Really enjoyed the thread.

Perhaps tangential, but don’t the Climategate emails on the MWP demonstrate the integrity of the climate science community rather than the reverse ?

From “Dealing A Mortal Blow To The MWP” on this blog (http://climateaudit.org/2010/04/08/dealing-a-mortal-blow-to-the-mwp/) the documentary record of Climategate MWP emails between Overpeck and Briffa demonstrates that climate scientists reacted negatively to any hint that they should conceal or manipulate data and that this commitment to impartiality was forcefully re-stated by Overpeck.

The exchange reads like this:

Overpeck: I wish to deal a mortal blow to misuse of the MWP.
Briffa: Are you asking us to cheat ? I find that disturbing.
Overpeck: Absolutely not.

But surely if Climategate proves deceit the exchange should have said:

Overpeck: I wish to deal a mortal blow to the MWP.
Briffa: Great. Let’s cook the data.
Overpeck: Yeah. Go for it. Let’s all get rich.

The Climategate trove is meant to be an open window on the venality of the climat eresearch culture. But on the MWP they demonstrate integrity.

Comparison of the new timeseries with five existing tree-ring based reconstructions from northern Scandinavia revealed synchronized climate fluctuations but substantially different absolute temperatures. Level offset among the various reconstructions in extremely cold and warm years (up to 3 °C) and cold and warm 30-year periods (up to 1.5 °C) are in the order of the total temperature variance of each individual reconstruction over the past 1500 to 2000 years. These findings demonstrate our poor understanding of the absolute temperature variance in a region where high-resolution proxy coverage is denser than in any other area of the world.

Steve: This is a companion paper to the Esper et al 2012 paper in Nature last summer. I found the Esper papers interesting for different reasons than WUWT. There were a couple of points in it that I hadn’t thought about it. The Nature paper made a nice sensitivity discussion of Kaufman et al 2009 that was very much in CA style – but it was something that I hadnt noticed and rather smiled at them pointing it out.

Steve: it looks like another screen by correlation paper a la Gergis. I have corresponded with Ljungqvist from time to time and have data for this.

As I said, we’ll have to look at the paper and judge it on its merits. I know Christiansen knows about the variance loss, he’s debated this on different blogs, including Lucia’s blog, Jeff Id’s blog where his correspondence with Jeff was reproduced, including this:

1) All methods strongly underestimates the amplitude of low-frequency variability and trends. This means that it is almost impossible to conclude from reconstruction studies that the present period is warmer than any period in the reconstructed period.

See Eduardo’s post here too.

Steve: Variance loss and bias from correlation-screening are different issues.

I also tried to get clarification on their decision to use the Dulan series, a precipitation series, as a temperature proxy. The response was basically that one author had discussed the matter with Chinese scholars other than the ones who created the series, and he was told it could be interpreted either way and the region has a strong correlation between temperature and precipitation. I tried to pursue the matter further, but after not getting a response to an e-mail, I lost interest and dropped it.

Long story short, the paper has issues though I don’t know how much impact those issues have. What I do know is at least five of the 16 series they used in their millennial reconstruction are questionable, at best. That includes one series which doesn’t meet their criteria for inclusion, as well as the Avam-Taimyr, Yang, Dulan and Yamal series.

It may relate to this comment I made:

Addressing that fully would amount to a full-fledged research paper. Nonetheless, with the uncertainties in comparing reconstructed to true temperature, while it seems unlikely, it is at least possible that MWP temperatures could be similar to current global mean temperatures. I would predict they are not warmer, but we are also missing a lot of frequency content for that period, so I do not think you can categorically state even in 2012 that current temperatures are warmer than the MWP.

Steve: it looks like another screen by correlation paper a la Gergis. I have corresponded with Ljungqvist from time to time and have data for this.

The talking point crowd(s) will have fun with one.

“Mosher,
you are perfectly right to expect documentation of a claim unless there is additional supporting evidence. For instance, it seems probable that the ANU scientists were threatened on site, because the University took the trouble of shifting their location, and providing security guards for their new location (which they did not publicize at the time).

##############
I don’t see the move as additional evidence of anything except that a claim was made. It is not evidence about the claim, it is evidence that a claim was made.

“In the case of the CRU non-disclosure agreements, if the original source of the data sells the data commercially, then the existence of a non-disclosure agreement with the CRU requires no further evidence. If, on the other hand, they provide it to all comers, the claim of a non-disclosure agreement would be highly suspect and I would require sight of the documentation to assuage my skepticism.”

Well then you need to actually review the case. Since the data in question was supplied to peter webster and we had evidence of that the claim of non disclosure was suspect. Second, when we asked for a list of those countries which had non disclosures so we could approach them, we were rebuffed. Third, when I consulted the CRU guidelines about entering into non disclosures and found that CRU was not allowed to unless the data was NECESSARY TO THE MISSION, I considered that as additional evidence that there was no agreement.
Fourth, when they denied a request on a false basis ( they argued a use restriction that made no legal sense given my years of experience with licencing ) I considered that as additional evidence.
The final argument of course is that we were right to be skeptical and the ICO agreed. game set match.

“Of course, in the later case the willingness or unwillingness of CRU to disclose the data, is irrelevant as any person attempting replication can simply obtain it from the original source.”

Wrong. The goal was not to replicate the study. My goal was to AUDIT the work. To audit the work I would need both the copy provided by the source to ME and CRU’s copy of the “same” data. You don’t understand this work. The first order of business is to get a list from CRU of all the stations they used. They fought that. They next stage would be to get their copies of the data AS USED. The last step would be to get the data from the original source and compare. basic quality checks. You can stop loosing arguments by simply agreeing with the ICO.

http://joannenova.com.au/2012/05/pathological-exaggerators-caught-on-death-threats-how-11-rude-emails-became-a-media-blitz/

http://www.co2science.org/data/timemap/mwpmap.html

The map contains links to short descriptions of the actual studies…