U.S. Air Quality Continues to Improve

Published October 1, 2009

Sulfur dioxide emissions from U.S. power plants have fallen sharply this year, according to a recent report by energy research firm Genscape. Emissions of other pollutants have dropped as well.

For the first half of 2009, SO2 emissions dropped 24 percent versus the first half of 2008. Emissions of nitrogen oxide (NOx) fell 5 percent in May and 11 percent in June compared against the same months last year.

Long-Term Reduction

According to data from the U.S. Environmental Protection Agency, which regulates emissions of air pollutants such as SO2 and NOx, nationwide air quality for the six air pollutants (known as “principal pollutants”) for which there are national standards has improved significantly in recent decades.

“Since 1980, emissions of the six principal pollutants have declined significantly, with the greatest drop in lead,” the EPA publication Six Principal Pollutants reports.

“During that same time period, NOx emissions have dropped by one-third, and VOC [volatile organic compounds], SO2, and CO [carbon monoxide] emissions have been cut by roughly one half. Combined, the emissions of the six principal pollutants dropped 49 percent since 1980,” EPA noted.

“All of this progress has occurred while the U.S. economy continued to grow, Americans drove more miles, and population and energy use increased,” EPA explained.

Technology Fuels Progress

Steven Hayward, the F.K. Weyerhaeuser Fellow at the American Enterprise Institute, says no one should be surprised by the continuing decline in air pollution.

“There’s much more still to come, as new technologies replace the old in our auto fleets, power plants, and industrial facilities,” Hayward said. “The EPA’s own internal models predict a further emissions decline of about 70 percent from the auto and truck fleet over the next 20 years. The only surprise is that environmentalists are still surprised, but that’s because environmentalists live for bad news.

“Government regulations have driven much of this story but are not the most important part of it,” Hayward explained. “Were it not for the engineering talent and innovation of the private sector, no amount of make-it-so regulations would clear up air pollution. This should be a lesson for Congress as it looks at regulating ‘greenhouse gas’ emissions, which are of a very different character than traditional air pollution. Just because sulfur dioxide and carbon dioxide both end in ‘dioxide’ doesn’t mean they are the same kind of thing.”


Drew Thornley ([email protected]) writes from Texas.

For more information …

Six Principal Pollutants, U.S. Environmental Protection Agency: http://www.epa.gov/air/airtrends/2007/report/sixprincipalpollutants.pdf