissions, which also show differences between top-down and bottom-up emission estimates, demonstrating the need for atmospheric measurements, comprehensive data analysis and accurate reporting for precise emissions management.

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Long-term temporal variations and source changes of halocarbons in the Greater Pearl River Delta region, China

Cited by 19 publications

References 66 publications

In Situ Observations of Halogenated Gases at the Shangdianzi Background Station and Emission Estimates for Northern China

In Situ Observations of Halogenated Gases at the Shangdianzi Background Station and Emission Estimates for Northern China

Constraining Emission Estimates of CFC-11 in Eastern China Based on Local Observations at Surface Stations and Mount Tai

Revealing the significant acceleration of Hydrofluorocarbon (HFCs) emissions in eastern Asia through long-term atmospheric observations

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