consensus v. certainty

Uh, Rich:
In the Boston Globe, MIT climate scientist Kerry Emanuel marshals what will have to be the fall-back argument for fighting warming: “We do not have the luxury of waiting for scientific certainty, which will never come.” Really? That’s not what we were told even a few months ago — before climate alarmism acknowledged doubt.
There's a difference between consensus and certainty. E.g.: though there's general consensus Rich Lowry is stupid, we can never be entirely certain if he's just stupid or likes making stuff up.