Articles | Volume 26, issue 15
https://doi.org/10.5194/acp-26-10979-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-26-10979-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
06 Aug 2026
Research article |
| 06 Aug 2026
| 06 Aug 2026
Confirming the minimal role of in-atmosphere production on the global HFC-23 budget using a 3D chemical and transport model
School of Chemistry, University of Bristol, Bristol, United Kingdom
Rayne Holland
School of Chemistry, University of Bristol, Bristol, United Kingdom
Daniel Van Hoomissen
Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration (NOAA), 325 Broadway, Boulder, CO 80305-3328, USA
James B. Burkholder
Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration (NOAA), 325 Broadway, Boulder, CO 80305-3328, USA
M. Anwar H. Khan
School of Chemistry, University of Bristol, Bristol, United Kingdom
Paul Griffiths
School of Chemistry, University of Bristol, Bristol, United Kingdom
Jens Mühle
Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0244, USA
Dudley Shallcross
School of Chemistry, University of Bristol, Bristol, United Kingdom
Matt Rigby
School of Chemistry, University of Bristol, Bristol, United Kingdom
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Luke M. Western, Stephen Bourguet, Molly Crotwell, Lei Hu, Paul B. Krummel, Hélène De Longueville, Alistair J. Manning, Jens Mühle, Dominique Rust, Isaac Vimont, Martin K. Vollmer, Minde An, Jgor Arduini, Andreas Engel, Paul J. Fraser, Anita L. Ganesan, Christina M. Harth, Chris Lunder, Michela Maione, Stephen A. Montzka, David Nance, Simon O'Doherty, Sunyoung Park, Stefan Reimann, Peter K. Salameh, Roland Schmidt, Kieran M. Stanley, Thomas Wagenhäuser, Dickon Young, Matt Rigby, Ronald G. Prinn, and Ray F. Weiss
Atmos. Chem. Phys., 25, 17761–17778, https://doi.org/10.5194/acp-25-17761-2025, https://doi.org/10.5194/acp-25-17761-2025, 2025
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We used atmospheric measurements to estimate emissions of two hydrochlorofluorocarbon (HCFC) gases, called HCFC-123 and HCFC-124, that harm the ozone layer. Despite international regulation to stop their production, their emissions have not fallen. This may be linked to how they are used to make other chemicals. Our findings show that some banned substances are still reaching the atmosphere, likely through leaks during chemical production, which could slow the recovery of the ozone layer.
Luke M. Western, Matthew Rigby, Jens Mühle, Paul B. Krummel, Chris R. Lunder, Simon O'Doherty, Stefan Reimann, Martin K. Vollmer, Dickon Young, Ben Adam, Paul J. Fraser, Anita L. Ganesan, Christina M. Harth, Ove Hermansen, Jooil Kim, Ray L. Langenfelds, Zoë M. Loh, Blagoj Mitrevski, Joseph R. Pitt, Peter K. Salameh, Roland Schmidt, Kieran Stanley, Ann R. Stavert, Hsiang-Jui Wang, Ray F. Weiss, and Ronald G. Prinn
Earth Syst. Sci. Data, 17, 6557–6582, https://doi.org/10.5194/essd-17-6557-2025, https://doi.org/10.5194/essd-17-6557-2025, 2025
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Sebastian H. M. Hickman, Makoto M. Kelp, Paul T. Griffiths, Kelsey Doerksen, Kazuyuki Miyazaki, Elyse A. Pennington, Gerbrand Koren, Fernando Iglesias-Suarez, Martin G. Schultz, Kai-Lan Chang, Owen R. Cooper, Alex Archibald, Roberto Sommariva, David Carlson, Hantao Wang, J. Jason West, and Zhenze Liu
Geosci. Model Dev., 18, 8777–8800, https://doi.org/10.5194/gmd-18-8777-2025, https://doi.org/10.5194/gmd-18-8777-2025, 2025
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Machine learning is being more widely used across environmental and climate science. This work reviews the use of machine learning in tropospheric ozone research, focusing on three main application areas in which significant progress has been made. Common challenges in using machine learning across the three areas are highlighted, and future directions for the field are indicated.
Kirstin Gerrand, Elena Fillola, Alistair J. Manning, Jgor Arduini, Paul B. Krummel, Chris R. Lunder, Jens Mühle, Simon O'Doherty, Sunyoung Park, Ronald G. Prinn, Stefan Reimann, Dickon Young, and Matthew Rigby
EGUsphere, https://doi.org/10.5194/egusphere-2025-4137, https://doi.org/10.5194/egusphere-2025-4137, 2025
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To analyse long-term trends in atmospheric trace gas concentrations, it is important to identify data points minimally affected by local pollution sources or air masses carried from other latitudes or altitudes. Traditional methods for detecting these “baselines” are computationally expensive or lack a basis in physical principles. This paper introduces a machine-learning method that uses meteorological data and offers significantly lower computational costs compared to physics-based techniques.
Paul T. Griffiths, Laura J. Wilcox, Robert J. Allen, Vaishali Naik, Fiona M. O'Connor, Michael Prather, Alex Archibald, Florence Brown, Makoto Deushi, William Collins, Stephanie Fiedler, Naga Oshima, Lee T. Murray, Bjørn H. Samset, Chris Smith, Steven Turnock, Duncan Watson-Parris, and Paul J. Young
Atmos. Chem. Phys., 25, 8289–8328, https://doi.org/10.5194/acp-25-8289-2025, https://doi.org/10.5194/acp-25-8289-2025, 2025
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The Aerosol Chemistry Model Intercomparison Project (AerChemMIP) aimed to quantify the climate and air quality impacts of aerosols and chemically reactive gases. We review its contribution to AR6 (Sixth Assessment Report of the Intergovernmental Panel on Climate Change) and the wider understanding of the role of these species in climate and climate change. We identify challenges and provide recommendations to improve the utility and uptake of climate model data, detailed summary tables of CMIP6 models, experiments, and emergent diagnostics.
Piers M. Forster, Chris Smith, Tristram Walsh, William F. Lamb, Robin Lamboll, Christophe Cassou, Mathias Hauser, Zeke Hausfather, June-Yi Lee, Matthew D. Palmer, Karina von Schuckmann, Aimée B. A. Slangen, Sophie Szopa, Blair Trewin, Jeongeun Yun, Nathan P. Gillett, Stuart Jenkins, H. Damon Matthews, Krishnan Raghavan, Aurélien Ribes, Joeri Rogelj, Debbie Rosen, Xuebin Zhang, Myles Allen, Lara Aleluia Reis, Robbie M. Andrew, Richard A. Betts, Alex Borger, Jiddu A. Broersma, Samantha N. Burgess, Lijing Cheng, Pierre Friedlingstein, Catia M. Domingues, Marco Gambarini, Thomas Gasser, Johannes Gütschow, Masayoshi Ishii, Christopher Kadow, John Kennedy, Rachel E. Killick, Paul B. Krummel, Aurélien Liné, Didier P. Monselesan, Colin Morice, Jens Mühle, Vaishali Naik, Glen P. Peters, Anna Pirani, Julia Pongratz, Jan C. Minx, Matthew Rigby, Robert Rohde, Abhishek Savita, Sonia I. Seneviratne, Peter Thorne, Christopher Wells, Luke M. Western, Guido R. van der Werf, Susan E. Wijffels, Valérie Masson-Delmotte, and Panmao Zhai
Earth Syst. Sci. Data, 17, 2641–2680, https://doi.org/10.5194/essd-17-2641-2025, https://doi.org/10.5194/essd-17-2641-2025, 2025
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In a rapidly changing climate, evidence-based decision-making benefits from up-to-date and timely information. Here we compile monitoring datasets to track real-world changes over time. To make our work relevant to policymakers, we follow methods from the Intergovernmental Panel on Climate Change (IPCC). Human activities are increasing the Earth's energy imbalance and driving faster sea-level rise compared to the IPCC assessment.
