I didn't set out to spend all week endorsing Jonathan Chait posts, but he's got a follow-up to the cover story he wrote last week and, well, I endorse it. Like Chait, I continue to believe that Obama's EPA will issue CO2 standards on existing power plants. At the very least, there's no dispositive evidence that it won't. And I too believe that those standards are the most important piece of Obama's climate legacy, if not his overall legacy.
But Chait passes over a key fact that, to my eternal puzzlement, plays little role in the discussion about EPA rules. Quite simply, EPA is legally obligated to issue these rules.
I said it all in a post I wrote early last year, but to recap:
1. In 2007, the Supreme Court ruled in Mass v. EPA that CO2 qualifies as a pollutant under the Clean Air Act.
2. In 2009, EPA issued an endangerment finding that deemed CO2 a threat to public health.
Once those two things happened, a cascading series of of legal obligations was set into motion.