Regional trends and drivers of the global methane budget

The ongoing development of the GCP global methane (CH4) budget shows a continuation of increasing CH4 emissions and CH4 accumulation in the atmosphere over 2000-2017. Here we decompose the global budget into 19 regions (18 land and 1 oceanic) and five key source sectors to attribute the observed global trends spatially. A comparison of top-down (atmospheric-based) and bottom-up (inventory- and model-based) CH4 emission estimates demonstrates robust temporal trends with CH4 emissions increasing in 16 of the 19 regions. Five regions - China, Southeast Asia, USA, South Asia, and Brazil - account for > 40% of the global total (the sum of anthropogenic and natural sources) CH4 emissions (together totalling >250 Tg CH4 yr-1 in 2008-2017). Two of these regions, China and South Asia, emit predominantly anthropogenic emissions (> 75%) and together produce > 25% of global anthropogenic emissions; the other three regions have a more balanced mix of anthropogenic and natural emissions. Globally the tropical band (30°N to 30°S) contributes more than half of all CH4 emissions and is dominated by agricultural, waste and wetland emissions with absolute emissions increasing proportionally with the global total between 2000 and 2017. China and the Middle East show the most rapid increase in total emission rates over the 2000 to 2017 period with emissions increasing by > 20%. In contrast, two regions, Europe and Korea & Japan, show a steady decline in CH4 emission rates, with total emissions decreasing by ~10% between 2000 and 2017. Livestock (especially enteric fermentation), waste (predominantly solid waste disposal) and coal are common drivers of both emissions increases and declines making these sectors both the greatest risks of increasing the atmospheric CH4 burden and the greatest opportunities for greenhouse gas abatement.

STAVERT Ann;  SAUNOIS Marielle;  CANADELL Josep G.;  POULTER Benjamin;  JACKSON Robert B.;  REGNIER Pierre;  LAUERWALD Ronny;  RAYMOND P.;  ALLEN G.;  PATRA Prabir;  BERGAMASCHI Peter;  BOUSQUET Philippe;  CHANDRA Naveen;  CIAIS Philippe;  GUSTAFSON Adrian;  ISHIZAWA Misa;  ITO Akihiko;  KLEINEN Thomas;  MAKSYUTOV Shamil;  MCNORTON Joe;  MELTON Joe R.;  MÜLLER Jurek;  NIWA Y;  PENG Shushi;  RILEY William J.;  SEGERS Arjo;  TIAN Hanqin;  TSURUTA Aki;  YIN Yi;  ZHANG Zhen;  ZHENG Bo;  ZHUANG Qianlai; 

2021-12-13

WILEY

JRC122220

1354-1013 (online),   

https://onlinelibrary.wiley.com/doi/10.1111/gcb.15901,    https://publications.jrc.ec.europa.eu/repository/handle/JRC122220,   

10.1111/gcb.15901 (online),