Ambiguous Pollution Response to COVID-19 in China

Reductions in ambient pollution have been taken as an indisputable "silver lining" to the COVID-19 Pandemic. Indeed, worldwide economic contraction induced by COVID-19 lockdowns should generate global air quality improvements ceteris paribus, including to China's notoriously-poor air quality. We analyze China's official pollution monitor data and account for the large, recurrent improvement in air quality following Lunar New Year (LNY), which essentially coincided with lock-downs in 2020. With the important exception of NO2, China's air quality improvements in 2020 are smaller than we should expect near the pandemic's epicenter: Hubei province. Compared with LNY improvements experienced in 2018 and 2019 in Hubei, we see smaller improvements in SO2 while ozone concentrations increased in both relative and absolute terms (roughly doubling). Similar patterns are found for the six provinces neighboring Hubei. We conclude that COVID-19 had ambiguous impacts on China's pollution, with evidence of relative deterioration in air quality near the Pandemic's epicenter.