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Coronavirus: China lockdowns lead to big dip in NO2 but air pollution stays steady, study finds
- Curtailment of transport brought down nitrogen dioxide levels In February, researchers say
- More analysis needed to understand complexities of regional atmospheric contamination, activist says
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Severe epidemic lockdowns imposed across China in February led to a “striking” drop in nitrogen dioxide, but other pollutants remained at roughly the same levels, a study has found.
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Readings for nitrogen dioxide – a major component of air pollution – fell by about half in February compared with projected levels, an unprecedented decline, according to the researchers.
Michael Diamond, lead author of the study and a University of Washington doctoral student in atmospheric sciences, said the difference was more than “twice as large a drop as anything we saw in the record from 2005 to 2019, including from the 2008 great recession”.
“In the statistics of atmospheric science, that’s a giant signal. It is rare to see anything that striking,” Diamond said in an interview published on the university’s website.
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Coronavirus: blue skies over Chinese cities as Covid-19 lockdown temporarily cuts air pollution
Coronavirus: blue skies over Chinese cities as Covid-19 lockdown temporarily cuts air pollution
The study was published on August 19 in the peer-reviewed Geophysical Research Letters.
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By using satellite data, the researchers looked at monthly mean pollution and cloud properties from January 2005 to May 2020. It also used a statistical method that compared what was seen in February with what would have been expected without the pandemic.
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