http://strata-sphere.com/blog/index.php/archives/11891
From: Ed Cook <drdendro@xxxxxxxxx.xxx>
To: Keith Briffa <k.briffa@xxxxxxxxx.xxx>
Subject: Re: Esper et al. and Mike Mann
Date: Mon, 17 Jun 2002 13:20:40 -0400
<x-flowed>
Hi Keith,
Of course, I agree with you. We both know the probable flaws in
Mike’s recon, particularly as it relates to the tropical stuff. Your
response is also why I chose not to read the published version of his
letter. It would be too aggravating. The only way to deal with this
whole issue is to show in a detailed study that his estimates are
clearly deficient in multi-centennial power, something that you
actually did in your Perspectives piece, even if it was not clearly
stated because of editorial cuts. It is puzzling to me that a guy as
bright as Mike would be so unwilling to evaluate his own work a bit
more objectively.
Ed
>I have just read this lettter – and I think it is crap. I am sick to
>death of Mann stating his reconstruction represents the tropical
>area just because it contains a few (poorly temperature
>representative ) tropical series. He is just as capable of
>regressing these data again any other “target” series , such as the
>increasing trend of self-opinionated verbage he has produced over
>the last few years , and … (better say no more)
>Keith
I know Mike thinks his series is the ‘best’ and he might be right – but he may also be too dismissive of other data and possibly over confident in his (or should I say his use of other’s). After all, the early ( pre-instrumental) data are much less reliable as indicators of global temperature than is apparent in modern calibrations that include them and when we don’t know the precise role of particular proxies in the earlier portions of reconstruction it remains problematic to assign genuine confidence limits at multidecadal and longer timescales. I still contend that multiple regression against the recent very trendy global mean series is potentially dangerous. You could calibrate the proxies to any number of seasons , regardless of their true optimum response . Not for a moment am I saying that the tree-ring , or any other proxy data, are better than Mike’s series – indeed I am saying that the various reconstructions are not independent but that they likely contribute more information about reality together than they do alone. I do believe , that it should not be taken as read that Mike’s series (or Jone’s et al. for that matter) is THE CORRECT ONE.
From: Ed Cook <drdendro@xxxxxxxxx.xxx>
To: Keith Briffa <k.briffa@xxxxxxxxx.xxx>
Subject: Re: Esper et al. and Mike Mann
Date: Mon, 17 Jun 2002 13:20:40 -0400
<x-flowed>
Hi Keith,
Of course, I agree with you. We both know the probable flaws in
Mike’s recon, particularly as it relates to the tropical stuff. Your
response is also why I chose not to read the published version of his
letter. It would be too aggravating. The only way to deal with this
whole issue is to show in a detailed study that his estimates are
clearly deficient in multi-centennial power, something that you
actually did in your Perspectives piece, even if it was not clearly
stated because of editorial cuts. It is puzzling to me that a guy as
bright as Mike would be so unwilling to evaluate his own work a bit
more objectively.
Ed
>I have just read this lettter – and I think it is crap. I am sick to
>death of Mann stating his reconstruction represents the tropical
>area just because it contains a few (poorly temperature
>representative ) tropical series. He is just as capable of
>regressing these data again any other “target” series , such as the
>increasing trend of self-opinionated verbage he has produced over
>the last few years , and … (better say no more)
>Keith
I know Mike thinks his series is the ‘best’ and he might be right – but he may also be too dismissive of other data and possibly over confident in his (or should I say his use of other’s). After all, the early ( pre-instrumental) data are much less reliable as indicators of global temperature than is apparent in modern calibrations that include them and when we don’t know the precise role of particular proxies in the earlier portions of reconstruction it remains problematic to assign genuine confidence limits at multidecadal and longer timescales. I still contend that multiple regression against the recent very trendy global mean series is potentially dangerous. You could calibrate the proxies to any number of seasons , regardless of their true optimum response . Not for a moment am I saying that the tree-ring , or any other proxy data, are better than Mike’s series – indeed I am saying that the various reconstructions are not independent but that they likely contribute more information about reality together than they do alone. I do believe , that it should not be taken as read that Mike’s series (or Jone’s et al. for that matter) is THE CORRECT ONE.
