Sulfur dioxide emissions from metallurgical industry sources and major coal-fired power plants in Russia (there are no significant point sources north of 60º N in other Arctic countries; pale coloured symbols are sources south of 60º N). Also shown are total emissions of SO2 in 2002 from the five regions of northwestern Russia. Subplots show trends in emissions from Russian non-ferrous metal smelters. Orange columns on the subplots, and on the map (for the four power plants with the largest SO2 emissions), represent emissions in 2002 (note: the scale on the Norilsk subplot is different from all other data shown)