Global inventory of doubly substituted isotopologues of methane (Δ13CH3D and Δ12CH2D2)
Abstract
Measurements of methane (CH4) molecules containing two rare isotopes (13CH3D and 12CH2D2), also termed doubly substituted or "clumped" isotopologues, have the potential to provide two additional isotopic dimensions to help investigate the mechanisms underlying global atmospheric trends in CH4. In this work, we summarise the current state of research on doubly substituted CH4 isotopologues, with an emphasis on compiling results of all relevant work. The database comprises 1475 records compiled from the literature published until April 2025 (10.5285/51ae627da5fb41b8a767ee6c653f83e6, Defratyka et al., 2025). For field samples, 40 % of records were sourced from natural gas reservoirs, while microbial terrestrial (e.g., agriculture, lake, wetland) samples account only for 12.5 %. Lakes samples contribute 75 % to collected microbial terrestrial samples. There is limited or no representation of samples coming from significant microbial CH4 sources to the atmosphere, like wetlands, agricultural practices and landfills. To date, laboratory experiments were mostly focused on microbial (28 % of samples from laboratory experiments) and pyrogenic (15 %) methanogenesis or anaerobic (16 %), and aerobic (8 %) CH4 oxidation, with only single study of photochemical oxidation via OH and Cl, which constitutes 5 % of the laboratory experiments entries. The distinct ranges of Delta 13CH3D and Delta 12CH2D2 values measured in these studies suggests their potential to improve our understanding of atmospheric CH4. This work provides an overview of the major gaps in measurements and identifies where further studies should be focussed to enable the highest impact on understanding global CH4.
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BibTeX
@article{defratyka2026global,
title = {{Global inventory of doubly substituted isotopologues of methane (Δ13CH3D and Δ12CH2D2)}},
author = {Sara M. Defratyka and Julianne M. Fernandez and Getachew A. Adnew and Guannan Dong and Peter M. J. Douglas and Daniel L. Eldridge and Giuseppe Etiope and Thomas Giunta and Mojhgan A. Haghnegahdar and Alexander N. Hristov and Nicole Hultquist and Inaki Vadillo and Josue Jautzy and Ji-Hyun Kim and Jabrane Labidi and Ellen Lalk and Wil Leavitt and Jiawen Li and Li-Hung Lin and Jiarui Liu and Lucia Ojeda and Shuhei Ono and Jeemin H. Rhim and Thomas Rockmann and Barbara Sherwood Lollar and Malavika Sivan and Jiayang Sun and Gregory T. Ventura and David T. Wang and Edward D. Young and Naizhong Zhang and Tim Arnold},
journal = {Earth System Science Data},
year = {2026},
month = sep,
doi = {10.5194/essd-17-6889-2025},
url = {https://hal.science/hal-05454544v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Global inventory of doubly substituted isotopologues of methane (Δ13CH3D and Δ12CH2D2)
AU - Sara M. Defratyka
AU - Julianne M. Fernandez
AU - Getachew A. Adnew
AU - Guannan Dong
AU - Peter M. J. Douglas
AU - Daniel L. Eldridge
AU - Giuseppe Etiope
AU - Thomas Giunta
AU - Mojhgan A. Haghnegahdar
AU - Alexander N. Hristov
AU - Nicole Hultquist
AU - Inaki Vadillo
AU - Josue Jautzy
AU - Ji-Hyun Kim
AU - Jabrane Labidi
AU - Ellen Lalk
AU - Wil Leavitt
AU - Jiawen Li
AU - Li-Hung Lin
AU - Jiarui Liu
AU - Lucia Ojeda
AU - Shuhei Ono
AU - Jeemin H. Rhim
AU - Thomas Rockmann
AU - Barbara Sherwood Lollar
AU - Malavika Sivan
AU - Jiayang Sun
AU - Gregory T. Ventura
AU - David T. Wang
AU - Edward D. Young
AU - Naizhong Zhang
AU - Tim Arnold
PY - 2026
DA - 2026/09/04
JO - Earth System Science Data
DO - 10.5194/essd-17-6889-2025
UR - https://hal.science/hal-05454544v1
AB - Measurements of methane (CH4) molecules containing two rare isotopes (13CH3D and 12CH2D2), also termed doubly substituted or "clumped" isotopologues, have the potential to provide two additional isotopic dimensions to help investigate the mechanisms underlying global atmospheric trends in CH4. In this work, we summarise the current state of research on doubly substituted CH4 isotopologues, with an emphasis on compiling results of all relevant work. The database comprises 1475 records compiled from the literature published until April 2025 (10.5285/51ae627da5fb41b8a767ee6c653f83e6, Defratyka et al., 2025). For field samples, 40 % of records were sourced from natural gas reservoirs, while microbial terrestrial (e.g., agriculture, lake, wetland) samples account only for 12.5 %. Lakes samples contribute 75 % to collected microbial terrestrial samples. There is limited or no representation of samples coming from significant microbial CH4 sources to the atmosphere, like wetlands, agricultural practices and landfills. To date, laboratory experiments were mostly focused on microbial (28 % of samples from laboratory experiments) and pyrogenic (15 %) methanogenesis or anaerobic (16 %), and aerobic (8 %) CH4 oxidation, with only single study of photochemical oxidation via OH and Cl, which constitutes 5 % of the laboratory experiments entries. The distinct ranges of Delta 13CH3D and Delta 12CH2D2 values measured in these studies suggests their potential to improve our understanding of atmospheric CH4. This work provides an overview of the major gaps in measurements and identifies where further studies should be focussed to enable the highest impact on understanding global CH4.
SN - 1866-3508
SN - 1866-3516
ER -