On the atmospheric budget of 1,2-dichloroethane and its impact on stratospheric chlorine and ozone (2002–2020)
Year: 2024
Type: article
Abstract: . Ethylene dichloride (EDC), or 1-2-dichloroethane, is an industrial very short-lived substance (VSLS) whose major use is as a feedstock in the production chain of polyvinyl chloride (PVC). Like other chlorinated VSLS, transport of EDC (or its atmospheric oxidation products) to the stratosphere could contribute to ozone depletion there. However, despite annual production volumes greatly exceeding those of more prominent VSLS (e.g. dichloromethane), global EDC observations are sparse, thus the magnitude and distribution of EDC emissions and trends in its atmospheric abundance are poorly known. In this study we performed an exploratory analysis of the global EDC budget between 2002 and 2020. Combining bottom-up data on annual production and assumptions around fugitive losses during production and feedstock use, we assessed the EDC source strength required to reproduce atmospheric EDC observations. We show that the TOMCAT/SLIMCAT 3-D chemical transport model (CTM) reproduces EDC measurements from various aircraft missions well, including HIPPO (2009–2011), ATom (2016–2018) and KORUS-AQ (2016), along with surface measurements from South East Asia, when assuming a regionally varying production emission factor in the range 0.5–1.5 %. Our findings imply substantial fugitive losses of EDC and/or substantial emissive applications (e.g. solvent use) that are poorly reported. We estimate EDC’s global source increased by ~45 % between 2002 (349±61 Gg/yr) and 2020 (505±90 Gg/yr) with its contribution to stratospheric chlorine increasing from 8.2 (±1.5) ppt Cl to ~12.9 (±2.4) ppt Cl over this period. EDC’s relatively short overall tropospheric lifetime (~83 days) limits, though does not preclude, its transport to the stratosphere and we show that its impact on ozone is small at present. Annually averaged, EDC is estimated to have decreased ozone in the lower stratosphere by up to several ppb (<1 %) in 2020, though a larger effect in the springtime Southern Hemisphere polar lower stratosphere is apparent (decreases of up to ~1.3 %). Given strong potential for growth in EDC production tied to demand for PVC, ongoing measurements would be of benefit to monitor potential future increases in its atmospheric abundance and its contribution to ozone depletion.
Authors: Ryan Hossaini, David Sherry, Zihao Wang, Martyn P. Chipperfield, Wuhu Feng, David E. Oram, Karina E. Adcock, Stephen A. Montzka, Isobel J. Simpson, Andrea Mazzeo, Amber A. Leeson, Elliot Atlas, Charles C.-K. Chou
Institutions: Lancaster University, University of Leeds, Southern University of Science and Technology, National Centre for Earth Observation, National Centre for Atmospheric Science, University of East Anglia, National Oceanic and Atmospheric Administration, NOAA Global Monitoring Laboratory, University of California, Irvine, University of Miami, Research Center for Environmental Changes, Academia Sinica, Academia Sinica
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
SDG: Climate action
Open Access status: gold
Estimated APC paid: $1,725
Awards: G1024992396, Why is Lower Stratospheric Ozone Not Recovering?, G2369505046, G2976422351, Environment East (EnvEast) Doctoral Training Partnership, G3443401077, G3667022569, G381123542, Advances in halocarbon research to ensure success of the next phase of the Montreal Protocol in protecting the ozone layer and climate, Sources and Impacts of Short-Lived Anthropogenic Chlorine, G4431032633, G4549616991, UK-Taiwan Collaboration on Transport and Deposition of Air Pollution over the South China Sea, Collaborative Research: Analyses, Measurements and Modeling in Support of the Asian Monsoon Chemical and Climate Impact Project (ACCLIP), G511364388, G5311668180, Whole Air Sampling Measurements and Data Analysis from the Stratosphere-Troposphere Analyses of Regional Transport 2008 Experiment and the HIAPER Pole-to-Pole Observation Campaign, G6708635688, G7172767342, G7771355805, G7945738299, International Collaboration on Measurement of Globally-important Gases in the Atmosphere of the Tropical Maritime Continent, G8389817396
OpenAlex ID: W4405115158