For the second year, HYGEOS led the aerosol section of the BAMS State of the Climate in 2020 bulletin. The BAMS State of the Climate is an international peer-reviewed publication released each summer; it is an authoritative annual summary of the global climate, published as a supplement to the Bulletin of the American Meteorological Society. HYGEOS also contributed to the first WMO Air Quality and Climate Bulletin. 2020 was a year of extreme events from an aerosol perspective, with exceptional biomass burning events in the winter 2019/2020 in Australia, which injected a large amount of aerosols in the stratosphere, and in the summer of 2020 in Western U.S. and Siberia. June 2020 also witnessed the largest transatlantic dust transport event of the past years, which had a significant impact on air quality in the South of the U.S.