Satellite images show resurgence of air pollution over China

Emission levels starting to return in China New satellite data shows a rise in the amount of nitrogen dioxide being emitted by China as the country tries to rebound from COVID-19.

TORONTO — When strict measures were put in place to control the spread of the novel coronavirus in China, pollution levels decreased, but analysts were worried that efforts to get the Chinese economy back on track would quickly reverse the reduction in emissions.

A new animation from the European Space Agency(ESA) shows that emissions of nitrogen dioxide have already begun to increase.

Using data from the ESA's Copernicus satellite, the animation shows concentrations of nitrogen dioxide, a pollutant found in emissions from vehicles and power plants, dropping from late January until early March, when they begin to increase again.

By March 16, the final date shown in the animation, a sizeable cloud of nitrogen dioxide can be seen once again hanging above China.

"We can certainly attribute a part of the nitrogen dioxide concentration reduction to the impact of the coronavirus," says Claus Zehner, ESA's Copernicus Sentinel-5P mission manager.

It is still uncertain how quickly emission in China could return to pre-coronavirus levels, and to what extent COVID-19 has actually had on the reduction of pollutants in the region.

"We currently see around a 40per cent reduction over Chinese cities, however these are rough estimates, as weather also has an impact on emissions," says Zehner.

According to Zehner, the ESA will conduct a detailed scientific analysis of the satellite data in the coming weeks and months.