Novel quantification of regional fossil fuel CO2 reductions during COVID-19 lockdowns using atmospheric oxygen measurements

Penelope A Pickers; Andrew C Manning; Corinne Le Quéré; Grant L Forster; Ingrid T Luijkx; Christoph Gerbig; Leigh S Fleming; William T Sturges

doi:10.1126/sciadv.abl9250

Novel quantification of regional fossil fuel CO₂ reductions during COVID-19 lockdowns using atmospheric oxygen measurements

Sci Adv. 2022 Apr 22;8(16):eabl9250. doi: 10.1126/sciadv.abl9250. Epub 2022 Apr 22.

Authors

Penelope A Pickers¹, Andrew C Manning¹, Corinne Le Quéré¹, Grant L Forster^{1

2}, Ingrid T Luijkx³, Christoph Gerbig⁴, Leigh S Fleming¹, William T Sturges¹

Affiliations

¹ Centre for Ocean and Atmospheric Sciences, School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
² National Centre for Atmospheric Science, University of East Anglia, Norwich NR4 7TJ, UK.
³ Department of Meteorology and Air Quality, Wageningen University and Research, 6700AA Wageningen, the Netherlands.
⁴ Department of Biogeochemical Systems, Max Planck Institute for Biogeochemistry, Jena, Germany.

Abstract

It is not currently possible to quantify regional-scale fossil fuel carbon dioxide (ffCO₂) emissions with high accuracy in near real time. Existing atmospheric methods for separating ffCO₂ from large natural carbon dioxide variations are constrained by sampling limitations, so that estimates of regional changes in ffCO₂ emissions, such as those occurring in response to coronavirus disease 2019 (COVID-19) lockdowns, rely on indirect activity data. We present a method for quantifying regional signals of ffCO₂ based on continuous atmospheric measurements of oxygen and carbon dioxide combined into the tracer "atmospheric potential oxygen" (APO). We detect and quantify ffCO₂ reductions during 2020-2021 caused by the two U.K. COVID-19 lockdowns individually using APO data from Weybourne Atmospheric Observatory in the United Kingdom and a machine learning algorithm. Our APO-based assessment has near-real-time potential and provides high-frequency information that is in good agreement with the spread of ffCO₂ emissions reductions from three independent lower-frequency U.K. estimates.