"Why should I do something that Congress and the president have decided they don't want to do as a matter of policy?" Judge Loretta Preska asked lawyers for the states.
Connecticut Attorney General Richard Blumenthal said the states would prove that the five power companies are responsible for 10 percent of the nation's carbon dioxide emissions.
The states are asking the judge to order the companies to reduce their carbon dioxide emissions by 3 percent annually for 10 years.
"Control over interstate pollution is primarily a matter of federal law," Blumenthal said.
Joseph R. Guerra, a lawyer for the companies, said the plaintiffs were asking the court to create a "piecemeal response to the problems that will allegedly flow from a worldwide phenomenon known as global climate change."
He said the states wanted the judge to "resolve an environmental policy question with sweeping implications for the nation's economy, its foreign relations and even potentially its national security."
The complaint seeks to force a reduction of carbon dioxide emissions by AEP and Cinergy of Ohio, Southern Co. Inc. of Georgia, Xcel Energy Inc. of Minnesota, and the federal Tennessee Valley Authority.
Preska said she doubted any ruling she could issue against the power companies would have much effect on global warming.
"All it does is slow it down," she said. "Unless something else is done, it won't reduce the threat."
Peter Lehner, a lawyer for the state of New York, said the states were only asking her to limit pollutants by five companies, not to solve global warming.
In addition to New York and Connecticut, California, Iowa, New Jersey, Rhode Island, Vermont, Wisconsin, New York City and three nonprofit land trusts are also involved in the complaint.