Nisbet, Euan G.; Manning, Martin R.; Dlugokencky, Ed J.; Michel, Sylvia Englund; Lan, Xin; Röckmann, Thomas; Denier van der Gon, Hugo A. C.; Schmitt, Jochen; Palmer, Paul I.; Dyonisius, Michael N.; Oh, Youmi; Fisher, Rebecca E.; Lowry, David; France, James L.; White, James W. C.; Brailsford, Gordon; Bromley, Tony (2023). Atmospheric Methane: Comparison Between Methane's Record in 2006–2022 and During Glacial Terminations. Global biogeochemical cycles, 37(8) American Geophysical Union 10.1029/2023GB007875
|
Text
Nisbet_CH4_budget_2006_2022_GBC_23.pdf - Published Version Available under License Creative Commons: Attribution (CC-BY). Download (2MB) | Preview |
Atmospheric methane's rapid growth from late 2006 is unprecedented in the observational record.
Assessment of atmospheric methane data attributes a large fraction of this atmospheric growth to increased natural emissions over the tropics, which appear to be responding to changes in anthropogenic climate forcing.
Isotopically lighter measurements of d13C-CH4 are consistent with the recent atmospheric methane growth being mainly driven by an increase in emissions from microbial sources, particularly wetlands. The global methane budget is currently in disequilibrium and new inputs are as yet poorly quantified. Although microbial emissions from agriculture and waste sources have increased between 2006 and 2022 by perhaps 35 Tg/yr, with wide uncertainty, approximately another 35–45 Tg/yr of the recent net growth in methane emissions may have been driven by natural biogenic processes, especially wetland feedbacks to climate change. A model comparison shows that recent changes may be comparable or greater in scale and speed than methane's growth and isotopic shift during past glacial/interglacial termination events. It remains possible that methane's current growth is within the range of Holocene variability, but it is also possible that methane's recent growth and isotopic shift may indicate a large-scale reorganization of the natural climate and biosphere is under way.
Item Type: |
Journal Article (Original Article) |
---|---|
Division/Institute: |
08 Faculty of Science > Physics Institute > Climate and Environmental Physics 10 Strategic Research Centers > Oeschger Centre for Climate Change Research (OCCR) 08 Faculty of Science > Physics Institute |
UniBE Contributor: |
Schmitt, Jochen |
Subjects: |
500 Science > 530 Physics 500 Science > 550 Earth sciences & geology 500 Science > 570 Life sciences; biology |
ISSN: |
0886-6236 |
Publisher: |
American Geophysical Union |
Language: |
English |
Submitter: |
Jochen Schmitt |
Date Deposited: |
09 Aug 2023 06:55 |
Last Modified: |
09 Aug 2023 07:01 |
Publisher DOI: |
10.1029/2023GB007875 |
BORIS DOI: |
10.48350/185311 |
URI: |
https://boris.unibe.ch/id/eprint/185311 |