"How dangerous is air pollution in national parks? It would have been less threatening to your health yesterday morning to walk to work here in Washington, D.C., which was under a code red pollution alert, than to have hiked an equal distance on the Appalachian Trail in Great Smoky Mountains National Park, where ozone levels were about three times the level of those in Washington. Over the past four summers, the park has issued 140 notices of 'unhealthful air' to park staff and visitors.

"Air pollution is one of the most dangerous threats our parks face. While visibility impairment from air pollution is widespread throughout the park system, scenic views are not the only resource at risk. The same pollutants that reduce visibility also contribute to 30,000 premature human deaths yearly. Acid deposition damages natural and cultural resources. Mercury deposition threatens fish and wildlife in a number of parks. Ground level ozone, or smog, threatens the health of park visitors and workers and damages park vegetation. Finally, as the Bush Administration's 2002 U.S. Climate Action Report concludes, global warming—a byproduct of air pollution—threatens parks in many ways, from rising sea level to melting glaciers to changes in biodiversity.

"S. 556 would require significant and timely reductions in sulfur dioxide, nitrogen oxides, mercury, and carbon dioxide. Twenty-one senators have co-sponsored the bill, now expected to be marked up in committee this summer.

"There is simply no combination of emissions reductions that will clear the air in our parks without cleaning up old, grandfathered power plants. NPCA strongly supports S.556, the Clean Power Act, and urges its swift adoption. A simple emissions cap-and-trade program instituted in lieu of, rather than in addition to, the current effect-based standards of the Clean Air Act—as proposed by the Bush Administration—cannot protect national parks from existing or future adverse impacts."