Why methane surged in the atmosphere during the early 2020s [Research article summary]
Pourquoi le méthane a-t-il connu une forte augmentation dans l'atmosphère au début des années 2020 ? [Résumé d'un article de recherche]
Ciais, P. ; Zhu, Y. ; Cai, Y. ; Lan, X. ; Michel, S. E. ; Zheng, B. ; Zhao, Y. ; Hauglustaine, D. A. ; Lin, X. ; Zhang, Y. ; Sun, S. ; Tian, X. ; Zhao, M. ; Wang, Y. ; Chang, J. ; Dou, X. ; Liu, Z. ; Andrew, R. ; Quinn, C. A. ; Poulter, B. ; Ouyang, Z. ; Yuan, W. ; Yuan, K. ; Zhu, Q. ; Li, F. ; Pan, N. ; Tian, H. ; Yu, X. ; Rocher-Ros, G. ; Johnson, M. S. ; Li, M. ; Feng, D. ; Raymond, P. ; Yang, X. ; Canadell, J. G. ; Jackson, R. B. ; Li, Y. ; Saunois, M. ; Bousquet, P. ; Peng, S.
Année de publication
2026
The atmospheric methane (CH4) growth rate surged after 2019, peaking at 16.2 parts per billion per year (ppb year?1) in 2020 before declining to 8.6 ppb year?1 in 2023. Using multiple atmospheric inversions constrained by observation- and model-based prescribed hydroxyl radical (OH) fields and CH4 atmospheric data, we show that a drop of OH radicals in 2020-2021, followed by recovery in 2022-2023, accounted for 83% of year-on-year variations in the CH4 growth rate, the rest being explained by wetland and inland water emissions, which increased between 2019 and 2020-2022 [+8.6 ± 2.6 teragrams of CH4 per year (TgCH4 year?1)] and then decreased between 2022 and 2023 (?9.9 ± 3.3 TgCH4 year?1). Most emission changes from 2019 to 2023 occurred in northern tropical wetlands in Africa and Asia, whereas South American wetlands emissions declined and Arctic emissions increased after 2019.</div>
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