Carol BrownerCarol Browner, headed for the door.Photo: White HouseCarol Browner, one of Obama’s top climate and energy advisers, is stepping down and leaving the White House in a few weeks — Politico got the story last night. What does it mean?

For one thing, it probably means the end of a position, “Assistant to the President for Energy and Climate Change,” that was more or less created for Browner. She believes that “the mission of her office will remain critical to the president,” according to a White House aide, which is of course quite different from believing her actual office will.

Browner is a player, so she knows what she’s doing. There was a chance she was going to move up; her name was on the short list for a deputy chief of staff job, but it looks like new Chief of Staff William Daley is going to bring in his long-time ally David Lane.

That would leave Browner stuck where she is, which isn’t likely to be any fun for the next two years. Her position was created to shepherd efforts toward a comprehensive climate bill, an enterprise that failed spectacularly. It’s hard to know how much blame for that can be laid at Browner’s feet, given that the White House never really threw its weight behind the effort and, oh, so many other people and institutions were busy screwing it up, but it’s deader than a doorknob.

What lies ahead is a massive, coordinated conservative assault on Obama’s climate/energy agenda — green stimulus, the EPA, efficient lightbulbs, just about everything in Browner’s wheelhouse. She would spend the next two years parrying absurd Republican attacks (the same attacks she’s been parrying for almost 20 years now), getting dragged in to testify at hearings, and generally playing defense in a hostile climate. After the emotional ringer of the last two years, it’s no surprise she didn’t want to take that on.

The question is, could anyone fill her shoes? Does anyone need to?

It’s hard to think of another figure with the same combination of climate/energy focus and political acumen. There aren’t a lot of people with policy chops who would relish wrangling bureaucracy in a game of defense for two years. A couple of people have suggested Arnold Schwarzenegger, but he a) didn’t prove particularly adept at wrangling the California bureaucracy, and b) is not really what you’d call a behind-the-scenes guy. He might be good as some kind of envoy or spokesman, but not a backstage wrangler.

Does Obama still need one? Obviously no substantial climate legislation is going to get done in the 112th Congress, certainly not anything requiring a massive, multi-agency push. But there is defending EPA. Perhaps Obama intends to leave that in Lisa Jackson’s hands, but EPA rules affect public health, too. They have housing implications, land-use implications, infrastructure implications … certainly one can imagine a coordinated push by the administration to defend EPA rules as integral to Obama’s agenda.

I’ve seen no sign of such a push, or even any real plan to defend EPA at all. In the absence of that, it’s hard to see what Browner’s position is good for any more. Apparently she feels the same way.