Juckes also replied to CA reader Mark Rostron and there were a couple of interesting aspects to the response.
1. In a Millenial reconstruction, it would be helpfull to know how many data points were
available for each measured time period over the thousand years. Fig 2 indicates that
the number in the early years may be quite small.
(1) Figure 2 refers to data used in the Mann et al. (1999) paper. In our reconstruction
we use only data which are available throughout the study period, 13 time series in the
2. How much recent data is there? Does the sampling end in 1980, 26 years ago?
(2) Many of the proxy series end in the 1980’s. For calibration purposes it is important
that proxies are from sites which have been undisturbed. This is now rather harder to
ensure because of the spread of agriculture and nitrogen pollution.
3 Although Climate Models are mentioned, there are no references to any climate
model that has accurately predicted temperature, are any available?
(3) There is a discussion in the IPCC report.
4 Appendix A2 says that “This method starts out from the hypothesis that different
proxies represent different parts of the globe”, but there are no correlations shown to
local temperature see Table 1 and 2. Has any test been done to see if the Proxies
correlate well with local temperatures. Is any local temperature data and correlation
(4) Local correlations are only meaningful if the signal to noise ratio is greater than
unity. This is not the case here.
5 What is the justification for including low correlation proxies listed in Table 1?
(5) As above.
6 Although Table 2 shows a cross correlation between different data bases, there is no
cross correlation between individual proxies. Do the various Proxies correlate well with
each other in the non instrumental temperature period?
(6) Yes: Jones et al (1998) comment on this. We have looked at this, but have not
found any new results.
Here are a couple of points that caught my eye here. The original Juckes et al submission had 18 proxies; now they have 13 proxies. I wonder which proxies have been subtracted. I presume that the duplicate versions of Tornetrask have gone to one version, but who knows. There’s an amusing aspect to this. Juckes’ statistical model for CVM stated:
This method starts out from the hypothesis that different proxies represent different parts of the globe
This can obviously be said about anything. So Juckes et al used two Tornetrask versions – did these “represent different parts of the globe”? Maybe one Tornetrask series “represented” Sweden and the other Tornetrask series “represented” Antarctica or South Africa. Anything is possible in their model as stated. Alternatively, if one wanted to test the hypothesis that the Juckes proxies represented different parts of the globe, one way of testing the hypothesis would be to plot the locations. Now Juckes had multiple different geographical locations for Tornetrask, including the middle of the Baltic Sea, but I think that he’s prepared to grudgingly concede that all the data comes from northern Sweden. So I guess he was just kidding us when he said that the proxies in the first submission “represented” different parts of tghe globe.
There are still some puzzles in the next step of this beauty contest. The submission included two series from one Quelccaya ice core – one for dO18 and one for accumulation. Did these two series from the same ice core “represent different parts of the globe”? Maybe one of the series “represented” northern Sweden? Or Australia? Or Crawford, Texas? Or Minneapolis? He had 4 different bristlecone and foxtail series, including series only a few tens of miles apart. Did these “represent” different parts of the world through Mannian teleconnection? Maybe the Upper Wright Lakes foxtails represented Poland, Boreal foxtails Afghanistan, the Methuselah Walk bristlecones Thailand and the Indian Garden bristlecone the South Atlantic? IT sounds silly expressed like this, but the assumptions of the “model” do not preclude this.
Here’s something else that’s fun. We’ve talked before about Mann’s explanation for the failure to use up-to-date proxies: difficulties in deploying “heavy equipment” to remote parts of the world. Bringing the bristlecones up to date for example would require the coring of bristlecones in Sheep Mountain CA, which is at least an hour’s drive from the nearest airport in Bishop CA. Updating these records is clearly impossible without a commitment equivalent to the space program. Or is it? Hasn’t Hughes already updated these records? It’s just that he hasn’t reported this in the 5 years since re-sampling in 2002. I’ve speculated that, if bristlecone ring widths were off the charts as Mannian methodology would predict, we would have heard about it by now, just as we would have heard about Thompson’s drilling at Bona -Churchill if there had been an increase in dO18.
Instead of blaming the update failure on the insuperable logistics of going one hour from Bishop CA< Juckes points to potential site contamination by "nitrogen" pollution. Excuse me, wasn't potential nitrogen fertilization one of the possible problems with bristlecones (e..g. NAS Panel)? If fertilization and such are problems in updating the proxies, isn't it possible that fertilization was a problem before 1980?