EPA's efforts rest on three pillars. Last year the agency finalized an official "endangerment finding" declaring that greenhouse gasses endanger public health or welfare. Then they set up rules to regulate those emissions from cars. Following that they proposed rules to define which sizes of existing or new industrial facilities required regulation, and when.

All three elements are at issue in one mega-case being litigated in the U.S. Court of Appeals for the District of Columbia Circuit. That case, called Coalition for Responsible Regulation Inc. et al. v. EPA, combines 16 lawsuits which have all been appealed from federal district courts. Two weeks ago, EPA fended off an effort by the litigants to receive a legal "injunction" which would have temporarily blocked EPA from moving forward on the whole program. Sixteen states have weighed in on the side of EPA,, 14 oppose it; enviros are mostly allied with the Obama Administration while a wide variety of pro-business or right-leaning groups side with industry. Briefs on the case, which the judges will hear in parts corresponding to the three pillars, are due some time this spring.

Meanwhile, as ScienceInsider wrote yesterday, Texas has resisted efforts by EPA to either oversee the state's own regulation of CO2, or step in itself to do so. Earlier this month a court rejected the state's request to block the EPA's instruction to state regulators to set up greenhouse gas regulationss. ("Recognizing the proper role of the States, the Clean Air Act declares pollution prevention to be 'the primary responsibility of States and local governments,' " Texas had argued.) Now the state says that new or modified facilities will face a defacto moratorium because they won't be able to get a permit. EPA says that if the state were to cooperate it could offer those permits. "EPA is offering Texas a life-preserver and, bizarrely, Texas is treating it like a torpedo," David Doniger of the Natural Resources Defense Council in Washington, D.C., said in a blog entry.

Some cases working their way through the courts could engender new ways to cut emissions. In December, the Supreme Court agreed to take a case in which states and allied land trust organizations have charged that greenhouse gases emitted by a few big power companies constitute a "nuisance" under common law. (Briefs for American Electric Power v. Connecticut, which consolidates three similar lawsuits, are due in late January). Were the court to rule that pollutants did constitute a nuisance, it could give emitters' opponents a tool apart from the Clean Air Act to tackle greenhouse gases.

But that seems unlikely. Because U.S. Supreme Court Justice Sonia Sotomayor sat on an appeals court which heard one of the lawsuits, she will likely recuse herself, leaving the real possibility that the case will receive a 4-4 decision. That would send it back to the appeals level where courts have ruled on the side of the states. But it's unclear whether the case would get a review from all three appeals courts, which could lower the chances that the "nuisance" tool could come into use. (Plus there's the fact that the Obama Administration has not sided with the foes of industry as one might expect. Instead it has asked the Supreme Court to send the case back to the appellate court so that it can be reconsidered in light of the new greenhouse gas regulatory regime.)

It's worth noting that some power companies are not only staying out of court but defending the EPA regime. Earlier this month, west coast utility Pacific Gas and Electric and seven other big power companies wrote in support of the new rules:

The electric sector has known that these rules were coming. Many companies, including ours, have already invested in modern air-pollution control technologies and cleaner and more efficient power plants. For over a decade, companies have recognized that the industry would need to install controls to comply with the act's air toxicity requirements, and the technology exists to cost effectively control such emissions, including mercury and acid gases. The EPA is now under a court deadline to finalize that rule before the end of 2011 because of the previous delays.

To suggest that plants are retiring because of the EPA's regulations fails to recognize that lower power prices and depressed demand are the primary retirement drivers. The units retiring are generally small, old and inefficient. These retirements are long overdue.