Comments on: Conflicted Reviewers Distort Literature

By: Weekend Roundup – August 14, 2010 « The Policy Lass

Weekend Roundup – August 14, 2010 « The Policy Lass — Sat, 14 Aug 2010 18:32:11 +0000

[...] at my favorite climate skeptic blog, CA, Steve McIntyre has several posts about his recent co-authored paper reviewing Santer 08′s analysis of the climate model’s [...]

By: Christy actualiza la disparidad modelos – realidad « PlazaMoyua.org

Christy actualiza la disparidad modelos – realidad « PlazaMoyua.org — Sat, 14 Aug 2010 09:45:50 +0000

[...] McIntyre (co-autor de MMH10): http://climateaudit.org/2010/08/10/conflicted-reviewers-distort-literature/ [...]

By: Climate Blog and News Recap: 2010 08 13 « The Whiteboard

Climate Blog and News Recap: 2010 08 13 « The Whiteboard — Fri, 13 Aug 2010 15:07:58 +0000

[...] comments MMH2010 http://rossmckitrick.weebly.com/uploads/4/8/0/8/4808045/mmh_asl2010.pdf Steve expands on the [...]

By: Nick Stokes

Nick Stokes — Thu, 12 Aug 2010 02:40:47 +0000

Re: Kenneth Fritsch (Aug 11 16:46), Kenneth, I did that on the forward calc. But it doesn't make much difference, so I didn't do it on the back-calc.

By: TAG

TAG — Wed, 11 Aug 2010 23:30:41 +0000

Why is Annan assuming that the model mean will have the same properties as the individual models. if it did then wouldn’t that make the creation of multiple models pointless. For the mean and the models to match in properties they must all have the same properties. So one model would represent all of them and the generation of more than one is pointless. For the mean to be a better predictor of reality than the individual models, the process of creating it must somehow suppress some properties that cause errors in the prediction of reality.

By: TAG

TAG — Wed, 11 Aug 2010 23:23:40 +0000

Annan wrote on his blog

Well, duh. Of course the obs don’t match the ensemble mean. Even the models don’t match the ensemble mean – and this difference will frequently be statistically significant (depending on how much data you use). Is anyone seriously going to argue on the basis of this that the models don’t predict their own behaviour? If not, why on Earth should it be considered a meaningful test of how well the models simulate reality?

I’m just a layman but is this a group of rather strange statements that miss the point of the paper entirely

It is acknowledged that models are immature and that they do not. as yet, make useful predictions individually. However it is asserted that the mean of the models may make a better prediction than individual models. The new paper is a test of that assertion.

One puzzling statement – if it is acknowledged that the individual models are poor predictors of reality and that the model mean can be then why is it surprising that the models do not match the mean? Isn’t that a rather essential part of the assertion that the model mean is a predictor of reality and is used as such by the IPCC.

Another puzzling statement – the paper’s test was of the model mean which supposedly has different properties than the individual models. However there is an assertion that this is a test of how well the individual models simulate reality.

By: Kenneth Fritsch

Kenneth Fritsch — Wed, 11 Aug 2010 22:52:52 +0000

The Shapiro-Wilkes test for normality does not reject the hypothesis that the distribution of model means used in MMH 2010 has a normal distribution.

By: Kenneth Fritsch

Kenneth Fritsch — Wed, 11 Aug 2010 21:48:04 +0000

Nick Stokes, the means and sds have to be considered based on the weighting used in MMH 2010 for the model ensemble means. The weightings are based on the number of runs made with each model.

By: Kenneth Fritsch

Kenneth Fritsch — Wed, 11 Aug 2010 21:46:30 +0000

Nick Stokes, the means and sds have to considered based on the weighting used in MMH 2010 for the model ensemble means which is based on the number of runs made with each model.

By: Kenneth Fritsch

Kenneth Fritsch — Wed, 11 Aug 2010 20:32:50 +0000

I have posted this comment at TAV:

After my second read of MMH 2010 it is apparent that the statistic used was not a trend of a difference series between the surface and troposphere temperature anomalies, but rather the LT and MT series. I thought that it was that measure (difference between surface and troposphere) that was important in the debate about the tropical surface and troposphere trends. I also thought that at CA (and in Santer et al. (2008)) it had been shown that using the differences series allowed one to more readily show significant differences between models and observed results because the difference series has less variation. Could not a panel regression have been used with difference series?