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TobiasBiermann.jpg

Tobias Biermann

Research engineer

TobiasBiermann.jpg

Multi-observational estimation of regional and sectoral emission contributions to the persistent high growth rate of atmospheric CH4 for 2020-2022

Author

  • Yosuke Niwa
  • Yasunori Tohjima
  • Yukio Terao
  • Tazu Saeki
  • Akihiko Ito
  • Taku Umezawa
  • Kyohei Yamada
  • Motoki Sasakawa
  • Toshinobu Machida
  • Shin Ichiro Nakaoka
  • Hideki Nara
  • Hiroshi Tanimoto
  • Hitoshi Mukai
  • Yukio Yoshida
  • Shinji Morimoto
  • Shinya Takatsuji
  • Kazuhiro Tsuboi
  • Yousuke Sawa
  • Hidekazu Matsueda
  • Kentaro Ishijima
  • Ryo Fujita
  • Daisuke Goto
  • Xin Lan
  • Kenneth Schuldt
  • Michal Heliasz
  • Tobias Biermann
  • Lukasz Chmura
  • Jarsolaw Necki
  • Irène Xueref-Remy
  • Damiano Sferlazzo
Show all

Summary, in English

Atmospheric methane (CH4) growth rates reached unprecedented values in the years 2020-2022. To identify the main drivers of this increase, an inverse modeling study estimated regional and sectoral emission changes for 2016-2022. Three inverse estimates based on different sets of atmospheric CH4 observations (surface observations only, surface and aircraft observations, and GOSAT observations) consistently suggest notable emission increases from 2016-2019 to 2020-2022 in the tropics (15° S-10° N) (10-18 Tg CH4 yr-1) and in northern low latitudes (10-35° N) (ca. 20 Tg CH4 yr-1), the latter of which likely contributed to the growth rate surge from 2020. The emission increase in the northern low latitudes is attributed to emissions in South Asia and northern Southeast Asia, which abruptly increased from 2019 to 2020, and elevated emissions continued until 2022. Meanwhile, the tropical emission increase is dominated by Tropical South America and Central Africa, but emissions were continuously increasing before 2019. Agreement was found in the sectoral estimates of the three inversions in the tropics and northern low latitudes, suggesting the largest contribution of biogenic emissions. Uncertainty reductions demonstrate that the flux estimates in Asia are well constrained by surface and aircraft observations. Furthermore, a sensitivity test with the probable reduction of OH radicals showed smaller emissions by up to 2-3 Tg CH4 yr-1 in each Asian region for 2020, still suggesting notable emission contributions. These results highlight the importance of biogenic emissions in Asian regions for the persistent high growth rate observed during 2020-2022.

Department/s

  • Centre for Environmental and Climate Science (CEC)
  • BECC: Biodiversity and Ecosystem services in a Changing Climate

Publishing year

2025

Language

English

Pages

6757-6785

Publication/Series

Atmospheric Chemistry and Physics

Volume

25

Issue

13

Document type

Article

Publisher

Copernicus GmbH

Topic

  • Climate Science
  • Meteorology and Atmospheric Sciences

Keywords

  • SDG 13 - Climate Action

Status

Published

ISBN/ISSN/Other

  • ISSN: 1680-7316