idw – Informationsdienst Wissenschaft
Nachrichten, Termine, Experten
Nachrichten, Termine, Experten
An international consortium of multi-disciplinary scientists has compiled a synthesis of the global methane budget, documenting and analyzing its enigmatic changes since the year 2000. Unlike carbon dioxide, in the late 1990s the growth rate of methane slowed to zero, and scientists struggled to explain this unexpected change. After a period of stability until around 2006, the amount of methane in the atmosphere began to rise again. Since 2014 atmospheric methane concentrations are rising at a faster rate than at any time in the previous two decades, approaching the most greenhouse-gas-intensive scenarios proposed. The reasons for this increase are hotly debated.
The new comprehensive study, published today in Earth System Science Data, attributes the recent rapid rise in global methane concentrations to increased biogenic emissions, mostly from agriculture, rather than to increases from fossil fuels or wetlands. The study does not rule out the possibility that the rise might be in part due to a reduction of the chemical sink through which methane is destroyed in the atmosphere. A combination of top-down (atmospheric observations and inverse modeling using transport models) and bottom-up (land surface process models, inventories for anthropogenic emissions) approaches enabled the consortium to analyze and synthesize current knowledge about the global and regional methane budgets.
“One of the most difficult aspects of determining methane fluxes through atmospheric inversion is the fact that all the source categories and even the sinks are rather uncertain”, explains Julia Marshall of the Max Planck Institute for Biogeochemistry in Jena, Germany, who contributed model simulations to the study. “This has led to a variety of contradictory theories being put forward in the literature to explain both the flattening of the growth rate as well as the subsequent increase. Based upon the available measurements of atmospheric methane alone, it is difficult to convincingly prove a given theory. This is where the combination of top-down and bottom-up approaches, organized within the Global Carbon Project, can help constrain the problem.”
The study estimated the global methane emissions to be approximately 559 [540-570] TgCH4/yr over the period 2003-2012 through an ensemble of “top-down” approaches. The global methane sources are distributed across a range of categories, with approximately 60% considered to be anthropogenic, or directly attributable to human activity. Natural methane sources include wetlands and geologic seeps. Of the anthropogenic emissions, approximately 60% are due to agricultural activities and waste management, while approximately one third is linked to fossil fuel production and use.
Methane is a potent greenhouse gas, 28 times more powerful - per kg - than carbon dioxide on a 100-year time horizon, and its concentration in the atmosphere has increased by 150% since 1750, largely due to human activity.
Publication:
Marielle Saunois, Philippe Bousquet, Ben Poulter, Anna Peregon, Philippe Ciais, Josep G. Canadell, Edward J. Dlugokencky, Giuseppe Etiope, David Bastviken, Sander Houweling, Greet Janssens-Maenhout, Francesco N. Tubiello, Simona Castaldi, Robert B. Jackson, Mihai Alexe, Vivek K. Arora, David J. Beerling, Peter Bergamaschi, Donald R. Blake, Gordon Brailsford, Victor Brovkin, Lori Bruhwiler, Cyril Crevoisier, Patrick Crill, Kristofer Covey, Charles Curry, Christian Frankenberg, Nicola Gedney, Lena Höglund-Isaksson, Misa Ishizawa, Akihiko Ito, Fortunat Joos, Heon-Sook Kim, Thomas Kleinen, Paul Krummel, Jean-François Lamarque, Ray Langenfelds, Robin Locatelli, Toshinobu Machida, Shamil Maksyutov, Kyle C. McDonald, Julia Marshall, Joe R. Melton, Isamu Morino, Vaishali Naik, Simon O’Doherty, Frans-Jan W. Parmentier, Prabir K. Patra, Changhui Peng, Shushi Peng, Glen P. Peters, Isabelle Pison, Catherine Prigent, Ronald Prinn, Michel Ramonet, William J. Riley, Makoto Saito, Monia Santini, Ronny Schroeder, Isobel J. Simpson, Renato Spahni, Paul Steele, Atsushi Takizawa, Brett F. Thornton, Hanqin Tian, Yasunori Tohjima, Nicolas Viovy, Apostolos Voulgarakis, Michiel van Weele, Guido R. van der Werf, RayWeiss, Christine Wiedinmyer, David J. Wilton, Andy Wiltshire, Doug Worthy, Debra Wunch, Xiyan Xu, Yukio Yoshida, Bowen Zhang, Zhen Zhang, Qiuan Zhu (2016),
Global Methane budget 2000-2012. Earth System Science Data.
DOI:10.5194/essd-8-697-2016
Editorial:
Saunois M, RB Jackson, P Bousquet, B Poulter, JG Canadell 2016 The growing role of methane in anthropogenic climate change. Environmental Research Letters 11, 120207, doi: 10.1088/1748-9326/11/12/120207. http://iopscience.iop.org/article/10.1088/1748-9326/11/12/120207
Access:
● Data and figures: http://www.globalcarbonproject.org/methanebudget
● Data at CDIAC: http://cdiac.ornl.gov/GCP/methanebudget/2016/
Social media:
● Facebook https://www.facebook.com/globalcarbonproject
● Twitter: @gcarbonproject
● Infographics: http://www.globalcarbonatlas.org
Funding disclosure:
● Contributors to the Global Carbon Budget 2016 are funded by research organisations and government departments in multiple countries and supported by their organisations.
● The Global Carbon Atlas is funded by the BNP Paribas Foundation
Contact:
Julia Marshall
MPI for Biogeochemistry
07745 Jena, Germany
Phone: +49 (0)3641-57 6383
Email: marshall@bgc-jena.mpg.de
Livestock is a major source of anthropogenic methane emissions, through both manure management and e ...
Source: Photo: Susanne Héjja
Methane Budget - Key Messages
Criteria of this press release:
Journalists
Environment / ecology, Oceanology / climate
transregional, national
Research results, Scientific Publications
English
Livestock is a major source of anthropogenic methane emissions, through both manure management and e ...
Source: Photo: Susanne Héjja
You can combine search terms with and, or and/or not, e.g. Philo not logy.
You can use brackets to separate combinations from each other, e.g. (Philo not logy) or (Psycho and logy).
Coherent groups of words will be located as complete phrases if you put them into quotation marks, e.g. “Federal Republic of Germany”.
You can also use the advanced search without entering search terms. It will then follow the criteria you have selected (e.g. country or subject area).
If you have not selected any criteria in a given category, the entire category will be searched (e.g. all subject areas or all countries).
