China Leads in Sulfur Emissions.

• Position: Brief Article

At the dawn of the new century, the dark reaches of the world have shifted from the West to the East. An analysis of global sulfur emissions estimates spanning two centuries shows that the U.S., Europe, and the former Soviet Union have stabilized their emissions over the past 20 years, while mainland China's have soared. It now leads the world in the dubious distinction of most sulfur emissions produced. Coal consumption overwhelmingly accounted for the highest contributions to sulfur emissions worldwide. Other activities taken into account in the analysis were metal smelting and oil consumption.

According to Rudolf B. Husar, professor of mechanical engineering and director of the Center for Air Pollution Impact, Trends and Analysis, the world's largest private library of air pollution statistics, located at Washington University in St. Louis (Mo.), "Fuel consumption is the key piece of data. And it is relatively easy to get because most countries have kept track of their consumption." Husar and his colleagues estimated the yearly emissions per nation based on net fuel production--production plus imports minus exports. Sulfur content and sulfur retention information based on the individual country's activities also figured into the estimates.

"The stabilizing U.S. and Soviet Union sulfur emissions have occurred in part by switches in the United States from high- to low-sulfur coals and tighter environmental controls," Husar explains. "In the former Soviet Union, there has been a greater reliance on...