Marielle Saunois, Adrien Martinez, Benjamin Poulter, Zhen Zhang, Peter A. Raymond, Pierre Regnier, Josep G. Canadell, Robert B. Jackson, Prabir K. Patra, Philippe Bousquet, Philippe Ciais, Edward J. Dlugokencky, Xin Lan, George H. Allen, David Bastviken, David J. Beerling, Dmitry A. Belikov, Donald R. Blake, Simona Castaldi, Monica Crippa, Bridget R. Deemer, Fraser Dennison, Giuseppe Etiope, Nicola Gedney, Lena Höglund-Isaksson, Meredith A. Holgerson, Peter O. Hopcroft, Gustaf Hugelius, Akihiko Ito, Atul K. Jain, Rajesh Janardanan, Matthew S. Johnson, Thomas Kleinen, Paul B. Krummel, Ronny Lauerwald, Tingting Li, Xiangyu Liu, Kyle C. McDonald, Joe R. Melton, Jens Mühle, Jurek Müller, Fabiola Murguia-Flores, Yosuke Niwa, Sergio Noce, Shufen Pan, Robert J. Parker, Changhui Peng, Michel Ramonet, William J. Riley, Gerard Rocher-Ros, Judith A. Rosentreter, Motoki Sasakawa, Arjo Segers, Steven J. Smith, Emily H. Stanley, Joël Thanwerdas, Hanqin Tian, Aki Tsuruta, Francesco N. Tubiello, Thomas S. Weber, Guido R. van der Werf, Douglas E. J. Worthy, Yi Xi, Yukio Yoshida, Wenxin Zhang, Bo Zheng, Qing Zhu, Qiuan Zhu, and Qianlai Zhuang
Earth Syst. Sci. Data, 17, 1873–1958, https://doi.org/10.5194/essd-17-1873-2025, https://doi.org/10.5194/essd-17-1873-2025, 2025
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Methane (CH4) is the second most important human-influenced greenhouse gas in terms of climate forcing after carbon dioxide (CO2). A consortium of multi-disciplinary scientists synthesise and update the budget of the sources and sinks of CH4. This edition benefits from important progress in estimating emissions from lakes and ponds, reservoirs, and streams and rivers. For the 2010s decade, global CH4 emissions are estimated at 575 Tg CH4 yr-1, including ~65 % from anthropogenic sources.
Zachary Finewax, Aparajeo Chattopadhyay, J. Andrew Neuman, James M. Roberts, and James B. Burkholder
Atmos. Meas. Tech., 17, 6865–6873, https://doi.org/10.5194/amt-17-6865-2024, https://doi.org/10.5194/amt-17-6865-2024, 2024
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This work provides a comprehensive sensitivity calibration of a chemical ionization instrument commonly used in field measurements for the measurement of the toxic isomers methyl isocyanate and hydroxyacetonitrile that are found in the atmosphere. The results from this work have demonstrated that the hydroyacetonitrile isomer was observed in previous field studies rather than the stated identification of methyl isocyanate.
Martin Vojta, Andreas Plach, Saurabh Annadate, Sunyoung Park, Gawon Lee, Pallav Purohit, Florian Lindl, Xin Lan, Jens Mühle, Rona L. Thompson, and Andreas Stohl
Atmos. Chem. Phys., 24, 12465–12493, https://doi.org/10.5194/acp-24-12465-2024, https://doi.org/10.5194/acp-24-12465-2024, 2024
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We constrain the global emissions of the very potent greenhouse gas sulfur hexafluoride (SF6) between 2005 and 2021. We show that SF6 emissions are decreasing in the USA and in the EU, while they are substantially growing in China, leading overall to an increasing global emission trend. The national reports for the USA, EU, and China all underestimated their SF6 emissions. However, stringent mitigation measures can successfully reduce SF6 emissions, as can be seen in the EU emission trend.
Haklim Choi, Alison L. Redington, Hyeri Park, Jooil Kim, Rona L. Thompson, Jens Mühle, Peter K. Salameh, Christina M. Harth, Ray F. Weiss, Alistair J. Manning, and Sunyoung Park
Atmos. Chem. Phys., 24, 7309–7330, https://doi.org/10.5194/acp-24-7309-2024, https://doi.org/10.5194/acp-24-7309-2024, 2024
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We analyzed with an inversion model the atmospheric abundance of hydrofluorocarbons (HFCs), potent greenhouse gases, from 2008 to 2020 at Gosan station in South Korea and revealed a significant increase in emissions, especially from eastern China and Japan. This increase contradicts reported data, underscoring the need for accurate monitoring and reporting. Our findings are crucial for understanding and managing global HFCs emissions, highlighting the importance of efforts to reduce HFCs.
Hanqin Tian, Naiqing Pan, Rona L. Thompson, Josep G. Canadell, Parvadha Suntharalingam, Pierre Regnier, Eric A. Davidson, Michael Prather, Philippe Ciais, Marilena Muntean, Shufen Pan, Wilfried Winiwarter, Sönke Zaehle, Feng Zhou, Robert B. Jackson, Hermann W. Bange, Sarah Berthet, Zihao Bian, Daniele Bianchi, Alexander F. Bouwman, Erik T. Buitenhuis, Geoffrey Dutton, Minpeng Hu, Akihiko Ito, Atul K. Jain, Aurich Jeltsch-Thömmes, Fortunat Joos, Sian Kou-Giesbrecht, Paul B. Krummel, Xin Lan, Angela Landolfi, Ronny Lauerwald, Ya Li, Chaoqun Lu, Taylor Maavara, Manfredi Manizza, Dylan B. Millet, Jens Mühle, Prabir K. Patra, Glen P. Peters, Xiaoyu Qin, Peter Raymond, Laure Resplandy, Judith A. Rosentreter, Hao Shi, Qing Sun, Daniele Tonina, Francesco N. Tubiello, Guido R. van der Werf, Nicolas Vuichard, Junjie Wang, Kelley C. Wells, Luke M. Western, Chris Wilson, Jia Yang, Yuanzhi Yao, Yongfa You, and Qing Zhu
Earth Syst. Sci. Data, 16, 2543–2604, https://doi.org/10.5194/essd-16-2543-2024, https://doi.org/10.5194/essd-16-2543-2024, 2024
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Atmospheric concentrations of nitrous oxide (N2O), a greenhouse gas 273 times more potent than carbon dioxide, have increased by 25 % since the preindustrial period, with the highest observed growth rate in 2020 and 2021. This rapid growth rate has primarily been due to a 40 % increase in anthropogenic emissions since 1980. Observed atmospheric N2O concentrations in recent years have exceeded the worst-case climate scenario, underscoring the importance of reducing anthropogenic N2O emissions.
Piers M. Forster, Chris Smith, Tristram Walsh, William F. Lamb, Robin Lamboll, Bradley Hall, Mathias Hauser, Aurélien Ribes, Debbie Rosen, Nathan P. Gillett, Matthew D. Palmer, Joeri Rogelj, Karina von Schuckmann, Blair Trewin, Myles Allen, Robbie Andrew, Richard A. Betts, Alex Borger, Tim Boyer, Jiddu A. Broersma, Carlo Buontempo, Samantha Burgess, Chiara Cagnazzo, Lijing Cheng, Pierre Friedlingstein, Andrew Gettelman, Johannes Gütschow, Masayoshi Ishii, Stuart Jenkins, Xin Lan, Colin Morice, Jens Mühle, Christopher Kadow, John Kennedy, Rachel E. Killick, Paul B. Krummel, Jan C. Minx, Gunnar Myhre, Vaishali Naik, Glen P. Peters, Anna Pirani, Julia Pongratz, Carl-Friedrich Schleussner, Sonia I. Seneviratne, Sophie Szopa, Peter Thorne, Mahesh V. M. Kovilakam, Elisa Majamäki, Jukka-Pekka Jalkanen, Margreet van Marle, Rachel M. Hoesly, Robert Rohde, Dominik Schumacher, Guido van der Werf, Russell Vose, Kirsten Zickfeld, Xuebin Zhang, Valérie Masson-Delmotte, and Panmao Zhai
Earth Syst. Sci. Data, 16, 2625–2658, https://doi.org/10.5194/essd-16-2625-2024, https://doi.org/10.5194/essd-16-2625-2024, 2024
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This paper tracks some key indicators of global warming through time, from 1850 through to the end of 2023. It is designed to give an authoritative estimate of global warming to date and its causes. We find that in 2023, global warming reached 1.3 °C and is increasing at over 0.2 °C per decade. This is caused by all-time-high greenhouse gas emissions.
