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On the Detection of COVID‐Driven Changes in Atmospheric Carbon Dioxide

Lovenduski, Nicole S. and Chatterjee, Abhishek and Swart, Neil C. and Fyfe, John C. and Keeling, Ralph F. and Schimel, David (2021) On the Detection of COVID‐Driven Changes in Atmospheric Carbon Dioxide. Geophysical Research Letters, 48 (22). Art. No. e2021GL095396. ISSN 0094-8276. doi:10.1029/2021gl095396.

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We assess the detectability of COVID-like emissions reductions in global atmospheric CO₂ concentrations using a suite of large ensembles conducted with an Earth system model. We find a unique fingerprint of COVID in the simulated growth rate of CO₂ sampled at the locations of surface measurement sites. Negative anomalies in growth rates persist from January 2020 through December 2021, reaching a maximum in February 2021. However, this fingerprint is not formally detectable unless we force the model with unrealistically large emissions reductions (2 or 4 times the observed reductions). Internal variability and carbon-concentration feedbacks obscure the detectability of short-term emission reductions in atmospheric CO₂. COVID-driven changes in the simulated, column-averaged dry air mole fractions of CO₂ are eclipsed by large internal variability. Carbon-concentration feedbacks begin to operate almost immediately after the emissions reduction; these feedbacks reduce the emissions-driven signal in the atmosphere carbon reservoir and further confound signal detection.

Item Type:Article
Related URLs:
URLURL TypeDescription ItemData ItemData
Lovenduski, Nicole S.0000-0001-5893-1009
Chatterjee, Abhishek0000-0002-3680-0160
Swart, Neil C.0000-0002-8200-6187
Fyfe, John C.0000-0003-2524-0652
Keeling, Ralph F.0000-0002-9749-2253
Schimel, David0000-0003-3473-8065
Additional Information:© 2021. American Geophysical Union. Issue Online: 19 November 2021; Version of Record online: 19 November 2021; Accepted manuscript online: 11 November 2021; Manuscript accepted: 07 November 2021; Manuscript revised: 25 October 2021; Manuscript received: 26 July 2021. This work had its inception at the “COVID-19: Identifying Unique Opportunities for Earth System Science” virtual workshop funded by the W.M. Keck Institute for Space Studies. This research was supported by the National Science Foundation (OCE-1752724 and OCE-1948664). A.C. was supported by funding from the NASA Grant/Cooperative Agreement 80NSSC20K0006. We acknowledge the CCCma staff who contributed to producing these simulations. Data Availability Statement: The data from the CanESM5 simulations used in this study are published through the Government of Canada Open Data Portal, and can be accessed at The χCO₂ flask data are from the Scripps CO2 program, and can be accessed at
Group:COVID-19, Keck Institute for Space Studies
Funding AgencyGrant Number
Keck Institute for Space Studies (KISS)UNSPECIFIED
Subject Keywords:carbon dioxide; COVID; large ensemble; ocean carbon sink; land carbon sink; carbon climate feedbacks
Issue or Number:22
Record Number:CaltechAUTHORS:20211124-174243639
Persistent URL:
Official Citation:Lovenduski, N. S., Chatterjee, A., Swart, N. C., Fyfe, J. C., Keeling, R. F., & Schimel, D. (2021). On the detection of COVID-driven changes in atmospheric carbon dioxide. Geophysical Research Letters, 48, e2021GL095396.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:112043
Deposited By: Tony Diaz
Deposited On:24 Nov 2021 17:58
Last Modified:29 Nov 2022 22:56

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