This dangerous air pollutant is dropping because of COVID-19, maps show
It’s one tiny light at the end of the long coronavirus tunnel.
Nitrogen dioxide (NO2) — a highly reactive gas — pollution has reached record lows across the world as stay-at-home orders, business closures and decreased ground and air travel puts a pause on the burning of fossil fuels.
“It is a big, natural experiment that you could never reproduce on this scale,” James Lee, a professor of atmospheric chemistry at the University of York in England, told the Financial Times. “We will be able to get a much better handle on where the pollution is coming from in normal circumstances, because things like power generation will continue, but road traffic is shutting down.”
The drops in NO2 are evident in side-by-side maps of major cities such as Los Angeles, London and Prague made by visual journalist Steven Bernard. The data was processed by Descartes Labs, a company in Santa Fe, New Mexico, that performs global-scale analyses.
The purple regions indicate higher concentrations of NO2 per square meter and the yellow regions indicate lower levels of the gas.
NO2 levels in March were 30% lower on average in the region between Washington, D.C, and Boston, compared to the average levels from 2015 to 2019, according to NASA.
The agency notes that these recent improvements in air quality have come at a high cost.
As of April 20, there were over 780,000 confirmed cases of the new coronavirus in the U.S. and more than 41,000 deaths, according to a Johns Hopkins University map.
NO2 is emitted into the air after burning fossil fuels such as diesel, gasoline and coal, according to NASA, and comes out of tailpipes when driving cars and smokestacks when generating electricity.
As a result, changes in NO2 levels can paint a picture of what human activity looks like, the agency says.
High concentrations of the gas can irritate humans’ respiratory systems and can aggravate diseases such as asthma, the United State Environmental Protection Agency says.
It can also interact with other chemicals in the air to form acid rain, which harms ecosystems such as lakes and forests, and can make the air cloudy, ruining precious views that can be seen from national parks, the EPA says.
But recent data show China’s NO2 levels are slowly rising as lockdown restrictions ease, NASA data reveal.
In another silver lining, experts forecast that emissions from energy-related carbon dioxide — a heat-trapping greenhouse gas released by human activities — will decrease by 7.5% in 2020 as a result of decreased activity related to COVID-19, the disease the new coronavirus causes, according to the U.S. Energy Information Administration.
This story was originally published April 20, 2020 at 5:29 PM with the headline "This dangerous air pollutant is dropping because of COVID-19, maps show."