The urgent need to cut methane emissions.
The urgent need to cut methane emissions.
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DOI：
10.1093/nsr/nwab221
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发表时间：
2022-05
影响因子：
20.6
通讯作者：
中科院分区：
文献类型：
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作者：
大气甲烷是一种强大的温室气体，其对人类增加的变暖影响仅次于二氧化碳。从工业化开始，当人类开始改变空气时，大气中甲烷的数量比二氧化碳的数量增加得更多。2020年，甲烷的增长是详细观测记录中最高的（图1）。但是，尽管对全球甲烷预算[1]进行了大量研究，但我们并不完全理解为什么最近会出现这种增长，也不完全理解为什么增长似乎越来越强劲[2，3]。甲烷的增加是由新的人类排放造成的吗？反馈是否在推动自然排放的增加，因为变暖会导致变暖？或者是发生了什么事情，减少了大气的氧化能力，从而削弱了主要的甲烷汇，大气羟基的破坏？在这个问题上，Zhang et al. [4]利用源估计和同位素源特征调查甲烷增长的原因。碳有两种稳定的同位素，常见的碳12和不太常见的碳13。甲烷源具有独特的碳同位素特征，表示为δ 13 CCH 4，这是与碳酸盐标准进行比较的一种措施。甲烷在2007年后的近期增长的特点是δ 13 CCH 4持续向更负的方向转变[3]。来自湿地、牲畜、垃圾填埋场等的生物甲烷，相对来说，甲烷的碳-13含量较低（即δ 13 CCH 4非常负），而来自地质来源和火灾产生的热成因甲烷往往相对富含碳-13（即δ 13 CCH 4负值较小）。
Atmospheric methane is a powerful greenhouse gas, surpassed only by CO2 in its human-added warming impact. From the start of industrialization, when humans began altering the air, the amount of methane in the atmosphere has grown proportionately more than CO2. In 2020, methane’s growth was the highest in the detailed observational record (Fig. 1). But although there has been much work on the global methane budget [1], we do not fully understand why this recent growth is taking place, nor why growth seems to be increasingly strong [2, 3]. Is methane’s rise driven by new human emissions? Are feedbacks driving increased natural emissions as warming feeds warming? Or is something happening to reduce the oxidative power of the atmosphere and thus weaken the main methane sink, destruction by atmospheric hydroxyl, OH? In this issue, Zhang et al.[4] investigate the causes of methane growth by using both source estimates and isotopic source signatures. Carbon has two stable isotopes—common carbon-12 and less common carbon-13. Methane sources have distinctive carbon isotopic signatures, expressed as δ13CCH4, which is a measure of comparison against a carbonate standard. Methane’s recent growth post-2007 has been marked by a sustained shift to more negative δ13CCH4 [3]. Biogenic methane, from wetlands, cattle, landfills, etc., is relatively poor in carbon-13 (ie very negative δ13CCH4), while thermogenic methane, from geological sources and also produced in fires, tends to be relatively richer in carbon-13 (ie less negative δ13CCH4).
DOI：
10.1098/rsta.2020.0440
发表时间：
2021-11-15
期刊：
Philosophical transactions. Series A, Mathematical, physical, and engineering sciences
影响因子：
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作者：
Lan X;Nisbet EG;Dlugokencky EJ;Michel SE
通讯作者：
Michel SE
影响因子：
20.6
作者：
通讯作者：
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影响因子：
5.2
作者：
Nisbet, E. G.;Manning, M. R.;White, J. W. C.
通讯作者：
White, J. W. C.