When the COVID lockdowns came in spring 2020 the impact on cities was immediate. In the weeks and months that followed data showing how pollution changed was collated and analysed.
This data showed a clear and rapid drop in pollution across European Cities, the same pattern had been seen in China due to lockdown. China also shows a similar, but less severe, drop-in No2 every year – due to the holidays on Chinese New Year.
These global, regional, and city-level studies showing NO2 drop during lockdown all relied on satellite data – including ESA‘s Sentinel-5. The same analysis has been conducted throughout the year. The data is now showing how the pollution levels returned, albeit slowly, to the same cities.
In some cities, the pollution in the summer of 2020 was slightly higher than in 2019. This probably due to the fact that people were not leaving their cities for the usual summer holidays. Instead, people were staying in the city and using the car more.
The video below shows air and environment changed in the first lockdown