Using global isotopic data to constrain the role of shale gas production in recent increases in atmospheric methane
Autor: | S. Schwietzke, Owen A. Sherwood, Giuseppe Etiope, Grant Allen, Alexei V. Milkov |
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Jazyk: | angličtina |
Rok vydání: | 2020 |
Předmět: |
Solid Earth sciences
010504 meteorology & atmospheric sciences Shale gas lcsh:Medicine Wetland 010501 environmental sciences Atmospheric sciences 01 natural sciences Article Methane Atmosphere chemistry.chemical_compound Shale oil General lcsh:Science 0105 earth and related environmental sciences geography Multidisciplinary geography.geographical_feature_category Atmospheric methane lcsh:R Carbon cycle Biogeochemistry Chemistry Isotopic ratio chemistry Environmental science lcsh:Q Oil shale |
Zdroj: | Scientific Reports, Vol 10, Iss 1, Pp 1-7 (2020) Milkov, A V, Schwietzke, S, Allen, G, Sherwood, O A & Etiope, G 2020, ' Using global isotopic data to constrain the role of shale gas production in recent increases in atmospheric methane ', Scientific Reports, vol. 10, no. 1, 4199 . https://doi.org/10.1038/s41598-020-61035-w Scientific Reports |
ISSN: | 2045-2322 |
Popis: | The accelerated increase in global methane (CH4) in the atmosphere, accompanied by a decrease in its 13C/12C isotopic ratio (δ13CCH4) from −47.1‰ to −47.3‰ observed since 2008, has been attributed to increased emissions from wetlands and cattle, as well as from shale gas and shale oil developments. To date both explanations have relied on poorly constrained δ13CCH4 source signatures. We use a dataset of δ13CCH4 from >1600 produced shale gas samples from regions that account for >97% of global shale gas production to constrain the contribution of shale gas emissions to observed atmospheric increases in the global methane burden. We find that US shale gas extracted since 2008 has volume-weighted-average δ13CCH4 of −39.6‰. The average δ13CCH4 weighted by US basin-level measured emissions in 2015 was −41.8‰. Therefore, emission increases from shale gas would contribute to an opposite atmospheric δ13CCH4 signal in the observed decrease since 2008 (while noting that the global isotopic trend is the net of all dynamic source and sink processes). This observation strongly suggests that changing emissions of other (isotopically-lighter) CH4 source terms is dominating the increase in global CH4 emissions. Although production of shale gas has increased rapidly since 2008, and CH4 emissions associated with this increased production are expected to have increased overall in that timeframe, the simultaneously-observed increase in global atmospheric CH4 is not dominated by emissions from shale gas and shale oil developments. |
Databáze: | OpenAIRE |
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