Population, Economy and Energy Use’s Influence on Sulfur Emissions in the United States Since 1900

This paper seeks to identify how changes in population, economic activity, and energy use have influenced sulfur emissions during this century. A linear model is presented which characterizes sulfur emissions as the product of these driving forces. The change in sulfur emissions is formulated as a function of changes in these trends. During this century, population growth and increasing economic activity have put upward pressure on sulfur emissions. The declining energy intensity of the economy and the transition from coal to less sulfur intensive fuels have reduced sulfur emissions. The net effect of all drivers has been moderate growth in sulfur emissions from 1900 to present. Since 1973, increased energy efficiency and the shift from an industrial to a commercially oriented economy have lowered the energy intensity of the economy. The increased use of low sulfur coal and reduced sulfur emissions from metal smelters have lowered the sulfur intensity of energy. These factors have combined to cause sulfur emissions to decline by 25%