HARTFORD, Conn. (AP) – Maine and two other states filed a lawsuit Wednesday against the Environmental Protection Agency in an attempt to force the federal government to regulate the levels of carbon dioxide permitted in the air.

The suit seeks to add carbon dioxide to the list of pollutants that are regulated under the Clean Air Act. The current list includes six pollutants: carbon monoxide, lead, nitrogen oxides, ozone, particulates, and sulfur oxides.

“Our lawsuit is a last resort,” said Connecticut Attorney General Richard Blumenthal, who filed the lawsuit with Massachusetts Attorney General Thomas Reilly and Maine Attorney General Steven Rowe.

Blumenthal said the EPA had failed to use its authority to protect the public. “Now, the courts must compel it,” he said.

A message seeking comment was left with an EPA spokesman in Washington D.C.

Research shows that carbon dioxide is a source of global warming, and therefore is subject to regulation under the Clean Air Act, the lawsuit states. It alleges that without EPA intervention and regulation the problems of global warming will intensify in the next several years. That could mean increased temperatures, rising sea levels, and health risks like insect-borne diseases, the attorneys general said.

“It is well-accepted in the scientific community that emissions of this leading greenhouse gas are contributing to global warming,” Rowe said, adding, “We are already seeing the effects.”

Reilly said, “The federal government not only has a clear responsibility to address the problem, but a legal obligation as well under the provisions of the Clean Air Act.”

In a letter to EPA Administrator Christine Todd Whitman in late January, the three were critical of the Bush administration, saying it has failed to act on carbon dioxide emissions.

The White House has said it is developing a five-year plan for research on climate change. But critics have said it is a move that would put off difficult decisions until Bush is out of office.

The attorneys general argue that the EPA has admitted in a legal memorandum and in testimony to Congress in 1988 and 1999 that carbon dioxide is a pollutant.

“We are already seeing its effects, and EPA itself predicts that the problems associated with atmospheric warming will intensify,” said Rowe.

If the lawsuit succeeds, the EPA would be required to set standards for acceptable levels of carbon dioxide in the air. In 1976, lead was added to the list of pollutants after the Natural Resources Defense Council sued to have it added.

AP-ES-06-04-03 1301EDT