The ongoing COVID-19 pandemic has completely altered human activity across the globe. The human toll in deaths related to coronavirus and healthcare systems strained beyond reason in cities worldwide are the worst effects by far. A secondary effect of essentially everyone on Earth being impacted in some fashion is the world’s economy has shuddered to a near halt.
The economic shock stems from policies either asking or requiring people to shelter in place or self-quarantine to avoid spreading the disease with no current silver-bullet treatment or vaccine. In many cities these policies extend to closing places where people gather such as bars, restaurants, gyms and churches by edict. And global air travel has been largely shut down for some time.
Because people aren’t moving around there’s been a noticeable decrease in global air pollution as noted by a recent Nerdist report
highlighting online tools that vividly illustrate the reduction in pollution. Given the global and ongoing large-scale change in human behavior, there’s even a small silver lining in the opportunity to perform science on air pollution that would otherwise be impossible.
“The air pollution monitoring data collected during the covid-19 shutdown will be useful to test our fundamental understanding of the sources of pollutants (economic sectors, natural emissions, etc.), the chemistry of nitrogen dioxide, ozone and particulate matter, and short term health and ecosystem effects of air pollution,” wrote Harvard postdoc Viral Shah to Earther.
Shah’s quote appeared in an article where Earther shared its tool visualizing the drop in air pollution. The tool uses Google Earth Engine and data from the Sentinel-5P satellite, part of the EU and European Space Agency’s (ESAs) “Copernicus Programme” on understanding the environment. Earther’s tool provides users with before and after images representing daily nitrogen dioxide levels across the planet from December 2019 through March 2020.
“Nitrogen dioxide is produced by fossil fuel burning and therefore often used as an urban pollution tracer. The rapid decrease we see in nitrogen dioxide due to covid-19 is unprecedented. We are now witnessing a global experiment where one emission source is rapidly turned down (NOx), while other sources are still up or will decrease more slowly,” Barbara Dix, atmospheric researcher at the Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder, told Earther in an email.
The ESA put out its own tool covering January 2020 through March 2020 which picked up a significant drop in nitrogen dioxide in Northern Italy after its national lockdown.