Variability and quasi-decadal changes in the methane budget over the period 2000–2012
Marielle Saunois
(1, 2)
,
Philippe Bousquet
(1, 2)
,
Ben Poulter
(3)
,
Anna Peregon
(1)
,
Philippe Ciais
(1, 4)
,
Josep Canadell
(5)
,
Edward Dlugokencky
(6)
,
Giuseppe Etiope
(7)
,
David Bastviken
(8)
,
Sander Houweling
(9)
,
Greet Janssens-Maenhout
(10)
,
Francesco Tubiello
(11)
,
Simona Castaldi
(12)
,
Robert Jackson
(13)
,
Mihai Alexe
(14)
,
Vivek Arora
(15)
,
David Beerling
(16)
,
Peter Bergamaschi
(10)
,
Donald Blake
(17)
,
Gordon Brailsford
(18)
,
Lori Bruhwiler
(6)
,
Cyril Crevoisier
(19)
,
Patrick Crill
(20)
,
Kristofer Covey
(21)
,
Christian Frankenberg
(22)
,
Nicola Gedney
(23)
,
Lena Höglund-Isaksson
(24)
,
Misa Ishizawa
(25)
,
Akihiko Ito
(25)
,
Fortunat Joos
(26)
,
Heon-Sook Kim
(25)
,
Thomas Kleinen
(27)
,
Paul Krummel
,
Jean-François Lamarque
(28)
,
Ray Langenfelds
,
Robin Locatelli
(1)
,
Toshinobu Machida
(25)
,
Shamil Maksyutov
(25)
,
Joe Melton
(29)
,
Isamu Morino
(25)
,
Vaishali Naik
(30)
,
Simon O'Doherty
(31)
,
Frans-Jan Parmentier
(32)
,
Prabir Patra
(33)
,
Changhui Peng
(34)
,
Shushi Peng
(35)
,
Glen Peters
(36)
,
Isabelle Pison
(1, 37)
,
Ronald Prinn
(38)
,
Michel Ramonet
(1, 37)
,
William Riley
(39)
,
Makoto Saito
(25)
,
Monia Santini
(40)
,
Ronny Schroeder
(41)
,
Isobel Simpson
(17)
,
Renato Spahni
(26)
,
Atsushi Takizawa
(42)
,
Brett Thornton
(20)
,
Hanqin Tian
(43)
,
Yasunori Tohjima
(25)
,
Nicolas Viovy
(1, 44)
,
Apostolos Voulgarakis
(45)
,
Ray F. Weiss
(46)
,
David Wilton
(47)
,
Andy Wiltshire
(48)
,
Doug Worthy
(49)
,
Debra Wunch
(50)
,
Xiyan Xu
,
Yukio Yoshida
(25)
,
Bowen Zhang
(51)
,
Zhen Zhang
(52)
,
Qiuan Zhu
(53)
1
LSCE -
Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]
2 SATINV - Modélisation INVerse pour les mesures atmosphériques et SATellitaires
3 GSFC - NASA Goddard Space Flight Center
4 ICOS-ATC - ICOS-ATC
5 CSIRO - Oceans and Atmosphere Flagship
6 ESRL - NOAA Earth System Research Laboratory
7 INGV - Istituto Nazionale di Geofisica e Vulcanologia - Sezione di Bologna
8 The Department of Thematic Studies - Water and Environmental Studies
9 SRON - SRON Netherlands Institute for Space Research
10 IES - JRC Institute for Environment and Sustainability
11 FAO - Food and Agriculture Organization of the United Nations, Regional Office for the Near East and North Africa
12 Seconda Università degli Studi di Napoli = Second University of Naples
13 Stanford University
14 JRC - European Commission - Joint Research Centre [Ispra]
15 CCCma - Canadian Centre for Climate Modelling and Analysis
16 Department of Animal and Plant Sciences
17 UC Irvine - University of California [Irvine]
18 NIWA - National Institute of Water and Atmospheric Research [Wellington]
19 LMD - Laboratoire de Météorologie Dynamique (UMR 8539)
20 Bolin Centre for Climate Research
21 Yale University [New Haven]
22 JPL - Jet Propulsion Laboratory
23 JCHMR - Joint Centre for Hydro-Meteorological Research, Met Office Hadley Centre
24 IIASA - International Institute for Applied Systems Analysis [Laxenburg]
25 NIES - National Institute for Environmental Studies
26 CEP - Climate and Environmental Physics [Bern]
27 MPI-M - Max Planck Institute for Meteorology
28 NCAR - National Center for Atmospheric Research [Boulder]
29 ECCC - Environment and Climate Change Canada
30 NOAA - National Oceanic and Atmospheric Administration
31 University of Bristol [Bristol]
32 UiT - The Arctic University of Norway [Tromsø, Norway]
33 JAMSTEC - Japan Agency for Marine-Earth Science and Technology
34 CEREGE - Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement
35 Peking University [Beijing]
36 CICERO - Center for International Climate and Environmental Research [Oslo]
37 ICOS-RAMCES - ICOS-RAMCES
38 MIT - Massachusetts Institute of Technology
39 LBNL - Lawrence Berkeley National Laboratory [Berkeley]
40 FEFU - Far Eastern Federal University [Vladivostok]
41 UNH - University of New Hampshire
42 JMA - Japan Meteorological Agency
43 SDAU - Shandong Agricultural University
44 MOSAIC - Modélisation des Surfaces et Interfaces Continentales
45 Department of Physics [Imperial College London]
46 SIO - UC San Diego - Scripps Institution of Oceanography
47 University of Sheffield [Sheffield]
48 MOHC - Met Office Hadley Centre
49 Climate Research Division [Toronto]
50 CALTECH - California Institute of Technology
51 USC Viterbi School of Engineering
