WASHINGTON - For decades, California has set the pace for the country on air pollution and climate change, adopting ever-higher standards for controlling auto emissions and, more recently, greenhouse gases that scientists say have led to global warming.

Now, California's dominance is being challenged - under attack from another mega-state that wants to displace California by calling for a freeze of the status quo instead of a move toward tighter controls.

In effect, Texas is staking out a role as the anti-California.

With Republicans in control of the House of Representatives, powerful Texans such as Rep. Joe Barton of the House Energy and Commerce Committee have vowed to check the Environmental Protection Agency's efforts to use its existing authority to curtail greenhouse gases.

An even more ambitious challenge is coming directly from the Texas state government and leading Texas politicians. State Attorney General Greg Abbott, with the support of Republican Gov. Rick Perry, has filed seven lawsuits against the EPA in the last nine months.

In some ways, Texas' attack was bound to be bigger and bolder than it might have been from other states.

"At times, they're their own country," said Bill Becker, executive director of the National Association of Clean Air Agencies, a group of state environmental regulators.

"They feel strongly, politically, that this is an issue that shouldn't pertain to them, and they would like to proceed on their own terms."

And Texas corporations clearly have California in their sights, as reflected in their determined though ultimately unsuccessful attempt to roll back California state law in the recent election.

In a recent letter to the EPA, state officials likened the agency's efforts to regulate greenhouse gases to a socialist "plan for centralized control of industrial development."

Texas officials and their allies assert that regulations they consider hasty and onerous would hurt the state's vast economy, which relies on oil refineries, coal-burning power plants and manufacturing.

Those facilities have made Texas the nation's largest emitter of greenhouse gases from power plants, industrial facilities and other so-called stationary sites, according to an Environmental Defense Fund analysis of EPA data.