One of the big reasons a cap-and-trade bill could still pass Congress this year is the fact that the EPA is making preparations to put forward its own carbon regulations on power plants and other industrial sources. (I wrote a primer on what those rules would entail here.) That puts pressure on reluctant senators: Either they write a bill to deal with carbon emissions or else the EPA will use the clumsy tools under the Clean Air Act and do the job itself. Many businesses would prefer Door #1.

Of course, there's a third alternative, too: Congress could just weaken or abolish the EPA's authority over greenhouse gases. Alaska Republican Lisa Murkowski had a plan to do just that, in an amendment she was planning to introduce on January 20. (She's even found a House ally: North Dakota Democrat Earl Pomeroy.) Granted, it's doubtful her amendment could muster 60 votes and overcome a filibuster, but if she narrowed its scope—say, by simply postponing EPA regulations for a year—then who knows?

Except now it's unclear what Murkowski's going to do. Yesterday, The Washington Post revealed that two industry lobbyists had helped her craft the beta version of her EPA amendment back in September (that one failed because automakers pointed out it would also scotch the new fuel-economy rules for vehicles). So Murkowski's staff is playing defense with the press and reportedly might hold off on any new amendments for now.

Then there are other complications: Even if Murkowski does move ahead, some industry types worry that Democrats could tack on their own "second-degree" amendments that actually boost the EPA's efforts. For instance, the agency is trying to tailor its greenhouse-gas rules so that they only apply to the largest polluters (if every small source of CO2 was regulated, it'd be a nightmare). Opponents of regulation are trying to fight this move in court—they want the nightmare scenario. But congressional Dems could just pass their own tailoring rule and put an end to the lawsuits. So there's a lot of scrambling, and this will be the first big climate-related story to watch when Congress comes back from recess.

(Flickr photo credit: cordovaraven)