A Bush proposal for reducing power-plant emissions of carbon dioxide, the leading cause of global warming, calls for voluntary cutbacks and sets neither firm limits nor deadlines for achieving these cutbacks. "The administration has folded on carbon dioxide thanks to pressure from coal companies and utilities that burn coal," Kiernan said. "It is a major failing." The carbon dioxide plan is supposed to serve as an alternative to the Kyoto Protocol developed by 180 nations to reduce greenhouse gases, which the administration has refused to join. A previous accord on carbon dioxide reduction, ratified by the Senate in 1992 and signed by President George Herbert Walker Bush, called for reducing carbon dioxide emissions to 1990 levels by 2000. Today, the nation is 14 percent above 1990 levels. The Bush plan would slow growth in carbon dioxide emissions but would not reduce it. "This approach is a dereliction of government responsibility for protecting the American people," Kiernan said.

Another proposal calls for limits on mercury, sulfur dioxide, and nitrogen oxides, but allows companies to exceed the limits by buying credits from other companies that reduce emissions below the limits—a process called "cap and trade." This process leaves national parks and local communities vulnerable to air pollution because nearby power plants can acquire credits by early compliance to required reductions or by buying the credits from low-polluting companies in other states and increase their pollution above desirable limits. "We need dramatic reductions in these emissions to turn around the ongoing pollution of our national parks," said Don Barger, NPCA Southeast regional director. "This plan is quite simply a huge step in the wrong direction."

Global warming is melting the glaciers of Glacier National Park, where dozens of the ice formations may be reduced to none within 30 years. Sulfur dioxide-based pollution in Great Smoky Mountains National Park creates summer haze that blocks out once distant vistas, and nitrogen oxides that contribute to ozone are damaging plants in the park. Mercury contamination affects parks throughout the East.

"We're especially concerned that the administration soon will replace current Clean Air Act provisions with weaker measures that will increase air pollution," Kiernan said. "Upcoming revisions to the New Source Review program, which that covers upgrades in power plants, will worsen air quality in the parks."