Hannah Chawner, Eric Saboya, Karina E. Adcock, Tim Arnold, Yuri Artioli, Caroline Dylag, Grant L. Forster, Anita Ganesan, Heather Graven, Gennadi Lessin, Peter Levy, Ingrid T. Luijkx, Alistair Manning, Penelope A. Pickers, Chris Rennick, Christian Rödenbeck, and Matthew Rigby
Atmos. Chem. Phys., 24, 4231–4252, https://doi.org/10.5194/acp-24-4231-2024, https://doi.org/10.5194/acp-24-4231-2024, 2024
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The quantity of atmospheric potential oxygen (APO), derived from coincident measurements of carbon dioxide (CO2) and oxygen (O2), has been proposed as a tracer for fossil fuel CO2 emissions. In this model sensitivity study, we examine the use of APO for this purpose in the UK and compare our model to observations. We find that our model simulations are most sensitive to uncertainties relating to ocean fluxes and boundary conditions.
Stephanie Fiedler, Vaishali Naik, Fiona M. O'Connor, Christopher J. Smith, Paul Griffiths, Ryan J. Kramer, Toshihiko Takemura, Robert J. Allen, Ulas Im, Matthew Kasoar, Angshuman Modak, Steven Turnock, Apostolos Voulgarakis, Duncan Watson-Parris, Daniel M. Westervelt, Laura J. Wilcox, Alcide Zhao, William J. Collins, Michael Schulz, Gunnar Myhre, and Piers M. Forster
Geosci. Model Dev., 17, 2387–2417, https://doi.org/10.5194/gmd-17-2387-2024, https://doi.org/10.5194/gmd-17-2387-2024, 2024
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Climate scientists want to better understand modern climate change. Thus, climate model experiments are performed and compared. The results of climate model experiments differ, as assessed in the latest Intergovernmental Panel on Climate Change (IPCC) assessment report. This article gives insights into the challenges and outlines opportunities for further improving the understanding of climate change. It is based on views of a group of experts in atmospheric composition–climate interactions.
Rona L. Thompson, Stephen A. Montzka, Martin K. Vollmer, Jgor Arduini, Molly Crotwell, Paul B. Krummel, Chris Lunder, Jens Mühle, Simon O'Doherty, Ronald G. Prinn, Stefan Reimann, Isaac Vimont, Hsiang Wang, Ray F. Weiss, and Dickon Young
Atmos. Chem. Phys., 24, 1415–1427, https://doi.org/10.5194/acp-24-1415-2024, https://doi.org/10.5194/acp-24-1415-2024, 2024
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The hydroxyl radical determines the atmospheric lifetimes of numerous species including methane. Since OH is very short-lived, it is not possible to directly measure its concentration on scales relevant for understanding its effect on other species. Here, OH is inferred by looking at changes in hydrofluorocarbons (HFCs). We find that OH levels have been fairly stable over our study period (2004 to 2021), suggesting that OH is not the main driver of the recent increase in atmospheric methane.
Tanja J. Schuck, Johannes Degen, Eric Hintsa, Peter Hoor, Markus Jesswein, Timo Keber, Daniel Kunkel, Fred Moore, Florian Obersteiner, Matt Rigby, Thomas Wagenhäuser, Luke M. Western, Andreas Zahn, and Andreas Engel
Atmos. Chem. Phys., 24, 689–705, https://doi.org/10.5194/acp-24-689-2024, https://doi.org/10.5194/acp-24-689-2024, 2024
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We study the interhemispheric gradient of sulfur hexafluoride (SF6), a strong long-lived greenhouse gas. Its emissions are stronger in the Northern Hemisphere; therefore, mixing ratios in the Southern Hemisphere lag behind. Comparing the observations to a box model, the model predicts air in the Southern Hemisphere to be older. For a better agreement, the emissions used as model input need to be increased (and their spatial pattern changed), and we need to modify north–south transport.
Ben A. Cala, Scott Archer-Nicholls, James Weber, N. Luke Abraham, Paul T. Griffiths, Lorrie Jacob, Y. Matthew Shin, Laura E. Revell, Matthew Woodhouse, and Alexander T. Archibald
Atmos. Chem. Phys., 23, 14735–14760, https://doi.org/10.5194/acp-23-14735-2023, https://doi.org/10.5194/acp-23-14735-2023, 2023
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Dimethyl sulfide (DMS) is an important trace gas emitted from the ocean recognised as setting the sulfate aerosol background, but its oxidation is complex. As a result representation in chemistry-climate models is greatly simplified. We develop and compare a new mechanism to existing mechanisms via a series of global and box model experiments. Our studies show our updated DMS scheme is a significant improvement but significant variance exists between mechanisms.
Nicola J. Warwick, Alex T. Archibald, Paul T. Griffiths, James Keeble, Fiona M. O'Connor, John A. Pyle, and Keith P. Shine
Atmos. Chem. Phys., 23, 13451–13467, https://doi.org/10.5194/acp-23-13451-2023, https://doi.org/10.5194/acp-23-13451-2023, 2023
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A chemistry–climate model has been used to explore the atmospheric response to changes in emissions of hydrogen and other species associated with a shift from fossil fuel to hydrogen use. Leakage of hydrogen results in indirect global warming, offsetting greenhouse gas emission reductions from reduced fossil fuel use. To maximise the benefit of hydrogen as an energy source, hydrogen leakage and emissions of methane, carbon monoxide and nitrogen oxides should be minimised.
Hyeri Park, Jooil Kim, Haklim Choi, Sohyeon Geum, Yeaseul Kim, Rona L. Thompson, Jens Mühle, Peter K. Salameh, Christina M. Harth, Kieran M. Stanley, Simon O'Doherty, Paul J. Fraser, Peter G. Simmonds, Paul B. Krummel, Ray F. Weiss, Ronald G. Prinn, and Sunyoung Park
Atmos. Chem. Phys., 23, 9401–9411, https://doi.org/10.5194/acp-23-9401-2023, https://doi.org/10.5194/acp-23-9401-2023, 2023
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Based on atmospheric HFC-23 observations, the first estimate of post-CDM HFC-23 emissions in eastern Asia for 2008–2019 shows that these emissions contribute significantly to the global emissions rise. The observation-derived emissions were much larger than the bottom-up estimates expected to approach zero after 2015 due to national abatement activities. These discrepancies could be attributed to unsuccessful factory-level HFC-23 abatement and inaccurate quantification of emission reductions.
Laura J. Wilcox, Robert J. Allen, Bjørn H. Samset, Massimo A. Bollasina, Paul T. Griffiths, James Keeble, Marianne T. Lund, Risto Makkonen, Joonas Merikanto, Declan O'Donnell, David J. Paynter, Geeta G. Persad, Steven T. Rumbold, Toshihiko Takemura, Kostas Tsigaridis, Sabine Undorf, and Daniel M. Westervelt
Geosci. Model Dev., 16, 4451–4479, https://doi.org/10.5194/gmd-16-4451-2023, https://doi.org/10.5194/gmd-16-4451-2023, 2023
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Changes in anthropogenic aerosol emissions have strongly contributed to global and regional climate change. However, the size of these regional impacts and the way they arise are still uncertain. With large changes in aerosol emissions a possibility over the next few decades, it is important to better quantify the potential role of aerosol in future regional climate change. The Regional Aerosol Model Intercomparison Project will deliver experiments designed to facilitate this.
Alison L. Redington, Alistair J. Manning, Stephan Henne, Francesco Graziosi, Luke M. Western, Jgor Arduini, Anita L. Ganesan, Christina M. Harth, Michela Maione, Jens Mühle, Simon O'Doherty, Joseph Pitt, Stefan Reimann, Matthew Rigby, Peter K. Salameh, Peter G. Simmonds, T. Gerard Spain, Kieran Stanley, Martin K. Vollmer, Ray F. Weiss, and Dickon Young
Atmos. Chem. Phys., 23, 7383–7398, https://doi.org/10.5194/acp-23-7383-2023, https://doi.org/10.5194/acp-23-7383-2023, 2023
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Chlorofluorocarbons (CFCs) were used in Europe pre-1990, damaging the stratospheric ozone layer. Legislation has controlled production and use, and global emissions have decreased sharply. The global rate of decline in CFC-11 recently slowed and was partly attributed to illegal emission in eastern China. This study concludes that emissions of CFC-11 in western Europe have not contributed to the unexplained part of the global increase in CFC-11 observed in the last decade.
