William Connolley has been reading the House of Lords report on The Economics of Climate Change and he's not impressed:
Because they decided to talk nonsense about the Great Hockey Stick debate. They manage to say: "We sought evidence that refuted the claims of McIntyre and McKitrick, but have not come across any detailed rebuttal." But this is where they have degenerated into bald-faced lying. Because had they contacted Mann (clearly they didn't) he would have pointed them to such. For heavens sake, its on the web at RC: Dummies guide to the latest "Hockey Stick" controversy has some info and links.
Later on they manage to say: "apparent divergences between land-based temperature records and satellite-based measurements, the latter showing some cooling rather than warming in recent years"
I think calling it lying is a bit harsh, since it may just be gross incompetence, but getting basic stuff like this so badly wrong leaves you with no confidence in the accuracy of the rest of the report.
I read parts yesterday. I concur with William. Rather than actually reviewing the evidence, they relied heavily on the interpretations of Paul Reiter and McKitrick to draw their conclusions.
Tim, you're being very generous to these people. As I noted on Stoat, the speed and timing of the Econ Committee's report (6 months from inception to publication, which seems to be some kind of record, and with its release timed for maximum political impact) makes it crystal clear that there was a pre-determined political agenda at work. Maybe we could call what they did "intentional incompetence," but in that case I would just agree with William that "lie" is more accurate.
Also, there are two other Lords committees (Science & Technology, EU Environment; committees with actual scientists among their members) for whom the subject of climate change is a little more central, and a review of their web pages indicates that they differ with the Econ Committee.
By the way, were you aware that the Econ Committee chair was a member of the Enron Board of Directors during the unfortunate events? In a sane world, this guy would be writing his propaganda from a jail cell.
Maybe they were talking about a rebuttal in the peer-reviewed literature. A posting at realclimate.org wouldn't qualify. Hasn't an anti-M&M paper by Mann been rejected?
In fact the funny thing is that they get caught up in the fine lines and split hairs produced by M&M. The first document (I wouldn't call it a paper) M&M produced made much of the warm 15th century they found. In recent years they have backed off this and they don't really draw attention to it unless specifically asked and then claim that they don;t think the 15th was warm but that it just shows the study was flawed.
However I guess they didn;t explain this to the House of Lords because they claim that M&M show a warm 15th century and thus if it is true then the current temperature is not unusual. This highlights one of the things I find disturbing about M&M. They are not very clear in how they present their information.
Nigel: I am not aware of any paper by Mann, although I have heard that GRL rejected a letter by A&W.
However more to the point, M&M have only published one peer-reviewed paper. I do not count E&E as a peer-reviewed journal. In terms of what they published in GRL - the most important aspect was the centered vs. de-centered issue and I think that we are all in agreement that this is a non issue in regards to MBH.
Jones and Mann 2004 refers to a submission by Mann to Climatic Change, which has never appeared. It seems odd that Mann wouldn't get published at Climatic Change.
I think that it's been proven that Mann's PC method mines for hockey stick shaped series. M&M argue that this matters because the method overweights bristlecone pines, which are flawed proxies.
I see that there are two big outstanding issues raised in M&M, both of which are live:
1) the lack of robustness of MBH98 to presence/absence of bristlecone pines. I've never seen a clear answer to this at realclimate and I can't make sense of the W&A scenarios as they apply to this issue.
2) the failure of MBH98 cross-validation statistics (R2) alleged by M&M. Again I haven't seen a clear answer to this at realclimate and W&A haven't reported R2 so far.
No, it hasn't been proved that Mann's method mines for hockey sick shapes. You might as well say that Fourier transforms mine for sine curve shapes.
I'm inclined to say that it is proven that Mann's method mines for hockey sticks.
As yo your second sentence, analogies are slippery. It raises the question whether mining for hockey sticks is a bad thing or not. It is if you don't tell anyone.
Principal components do not intrinsically mine for hockey sticks - only Mann's PC method. Mann never said that he modified his PC method to mine for hockey sticks (if he did it intentionally which is not certain).
Nigel, you can say that it is proven, but that does make it so.
Am I missing something here....? The observed datapoints display a hockey-stick shape, which is closely matched by the Mann fitted curve. Is there a different curve fitting model which produces as close a match without the hypothetical "mining for hockey sticks"?
Tim, for #8, the grammar would make more sense if you changed the "but" to an "and"; however, it does make sense as written.
Who cares if someone says they're inclined to say that something is proven? The certainty of the word "proven" doesn't really gel with a wishy washy phrase like "inclined to". They just have an inclination, big deal.