Any major steps by the Bush administration to control air pollution or reduce emissions of heat-trapping gases came to a dead end on Friday, the combined result of a federal court ruling and a decision by the head of the Environmental Protection Agency.

In the morning, a federal appeals court struck down the cornerstone of the administration’s strategy to control industrial air pollution by agreeing with arguments by the utility industry that the E.P.A. had exceeded its authority when it established the Clean Air Interstate Rule in 2005. The court, the United States Court of Appeals for the District of Columbia Circuit, said the rule, which set new requirements for major pollutants, had “fatal flaws.”

A few hours later, the E.P.A. chief rejected any obligation to regulate heat-trapping gases like carbon dioxide under existing law, saying that to do so would involve an “unprecedented expansion” of the agency’s authority that would have “a profound effect on virtually every sector of the economy,” touching “every household in the land.”

Taken together, the developments make it clear that any significant new effort to fight air pollution will fall to the next president.