Air Pollution:

Global Pollution From Jet Aircraft Could Increase in the Future

RCED-92-72: Published: Jan 29, 1992. Publicly Released: Mar 4, 1992.

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Pursuant to a congressional request, GAO reviewed the impact of increased jet engine exhaust emissions on the environment, focusing on: (1) the impact of jet emissions on ground-level and global air pollution; and (2) federal agencies' roles controlling in jet aircraft emissions.

GAO found that: (1) jet aircraft emissions account for only 0.3 percent of hydrocarbon, nitrogen oxide, and carbon monoxide emissions produced nationwide; (2) jet engines built after 1982 produce 58 percent less of all three types of emissions; (3) officials from four cities with air pollution problems stated that jet aircraft emissions were a small source of pollution and it was more cost-effective to focus on large sources of pollution; (4) jets currently contribute a relatively small amount of carbon dioxide emissions to global pollution; (5) the National Aeronautics and Space Administration (NASA) agrees that supersonic jets flying in the stratosphere are not a threat to the upper ozone layer, but if fleet projections are correct and technology developments cannot reduce emissions to offset the increases it may be a concern in the future; (6) due to concerns regarding the potential impact of jet aircraft emissions at the global level, the Environmental Protection Agency (EPA) plans to add a staff position to monitor NASA research on the effect of jet emissions on upper-level ozone depletion problems; (7) EPA establishes aircraft emission standards and directs the Federal Aviation Administration (FAA) to enforce those standards; (8) EPA established a hydrocarbon standard in 1982 that reduced hydrocarbon and carbon monoxide emissions from jet engines; (9) FAA also represents the U.S. position on jet aircraft emissions in the international forum that sets ground-level emissions standards; and (10) NASA studies the global impact of jet aircraft emissions and is developing engine technology to reduce such emissions.