The first Covid-19 lockdown in India led to an improvement in air quality and a reduction in land surface temperature in Delhi, Mumbai, Kolkata, Chennai, Bangalore, and Hyderabad, say researchers. The study led by scientists from the Central University of Jharkhand and University of Southampton in the UK found that the significant environmental improvement was due to an abrupt reduction in industrial activities and a major decrease in the use of land and air transport.

The team used data from a range of Earth Observation sensors, including those from the European Space Agency's Sentinel-5p and NASA's MODIS sensors, to measure changes in surface temperature and atmospheric pollutants and aerosols. They compared data from the 2020 March to May lockdown with pre-pandemic years in Delhi, Mumbai, Kolkata, Chennai, Bangalore, and Hyderabad.