Preindustrial (CH4)-C-14 indicates greater anthropogenic fossil CH4 emissions

doi:10.1038/s41586-020-1991-8

GSTDTAP > 地球科学

DOI	10.1038/s41586-020-1991-8
	Preindustrial (CH4)-C-14 indicates greater anthropogenic fossil CH4 emissions
	Keener, Megan 1; Hunt, Camden 1; Carroll, Timothy G.1; Kampel, Vladimir 2; Dobrovetsky, Roman 2; Hayton, Trevor W.1; Menard, Gabriel 1
	2020-02-19
发表期刊	NATURE
ISSN	0028-0836
EISSN	1476-4687
出版年	2020
卷号	578 期号:7795 页码:409-+
文章类型	Article
语种	英语
国家	USA; Australia; New Zealand; Switzerland; France
英文关键词	Atmospheric methane (CH4) is a potent greenhouse gas, and its mole fraction has more than doubled since the preindustrial era(1). Fossil fuel extraction and use are among the largest anthropogenic sources of CH4 emissions, but the precise magnitude of these contributions is a subject of debate(2,3). Carbon-14 in CH4 ((CH4)-C-14) can be used to distinguish between fossil (C-14-free) CH4 emissions and contemporaneous biogenic sources however, poorly constrained direct (CH4)-C-14 emissions from nuclear reactors have complicated this approach since the middle of the 20th century(4,5). Moreover, the partitioning of total fossil CH4 emissions (presently 172 to 195 teragrams CH4 per year)(2,3) between anthropogenic and natural geological sources (such as seeps and mud volcanoes) is under debate emission inventories suggest that the latter account for about 40 to 60 teragrams CH4 per year(6,7). Geological emissions were less than 15.4 teragrams CH4 per year at the end of the Pleistocene, about 11,600 years ago(8), but that period is an imperfect analogue for present-day emissions owing to the large terrestrial ice sheet cover, lower sea level and extensive permafrost. Here we use preindustrial-era ice core (CH4)-C-14 measurements to show that natural geological CH4 emissions to the atmosphere were about 1.6 teragrams CH4 per year, with a maximum of 5.4 teragrams CH4 per year (95 per cent confidence limit)-an order of magnitude lower than the currently used estimates. This result indicates that anthropogenic fossil CH4 emissions are underestimated by about 38 to 58 teragrams CH4 per year, or about 25 to 40 per cent of recent estimates. Our record highlights the human impact on the atmosphere and climate, provides a firm target for inventories of the global CH4 budget, and will help to inform strategies for targeted emission reductions(9,10). Isotopic evidence from ice cores indicates that preindustrial-era geological methane emissions were lower than previously thought, suggesting that present-day emissions of methane from fossil fuels are underestimated.
领域	地球科学 ; 气候变化 ; 资源环境
收录类别	SCI-E
WOS记录号	WOS:000527042100005
WOS关键词	METHANE EMISSIONS ; GAS CONCENTRATIONS ; ICE ; FIRN ; RADIOCARBON ; BUDGET
WOS类目	Multidisciplinary Sciences
WOS研究方向	Science & Technology - Other Topics
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引用统计
文献类型	期刊论文
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/249266
专题	地球科学资源环境科学
作者单位	1.Univ Calif Santa Barbara, Dept Chem & Biochem, Santa Barbara, CA 93106 USA; 2.Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Chem, Tel Aviv, Israel
推荐引用方式 GB/T 7714	Keener, Megan,Hunt, Camden,Carroll, Timothy G.,et al. Preindustrial (CH4)-C-14 indicates greater anthropogenic fossil CH4 emissions[J]. NATURE,2020,578(7795):409-+.
APA	Keener, Megan.,Hunt, Camden.,Carroll, Timothy G..,Kampel, Vladimir.,Dobrovetsky, Roman.,...&Menard, Gabriel.(2020).Preindustrial (CH4)-C-14 indicates greater anthropogenic fossil CH4 emissions.NATURE,578(7795),409-+.
MLA	Keener, Megan,et al."Preindustrial (CH4)-C-14 indicates greater anthropogenic fossil CH4 emissions".NATURE 578.7795(2020):409-+.