WASHINGTON  The Environmental Protection Agency on Wednesday denied California and 16 other states the right to set their own standards for carbon dioxide emissions from automobiles.

The E.P.A. administrator, Stephen L. Johnson, said the proposed California rules were pre-empted by federal authority and made moot by the energy bill signed into law by President Bush on Wednesday. Mr. Johnson said California had failed to make a compelling case that it needed authority to write its own standards for greenhouse gas emissions from cars and trucks to help curb global warming.

The decision immediately provoked a heated debate over its scientific basis and whether political pressure was applied by the automobile industry to help it escape the proposed California regulations. Officials from the states and numerous environmental groups vowed to sue to overturn the edict.

In an evening conference call with reporters, Mr. Johnson defended his agency’s decision.

“The Bush administration is moving forward with a clear national solution, not a confusing patchwork of state rules,” he said. “I believe this is a better approach than if individual states were to act alone.”