Maria Rosa Russo, Brian John Kerridge, Nathan Luke Abraham, James Keeble, Barry Graham Latter, Richard Siddans, James Weber, Paul Thomas Griffiths, John Adrian Pyle, and Alexander Thomas Archibald
Atmos. Chem. Phys., 23, 6169–6196, https://doi.org/10.5194/acp-23-6169-2023, https://doi.org/10.5194/acp-23-6169-2023, 2023
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Tropospheric ozone is an important component of the Earth system as it can affect both climate and air quality. In this work we use observed tropospheric ozone derived from satellite observations and compare it to tropospheric ozone from model simulations. Our aim is to investigate recent changes (2005–2018) in tropospheric ozone in the North Atlantic region and to understand what factors are driving such changes.
Scott Archer-Nicholls, Rachel Allen, Nathan L. Abraham, Paul T. Griffiths, and Alex T. Archibald
Atmos. Chem. Phys., 23, 5801–5813, https://doi.org/10.5194/acp-23-5801-2023, https://doi.org/10.5194/acp-23-5801-2023, 2023
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The nitrate radical is a major oxidant at nighttime, but much less is known about it than about the other oxidants ozone and OH. We use Earth system model calculations to show how the nitrate radical has changed in abundance from 1850–2014 and to 2100 under a range of different climate and emission scenarios. Depending on the emissions and climate scenario, significant increases are projected with implications for the oxidation of volatile organic compounds and the formation of fine aerosol.
Elena Fillola, Raul Santos-Rodriguez, Alistair Manning, Simon O'Doherty, and Matt Rigby
Geosci. Model Dev., 16, 1997–2009, https://doi.org/10.5194/gmd-16-1997-2023, https://doi.org/10.5194/gmd-16-1997-2023, 2023
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Lagrangian particle dispersion models are used extensively for the estimation of greenhouse gas (GHG) fluxes using atmospheric observations. However, these models do not scale well as data volumes increase. Here, we develop a proof-of-concept machine learning emulator that can produce outputs similar to those of the dispersion model, but 50 000 times faster, using only meteorological inputs. This works demonstrates the potential of machine learning to accelerate GHG estimations across the globe.
Angharad C. Stell, Michael Bertolacci, Andrew Zammit-Mangion, Matthew Rigby, Paul J. Fraser, Christina M. Harth, Paul B. Krummel, Xin Lan, Manfredi Manizza, Jens Mühle, Simon O'Doherty, Ronald G. Prinn, Ray F. Weiss, Dickon Young, and Anita L. Ganesan
Atmos. Chem. Phys., 22, 12945–12960, https://doi.org/10.5194/acp-22-12945-2022, https://doi.org/10.5194/acp-22-12945-2022, 2022
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Nitrous oxide is a potent greenhouse gas and ozone-depleting substance, whose atmospheric abundance has risen throughout the contemporary record. In this work, we carry out the first global hierarchical Bayesian inversion to solve for nitrous oxide emissions. We derive increasing global nitrous oxide emissions over 2011–2020, which are mainly driven by emissions between 0° and 30°N, with the highest emissions recorded in 2020.
Luke M. Western, Alison L. Redington, Alistair J. Manning, Cathy M. Trudinger, Lei Hu, Stephan Henne, Xuekun Fang, Lambert J. M. Kuijpers, Christina Theodoridi, David S. Godwin, Jgor Arduini, Bronwyn Dunse, Andreas Engel, Paul J. Fraser, Christina M. Harth, Paul B. Krummel, Michela Maione, Jens Mühle, Simon O'Doherty, Hyeri Park, Sunyoung Park, Stefan Reimann, Peter K. Salameh, Daniel Say, Roland Schmidt, Tanja Schuck, Carolina Siso, Kieran M. Stanley, Isaac Vimont, Martin K. Vollmer, Dickon Young, Ronald G. Prinn, Ray F. Weiss, Stephen A. Montzka, and Matthew Rigby
Atmos. Chem. Phys., 22, 9601–9616, https://doi.org/10.5194/acp-22-9601-2022, https://doi.org/10.5194/acp-22-9601-2022, 2022
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The production of ozone-destroying gases is being phased out. Even though production of one of the main ozone-depleting gases, called HCFC-141b, has been declining for many years, the amount that is being released to the atmosphere has been increasing since 2017. We do not know for sure why this is. A possible explanation is that HCFC-141b that was used to make insulating foams many years ago is only now escaping to the atmosphere, or a large part of its production is not being reported.
Guus J. M. Velders, John S. Daniel, Stephen A. Montzka, Isaac Vimont, Matthew Rigby, Paul B. Krummel, Jens Muhle, Simon O'Doherty, Ronald G. Prinn, Ray F. Weiss, and Dickon Young
Atmos. Chem. Phys., 22, 6087–6101, https://doi.org/10.5194/acp-22-6087-2022, https://doi.org/10.5194/acp-22-6087-2022, 2022
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The emissions of hydrofluorocarbons (HFCs) have increased significantly in the past as a result of the phasing out of ozone-depleting substances. Observations indicate that HFCs are used much less in certain refrigeration applications than previously projected. Current policies are projected to reduce emissions and the surface temperature contribution of HFCs from 0.28–0.44 °C to 0.14–0.31 °C in 2100. The Kigali Amendment is projected to reduce the contributions further to 0.04 °C in 2100.
Haklim Choi, Mi-Kyung Park, Paul J. Fraser, Hyeri Park, Sohyeon Geum, Jens Mühle, Jooil Kim, Ian Porter, Peter K. Salameh, Christina M. Harth, Bronwyn L. Dunse, Paul B. Krummel, Ray F. Weiss, Simon O'Doherty, Dickon Young, and Sunyoung Park
Atmos. Chem. Phys., 22, 5157–5173, https://doi.org/10.5194/acp-22-5157-2022, https://doi.org/10.5194/acp-22-5157-2022, 2022
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We observed 12-year continuous CH3Br pollution signals at Gosan and estimated anthropogenic CH3Br emissions in eastern China. The analysis revealed a significant discrepancy between top-down estimates and the bottom-up emissions from the fumigation usage reported to the United Nations Environment Programme, likely due to unreported or inaccurately reported fumigation usage. This result provides information to monitor international compliance with the Montreal Protocol.
Alice E. Ramsden, Anita L. Ganesan, Luke M. Western, Matthew Rigby, Alistair J. Manning, Amy Foulds, James L. France, Patrick Barker, Peter Levy, Daniel Say, Adam Wisher, Tim Arnold, Chris Rennick, Kieran M. Stanley, Dickon Young, and Simon O'Doherty
Atmos. Chem. Phys., 22, 3911–3929, https://doi.org/10.5194/acp-22-3911-2022, https://doi.org/10.5194/acp-22-3911-2022, 2022
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Quantifying methane emissions from different sources is a key focus of current research. We present a method for estimating sectoral methane emissions that uses ethane as a tracer for fossil fuel methane. By incorporating variable ethane : methane emission ratios into this model, we produce emissions estimates with improved uncertainty characterisation. This method will be particularly useful for studying methane emissions in areas with complex distributions of sources.
Jens Mühle, Lambert J. M. Kuijpers, Kieran M. Stanley, Matthew Rigby, Luke M. Western, Jooil Kim, Sunyoung Park, Christina M. Harth, Paul B. Krummel, Paul J. Fraser, Simon O'Doherty, Peter K. Salameh, Roland Schmidt, Dickon Young, Ronald G. Prinn, Ray H. J. Wang, and Ray F. Weiss
Atmos. Chem. Phys., 22, 3371–3378, https://doi.org/10.5194/acp-22-3371-2022, https://doi.org/10.5194/acp-22-3371-2022, 2022
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Emissions of the strong greenhouse gas perfluorocyclobutane (c-C4F8) into the atmosphere have been increasing sharply since the early 2000s. These c-C4F8 emissions are highly correlated with the amount of hydrochlorofluorocarbon-22 produced to synthesize polytetrafluoroethylene (known for its non-stick properties) and related chemicals. From this process, c-C4F8 by-product is vented to the atmosphere. Avoiding these unnecessary c-C4F8 emissions could reduce the climate impact of this industry.
