Satellite reveals a steep decline in China's CO 2 emissions in early 2022.

Response actions to the coronavirus disease 2019 perturbed economies and carbon dioxide (CO 2 ) emissions. The Omicron variant that emerged in 2022 caused more substantial infections than in 2020 and 2021 but it has not yet been ascertained whether Omicron interrupted the temporary post-2021 rebound of CO 2 emissions. Here, using satellite nitrogen dioxide observations combined with atmospheric inversion, we show a larger decline in China's CO 2 emissions between January and April 2022 than in those months during the first wave of 2020. China's CO 2 emissions are estimated to have decreased by 15% (equivalent to -244.3 million metric tons of CO 2 ) during the 2022 lockdown, greater than the 9% reduction during the 2020 lockdown. Omicron affected most of the populated and industrial provinces in 2022, hindering China's CO 2 emissions rebound starting from 2021. China's emission variations agreed with downstream CO 2 concentration changes, indicating a potential to monitor CO 2 emissions by integrating satellite and ground measurements.