Why methane surged in the atmosphere during the early 2020s
- P. Ciais
- Y. Zhu
- Y. Cai
- X. Lan
- S. E. Michel
- B. Zheng
- Y. Zhao
- D. A. Hauglustaine
- X. Lin
- Y. Zhang
- S. Sun
- X. Tian
- M. Zhao
- Y. Wang
- J. Chang
- X. Dou
- Z. Liu
- R. Andrew
- C. A. Quinn
- B. Poulter
- Z. Ouyang
- W. Yuan
- K. Yuan
- Q. Zhu
- F. Li
- N. Pan
- H. Tian
- X. Yu
- G. Rocher-Ros
- M. S. Johnson
- M. Li
- D. Feng
- P. Raymond
- X. Yang
- J. G. Canadell
- R. B. Jackson
- Y. Li
- M. Saunois
- P. Bousquet
- S. Peng
2026-02-05
The atmospheric methane (CH 4 ) 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 CH 4 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 CH 4 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 CH 4 per year (TgCH 4 year −1 )] and then decreased between 2022 and 2023 (−9.9 ± 3.3 TgCH 4 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.