State Key Laboratory of Loess and Quaternary Geology, CAS Center for Excellence in Quaternary Science and Global Change, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China; Shaanxi Provincial Key Laboratory of Accelerator Mass Spectrometry Technology and Application, Joint Xi'an AMS Center Between IEECAS and Xi'an Jiaotong University, Xi'an, 710061, China.
State Key Laboratory of Loess and Quaternary Geology, CAS Center for Excellence in Quaternary Science and Global Change, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China; Shaanxi Provincial Key Laboratory of Accelerator Mass Spectrometry Technology and Application, Joint Xi'an AMS Center Between IEECAS and Xi'an Jiaotong University, Xi'an, 710061, China.
Environ Res. 2021 Jun;197:111208. doi: 10.1016/j.envres.2021.111208. Epub 2021 Apr 22.
Lockdown measures to control the spread of the novel coronavirus disease (COVID-19) sharply limited energy consumption and carbon emissions. The lockdown effect on carbon emissions has been studied by many researchers using statistical approaches. However, the lockdown effect on atmospheric carbon dioxide (CO) on an urban scale remains unclear. Here we present CO concentration and carbon isotopic (δC) measurements to assess the impact of COVID-19 control measures on atmospheric CO in Xi'an, China. We find that CO concentrations during the lockdown period were 7.5% lower than during the normal period (prior to the Spring Festival, Jan 25 to Feb 4, 2020). The observed CO (total CO minus background CO) during the lockdown period was 52.3% lower than that during the normal period, and 35.7% lower than the estimated CO with the effect of weather removed. A Keeling plot shows that in contrast CO concentrations and δC were weakly correlated (R = 0.18) during the lockdown period, reflecting a change in CO sources imposed by the curtailment of traffic and industrial emissions. Our study also show that the sharp reduction in atmospheric CO during lockdown were short-lived, and returned to normal levels within months after lockdown measures were lifted.
为控制新型冠状病毒病 (COVID-19) 的传播而采取的封锁措施大幅限制了能源消耗和碳排放。许多研究人员使用统计方法研究了封锁对碳排放的影响。然而，封锁对城市尺度大气二氧化碳 (CO) 的影响仍不清楚。在这里，我们展示了 CO 浓度和碳同位素 (δC) 的测量结果，以评估 COVID-19 控制措施对中国西安大气 CO 的影响。我们发现，封锁期间的 CO 浓度比正常时期（2020 年 1 月 25 日至 2 月 4 日春节前）低 7.5%。观测到的封锁期间的总 CO（总 CO 减去背景 CO）比正常时期低 52.3%，比去除天气影响后估计的 CO 低 35.7%。开尔文图表明，与正常时期相比，封锁期间 CO 浓度和 δC 的相关性较弱 (R = 0.18)，反映了交通和工业排放减少导致 CO 来源的变化。我们的研究还表明，封锁期间大气 CO 的急剧减少是短暂的，在封锁措施解除后的几个月内恢复到正常水平。
