Reductions in NO ₂ burden over north equatorial Africa from decline in biomass burning in spite of growing fossil fuel use, 2005 to 2017

Significance Socioeconomic development in low- and middle-income countries is thought to increase emissions of air pollutants, such as nitrogen dioxide (NO 2 ). In Africa, fossil fuel use has nearly doubled since 2000, but vegetation fires—which cause substantial NO 2 pollution—have declined, partly as a result of human activity. Satellite observations show that during the biomass burning season, NO 2 concentrations in Africa’s northern fire region declined by 4.5% between 2005 and 2017, potentially benefitting hundreds of millions of people. Statistical modeling suggests that this decline is associated with declining vegetation fires. During the biomass burning season, higher levels of economic productivity are associated with lower NO 2 concentrations, suggesting that socioeconomic development in this region is resulting in net improvements to air quality.