analysis Republicans in the new Congress will pose a greater threat to the Obama administration's strategy to regulate greenhouse gas polluters than a plethora of industry lawsuits.

The Environmental Protection Agency, or EPA, is marching ahead with rules requiring big polluters like coal-fired power plants, oil refiners, and cement manufacturers to get permits starting January 2 to emit gases blamed for warming the planet.

President Barack Obama has always said the EPA would regulate carbon emitters if lawmakers failed to pass a climate bill.

Republicans, who will control the House of Representatives in January after winning some 60 seats in the midterm elections, are organizing to stop that from happening. They say the regulations will cost industry jobs and billions of dollars as the country struggles to recover from the recession.

The EPA is already under fire from business groups like the Chamber of Commerce, the American Iron and Steel Institute, and the National Association of Manufacturers, who have filed suits to block it from regulating.

But the lawmakers represent a bigger threat. "Congress doesn't give the EPA nearly as much deference as the courts do, and there are about to be a lot more Republicans and unenthusiastic Democrats," said Michael Gerrard, the director of the Center for Climate Change Law at Columbia Law School.

The uncertainty about the future of emissions policy could stall billions of dollars of investments in power plants and factories and prove to be a painful hurdle to longer-term growth when the economy begins to recover.

It will also hamper the Obama administration from taking a leading role in annual global climate talks in Mexico that start later this month.

Bottom line Even before January, Republicans could add language that would delay the EPA from acting to a short-term spending bill that would fund the government until about February. Next year, they could attach it to longer-term spending bills that would fund the government through September or through fiscal year 2012.

Nobody says it will be easy to do, but the goal of Republicans is to attach language to a spending bill that Obama could not veto because doing so would shut down the government.

Efforts to do that or attach text to other bills stopping the government from funding EPA climate regulation would likely be widely supported in the House.

"The bottom line...is we're not going to allow (the EPA) to regulate what they cannot legislate," Representative Fred Upton, a contender for chairing the House Energy and Commerce Committee, told the Washington Examiner this week.

Representative Joe Barton, Upton's competition for the seat is also against EPA regulation.

Even before Republicans won all those seats, they tried to attach such language to spending bills in the House. An amendment that would have stopped such EPA efforts for two years was blocked by a vote of seven to seven in an appropriations subcommittee last summer.

Republicans in both chambers could also get support from Democrats in states where fossil fuels play an important economic role. Senator John Rockefeller, a Democrat from coal-rich West Virginia, will likely try to move legislation delaying the EPA from acting for two years.

And with Republicans also winning seats in the Senate, they are seeking more than just a delay.

"Longer term.. we would like to find common ground for a permanent removal of EPA's ability" to regulate carbon, said an aide to a senior senate Republican.

Columbia's Gerrard said some of the administration's moves to cut emissions in other industries, such as cars and trucks, should be safe from both legal and congressional moves because the auto industry has so far demonstrated it is willing to comply with the rules.

More vulnerable in the courts is the EPA's move to apply the Clean Air Act only to big polluters that emit at least 100,000 tons a year of carbon dioxide. Gerrard said the industry groups had about even chances in the courts of stopping the EPA on that so-called "tailoring rule." If industry wins, it could halt the EPA from regulating by drowning it in paperwork for the tens of thousands of smaller polluters would have to get carbon permits.

The industries have asked the U.S. Court of Appeals for the District of Columbia for a stay on the EPA rules that could be issued before the end of the year. That could give clues as to how successful the cases will be next year, Gerrard said.

In the meantime, liberals are wondering whether Republicans will stick to stopping EPA from regulating carbon, or whether they'll try to stop other agency regulations as well.

The new Republican leadership has indicated it may try to stop the EPA's plans to regulate mercury, smog, acid rain, and coal ash.

"This would be a disaster for public health as well as increase uncertainty for businesses that need certainty before making investments," said Daniel Weiss, senior fellow at the Center for American Progress Action Fund.

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