However, these results are in large part dependent on a detrending step not used by MBH, which is physically inappropriate and *statistically not required*.

So that detrending step was “statistically not required?” What ever happened to being statistically “robust?”

I have never seen any evidence that Mann, Wahl or any associate have approached either 1, or 2.

That’s because they’ve “moved-on.”

]]>MBH98: correlation r and squared-correlation r^2 statistics are also determined

Yes, but there is no mentioning of those calculated for the *temperature reconstructions*.

Mann Dec 2004: Our reconstruction passes both RE and R^2 verification statistics if calculated correctly.

Now the reduction of error (RE), usually called the *coefficient of determination* and called “conventional ‘resolved variance'” in MBH98, is usually denoted with the capital letter, i.e., R^2. So RE=R^2 :) Also, even if you take R^2 to be the squared sample correlation coefficient, the result holds if “calculated correctly”! This is because in the simple linear regression (one predictor) R^2=r^2.

Mann to NAS Panel Mar 2006: I did not calculate the verification r2 statistic. That would be a foolish and incorrect thing to do.

Again correct. His computer may or may not have calculated those, very likely he did not do that himself :) It would be foolish since his computer can do it much better, and incorrect because it just might show that there is no statistical skill in his recostructions.

]]>A couple of days ago, realclimate was huffing and puffing about how an amendment published by VZGT in an "obscure" journal was an insufficient correction – leaving aside the issue of whether detrended-nondetrended is germane to the point. GRL is not "obscure", but neither is it Nature. If Mann found that the confidence intervals published in NAture were wrong, isn’t that the place that he should have pointed this out? And even if he had failed to previously do so, how could he justify not doing so in the 2004 Corrigendum?

]]>The properties of the 1820 step differ from the properties of the 1400 step. Mann presumably noticed this in 1999 – hence the different confidence intervals in MBH99.

Did he even carry out a Mannian "inspection" on the residuals from steps other than AD1820? Or is this one more time, like the verification r2, where the results for the 1820 step wre reported but not the results for the problematic early step?

I wish that others would write to Nature and ask for the results of the individual steps so that these "inspections" can be checked.

]]>]]>The spectra of the calibration residuals for these quantities were, furthermore, found to be approximately “white’, showing little evidence for preferred or deficiently resolved timescales in the calibration process.

I claim discovery or at least co-discovery of the fact that Al Gore invented algorithms. ;-)

http://www.google.com/search?q=%22al+gore%22+%22only+discovery%22+algorithms

All the best

Lubos