The Death of the Hockey Stick?

McIntyre had wanted to see it for years, and in 2008, utilizing a bylaw of the Royal Society, he enlisted their aid in forcing Briffa to finally start to release the data. Unfortunately, he still didn’t get enough, at least initially, to make any sense of it. But he did notice that, first, it had sparse data for the twentieth century and second, that it, unlike the typical treatment of such data sets, was not supplemented by any regional data -- Briffa was using it by itself. When McIntyre did such a supplementation himself using other data (reluctantly) provided by Briffa, the twentieth-century hockey-stick blade completely disappeared.

That was where things stood in 2009, just before the so-called Climate-gate email and model leak. After that, the CRU actually started to pull down data that had been previously available for years. It was clear from the emails that Briffa had been telling one story publicly and another privately as to his reasons for not including the devastating data, but the tide finally turned last month, when the University of East Anglia was finally forced by the British Information Commissioner to at least tell McIntyre which data sets were used in its results. Let’s let blogger “Bishop Hill” (aka Andrew Montford, who has written the book on the subject) tell the rest of the story (and read the whole thing for a detailed description of the deception):

The list of 17 sites that was finally sent to McIntyre represented complete vindication. The presence of Yamal and Polar Urals had already been obvious from the Climategate emails, but the list showed that Briffa had also incorporated the Polar Urals update (which, as we saw above, did not have a hockey stick shape, and which Briffa claimed he had not looked at since 1995) and the Khadtya River site, McIntyre’s use of which the RealClimate authors had ridiculed.

Although the chronology itself was not yet available, the list of sites was sufficient for McIntyre to calculate the numbers himself, and the results were breathtaking. Firstly, the URALS regional chronology had vastly more data behind it than the Yamal-only figures presented in Briffa’s paper

But what was worse, the regional chronology did not have a hockey stick shape -- the twentieth century uptick that Briffa had got from the handful of trees in the Yamal-only series had completely disappeared.

Direct comparison of the chronology that Briffa chose to publish against the full chronology that he withheld makes the point clear:

It seems clear then that the URALS chronology Briffa prepared to go alongside the others he put together for the 2008 paper gave a message that did not comply with the message that he wanted to convey — one of unprecedented warmth at the end of the twentieth century. In essence the URALS regional chronology was suffering from the divergence problem -- the widely noted failure of some tree ring series to pick up the recent warming seen in instrumental temperature records, which led to the infamous ‘hide the decline’ episode.

Remarkably, however, Briffa did allude to the divergence problem in his paper:

These [regional chronologies] show no evidence of a recent breakdown in [the association between tree growth and temperature] as has been found at other high-latitude Northern Hemisphere locations.

The reason for dropping the URALS chronology looks abundantly clear. It would not have supported this message.

His emphasis.

And new results are coming out almost by the day. Earlier this week, McIntyre reportedly received new Yamal data, which continued to confirm that there is no blade to the stick

What does this all mean? First, let’s state what it doesn’t mean. It doesn’t mean that we know that the planet isn’t warming, and it doesn’t mean that if it is, that we can be sure that it is not due to human activity.

But at a minimum it should be the final blow to the hockey stick, and perhaps to the very notion that bristlecone pines and larches are accurate thermometers. It should also be a final blow to the credibility of many of the leading lights of climate “science,” but based on history, it probably won’t be, at least among the political class. What it really should be is the beginning of the major housecleaning necessary if the field is to have any scientific credibility, but that may have to await a general reformation of academia itself. It would help, though, if we get a new government next year that cuts off funding to such charlatans, and the institutions that whitewash their unscientific behavior.