Burning fossil fuels has resulted in a prominent yet unintended manipulation of the global
sulfur cycle. Emissions of sulfur dioxide and reactive sulfur to the atmosphere have caused
widespread health and environmental impacts and have led, ultimately, to calls to decrease
sulfur emissions. However, anthropogenic modification of the sulfur cycle is far from over.
Using four contrasting case studies from across the United States, we show how high levels
of sulfur are added to croplands as fertilizers and pesticides and constitute a major yet under …