52 Swiss Federal Research Institute
53 Northwest A and F University
2 SATINV - Modélisation INVerse pour les mesures atmosphériques et SATellitaires
3 GSFC - NASA Goddard Space Flight Center
4 ICOS-ATC - ICOS-ATC
5 CSIRO - Oceans and Atmosphere Flagship
6 ESRL - NOAA Earth System Research Laboratory
7 INGV - Istituto Nazionale di Geofisica e Vulcanologia - Sezione di Bologna
8 The Department of Thematic Studies - Water and Environmental Studies
9 SRON - SRON Netherlands Institute for Space Research
10 IES - JRC Institute for Environment and Sustainability
11 FAO - Food and Agriculture Organization of the United Nations, Regional Office for the Near East and North Africa
12 Seconda Università degli Studi di Napoli = Second University of Naples
13 Stanford University
14 JRC - European Commission - Joint Research Centre [Ispra]
15 CCCma - Canadian Centre for Climate Modelling and Analysis
16 Department of Animal and Plant Sciences
17 UC Irvine - University of California [Irvine]
18 NIWA - National Institute of Water and Atmospheric Research [Wellington]
19 LMD - Laboratoire de Météorologie Dynamique (UMR 8539)
20 Bolin Centre for Climate Research
21 Yale University [New Haven]
22 JPL - Jet Propulsion Laboratory
23 JCHMR - Joint Centre for Hydro-Meteorological Research, Met Office Hadley Centre
24 IIASA - International Institute for Applied Systems Analysis [Laxenburg]
25 NIES - National Institute for Environmental Studies
26 CEP - Climate and Environmental Physics [Bern]
27 MPI-M - Max Planck Institute for Meteorology
28 NCAR - National Center for Atmospheric Research [Boulder]
29 ECCC - Environment and Climate Change Canada
30 NOAA - National Oceanic and Atmospheric Administration
31 University of Bristol [Bristol]
32 UiT - The Arctic University of Norway [Tromsø, Norway]
33 JAMSTEC - Japan Agency for Marine-Earth Science and Technology
34 CEREGE - Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement
35 Peking University [Beijing]
36 CICERO - Center for International Climate and Environmental Research [Oslo]
37 ICOS-RAMCES - ICOS-RAMCES
38 MIT - Massachusetts Institute of Technology
39 LBNL - Lawrence Berkeley National Laboratory [Berkeley]
40 FEFU - Far Eastern Federal University [Vladivostok]
41 UNH - University of New Hampshire
42 JMA - Japan Meteorological Agency
43 SDAU - Shandong Agricultural University
44 MOSAIC - Modélisation des Surfaces et Interfaces Continentales
45 Department of Physics [Imperial College London]
46 SIO - UC San Diego - Scripps Institution of Oceanography
47 University of Sheffield [Sheffield]
48 MOHC - Met Office Hadley Centre
49 Climate Research Division [Toronto]
50 CALTECH - California Institute of Technology
51 USC Viterbi School of Engineering
52 Swiss Federal Research Institute
53 Northwest A and F University
Philippe Bousquet
- Fonction : Auteur
- PersonId : 966349
- IdHAL : philippe-bousquet
Philippe Ciais
- Fonction : Auteur
- PersonId : 756308
- ORCID : 0000-0001-8560-4943
- IdRef : 092241700
Josep Canadell
- Fonction : Auteur
- PersonId : 791004
- ORCID : 0000-0002-8788-3218
David Bastviken
- Fonction : Auteur
- PersonId : 887430
Sander Houweling
- Fonction : Auteur
- PersonId : 783792
- ORCID : 0000-0002-6189-1009
Greet Janssens-Maenhout
- Fonction : Auteur
- PersonId : 769265
- ORCID : 0000-0002-9335-0709
Francesco Tubiello
- Fonction : Auteur
- PersonId : 791875
- ORCID : 0000-0003-4617-4690
Peter Bergamaschi
- Fonction : Auteur
- PersonId : 966348
Christian Frankenberg
- Fonction : Auteur
- PersonId : 773097
- ORCID : 0000-0002-0546-5857
Akihiko Ito
- Fonction : Auteur
- PersonId : 759293
- ORCID : 0000-0001-5265-0791
Fortunat Joos
- Fonction : Auteur
- PersonId : 757568
- ORCID : 0000-0002-9483-6030
Paul Krummel
- Fonction : Auteur
- PersonId : 797408
- ORCID : 0000-0002-4884-3678
Ray Langenfelds
- Fonction : Auteur
Isamu Morino
- Fonction : Auteur
- PersonId : 777338
- ORCID : 0000-0003-2720-1569
Prabir Patra
- Fonction : Auteur
- PersonId : 769314
- ORCID : 0000-0001-5700-9389
Shushi Peng
- Fonction : Auteur
- PersonId : 770092
- ORCID : 0000-0001-5098-726X
Glen Peters
- Fonction : Auteur
- PersonId : 776412
- ORCID : 0000-0001-7889-8568
- IdRef : 138519307
Michel Ramonet
- Fonction : Auteur
- PersonId : 180817
- IdHAL : michel-ramonet
- ORCID : 0000-0003-1157-1186
- IdRef : 199680809
Hanqin Tian
- Fonction : Auteur
- PersonId : 760801
