Originally posted by pjclarke
The papers garnered together by 'CO2 Science' seem to be mainly single-proxy studies from single locations.
Trouble with that is that the variance at any individual point can be as much as 2-3C, more than enough to mask the long term trend, if there is one.
What you need to do in the context of quantifying a global change is to compile a multi-proxy reconstruction - the larger number of (reliable) proxies, the better. You can then average and weight the results to come up with a curve that represents a large area.
This is what Mann et al 2008 did, the paper analyses 1209 different proxies and finds
...recent warmth is unprecedented in the record.
Trouble with that is that the variance at any individual point can be as much as 2-3C, more than enough to mask the long term trend, if there is one.
What you need to do in the context of quantifying a global change is to compile a multi-proxy reconstruction - the larger number of (reliable) proxies, the better. You can then average and weight the results to come up with a curve that represents a large area.
This is what Mann et al 2008 did, the paper analyses 1209 different proxies and finds
...recent warmth is unprecedented in the record.
Professor Judith Curry
There is no question that the diagrams and accompanying text in the IPCC TAR, AR4 and WMO 1999 are misleading. I was misled. Upon considering the material presented in these reports, it did not occur to me that recent paleo data was not consistent with the historical record. The one statement in AR4 (put in after McIntyre’s insistence as a reviewer) that mentions the divergence problem is weak tea.
It is obvious that there has been deletion of adverse data in figures shown IPCC AR3 and AR4, and the 1999 WMO document. Not only is this misleading, but it is dishonest (I agree with Muller on this one). The authors defend themselves by stating that there has been no attempt to hide the divergence problem in the literature, and that the relevant paper was referenced. I infer then that there is something in the IPCC process or the authors’ interpretation of the IPCC process (i.e. don’t dilute the message) that corrupted the scientists into deleting the adverse data in these diagrams.
McIntyre’s analysis is sufficiently well documented that it is difficult to imagine that his analysis is incorrect in any significant way. If his analysis is incorrect, it should be refuted. I would like to know what the heck Mann, Briffa, Jones et al. were thinking when they did this and why they did this, and how they can defend this, although the emails provide pretty strong clues. Does the IPCC regard this as acceptable? I sure don’t.
Can anyone defend “hide the decline”? I would much prefer to be wrong in my interpretation, but I fear that I am not.
It is obvious that there has been deletion of adverse data in figures shown IPCC AR3 and AR4, and the 1999 WMO document. Not only is this misleading, but it is dishonest (I agree with Muller on this one). The authors defend themselves by stating that there has been no attempt to hide the divergence problem in the literature, and that the relevant paper was referenced. I infer then that there is something in the IPCC process or the authors’ interpretation of the IPCC process (i.e. don’t dilute the message) that corrupted the scientists into deleting the adverse data in these diagrams.
McIntyre’s analysis is sufficiently well documented that it is difficult to imagine that his analysis is incorrect in any significant way. If his analysis is incorrect, it should be refuted. I would like to know what the heck Mann, Briffa, Jones et al. were thinking when they did this and why they did this, and how they can defend this, although the emails provide pretty strong clues. Does the IPCC regard this as acceptable? I sure don’t.
Can anyone defend “hide the decline”? I would much prefer to be wrong in my interpretation, but I fear that I am not.
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