As far as policies to reduce greenhouse emissions go, most economists argue that a straight-up carbon tax would work more effectively than a cap-and-trade regime, like the one Europe's struggling with. But politicians generally avoid even talking about carbon taxes--all of the big climate bills in the Senate involve cap-and-trade--for fear of being branded a puppy-hating socialist and all that.

So it's a semi-big deal that Chris Dodd decided to break the taboo and propose a "Corporate Carbon Tax" in his big energy speech the other day. Granted, a carbon tax that was actually refunded to consumers would be a lot more feasible than what Dodd's proposing. Still, it's nice to see one of the long-shots do something dramatic to broaden the policy conversation a bit, rather than just mull around and wait to get voted off the island.

--Bradford Plumer