I would be very interested in a thread on Svalbard.

The Svalbard analysis can be seen as a case study in the dangers of basing an analysis on extreme observations, i.e., the LEAST reliable data points.

Basic humility tells you that when you find a 5-sigma event, either:

1) The data is perfect and your analysis is error free and you have found a completely amazing result.

2) There is an error somewhere in the data or your analysis.

The more extreme the finding, the more likely that 2) is the correct interpretation — erroneous analyses regularly produce extraordinary results, while correct analyses rarely do.

What glaring errors did you point out? Could you post them here? I also had some very reasonable concerns about the analysis and got censored.

w.

1. I understand that every blog post and email is not as good as a paper. All the more reason to publish more.
2. I do think you have a tendancy to not always have a rigorously logical train of thought, to wander at times in exposition. That’s ok. You’re still scarily bright and no one is perfect. But I think it’s something to watch.
3. I go on and on about the PC1 versus reconstruction because the “damage to the PC1″ is an overstatement of “damage to the reconstruction”. That you have at some other point connected the two is irrelevant, Steve. It’s still disingenuous in discussion and sloppy in analysis. The effect on the intermediate is not the same as the effect on the overall.

I don’t know why you go on about PC1 versus reconstruction so much.
We’ve been over this before but one more time. We’ve shown the impact on both NH reconstruction and PC1.

In the context of the time (and the circumstances are different now than in 2004), after MM03, Mann identified the North American PC1 as the “critical” series which accounted for the difference between MM03 and MBH results. So reconciling the two results had been isolated to the NOAMER PC1 – and reconciling the results was important at the time.

Analysis of the properties of the PC1 were critical. At that point it was a given that the this one series accounted for the differences. Now this needs to be explained to people, but that was understood between Mann and ourselves at the time. It’s gotten lost over time. You don’t have a whole lot of space to work with in GRL and we wanted to publish there as well so we had to pick issues. I wanted to deal with RE statistics. Nobody seems to have cared, but it’s really an important topic. The concept of spurious RE was not on anyone’s radar screen at the time. It still hasn’t been assimilated, but I’m hopeful that people will catch on. Some of these things take a while.

It’s amazing how many scientists in the field simply take their views from realclimate. As far as I can tell, the majority of them. I don’t think that the issue is exposition. While our exposition could undoubtedly have been better, our exposition has not prevented civilians like James Lane or Spence_UK from exactly grasping the points right away in a substantive way.