The first is that, as a policy matter, the deferral was absolutely the right thing to do. The science remains complex and not fully understood. Any regulations promulgated now are likely to be revised at some point. That kind of regulatory uncertainty is not any way to run an agency.
On the other hand, I find EPA’s legal justification less than fully convincing, to say the least. In fact, the more EPA defends its overall approach to GHG regulation under the Clean Air Act, the more the entire endeavor begins to feel like some vast Rube Goldberg construction, destined to come crashing down as the last domino is placed (and how’s that for a mixed metaphor?). It’s one thing for EPA to argue that the Tailoring Rule was necessary to avoid regulation of millions of de minimis sources of GHG. It’s another to rely on the same arguments to support deferral of regulation of a much smaller universe of biomass plants, however much EPA may have logic on its side. To defer because of scientific complexity is just not the same as deferral of millions of de minimis sources.
As I’ve acknowledged previously, this fine mess we’re in is not really EPA’s fault. EPA is just playing the hand it has been dealt by the combination of the decision in Massachusetts v. EPA and the refusal by Congress to enact legislation providing specific authority to regulate GHG.
It will be fascinating to watch what the Court of Appeals does with this case. It is certainly possible that the Tailoring Rule could survive while the Deferral Rule is struck down. This is one where I leave the speculation to others.