Satellite images released by NASA show a decline in air pollution in China due to countrywide quarantines after coronavirus outbreak in December 2019. Since many factories have been shut down and transportation has been restricted to prevent the further spread of the virus, there has been a significant drop in the level of air pollution.
Varying levels of nitrogen dioxide over China captured by NASA satellite / Image: NASA
The number of coronavirus cases has reached over 88,000 with more than 3,000 people dead, worldwide. It has spread to over 50 countries, though the vast majority of infections and deaths are in China.
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From January 1 to 20, the images show higher levels of nitrogen dioxide hovering over China, but from February 10 to 25, these gas traces are hardly visible. Nitrogen dioxide is a noxious gas and is emitted by vehicles, power plants, and industrial facilities. This yellow-brown gas can cause respiratory problems such as coughing, asthma, and breathing difficulty.
A comparison of levels of nitrogen dioxide for two consecutive years / Image: NASA
This is the first time I have seen such a dramatic drop-off over such a wide area for a specific event. This year, the reduction rate is more significant than in past years and it has lasted longer. I am not surprised because many cities nationwide have taken measures to minimize spread of the virus.
Said Fei Liu, an air quality researcher at Nasa’s Goddard Space Flight Center. She further added that she had observed a decline in nitrogen dioxide levels during the economic recession in 2008.
According to the NASA scientists, the most visible drop was initially seen over Wuhan, the epicenter of the virus outbreak. The scientists noted that the decline in air pollution coincided with the restrictions imposed on transportation and industrial activities, and millions of people went into quarantine.
The space agency also observed that China’s Lunar New Year celebrations in late January and early February have also been linked to a decrease in pollution in the past.
Source: EarthObservatory