TY - JOUR AB - 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 CH4yr−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 in AU - Saunois,M AU - Bousquet,P AU - Poulter,B AU - Peregon,A AU - Ciais,P AU - Canadell,JG AU - Dlugokencky,EJ AU - Etiope,G AU - Bastviken,D AU - Houweling,S AU - Janssens-Maenhout,G AU - Tubiello,FN AU - Castaldi,S AU - Jackson,RB AU - Alexe,M AU - Arora,VK AU - Beerling,DJ AU - Bergamaschi,P AU - Blake,DR AU - Brailsford,G AU - Bruhwiler,L AU - Crevoisier,C AU - Crill,P AU - Covey,K AU - Frankenberg,C AU - Gedney,N AU - Hoeglund-Isaksson,L AU - Ishizawa,M AU - Ito,A AU - Joos,F AU - Kim,H-S AU - Kleinen,T AU - Krummel,P AU - Lamarque,J-F AU - Langenfelds,R AU - Locatelli,R AU - Machida,T AU - Maksyutov,S AU - Melton,JR AU - Morino,I AU - Naik,V AU - O'Doherty,S AU - Parmentier,F-J AU - Patra,PK AU - Peng,C AU - Peng,S AU - Peters,GP AU - Pison,I AU - Prinn,R AU - Ramonet,M AU - Riley,WJ AU - Saito,M AU - Santini,M AU - Schroeder,R AU - Simpson,IJ AU - Spahni,R AU - Takizawa,A AU - Thornton,BF AU - Tian,H AU - Tohjima,Y AU - Viovy,N AU - Voulgarakis,A AU - Weiss,R AU - Wilton,DJ AU - Wiltshire,A AU - Worthy,D AU - Wunch,D AU - Xu,X AU - Yoshida,Y AU - Zhang,B AU - Zhang,Z AU - Zhu,Q DO - 10.5194/acp-17-11135-2017 EP - 11161 PY - 2017/// SN - 1680-7316 SP - 11135 TI - Variability and quasi-decadal changes in the methane budget over the period 2000-2012 T2 - Atmospheric Chemistry and Physics UR - http://dx.doi.org/10.5194/acp-17-11135-2017 UR - http://hdl.handle.net/10044/1/55004 VL - 17 ER -