Sulfur dioxide is a major air pollutant and has significant impacts upon human health. In addition the concentration of sulfur dioxide in the atmosphere can influence ecosytems. Sulfur dioxide emissions are a precursor to acid rain and atmospheric particulates. A new analysis of sulfur emissions appearing in the journal Atmospheric Chemistry and Physics shows that after declining for a decade, worldwide emissions rose again in 2000 due largely to international shipping and a growing Chinese economy. An accurate read on sulfur emissions will help researchers predict future changes in climate and determine present day effects on the atmosphere, health and the environment.