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Published November 28, 2021 | Supplemental Material + Published
Journal Article Open

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

Abstract

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.

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 http://crd-data-donnees-rdc.ec.gc.ca/CCCMA/publications/COVID19/. The χCO₂ flask data are from the Scripps CO2 program, and can be accessed at https://scrippsco2.ucsd.edu/data/atmospheric_co2/sampling_stations.html.

Attached Files

Published - 2021GL095396.pdf

Supplemental Material - 2021gl095396-sup-0001-supporting_information_si-s01.pdf

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Created:
September 22, 2023
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