Detectability of COVID-19 global emissions reductions in local CO 2 concentration measurements
Detectability of COVID-19 global emissions reductions in local CO 2 concentration measurements
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当地 CO 2 浓度测量中 COVID-19 全球减排量的可检测性
DOI：
10.1088/1748-9326/ac1eda
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发表时间：
2021
影响因子：
6.7
通讯作者：
Dacre H
中科院分区：
文献类型：
--
作者：
Dacre H
据估计，由于与 COVID-19 相关的经济活动低迷，2020 年初全球人为二氧化碳 (CO2) 排放量比近年来减少了 12%。尽管二氧化碳排放量大幅减少，但并未发现背景大气二氧化碳浓度有减少的趋势。那么，需要多长时间才能在每日和每月平均当地二氧化碳浓度测量中检测到持续的 COVID-19 二氧化碳排放量减少？英国和爱尔兰五个测量点的二氧化碳浓度测量结果与气象数值天气预报数据相结合，建立了可以预测未来二氧化碳浓度的统计模型。结果发现，观察到的每日变化可以通过这些简单的模型来解释。使用这些简单模型的减排情景实验表明，当地二氧化碳浓度的每日和季节变化较大，阻碍了可检测信号的快速出现。 COVID-19 排放量的减少只有在至少 38 个月后的每日二氧化碳浓度和持续减少 11 个月后的每月二氧化碳浓度中才能检测到。对于每月二氧化碳浓度，所有地点的出现时间都相似，因为季节性变化很大程度上是由陆地生物圈和大气之间的非局部二氧化碳通量驱动的。 COVID-19 二氧化碳人为减排量与实现《巴黎协定》将全球气温保持在摄氏以下的目标所需的减排量相似。这项研究表明，仅使用测量结果，全球人为排放量的变化与检测到的当地二氧化碳浓度趋势信号之间存在相当大的滞后。因此，旨在满足二氧化碳人为排放目标的政策变化与我们仅使用大气测量来检测这些政策对二氧化碳浓度影响的能力之间可能会存在数年的延迟。
It is estimated that global anthropogenic carbon dioxide (CO2) emissions reduced by up to 12% at the start of 2020 compared to recent years due to the COVID-19 related downturn in economic activity. Despite the large decrease in CO2emissions, no reduction in the trend in background atmospheric CO2concentrations has been detected. So, how long would it take for sustained COVID-19 CO2emission reductions to be detected in daily and monthly averaged local CO2concentration measurements? CO2concentration measurements for five measurement sites in the UK and Ireland are combined with meteorological numerical weather prediction data to build statistical models that can predict future CO2concentrations. It is found thatof the observed daily variability can be explained by these simple models. Emission reduction scenario experiments using these simple models illustrate that large daily and seasonal variability in local CO2concentrations precludes the rapid emergence of a detectable signal. COVID-19 magnitude emissions reductions would only be detectable in the daily CO2concentrations after at least 38 months and in monthly CO2concentrations after 11 months of sustained reductions. For monthly CO2concentrations the time of emergence is similar for all sites since the seasonal variability is largely driven by non-local fluxes of CO2between the terrestrial biosphere and the atmosphere. The COVID-19 CO2anthropogenic emissions reductions are similar in magnitude to those that are required to meet the Paris Agreement target of keeping global temperatures belowC. This study demonstrates that, using measurements alone, there will be a considerable lag between changes in global anthropogenic emissions and a detected signal in local CO2concentration trends. Thus, there is likely to be a delay of several years between changes in policy designed to meet CO2anthropogenic emissions targets and our ability to detect the impact of these policies on CO2concentrations using atmospheric measurements alone.