Andrew Zammit-Mangion, Michael Bertolacci, Jenny Fisher, Ann Stavert, Matthew Rigby, Yi Cao, and Noel Cressie
Geosci. Model Dev., 15, 45–73, https://doi.org/10.5194/gmd-15-45-2022, https://doi.org/10.5194/gmd-15-45-2022, 2022
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We present a framework for estimating the sources and sinks (flux) of carbon dioxide from satellite data. The framework is statistical and yields measures of uncertainty alongside all estimates of flux and other parameters in the underlying model. It also allows us to generate other insights, such as the size of errors and biases in the data. The primary aim of this research was to develop a fully statistical flux inversion framework for use by atmospheric scientists.
Jan C. Minx, William F. Lamb, Robbie M. Andrew, Josep G. Canadell, Monica Crippa, Niklas Döbbeling, Piers M. Forster, Diego Guizzardi, Jos Olivier, Glen P. Peters, Julia Pongratz, Andy Reisinger, Matthew Rigby, Marielle Saunois, Steven J. Smith, Efisio Solazzo, and Hanqin Tian
Earth Syst. Sci. Data, 13, 5213–5252, https://doi.org/10.5194/essd-13-5213-2021, https://doi.org/10.5194/essd-13-5213-2021, 2021
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We provide a synthetic dataset on anthropogenic greenhouse gas (GHG) emissions for 1970–2018 with a fast-track extension to 2019. We show that GHG emissions continued to rise across all gases and sectors. Annual average GHG emissions growth slowed, but absolute decadal increases have never been higher in human history. We identify a number of data gaps and data quality issues in global inventories and highlight their importance for monitoring progress towards international climate goals.
Mark F. Lunt, Alistair J. Manning, Grant Allen, Tim Arnold, Stéphane J.-B. Bauguitte, Hartmut Boesch, Anita L. Ganesan, Aoife Grant, Carole Helfter, Eiko Nemitz, Simon J. O'Doherty, Paul I. Palmer, Joseph R. Pitt, Chris Rennick, Daniel Say, Kieran M. Stanley, Ann R. Stavert, Dickon Young, and Matt Rigby
Atmos. Chem. Phys., 21, 16257–16276, https://doi.org/10.5194/acp-21-16257-2021, https://doi.org/10.5194/acp-21-16257-2021, 2021
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We present an evaluation of the UK's methane emissions between 2013 and 2020 using a network of tall tower measurement sites. We find emissions that are consistent in both magnitude and trend with the UK's reported emissions, with a declining trend driven by a decrease in emissions from England. The impact of various components of the modelling set-up on these findings are explored through a number of sensitivity studies.
Masanori Takeda, Hideaki Nakajima, Isao Murata, Tomoo Nagahama, Isamu Morino, Geoffrey C. Toon, Ray F. Weiss, Jens Mühle, Paul B. Krummel, Paul J. Fraser, and Hsiang-Jui Wang
Atmos. Meas. Tech., 14, 5955–5976, https://doi.org/10.5194/amt-14-5955-2021, https://doi.org/10.5194/amt-14-5955-2021, 2021
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This paper presents the first observations of atmospheric HFC-23 abundances with a ground-based remote sensing technique. The increasing trend of the HFC-23 abundances analyzed by this study agrees with that derived from other existing in situ measurements. This study indicates that ground-based FTIR observation has the capability to monitor the trend of atmospheric HFC-23 and could allow for monitoring the distribution of global atmospheric HFC-23 abundances in more detail.
R. Anthony Cox, Markus Ammann, John N. Crowley, Paul T. Griffiths, Hartmut Herrmann, Erik H. Hoffmann, Michael E. Jenkin, V. Faye McNeill, Abdelwahid Mellouki, Christopher J. Penkett, Andreas Tilgner, and Timothy J. Wallington
Atmos. Chem. Phys., 21, 13011–13018, https://doi.org/10.5194/acp-21-13011-2021, https://doi.org/10.5194/acp-21-13011-2021, 2021
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The term open-air factor was coined in the 1960s, establishing that rural air had powerful germicidal properties possibly resulting from immediate products of the reaction of ozone with alkenes, unsaturated compounds ubiquitously present in natural and polluted environments. We have re-evaluated those early experiments, applying the recently substantially improved knowledge, and put them into the context of the lifetime of aerosol-borne pathogens that are so important in the Covid-19 pandemic.
Alistair J. Manning, Alison L. Redington, Daniel Say, Simon O'Doherty, Dickon Young, Peter G. Simmonds, Martin K. Vollmer, Jens Mühle, Jgor Arduini, Gerard Spain, Adam Wisher, Michela Maione, Tanja J. Schuck, Kieran Stanley, Stefan Reimann, Andreas Engel, Paul B. Krummel, Paul J. Fraser, Christina M. Harth, Peter K. Salameh, Ray F. Weiss, Ray Gluckman, Peter N. Brown, John D. Watterson, and Tim Arnold
Atmos. Chem. Phys., 21, 12739–12755, https://doi.org/10.5194/acp-21-12739-2021, https://doi.org/10.5194/acp-21-12739-2021, 2021
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This paper estimates UK emissions of important greenhouse gases (hydrofluorocarbons (HFCs)) using high-quality atmospheric observations and atmospheric modelling. We compare these estimates with those submitted by the UK to the United Nations. We conclude that global concentrations of these gases are still increasing. Our estimates for the UK are 73 % of those reported and that the UK emissions are now falling, demonstrating an impact of UK government policy.
James Weber, Scott Archer-Nicholls, Nathan Luke Abraham, Youngsub M. Shin, Thomas J. Bannan, Carl J. Percival, Asan Bacak, Paulo Artaxo, Michael Jenkin, M. Anwar H. Khan, Dudley E. Shallcross, Rebecca H. Schwantes, Jonathan Williams, and Alex T. Archibald
Geosci. Model Dev., 14, 5239–5268, https://doi.org/10.5194/gmd-14-5239-2021, https://doi.org/10.5194/gmd-14-5239-2021, 2021
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The new mechanism CRI-Strat 2 features state-of-the-art isoprene chemistry not previously available in UKCA and improves UKCA's ability to reproduce observed concentrations of isoprene, monoterpenes, and OH in tropical regions. The enhanced ability to model isoprene, the most widely emitted non-methane volatile organic compound (VOC), will allow understanding of how isoprene and other biogenic VOCs affect atmospheric composition and, through biosphere–atmosphere feedbacks, climate change.
