Can states cut carbon? EPA says no.

The political tussle over whether carbon dioxide is a pollutant subject to government regulation has gone on for years.

Early in his first term as vice president, Al Gore pushed a tax on CO2. Democrats and Republicans in Congress were both skeptical. The idea went nowhere.

As a presidential candidate, George Bush seemed to think regulating CO2 was a good idea. At least he said so.

After his election, then-Environmental Protection Agency (EPA) administrator Christie Whitman marched forth in support of what she thought was White House policy. She quickly got reeled back. Two years later she resigned, complaining that Vice President Dick Cheney kept pushing for weaker air pollution controls.

Fast forward to the present, and the fight continues – this time pitting the Bush administration against a group of 19 governors led by Arnold Schwarzenegger (R) of California. California had passed a law forcing automakers to cut greenhouse-gas emissions by 30 percent in new cars and light trucks by 2016.

But the EPA failed to go along.

In explaining his refusal, EPA administrator Stephen Johnson last week wrote that California had not proved "compelling and extraordinary conditions" allowing it to be granted a waiver under the federal Clean Air Act because the rest of the nation also suffers the effects of global warming. Mr. Johnson told the Associated Press:

"I'm not saying that California isn't experiencing problems as a result of global climate change.... There are in fact other parts of the country that are actually worse."

Environmentalists and California officials disagree with Johnson's interpretation, contending that California has been granted Clean Air Act waivers in the past to deal with problems that are happening elsewhere, such as diesel pollution. The AP story points out:

"Critics also contend that California does, in fact, have uniquely worse problems from global warming compared with other states, including wildfire risks, air pollution, and water supply shortages."

Anything that makes air pollution worse can be harmful to Californians, many scientists contend. A recent study by atmospheric scientist Mark Jacobson at Stanford University concludes that warmer temperatures would mean fewer winds to blow pollution out of cities. Higher levels of water vapor in the air could also help catalyze the production of ozone, the main component of smog, the study says. The online news service ScienceNOW quotes two scientists:

" 'This work adds an important component to our overall understanding of the links between greenhouse gas emissions and adverse health impacts today,' says Kim Knowlton of Columbia University and the Natural Resources Defense Council in New York City. Bart Croes, a staff scientist at the state of California's official Air Resources Board in Sacramento, says the work's finding bolsters the state's argument that it should be allowed to set controls for air pollution that are stricter than national standards, including limits on CO2 emissions."

US auto manufacturers and overseas companies have fought the California proposal, saying it would hurt their businesses. Reuters reported:

"Automakers said trying to meet both federal efficiency standards and another, stricter standard adopted by states would add huge production costs and increase prices."

The California rules would require automakers to make vehicles that get 44 miles per gallon by 2020 – more than a new federal law requiring an increase to 35 miles per gallon by 2020. The San Francisco Chronicle reported:

"The ruling has even become an issue in the presidential race, with the leading Democrats, Hillary Rodham Clinton and Barack Obama, and the likely GOP nominee John McCain, all saying they back the states' efforts to set tougher rules."

The fight has revealed a rift between political appointee Johnson and the EPA's legal and technical staff, who argued that California's request was warranted and that rejecting it would not survive a court challenge. In an opinion piece, the Eugene, Ore., Register-Guard said:

"EPA staffers made the case that California's global warming problems are, in fact, 'compelling and extraordinary.' They include the loss of coastline due to rising sea levels, diminishing water supplies through reduced snowpacks, wildfires, air pollution, insect infestations, and ozone problems."

California and other states have filed suit to overturn Johnson's decision.