ABSTRACT
Despite awareness towards clean energy(e.g., solar, wind powers) production, dirty energies (e.g., fossil
fuel burnings) still dominate total power consumption, generating several harmful air pollutants that are
known to have manifold impacts on Earth’s climate and human society. The COVID-19 pandemic, which
unwillingly forced most of the countries to put restrictions on human activities, provided an opportunity to
view the human-made impact on atmosphere from a new horizon. Taking this opportunity, this study
analyzed air pollution concentrations of aerosols and trace gases over highly polluted countries of Asia
(China, India, and Thailand) during lockdown, pre-lockdown, and post-lockdown periods of 2020 and similar
periods of previous years. Though Thailand saw an increment in air pollution despite lockdown, which was
likely due to effects of forest fires, China and India saw a reduction in air pollution during the lockdown, but
immediate rebound after lockdown. Air pollution (aerosol, SO 2, NO 2, and CO) related data were obtained
from satellite observations (MODIS and Tropomi) and reanalysis (MERRA-2), whereas as energy
consumption and traffic congestion related data were obtained from various sources. A detailed study
focusing China indicated a reduction of air pollutants and energy consumption mainly in industrial and power sectors without any significant change in the household sector, suggesting less effectiveness of lockdown for air pollution reduction of the household sector. This study provides important clues for policymaking to cope with air pollution problem of developing countries, where dirty energies are heavily used.