SO2 sources are fairly well known, Acid Rain was first extensively studied back in the mid 1960s - https://en.wikipedia.org/wiki/Acid_rain https://en.wikipedia.

SO2 sources are fairly well known, Acid Rain was first extensively studied back in the mid 1960s - https://en.wikipedia.org/wiki/Acid_rain https://en.wikipedia.org/wiki/Acid_rain Marine fuels were the last remaining stronghold of anthropogenic SO2. The two large scale changes in recent years of atmospheric makeup were the SO2 generation reduduction from marine fuel phase outs and the unuual high altitude water vaper injection from a volcanic eruption. Atmospheric gas makeup changes are mapped from a number of global sites, and recently mutlispectral orbiting gas sensors have been fine scale mapping sources. * https://www.carbonbrief.org/analysis-how-low-sulphur-shipping-rules-are-affecting-global-warming/ https://www.carbonbrief.org/analysis-how-low-sulphur-shippin... * https://research.noaa.gov/hunga-tonga-2022-eruption/ https://research.noaa.gov/hunga-tonga-2022-eruption/ * https://research.csiro.au/acc/capabilities/cape-grim-baseline-air-pollution-station https://research.csiro.au/acc/capabilities/cape-grim-baselin...