Step aside, Affordable Care Act.

If you aren’t already, get used to hearing about the Clean Power Plan. Perhaps the most ambitious regulatory effort ever put forward by the EPA, the Plan represents the largest, farthest-reaching component of the Obama Administration’s response to greenhouse gas (GHG) emissions and climate change. So far, we’ve only seen EPA’s initial proposal; the Agency is expected to release its final rule this summer. But folks aren’t waiting for the final draft to start kvetching.

If ever a rule had “Supreme Court Review” written all over it, this would be the one. This past summer, in a decision upholding an earlier EPA regulation, the Court nonetheless admonished the EPA about “claim[ing] to have discovered in a long extant statute [i.e., the Clean Air Act] an unheralded power to regulate a significant portion of the American economy.” Many Court watchers suspect this was a warning shot or at least an omen of grave portent for the EPA.

In the months to come, you’re going to get earfuls about the Plan whether you get your news fromNPR, the Economist, or somewhere in between. So consider it a public service that I’m going to boil it all down for you right here on Notice & Comment. And I’m even going to do it in a reader-friendly, question-and-answer format.

Really? That’s exceedingly thoughtful of you.

Yes, it is. Now let’s get on with it.

Right. So what’s the Clean Power Plan about, anyhow? I mean, haven’t we been cleaning up our power for some time now?

We have, but the Clean Power Plan is new. It’s the first comprehensive rule that the EPA has ever written to deal with GHG emissions from existing power generating units in the utility sector.

“Existing”? As opposed to what, all those “non-existing” power plants?

As opposed to new plants. Under the Clean Air Act, if you build a brand new power plant, it must comply with one set of rules; existing plants get different rules. It’s just like cars: new cars are required to have really low emissions, but your old car—your “existing” car—will never be subjected to that standard. For this reason the Clean Air Act has been said to have a “new source bias.” Rules for new sources have historically been quite stringent; rules for existing sources are much more lenient. This has caused many power plant managers to keep their old facilities up and running for decades longer than previously expected.

Interesting. So tighter standards might not mean cleaner air?

That’s exactly right. This has been a leading criticism of the Clean Air Act for a very long time. In particular, folks have been quite concerned about older coal-fired power plants. The authors of the Clean Air Act weren’t too concerned about them, apparently because they thought they’d be retired soon. They didn’t realize that the law they were passing would create strong incentives to keep them alive much, much longer. Many of those plants are still in operation today—even though they were already nearing obsolescence when the modern Clean Air Act was passed in 1970.

So it’s these plants that are targeted by the Clean Power Plan?

Sort of. Existing power plants were already subject to regulation, but that regulation was on the basis of pollutants other than GHGs. The Clean Power Plan is the first rule to address GHGs from these facilities. But a big part of what makes the Plan so controversial is that it doesn’t exactly require those plants to clean up their act. It goes farther than that. It could force states to reduce GHG emissions from many other sources and sectors, too. But let’s pause for now, and take that up in our next post.

I wait with bated breath.

I’m sure you do. But the blogosphere will have to wait a few days for the gripping continuation.