Yesterday, EPA Administrator Jackson issued a letter to Senator Jay Rockefeller responding to certain questions regarding EPA regulation of GHGs under existing Clean Air Act authority, including promulgation of the so-called “Tailoring Rule”, describing how stationary source regulation under the existing PSD program would be phased-in once GHGs are subject to regulation. Here are the highlights:

EPA still expects to promulgate the Tailoring Rule by April 2010.

The GHG permitting threshold will be “substantially higher than the 25,000-ton limit that EPA originally proposed.”

No permits will be required until 2011. Initially, only facilities otherwise subject to CAA permitting will be required to obtain permits. The smallest facilities will not be subject to GHG permitting before 2016.

You can talk all you want about global warming, but it seems to me as though it’s EPA that’s feeling the heat. EPA has clearly heard the threats of a Congressional resolution barring EPA regulation of GHGs under existing authority. The reaction from Congress is all the evidence one needs. Both Senators Rockefeller and Murkowski praised the letter. While neither indicated that the letter would be sufficient to stop them from pursuing Congressional action, it might be enough to peel off some fence-sitters who might otherwise have felt compelled to support the legislation.

What does EPA’s statement of intent mean for various law suits swirling around this issue?

I don’t see any impact on litigation against the Endangerment Finding; it will still proceed and it will still lose.

The likelihood of law suits from environmental groups alleging that EPA is shirking its responsibilities under the CAA has certainly increased. Moreover, while EPA has a lot of discretion, I could imagine courts saying to EPA: “Nice try, but the CAA doesn’t give you the kind of flexibility you have asserted in the Tailoring Rule. Only Congress can provide that flexibility by amending the CAA.” In this respect, the situation is similar to litigation over the CAIR regulations, which pretty much everyone liked, but which were struck down because the approach EPA took in the CAIR rule wasn’t consistent with the CAA.

Finally, any kind of regulation by EPA will provide an additional defense to private nuisance litigation. As I have previously noted, one question raised by the nuisance law suits is whether EPA has regulated GHG in a manner sufficient to “displace” the common law of nuisance. In this respect, the sort of program described yesterday by Administrator Jackson may be the best possible outcome for the regulated community, because it will narrow EPA regulations while providing a ground to preclude nuisance litigation.