Changing Trends in Sulfur Emissions in Asia: Implications for Acid Deposition, Air Pollution, and Climate.

In the early 1990s, it was projected that annual SO[sub 2] emissions in Asia might grow to 80-110 Tg yr[sup -1] by 2020. Based on new high-resolution estimates from 1975 to 2000, we calculate that SO[sub 2] emissions in Asia might grow only to 40-45 Tg yr[sup -1] by 2020. The main reason for this lower estimate is a decline of SO[sub 2] emissions from 1995 to 2000 in China, which emits about two-thirds of Asian SO[sub 2]. The decline was due to a reduction in industrial coal use, a slowdown of the Chinese economy, and the closure of small and inefficient plants, among other reasons. One effect of the reduction in SO[sub 2] emissions in China has been a reduction in acid deposition not only in China but also in Japan. Reductions should also improve visibility and reduce health problems. SO[sub 2] emission reductions may increase global warming, but this warming effect could be partially offset by reductions in the emissions of black carbon. How SO[sub 2] emissions in the region change in the coming decades will depend on many competing factors (economic growth, pollution control laws, etc.). However a continuation of current trends would result in sulfur emissions lower than any IPCC forecasts. [ABSTRACT FROM AUTHOR]