COVID-19 Emission Reductions Reveal the Efficiency and Warming Impact of Short-Lived Greenhouse Gases
Abstract
The COVID-19 response provided a natural experiment to quantify the climate forcing efficiency of short-lived pollutants. Using satellite-constrained reanalysis and chemistry-climate simulations, we isolate the radiative impacts of anthropogenic NOₓ reductions through two modes: a rapid ozone decrease and a slower methane-driven adjustment that dominates the net effect. Globally, these responses produce a net radiative forcing of +17.87 ± 3.83 mW m⁻², indicating that methane-driven warming outweighs the initial ozone cooling. The rapid response is strongly regional: South and Southeast Asia (excluding China) contributes most by -2.96±0.78 mW m⁻² , driven by large emission reductions, efficient convective export, and high upper-tropospheric radiative sensitivity, with North and South America secondary. Because our experiment isolates the gas-phase NOₓ–O₃–OH–CH₄ pathway, it is an upper bound on the methane-mediated warming; co-reduced CO and volatile organic compounds and lower nitrate aerosol would offset part of it. NOₓ mitigation alone can cause delayed warming unless methane is concurrently controlled.
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BibTeX
@misc{yang2026covid19,
title = {{COVID-19 Emission Reductions Reveal the Efficiency and Warming Impact of Short-Lived Greenhouse Gases}},
author = {Jiani Yang and Kazuyuki Miyazaki and Le Kuai and Kevin W. Bowman and Takashi Sekiya and Yuk Yung},
howpublished = {EarthArXiv},
year = {2026},
month = oct,
doi = {10.31223/x5cj70},
url = {https://eartharxiv.org/repository/view/15364/},
note = {CC BY-NC-SA 4.0},
}
RIS
TY - UNPB
TI - COVID-19 Emission Reductions Reveal the Efficiency and Warming Impact of Short-Lived Greenhouse Gases
AU - Jiani Yang
AU - Kazuyuki Miyazaki
AU - Le Kuai
AU - Kevin W. Bowman
AU - Takashi Sekiya
AU - Yuk Yung
PY - 2026
DA - 2026/10/05
PB - EarthArXiv
DO - 10.31223/x5cj70
UR - https://eartharxiv.org/repository/view/15364/
AB - The COVID-19 response provided a natural experiment to quantify the climate forcing efficiency of short-lived pollutants. Using satellite-constrained reanalysis and chemistry-climate simulations, we isolate the radiative impacts of anthropogenic NOₓ reductions through two modes: a rapid ozone decrease and a slower methane-driven adjustment that dominates the net effect. Globally, these responses produce a net radiative forcing of +17.87 ± 3.83 mW m⁻², indicating that methane-driven warming outweighs the initial ozone cooling. The rapid response is strongly regional: South and Southeast Asia (excluding China) contributes most by -2.96±0.78 mW m⁻² , driven by large emission reductions, efficient convective export, and high upper-tropospheric radiative sensitivity, with North and South America secondary. Because our experiment isolates the gas-phase NOₓ–O₃–OH–CH₄ pathway, it is an upper bound on the methane-mediated warming; co-reduced CO and volatile organic compounds and lower nitrate aerosol would offset part of it. NOₓ mitigation alone can cause delayed warming unless methane is concurrently controlled.
ER -