Cited articles
Adam, B., Western, L. M., Mühle, J., Choi, H., Krummel, P. B., O'Doherty, S., Young, D., Stanley, K. M., Fraser, P. J., Harth, C. M., Salameh, P. K., Weiss, R. F., Prinn, R. G., Kim, J., Park, H., Park, S., and Rigby, M.: Emissions of HFC-23 do not reflect commitments made under the Kigali Amendment, Commun. Earth Environ., 5, 1–8, https://doi.org/10.1038/s43247-024-01946-y, 2024. a, b
Adam, B., Holland, R., Van Hoomissen, D., Burkholder, J., Khan, M. A. H., Griffiths, P., Mühle, J., Shallcross, D., and Rigby, M.: STOCHEM-CRI model output to support 'Confirming the minimal role of in-atmosphere production on the global HFC-23 budget using a 3D chemical and transport model' (Version 20260731), Zenodo [data set], https://doi.org/10.5281/zenodo.21718364, 2026. a
Baumann, F., Fernholz, C., Lelieveld, J., and Crowley, J. N.: Kinetics of the reaction of CF3CHO with OH between 204 K and 361 K, Phys. Chem. Chem. Phys., https://doi.org/10.1039/D5CP02871J, 2025. a, b
Burkholder, J., Abbatt, J., Cappa, C., Dibble, T., Kolb, C., Orkin, V., Wilmouth, D., Sander, S., Barker, J., Crounse, J., Huie, Kurylo, M., Percival, C., and Wine, P.: JPL Publication 19-5. Chemical Kinetics and Photochemical Data for Use in Atmospheric Studies, Tech. rep., Jet Propulsion Laboratory, Pasadena, CA, https://doi.org/10.48577/jpl.KFQ0TZ, 2019. a, b, c, d, e, f, g, h
Burkholder, J., Hodnebrog, Ø., McDonald, B., Orkin, V., Papadimitriou, V., and Van Hoomissen, T.: Annex : Summary of Abundances, lifetimes, ODPs, REs, GWPs, and GTPs, in: Scientific Assessment of Ozone Depletion 2022, no. 278 in Global Ozone Research and Monitoring Project, World Meteorological Organization, Geneva, Switzerland, 435–492, https://ozone.unep.org/system/files/documents/Scientific-Assessment-of-Ozone-Depletion-2022.pdf (last access: 30 July 2026), 2022. a, b, c, d, e, f, g, h, i
Collins, W. J., Stevenson, D. S., Johnson, C. E., and Derwent, R. G.: Tropospheric Ozone in a Global-Scale Three-Dimensional Lagrangian Model and Its Response to NOX Emission Controls, J. Atmos. Chem., 26, 223–274, https://doi.org/10.1023/A:1005836531979, 1997. a
Collins, W. J., Daniel, J. S., Chipperfield, M. P., Cussac, M., Deushi, M., Faluvegi, G., Griffiths, P., Hodnebrog, Ø., Horowitz, L. W., Keeble, J., Kinnison, D., Naik, V., O'Connor, F. M., Shindell, D., Tilmes, S., Tsigaridis, K., Wang, Z., and Weber, J.: Indirect climate forcing from ozone depleting substances, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2025-6033, 2026. a
Crippa, M., Guizzardi, D., Pagani, F., Banja, M., Muntean, M., Schaaf, E., Becker, W., Monforti-Ferrario, F., Quadrelli, R., Risquez Martin, A., Taghavi-Moharamli, P., Grassi, G., Rossi, S., Brandao De Melo, J., Oom, D., Branco, A., San-Miguel, J., and Vignati, E.: EDGAR v8.0 Greenhouse Gas Emissions, Publications Office of the European Commissions, https://doi.org/10.2760/953322, 2023. a
Derwent, R., Stevenson, D., Doherty, R., Collins, W., and Sanderson, M.: How is surface ozone in Europe linked to Asian and North American NOx emissions?, Atmos. Environ., 42, 7412–7422, https://doi.org/10.1016/j.atmosenv.2008.06.037, 2008. a
Derwent, R. G., Jenkin, M. E., Stevenson, D. S., Utembe, S. R., Khan, A. H., and Shallcross, D. E.: Influence of the oxidation of non-methane volatile organic compounds on tropospheric hydrogen: A STOCHEM-CRI global Lagrangian model study, Atmos. Environ., 352, 121214, https://doi.org/10.1016/j.atmosenv.2025.121214, 2025. a
European Union: Regulation (EU) 2024/573 of the European Parliament and of the Council of 7 February 2024 on fluorinated greenhouse gases, amending Directive (EU) 2019/1937 and repealing Regulation (EU) No 517/2014, Official Journal of the European Union, https://eur-lex.europa.eu/eli/reg/2024/573/oj (last access: 30 July 2026), 2024. a
Garavagno, M. D. L. A., Wenger, A., Holland, R. E. T., Fena, B. R., Goldstein, S. D., Hicks, D. E., Liu, F., Madell, J. B., Solomon, S. J., Kuwata, K. T., McGillen, M. R., Khan, M. A. H., Shallcross, D. E., Stanley, K. M., and Orr-Ewing, A. J.: Atmospheric Oxidation of Hydrofluoroolefins and Hydrochlorofluoroolefins by Ozone Produces HFC-23, PFC-14, and CFC-13, Environ. Sci. Technol., 59, 26031–26040, https://doi.org/10.1021/acs.est.5c11383, 2025. a, b, c, d, e
Holland, R., Khan, M. A. H., Chhantyal-Pun, R., Orr-Ewing, A. J., Percival, C. J., Taatjes, C. A., and Shallcross, D. E.: Investigating the Atmospheric Sources and Sinks of Perfluorooctanoic Acid Using a Global Chemistry Transport Model, Atmosphere, 11, 407, https://doi.org/10.3390/atmos11040407, 2020. a
Holland, R., Khan, M. A. H., Driscoll, I., Chhantyal-Pun, R., Derwent, R. G., Taatjes, C. A., Orr-Ewing, A. J., Percival, C. J., and Shallcross, D. E.: Investigation of the Production of Trifluoroacetic Acid from Two Halocarbons, HFC-134a and HFO-1234yf and Its Fates Using a Global Three-Dimensional Chemical Transport Model, ACS Earth Space Chem., 5, 849–857, https://doi.org/10.1021/acsearthspacechem.0c00355, 2021. a, b, c
Jenkin, M. E., Watson, L. A., Utembe, S. R., and Shallcross, D. E.: A Common Representative Intermediates (CRI) mechanism for VOC degradation. Part 1: Gas phase mechanism development, Atmos. Environ., 42, 7185–7195, https://doi.org/10.1016/j.atmosenv.2008.07.028, 2008. a
Khan, M. A. H., Jenkin, M. E., Foulds, A., Derwent, R. G., Percival, C. J., and Shallcross, D. E.: A modeling study of secondary organic aerosol formation from sesquiterpenes using the STOCHEM global chemistry and transport model, J. Geophys. Res.-Atmos., 122, 4426–4439, https://doi.org/10.1002/2016JD026415, 2017. a
Khan, M. A. H., Lyons, K., Chhantyal-Pun, R., McGillen, M. R., Caravan, R. L., Taatjes, C. A., Orr-Ewing, A. J., Percival, C. J., and Shallcross, D. E.: Investigating the Tropospheric Chemistry of Acetic Acid Using the Global 3-D Chemistry Transport Model, STOCHEM-CRI, J. Geophys. Res.-Atmos., 123, 6267–6281, https://doi.org/10.1029/2018JD028529, 2018. a
Khan, M. A. H., Mendes, D. C., Holland, R. E. T., de los Angeles Garavagno, M., Orr-Ewing, A. J., Stanley, K. M., O'Doherty, S. J., Young, D., Vollmer, M. K., Antony, A. J., Karamshahi, F., Wallington, T. J., Percival, C. J., Bacak, A., Derwent, R. G., and Shallcross, D. E.: Global modeling of trifluoroacetic acid surface concentration and deposition from the gas-phase oxidation of a wide range of precursor hydrofluoroolefins, Environ. Sci.: Atmos., 6, 195–212, https://doi.org/10.1039/D5EA00108K, 2026. a
Killen, B., Fisher, J. A., Hansen, C. S., Krummel, P., Vollmer, M. K., and Kable, S.: Atmospheric fates and global warming potential of HFO-1234ze (E) and its degradation product trifluoroacetaldehyde (CF3CHO), Environ. Sci.-Atmos., 6, 913–932, https://doi.org/10.1039/D6EA00034G, 2026. a, b, c, d, e, f
