Lessons learned and questions raised during and post-COVID-19 anthropopause period in relation to the environment and climate

Abstract

In the first part, this work reports that during the global “anthropopause” period, that was imposed in March and April 2020 for limiting the spread of COVID-19, the concentrations of basic air pollutants over Europe were reduced by up to 70%. During May and June, the gradual lift of the stringent measures resulted in the recovery of these reductions with pollution concentrations approaching the levels before the lockdown by the end of June 2020. In the second part, this work examines the alleged correlations between the reported cases of COVID-19 and temperature, humidity and particulate matter for March and April 2020 in Europe. It was found that decreasing temperatures and relative humidity with increasing concentrations of particulate matter are correlated with an increase in the number of reported cases during these 2 months. However, when these calculations were repeated for May and June, we found a remarkable drop in the significance of the correlations which leads us to question the generally accepted inverse relation between pandemics and air temperature at least during the warmer months. Such a relationship could not be supported in our study for SARS-CoV-2 virus and the question remains open. In the third and last part of this work, we examine the question referring to the origin of pandemics. In this context we have examined the hypothesis that the observed climate warming in Siberia and the Arctic and the thawing of permafrost could result to the release of trapped in the permafrost pathogens in the atmosphere. We find that although such relations cannot be directly justified, they present a possible horrifying mechanism for the origin of viruses in the future during the developing global warming of our planet in the decades to come. Overall the findings of our study indicate that: (1) the reduction of anthropogenic emissions in Europe during the “anthropopause” period of March and April 2020 was significant, but when the lockdown measures were raised the concentrations of atmospheric pollutants quickly recovered to pre-pandemic levels and therefore any possible climatic feedbacks were negligible; (2) no robust relationship between atmospheric parameters and the spread of COVID-19 cases can be justified in the warmer part of the year and (3) more research needs to be done regarding the possible links between climate change and the release of new pathogens from thawing of permafrost areas.

Short-term impacts of air pollutants in three megacities of India during COVID-19 lockdown

“…In general, it is important to note that when comparing the NO 2 and (PM 10 ) reductions during the lockdown, it is important to note that rural background concentrations of atmospheric particulate originate from non-urban sources thereby their reductions are generally less than NO 2 , which is an urban pollutant. Similar results were reported in another study conducted in Europe (Zerefos et al, 2020 ).…”

“…In this context, it is important to mention that in general important rural background concentrations of atmospheric particulates generally originate from non-urban sources thereby their reduction is generally less important as for NO 2 , which is a typical urban pollutant. Similar results were also presented in a similar study reported for the European continent during the spring 2020 lockdown period (Zerefos et al, 2020 ).

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Radiative Effect and Mixing Processes of a Long-Lasting Dust Event over Athens, Greece, during the COVID-19 Period

“…The lockdown period started in most European cities (including Athens) during March 2020 and lasted mainly up to June 2020 [46]. During this period, air traffic was nearly canceled and car traffic and other means of ground transportation, as well as industrial activities, were minimized on a European level; therefore, air pollution levels in most European cities showed very low concentrations (e.g., a reduction in NO2 by 32% in Athens; see also Figure A1, by 48% in Madrid and by 57-61% in Milan [45,47,[52][53][54][55][56][57]). Similarly, an air pollution level reduction was also observed in many cities all over the world (Canada, Brazil, India, Cairo, Southeast Asia, etc.)…”

Interactions between climate and COVID-19

“…2020 and 2021 were characterised by notable climatic extremes, creating substantial interest in the intersection of the COVID-19 pandemic with climate risks. Research to date has investigated lessons learned from COVID-19 for climate policy, 10 , 13 , 14 , 15 disaster preparedness, 16 , 17 and support for climate action; 18 , 19 compared the politics of responding to COVID-19 with the politics of responding to climate change; 20 examined implications of the pandemic for greenhouse gas emissions 21 , 22 and the environment as a whole; 23 , 24 and focused on how to improve the sustainability of recovery packages to fulfil the UN Build Back Better campaign goals. 25 , 26 , 27 Studies have also focused on the associations between weather and COVID-19 transmission and, to a lesser extent, the ways climatic factors affect lived experience of and response to COVID-19.…”