Andy Revkin is interviewed on America's NPR on the subject of the aftermath of Climategate. A transcript can be seen here. During the course of the interview, a member of the public asks AR about the Hockey Stick.
The original paper was riddled with caveats, all these could, would, might, to be sure, kind of phrases. And it - but then it quickly got spun, including by the IPCC in 2001. In the illustration they derived from it, they removed the gray bands that showed you the error, the possible up and down error. And as you go farther back in time, the range of possible error in these estimates is much, much higher. So that was where the problem was. The National Academy of Sciences did a study that assessed this. And largely, there were some problems that they raised with the way it had been done. But since then also, the main thrust of that work has been repeatedly replicated by other groups of scientists.
So the idea that we're in a period of unusual warming in the last 50 years has not been erased. The - what's been returned is - for the original paper - the sense that it's important to be sure you talk about the things we don't know, even when you talk about what's been learned in climate science. And if you don't do that, then you can be accused of, kind of, oversimplifying things.
All very strange. Can Andy really be unaware that Mann was a lead author on the paleoclimate chapter of the Third Assessment Report? Does he also not know that the "repeated replications" mostly rely on the same faulty data as the Hockey Stick itself? And I can't say I was aware that the IPCC had removed the error bars from the graph either (perhaps he means in the spaghetti graphs?).