Laube, J. C., Newland, M. J., Hogan, C., Brenninkmeijer, C. A. M., Fraser, P. J., Martinerie, P., Oram, D. E., Reeves, C. E., Röckmann, T., Schwander, J., Witrant, E., and Sturges, W. T.: Newly detected ozone-depleting substances in the atmosphere, Nat. Geosci., 7, 266–269, https://doi.org/10.1038/ngeo2109, 2014. a
Liang, Q., Rigby, M., Fang, X., Godwin, D. S., Muhle, J., Saito, T., Stanley, K. M., and Velders, G. J. M.: Hydrofluorocarbons (HFCs), in: Scientific Assessment of Ozone Depletion 2022, edited by: Montzka, S. and Vollmer, M. K., no. 278 in Global Ozone Research and Monitoring Project, World Meteorological Organization, Geneva, Switzerland, 115–152, https://ozone.unep.org/system/files/documents/Scientific-Assessment-of-Ozone-Depletion-2022.pdf (last access: 30 July 2026), 2022. a, b, c, d, e
Long, B., Xia, Y., and Truhlar, D. G.: Quantitative Kinetics of HO2 Reactions with Aldehydes in the Atmosphere: High-Order Dynamic Correlation, Anharmonicity, and Falloff Effects Are All Important, J. Am. Chem. Soc., 144, 19910–19920, https://doi.org/10.1021/jacs.2c07994, 2022. a
McGillen, M. R., Bernard, F., Fleming, E. L., and Burkholder, J. B.: HCFC-133a (CF3CH2Cl): OH rate coefficient, UV and infrared absorption spectra, and atmospheric implications, Geophys. Res. Lett., 42, 6098–6105, https://doi.org/10.1002/2015GL064939, 2015. a
McGillen, M. R., Fried, Z. T. P., Khan, M. A. H., Kuwata, K. T., Martin, C. M., O'Doherty, S., Pecere, F., Shallcross, D. E., Stanley, K. M., and Zhang, K.: Ozonolysis can produce long-lived greenhouse gases from commercial refrigerants, P. Natl. Acad. Sci. USA, 120, e2312714120, https://doi.org/10.1073/pnas.2312714120, 2023. a, b, c, d
Nielsen, O. J., Andersen, M. P. S., and Franklin, J.: Comment on “Assessing the atmospheric fate of trifluoroacetaldehyde (CF3CHO) and its potential as a new source of fluoroform (HFC-23) using the AtChem2 box model” by Pérez-Peña et al., Environ. Sci.: Atmos., 2023, 3, 1767–1777, https://doi.org/10.1039/D3EA00120B, Environ. Sci.-Atmos., 5, 530–534, https://doi.org/10.1039/D4EA00123K, 2025a. a, b, c, d, e, f, g
Nielsen, O. J., Sulbaek Andersen, M. P., and Wallington, T. J.: CF3H production from the ozonolysis of HCFOs: E- and Z-CF3CH=CHCl, Atmos. Environ., 343, 120953, https://doi.org/10.1016/j.atmosenv.2024.120953, 2025b. a, b
Pérez-Peña, M. P., Fisher, J. A., Hansen, C., and Kable, S. H.: Assessing the atmospheric fate of trifluoroacetaldehyde (CF3CHO) and its potential as a new source of fluoroform (HFC-23) using the AtChem2 box model, Environ. Sci.: Atmos., 3, 1767–1777, https://doi.org/10.1039/D3EA00120B, publisher: RSC, 2023. a, b, c, d, e, f
Pérez-Peña, M. P., Fisher, J. A., Hansen, C. S., and Kable, S. H.: Reply to the 'Comment on “Assessing the atmospheric fate of trifluoroacetaldehyde (CF3CHO) and its potential as a new source of fluoroform (HFC-23) using the AtChem2 box model”' by O. J. Nielsen, M. P. Sulbaek Andersen and J. Franklin, Environ. Sci.: Atmos., 2025, 5, https://doi.org/10.1039/D4EA00123K, Environ. Sci.-Atmos., 5, 535–538, https://doi.org/10.1039/D4EA00154K, 2025. a
Prinn, R., Weiss, R., Arduini, J., Arnold, T., Fraser, P., Ganesan, A., Gasore, J., Harth, C., Hermansen, O., Kim, J., Krummel, P., Loh, Z., Lunder, C., Maione, M., Manning, A., Miller, B., Mitrevski, B., Mühle, J., O'Doherty, S., Park, S., Reimann, S., Rigby, M., Saito, T., Salameh, P., Schmidt, R., Simmonds, P., Stanley, K., Steel, P., Vollmer, M., Wang, H. R., Yao, B., Young, D., and Zhou, L.: The dataset of in-situ measurements of chemically and radiatively important atmospheric gases from the Advanced Global Atmospheric Gas Experiment (AGAGE) and affiliated stations (2023R2), ESS-DIVE, https://doi.org/10.15485/2216951, 2023. a, b
Prinn, R. G., Weiss, R. F., Arduini, J., Arnold, T., DeWitt, H. L., Fraser, P. J., Ganesan, A. L., Gasore, J., Harth, C. M., Hermansen, O., Kim, J., Krummel, P. B., Li, S., Loh, Z. M., Lunder, C. R., Maione, M., Manning, A. J., Miller, B. R., Mitrevski, B., Mühle, J., O'Doherty, S., Park, S., Reimann, S., Rigby, M., Saito, T., Salameh, P. K., Schmidt, R., Simmonds, P. G., Steele, L. P., Vollmer, M. K., Wang, R. H., Yao, B., Yokouchi, Y., Young, D., and Zhou, L.: History of chemically and radiatively important atmospheric gases from the Advanced Global Atmospheric Gases Experiment (AGAGE), Earth Syst. Sci. Data, 10, 985–1018, https://doi.org/10.5194/essd-10-985-2018, 2018. a, b, c
Rust, D., Katharopoulos, I., Vollmer, M. K., Henne, S., O'Doherty, S., Say, D., Emmenegger, L., Zenobi, R., and Reimann, S.: Swiss halocarbon emissions for 2019 to 2020 assessed from regional atmospheric observations, Atmos. Chem. Phys., 22, 2447–2466, https://doi.org/10.5194/acp-22-2447-2022, 2022. a
Rust, D., Vollmer, M. K., Henne, S., Bühlmann, T., Frumau, A., van den Bulk, P., Emmenegger, L., Zenobi, R., and Reimann, S.: First Atmospheric Measurements and Emission Estimates of HFO-1336mzz(Z), Environ. Sci. Technol., 57, 11903–11912, https://doi.org/10.1021/acs.est.3c01826, 2023. a
Rust, D., Vollmer, M. K., Henne, S., Frumau, A., van den Bulk, P., Hensen, A., Stanley, K. M., Zenobi, R., Emmenegger, L., and Reimann, S.: Effective realization of abatement measures can reduce HFC-23 emissions, Nature, 633, 96–100, https://doi.org/10.1038/s41586-024-07833-y, 2024. a
Sander, R.: Compilation of Henry's law constants (version 5.0.0) for water as solvent, Atmos. Chem. Phys., 23, 10901–12440, https://doi.org/10.5194/acp-23-10901-2023, 2023. a
Scollard, D. J., Treacy, J. J., Sidebottom, H. W., Balestra-Garcia, C., Laverdet, G., LeBras, G., MacLeod, H., and Teton, S.: Rate constants for the reactions of hydroxyl radicals and chlorine atoms with halogenated aldehydes, J. Phys. Chem., 97, 4683–4688, https://doi.org/10.1021/j100120a021, 1993. a
Sellevåg, S. R., Kelly, T., Sidebottom, H., and Nielsen, C. J.: A study of the IR and UV-Vis absorption cross-sections, photolysis and OH-initiated oxidation of CF3CHO and CF3CH2CHO, Phys. Chem. Chem. Phys., 6, 1243–1252, https://doi.org/10.1039/B315941H, 2004. a
Su, S., Fang, X., Li, L., Wu, J., Zhang, J., Xu, W., and Hu, J.: HFC-134a emissions from mobile air conditioning in China from 1995 to 2030, Atmos. Environ., 102, 122–129, https://doi.org/10.1016/j.atmosenv.2014.11.057, 2015. a
Sulbaek Andersen, M. P. and Nielsen, O. J.: Tropospheric photolysis of CF3CHO, Atmos. Environ., 272, 118935, https://doi.org/10.1016/j.atmosenv.2021.118935, 2022. a
Sulbaek Andersen, M. P., Nielsen, O. J., Hurley, M. D., Ball, J. C., Wallington, T. J., Stevens, J. E., Martin, J. W., Ellis, D. A., and Mabury, S. A.: Atmospheric Chemistry of n-CxF2x+1CHO (
Sulbaek Andersen, M. P., Madronich, S., Ohide, J. M., Frausig, M., and Nielsen, O. J.: Photolysis of CF3CHO at 254 nm and potential contribution to the atmospheric abundance of HFC-23, Atmos. Environ., 314, 120087, https://doi.org/10.1016/j.atmosenv.2023.120087, 2023. a, b
