Probably the environment is the only sector that got an immensely positive impact form this COVID-19 scenario . International energy agency reported that global coal use was 8 % lower in the first quarter in 2020 . Due to the Locked down , transport , industry , and all non - essential sectors were closed , which reduced emission significantly . NASA ( National Aeronautics and Space Administration ) and ESA ( European Space Agency ) published recent data ( Fig . 9 ) declaring that compared to last year , NO 2 emission reduced by 30 % ( Dutheil et al . , 2020 ) . The decline in PM2.5 was significant in the US , UAE , Italy , and Spain , in the month of March , due to cumulative lockdown ( Chauhan and Singh , 2020 ) . Noticeably , in China , the overall air quality improved as NO 2 reduced by 22.8 μg / m 3 , PM 2.5 decreased by 1.4 μg / m 3 particularly in Wuhan ( Zambrano - Monserrate et al . , 2020 ) and by 18.9 μg / m 3 in 367 other cities ( Lal et al . , 2020 ) . However , some cities also witnessed the air quality index over 100 . These reductions accounted for lowering the particle loadings ( Wang et al . , 2020f ) . Air quality showed improvement near the Yangtze River Delta ( YRD ) region , which is one of the economic city - clusters in Eastern China . However , the percentage of PM 2.5 attributed to residences and long - range transport . Additionally , 44 cities of northern China marked 69.5 % reduction in human mobility improving the air quality as SO 2 , PM2.5 , PM10 , NO 2 , and CO decreased by 6.76 % , 5.93 % , 13.66 % , 24.67 % , and 4.58 % , respectively ( Bao and Zhang , 2020 ) . In 2017 , the energy sector in Italy ( industry and transport ) contributed 80 % of the total country GHG emissions . COVID-19 related lockdown caused an overall 20 % reduction of GHG emission , lower than emissions of March and April in 2015 - 2019 ( Rugani and Caro , 2020 ) . In Milan , Italy , partial lockdown restricted the people movement , and total lockdown terminated industry and transport activities . Reduction of PM10 , PM2.5 , BC , benzene , CO , and NOx level was observed because of a decrease in road transport ( Collivignarelli et al . , 2020 ) . In Barcelona , PM10 reduced by 31 %   and NO 2 by 50 % ( Baldasano , 2020 ) . Initially , Madrid and Barcelona contributed 55 % and 56 % of NO 2 emission from traffic . However , due to the COVID-19 scenario - based lockdown , since March , Barcelona and Madrid ( Spain ) , emitted 50 % and 62 % less NO 2 respectively ( Baldasano , 2020 ) . In the continental USA , PM2.5 reduced during the lockdown , especially in urban counties and wherever non - essential businesses were closed ( Berman and Ebisu , 2020 ) . During the lockdown period ( March 19th to April 14th , 2020 ) , reduction in PM2.5 , NO 2 , and CO concentration by 21 % , by 35 % , CO by 49 % , was noticed in Almaty , Kazakhstan ( Kerimray et al . , 2020 ) . Sao Paolo Brazil also encountered a reduction in CO and NO 2 emission by 64.8 % , and 77.3 % ( Nakada and Urban , 2020 ) . Further , PM10 , NO 2 , and SO 2 emissions decreased by more than half during the COVID-19 lockdown period in Salé City , Morocco ( Otmani et al . , 2020 ) . India , every year battles more than 350,000 new cases of childhood asthma and 16000 premature death attributed to air pollution , mostly NO 2 and PM ( 2.5 - 10 μm ) generated from fossil fuels and transportation sector ( CREA , 2020 ) .