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.

That prompted immediate outrage from the likes of Environment Defence whose general counsel Jim Tripp said in a statement: "EPA is not following science or the law."

"This decision is like pulling over the fire trucks on their way to the blaze," added the organisation's president Fred Krupp. "For 40 years, EPA administrators have recognised the important role that California plays in innovating new standards to fight pollution."

According to the New York Times on Thursday, EPA administrator Stephen 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. Johnson reportedly 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 paper said 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 have vowed to sue to overturn the edict, the NYT added.

The New York Times said Johnson defended his agency's decision in a conference call with reporters and said: "The Bush administration is moving forward with a clear national solution, not a confusing patchwork of state rules. I believe this is a better approach than if individual states were to act alone."

The paper noted that the 17 states had waited two years for the Bush administration to issue a ruling on an application to set stricter air quality standards than those adopted by the federal government. The decision, technically known as a Clean Air Act waiver, was the first time California was refused permission to impose its own pollution rules; the federal government had previously granted the state more than 50 waivers.

The paper added that the emissions standards California proposed in 2004 — but never approved by the federal government — would have forced automakers to cut greenhouse gas emissions by 30% in new cars and light trucks by 2016, with the cutbacks to begin in 2009 models.

That would have translated into roughly 43 miles per [US] gallon for cars and some light trucks and about 27 miles per gallon for heavier trucks and sport utility vehicles, the report noted.

The new federal law signed by Bush on Wednesday will require automakers to meet a 35-mile-per-gallon fleet-wide standard for cars and trucks sold in the United States by 2020. The New York Times noted it does not address carbon dioxide emissions, but said such emissions would be reduced as cars were forced to become more fuel-efficient.

California's proposed rules had sought to address the impact of carbon dioxide and other pollutants from cars and trucks that scientists say contribute to the warming of the planet, the paper said.

According to the NYT, California governor Arnold Schwarzenegger said the states would go to federal court to reverse the EPA decision.

"It is disappointing that the federal government is standing in our way and ignoring the will of tens of millions of people across the nation," Schwarzenegger was quoted as saying. "We will continue to fight this battle."

Twelve other states — New York, New Jersey, Connecticut, Maine, Maryland, Massachusetts, New Mexico, Oregon, Pennsylvania, Rhode Island, Vermont and Washington — had proposed standards like California's, and the governors of Arizona, Colorado, Florida and Utah said they would do the same, the report added.

The New York Times said if the waiver had been granted and the 16 other states had adopted the California standard, it would have covered at least half of all vehicles sold in the United States.

Automakers reportedly praised the decision. "We commend EPA. for protecting a national, 50-state programme," David McCurdy, president of the Alliance of Automobile Manufacturers was quoted as saying.

"Enhancing energy security and improving fuel economy are priorities to all automakers, but a patchwork quilt of inconsistent and competing fuel economy programmes at the state level would only have created confusion, inefficiency and uncertainty for automakers and consumers."

Environment Defence said the Supreme Court ruled decisively in April 2007 that EPA does have the authority and the obligation to regulate global warming emissions. Two other federal courts - the 2nd district court in Vermont in September and the 9th district court in California earlier this month - also enforced states' rights to proceed with clean car rules.  The federal courts also dismissed automakers' claims that they did not have the technology to meet such standards.

The organisation said EPA had denied California's request because it believed the new CAFE standards in the recently authorised energy bill would suffice to reduce global warming emissions from new automobiles.

"New CAFE standards, if they go into effect, do not fully phase in until 2020," said general counsel Jim Marston. "The California greenhouse gas limits will occur earlier - beginning in 2009 and fully phased in by 2016. With the mounting evidence of climate change impacts occurring now, it is imperative that we are take action immediately."

The organisation claimed that implementation of the Clean Cars programme in the 17 states would lead to groundbreaking reductions in global warming pollution - by 2020, the program would prevent annual emissions equivalent to 100m tons of carbon dioxide, savings equivalent to closing over thirty 500 megawatt coal-fired power plants or removing 20m cars from the road.

The Clean Cars law, also known as the Pavley law and passed in California in 2003, would reduce carbon emissions by 22% by 2012 and by 30% by 2016.