Thomson, J. D., Campbell, J. S., Edwards, E. B., Medcraft, C., Nauta, K., Pérez-Peña, M. P., Fisher, J. A., Osborn, D. L., Kable, S. H., and Hansen, C. S.: Fluoroform (CHF3) Production from CF3CHO Photolysis and Implications for the Decomposition of Hydrofluoroolefins and Hydrochlorofluoroolefins in the Atmosphere, J. Am. Chem. Soc., 147, 33–38, https://doi.org/10.1021/jacs.4c11776, 2024. a, b, c, d, e
United Nations Environment Programme: Amendment to the Montreal Protocol on Substances That Deplete the Ozone Layer, type: treaty Place: Kigali, Rwanda, https://ozone.unep.org/treaties/montreal-protocol/amendments/kigali-amendment-2016-amendment-montreal-protocol-agreed (last access: 30 July 2026), 2016. a
United Nations Environment Programme: Report of the Technology and Economic Assessment Panel, September 2023. Volume 6: Response to Decision XXXIV/7: Strengthening Institutional Processes with respect to Information on HFC-23 By-Product Emissions, Tech. Rep. Volume 6, United Nations Environment Programme, https://ozone.unep.org/system/files/documents/TEAP-MCTOC-response-to-decision%20XXXIV7-report-september2023.pdf (last access: 30 July 2026), 2023. a
United Nations Environment Programme: Report of the Technology and Economic Assessment Panel, September 2024. Volume 5: Response to Decision XXXV/7: Emissions of HFC-23, Tech. Rep. Volume 5, United Nations Environment Programme, https://ozone.unep.org/system/files/documents/TEAP-reponse-to-decision-XXXV-7-report-september-2024.pdf (last access: 30 July 2026), 2024a. a
United Nations Environment Programme: Report of the Scientific Assessment Panel, September 2024. Response to Decision XXXV/7: Emissions of HFC-23, Tech. rep., United Nations Environment Programme, https://ozone.unep.org/system/files/documents/SAP_Report_on_HFC23_September2024.pdf (last access: 30 July 2026), 2024b. a, b, c
United Nations Environment Programme: Report of the Technology and Economic Assessment Panel, September 2025. Volume 2: Response to Decision XXXVI/3: Emissions of HFC-23, Tech. Rep. Volume 2, United Nations Environment Programme, https://ozone.unep.org/system/files/documents/TEAP-reponse-to-decision-XXXVI-3-report-september-2025.pdf (last access: 30 July 2026), 2025b. a, b
Utembe, S. R., Watson, L. A., Shallcross, D. E., and Jenkin, M. E.: A Common Representative Intermediates (CRI) mechanism for VOC degradation. Part 3: Development of a secondary organic aerosol module, Atmos. Environ., 43, 1982–1990, https://doi.org/10.1016/j.atmosenv.2009.01.008, 2009. a
Utembe, S. R., Cooke, M. C., Archibald, A. T., Jenkin, M. E., Derwent, R. G., and Shallcross, D. E.: Using a reduced Common Representative Intermediates (CRIv2-R5) mechanism to simulate tropospheric ozone in a 3-D Lagrangian chemistry transport model, Atmos. Environ., 44, 1609–1622, https://doi.org/10.1016/j.atmosenv.2010.01.044, 2010. a
Van Hoomissen, D., Chattopadhyay, A., Montzka, S. A., and Burkholder, J. B.: CHF3 (HFC-23) and CF3CHO Quantum Yields in the Pulsed Laser Photolysis of CF3CHO at 248, 266, 281, and 308 nm, ACS Earth Space Chem., 9, 589–602, https://doi.org/10.1021/acsearthspacechem.4c00316, 2025. a, b, c, d, e, f, g, h, i, j, k, l, m, n
Velders, G. J. M., Fahey, D. W., Daniel, J. S., McFarland, M., and Andersen, S. O.: The large contribution of projected HFC emissions to future climate forcing, P. Natl. Acad. Sci. USA, 106, 10949–10954, https://doi.org/10.1073/pnas.0902817106, 2009. a, b
Vollmer, M. K., Reimann, S., Hill, M., and Brunner, D.: First Observations of the Fourth Generation Synthetic Halocarbons HFC-1234yf, HFC-1234ze(E), and HCFC-1233zd(E) in the Atmosphere, Environ. Sci. Technol., 49, 2703–2708, https://doi.org/10.1021/es505123x, 2015. a
Vollmer, M. K., Pitt, J. R., Young, D., Henne, S., Mitrevski, B., Mühle, J., Ganesan, A., Arduini, J., Manning, A. J., Wagenhäuser, T., Redington, A. L., Melo, D. B., Murphy, B., Gluckmann, R., Stanley, K. M., Krummel, P. B., Lunder, C. R., Yun, J., Rust, D., Wenger, A., Guillevic, M., Kim, J., Wang, R. H. J., Rhee, T. S., Constantin, L., Frumau, A., Harth, C. M., Salameh, P. K., Hermansen, O., Rigby, M., Western, L. M., Engel, A., O'Doherty, S., Park, S., Maione, M., Fraser, P. J., Prinn, R. G., Weiss, R. F., and Reimann, S.: Global Observations and European emissions of the halogenated olefins HFO-1234yf, HFO-1234ze(E), and HCFO-1233zd(E) from the AGAGE (Advanced Global Atmospheric Gases Experiment) network, Atmos. Chem. Phys., 26, 6993–7012, https://doi.org/10.5194/acp-26-6993-2026, 2026. a, b, c
Watson, L. A., Shallcross, D. E., Utembe, S. R., and Jenkin, M. E.: A Common Representative Intermediates (CRI) mechanism for VOC degradation. Part 2: Gas phase mechanism reduction, Atmos. Environ., 42, 7196–7204, https://doi.org/10.1016/j.atmosenv.2008.07.034, 2008. a
Western, L. M., Rigby, M., Mühle, J., Krummel, P. B., Lunder, C. R., O'Doherty, S., Reimann, S., Vollmer, M. K., Young, D., Adam, B., Fraser, P. J., Ganesan, A. L., Harth, C. M., Hermansen, O., Kim, J., Langenfelds, R. L., Loh, Z. M., Mitrevski, B., Pitt, J. R., Salameh, P. K., Schmidt, R., Stanley, K., Stavert, A. R., Wang, H.-J., Weiss, R. F., and Prinn, R. G.: Global emissions and abundances of chemically and radiatively important trace gases from the AGAGE network, Earth Syst. Sci. Data, 17, 6557–6582, https://doi.org/10.5194/essd-17-6557-2025, 2025. a, b, c
Winiberg, F. A., Percival, C. J., Shannon, R., Khan, M. A. H., Shallcross, D. E., Liu, Y., and Sander, S. P.: Reaction kinetics of OH+ HNO 3 under conditions relevant to the upper troposphere/lower stratosphere, Phys. Chem. Chem. Phys., 20, 24652–24664, 2018. a
World Bank Group: World Bank Open Data, blackboxPlease add the name of the publisher/publishing institution., https://data.worldbank.org/indicator/NY.GDP.MKTP.CD (last access: 30 July 2026), 2025. a
Zhang, L., He, Z., Wu, Z., Macdonald, A. M., Brook, J. R., and Kharol, S.: A database of modeled gridded dry deposition velocities for 45 gaseous species and three particle size ranges across North America, J. Environ. Sci., 127, 264–272, https://doi.org/10.1016/j.jes.2022.05.030, 2023. a
Short summary
Some man-made gases emitted into the atmosphere can break down to form a powerful greenhouse gas called HFC-23 (hydrofluorocarbons). In this study, we use a full three-dimensional model of the atmosphere and its chemistry to improve on previous work and determine how much HFC-23 is produced from this route. Our model estimates HFC-23 production ten times lower than previously suggested, confirming that this source is a very small contributor to the total amount of HFC-23 in the atmosphere.
Some man-made gases emitted into the atmosphere can break down to form a powerful greenhouse gas...
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