NASA study shows how COVID-19 lockdown affected air pollution

It is a known fact that the air quality improved manifold in the lockdown and had been a talking point for months during the bleak times of lockdown due to the pandemic.

It became one of the few positive impacts of strict restrictions imposed on billions across the world.

This compelled scientists at NASA to further study the extend of this reduced pollution levels in atmosphere. The scientists developed a computer-generated model to study how the atmosphere would have been if there was no COVID-19 pandemic and how it turned out in these months.

NASA experts created a model projection of a COVID-free Earth atmosphere in 2020 keeping in account natural variations as well.

The model simulation and machine learning analysis showed an alternate reality version of 2020- one that did not experience any unexpected changes in human behaviour brought on by the pandemic.

The researchers received data from 46 countries with a total of 5,756 observation sites on the ground. The experts observed that in a city-level, 50 of the 61 cities show nitrogen dioxide reductions between 20-50%.

Wuhan in China, which was the first in the world to impose a strict lockdown after the COVID-19 outbreak originated there, showed the first reduction in nitrogen dioxide emissions. The emission in Wuhan was 60% less than expected. Milan in Italy’s Lombardy, the worst-hit regions in Europe, also saw a 60% reduction in nitrogen dioxide emissions.

New York, another worst hit city saw a 45% reduction in the pollution levels.

Meanwhile in India, a report released by the Central Pollution Control Board (CPCB), the pollution levels in India were reduced by 24% in the pre-lockdown days of early March. During the nationwide lockdown, it further went down by almost 50%.