> Now now. Per isn't McKitrick, and isn't McIntyre.
> Tim; as I recall, you are very good at ad hominem attacks, and kind of > short on backing it up. You will make ad hominem attacks as you see > fit.
Given your complaints about undisclosed vested interests I think Tim has a very good point. Asking who you are can't be considered to be an ad hominem. As Tim seems to know who you are and you ask him to "back it up" I think you should tell us, Tim. I'm curious.
peroxisome wrote: > I'm still not sure what your point is. There are uncertainties on the > measurements/reconstructions. How close an agreement do you expect, and
> why?
> I am not sure that the 2 sigma error range is necessarily the basis for > attempting to determine whether two reconstructions are statistically > significantly different.
> I am not sure that the process of "normalisation" hasn't already > completely skewed the comparison.
> In other words, when the claim is made that 10-15 other reconstructions > substantiate MBH'98, it is not clear to me what the basis for saying > this is. Even if there are other reconstructions; how close do they > have to be to substantiate MBH ?
The substantive point seems to be whether or not the late 20th century is abnormally warm and also perhaps warming at an abnormally rapid rate. These are the only reasons why the septics are desperate to attack MBH in the first place - it's not as if they actually care about the methods, or climate science in general.
The other reconstructions certainly seem to support the former (abnormally warm). It is not so clear to me that the rate of warming is abnormal, the Esper curve in particular shows some rapid changes.
If that doesn't answer your question, then I'm afraid I am still at a loss as to what you are asking.
>> Now now. Per isn't McKitrick, and isn't McIntyre.
>> Tim; as I recall, you are very good at ad hominem attacks, and kind of >> short on backing it up. You will make ad hominem attacks as you see >> fit.
> Given your complaints about undisclosed vested interests I think Tim has a > very good point. Asking who you are can't be considered to be an ad > hominem. As Tim seems to know who you are and you ask him to "back it up" I > think you should tell us, Tim. I'm curious.
OK, but I'm giving Per one last chance to disclose his real name. Per, are you going to tell or will I?
One must hope not, because http://www.numberwatch.co.uk/Temperatures.htm (updated april 2004) asserts that the satellite record shows a cooling trend, which we all know is nonsense.
-W.
-- William M Connolley | w...@bas.ac.uk | http://www.antarctica.ac.uk/met/wmc/ Climate Modeller, British Antarctic Survey | Disclaimer: I speak for myself I'm a .signature virus! copy me into your .signature file & help me spread!
On 4 Feb 2005 02:49:07 -0800, "peroxisome" <peroxis...@ntlworld.com> wrote:
>Now now. Per isn't McKitrick, and isn't McIntyre.
>Tim; as I recall, you are very good at ad hominem attacks, and kind of >short on backing it up. You will make ad hominem attacks as you see >fit.
Per, your real name, if you don't mind. John Brignell, is it? Coming clean about your name and affliliation isn't ad hominem, no matter how you twist things. I liked your tribute to John Daly. It's pretty hypocritical of you, though. Imagine posturing about the misuse of statistics and then writing a glowing tribute to Daly who was a master of misusing them.
> One must hope not, because http://www.numberwatch.co.uk/Temperatures.htm > (updated april 2004) asserts that the satellite record shows a cooling > trend, which we all know is nonsense.
I like the "line fitted to four points in the traditional way" shown on the first plot on this page
It is so obviously NOT "the one line of all possible lines that is closest to all the points while remaining straight" that it rather distracts attention from whatever point he might have been trying to make.
>The substantive point seems to be whether or not the late 20th century >is abnormally warm and also perhaps warming at an abnormally rapid
rate.
yes; this seems important.
>The other reconstructions certainly seem to support the former >(abnormally warm).
remind me James; how many of these proxy records go up to 2004, and how many show the unprecedented and abnormal warming ? As opposed to the instrumental record...
>It is not so clear to me that the rate of warming is >abnormal, the Esper curve in particular shows some rapid changes.
Let me rephrase the question again. If you are asserting that other reconstructions support MBH, how do we know that is so ? If someone else has done a reconstruction, is that in itself enough to support MBH ? Does it have to be within 0.1C ? Does it have to be within the +/- two sigma range, or can a line be within that two sigma range, but still be inconsistent with MBH ?
I notice you are quite wilfully neglecting to comment on the fact that different authors plot the same "spaghetti plot" data, and get considerably different results with the same data. yours per
>>RealClimate is a blog by professionals for people with at >>least a passing knowledge about the subject, and it can be assumed >that >>anyone reading that story would know the background
>>From realclimate, on the front page: >"RealClimate is a commentary site on climate science by working climate >scientists for the interested public and journalists. "
>Given that it is explicitly for the general public and journalists, and >that these groups will not necessarily know the background, would you >like to retract ? >And at the worst, I have to retract all the way from : >Mann has an undisclosed and vested self-interest >to: >Mann has a vested self-interest
>>However, neither >>reconstruction has any statistical significance." >Let me accept immediately that you are correct in one sense. I cannot >sustain a view that a "correct" MBH'98 would show a warm 15th century.
>But equally, if MM say that the dataset does not support statistical >significance, that doesn't mean that it is a wrong result. wmc's >initial premise was "if MM are correct".
>It would still be awfully embarrassing if MBH'98 was discredited.
Sure, or if Einstein was on Brownian motion, or Pauling on electronegativity.
>OK, but I'm giving Per one last chance to disclose his real name. Per, >are you going to tell or will I?
well, you are going to do what you want to do under any circumstances; so get on with it.
Why you think I need a last chance is beyond me. I have no reason to be ashamed of my name or my affiliations, and nor do I have any particular vested interest in this discussion.
Which will come as a great disappointment to those who are falling over themselves trying to concoct ad hominem attacks, rather than address the rather more difficult area of making specific and testable claims about where M&M are wrong.
>>It would still be awfully embarrassing if MBH'98 was discredited. >Sure, or if Einstein was on Brownian motion, or Pauling on >electronegativity.
Hi Lloyd you know, it is amazing how many people were dissing MM'03. Complete rubbish, they said; any real scientist would be able to replicate MBH'98, they said. Mann doesn't have to provide data to non-scientists like MM, they said; MM's claims are all wrong, they said. And on this very forum as well.
And then, all of a sudden, MBH were required to issue a correction, because Nature magazine evaluated M&M's claims, and found that MBH'98 had significant errors. MBH themselves had to admit that their original paper had errors in it.
Despite being badly burned, lots of people don't learn from their mistakes.
You could address the specific issues that MM'05 raises. The systematic bias introduced by decentred PCA, the allegation that the statistical analysis used by MBH was inadequate, and the fact that the American west coast bristlecone pines dominate the entire NH record. Some of these are difficult to square with MBH's statement of a "robust" NH reconstruction.
Alternatively, don't read the paper, announce that MM'05 is unimportant, and compare MBH to Einstein ! cheers per
Ah, W, who has retreated from reading papers and simply smears them as unimportant. I couldn't resist posting the following link (at the bottom of the page) from your Numberwatch suggestions. http://www.numberwatch.co.uk/2005%20February.htm
It is rare to see such a fine site posted on sci.environment.