- ORCID : 0000-0002-1806-4091
Nicolas Viovy
- Fonction : Auteur
- PersonId : 758722
- ORCID : 0000-0002-9197-6417
- IdRef : 159358914
Andy Wiltshire
- Fonction : Auteur
- PersonId : 791717
- ORCID : 0000-0001-7307-173X
Debra Wunch
- Fonction : Auteur
- PersonId : 795588
- ORCID : 0000-0002-4924-0377
Xiyan Xu
- Fonction : Auteur
Zhen Zhang
- Fonction : Auteur
- PersonId : 767884
- ORCID : 0000-0002-9704-6472
- IdRef : 204542138
Résumé
Following the recent Global Carbon Project (GCP) synthesis of the decadal methane (CH4) budget over 2000–2012 (Saunois et al., 2016), we analyse here the same dataset with a focus on quasi-decadal and inter-annual variability in CH4 emissions. The GCP dataset integrates results from top-down studies (exploiting atmospheric observations within an atmospheric inverse-modelling framework) and bottom-up models (including process-based models for estimating land surface emissions and atmospheric chemistry), inventories of anthropogenic emissions, and data-driven approaches.
The annual global methane emissions from top-down studies, which by construction match the observed methane growth rate within their uncertainties, all show an increase in total methane emissions over the period 2000–2012, but this increase is not linear over the 13 years. Despite differences between individual studies, the mean emission anomaly of the top-down ensemble shows no significant trend in total methane emissions over the period 2000–2006, during the plateau of atmospheric methane mole fractions, and also over the period 2008–2012, during the renewed atmospheric methane increase. However, the top-down ensemble mean produces an emission shift between 2006 and 2008, leading to 22 [16–32] Tg CH4 yr−1 higher methane emissions over the period 2008–2012 compared to 2002–2006. This emission increase mostly originated from the tropics, with a smaller contribution from mid-latitudes and no significant change from boreal regions.
The regional contributions remain uncertain in top-down studies. Tropical South America and South and East Asia seem to contribute the most to the emission increase in the tropics. However, these two regions have only limited atmospheric measurements and remain therefore poorly constrained.
The sectorial partitioning of this emission increase between the periods 2002–2006 and 2008–2012 differs from one atmospheric inversion study to another. However, all top-down studies suggest smaller changes in fossil fuel emissions (from oil, gas, and coal industries) compared to the mean of the bottom-up inventories included in this study. This difference is partly driven by a smaller emission change in China from the top-down studies compared to the estimate in the Emission Database for Global Atmospheric Research (EDGARv4.2) inventory, which should be revised to smaller values in a near future. We apply isotopic signatures to the emission changes estimated for individual studies based on five emission sectors and find that for six individual top-down studies (out of eight) the average isotopic signature of the emission changes is not consistent with the observed change in atmospheric 13CH4. However, the partitioning in emission change derived from the ensemble mean is consistent with this isotopic constraint. At the global scale, the top-down ensemble mean suggests that the dominant contribution to the resumed atmospheric CH4 growth after 2006 comes from microbial sources (more from agriculture and waste sectors than from natural wetlands), with an uncertain but smaller contribution from fossil CH4 emissions. In addition, a decrease in biomass burning emissions (in agreement with the biomass burning emission databases) makes the balance of sources consistent with atmospheric 13CH4 observations.
In most of the top-down studies included here, OH concentrations are considered constant over the years (seasonal variations but without any inter-annual variability). As a result, the methane loss (in particular through OH oxidation) varies mainly through the change in methane concentrations and not its oxidants. For these reasons, changes in the methane loss could not be properly investigated in this study, although it may play a significant role in the recent atmospheric methane changes as briefly discussed at the end of the paper.
| Origine | Fichiers éditeurs autorisés sur une archive ouverte |
|---|
Loading...
