气候变化领域集成服务门户(CCPortal): COVID-19 lockdown emission reductions have the potential to explain over half of the coincident increase in global atmospheric methane

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DOI	10.5194/acp-22-14243-2022
	COVID-19 lockdown emission reductions have the potential to explain over half of the coincident increase in global atmospheric methane
	Stevenson, David S.; Derwent, Richard G.; Wild, Oliver; Collins, William J.
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	14243
结束页码	14252
卷号	22 期号:21 页码:10
英文摘要	Compared with 2019, measurements of the global growth rate of background (marine air) atmospheric methane rose by 5.3 ppb yr(-1) in 2020, reaching 15.0 ppb yr(-1). Global atmospheric chemistry models have previously shown that reductions in nitrogen oxide (NO,) emissions reduce levels of the hydroxyl radical (OH) and lengthen the methane lifetime. Acting in the opposite sense, reductions in carbon monoxide (CO) and non-methane volatile organic compound (NMVOC) emissions increase OH and shorten methane's lifetime. Using estimates of NOx, CO, and NMVOC emission reductions associated with COVID-19 lockdowns around the world in 2020 as well as model-derived regional and aviation sensitivities of methane to these emissions, we find that NO, emission reductions led to a 4.8 (3.8 to 5.8) ppb yr(-1) increase in the global methane growth rate. Reductions in CO and NMVOC emissions partly counteracted this, changing (reducing) the methane growth rate by -1.4 (-1.1 to -1.7) ppb yr(-1) (CO) and -0.5 (-0.1 to -0.9) ppb yr(-1) (NMVOC), yielding a net increase of 2.9 (1.7 to 4.0) ppb yr(-1). Uncertainties refer to +/- 1 standard deviation model ranges in sensitivities. Whilst changes in anthropogenic emissions related to COVID-19 lockdowns are probably not the only important factor that influenced methane during 2020, these results indicate that they have had a large impact and that the net effect of NOx, CO, and NMVOC emission changes can explain over half of the observed 2020 methane changes. Large uncertainties remain in both emission changes during the lockdowns and methane's response to them; nevertheless, this analysis suggests that further research into how the atmospheric composition changed over the lockdown periods will help us to interpret past methane changes and to constrain future methane projections.
学科领域	Environmental Sciences; Meteorology & Atmospheric Sciences
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000879747100001
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/273511
作者单位	University of Edinburgh; Lancaster University; University of Reading
推荐引用方式 GB/T 7714	Stevenson, David S.,Derwent, Richard G.,Wild, Oliver,et al. COVID-19 lockdown emission reductions have the potential to explain over half of the coincident increase in global atmospheric methane[J],2022,22(21):10.
APA	Stevenson, David S.,Derwent, Richard G.,Wild, Oliver,&Collins, William J..(2022).COVID-19 lockdown emission reductions have the potential to explain over half of the coincident increase in global atmospheric methane.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(21),10.
MLA	Stevenson, David S.,et al."COVID-19 lockdown emission reductions have the potential to explain over half of the coincident increase in global atmospheric methane".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.21(2022):10.