Category Archives: Spurious

Rejected … by RC!

I have been rejected at RealClimate! My first rejection! I have not posted there in about two years although I have occasionally read some of their consensus defences when they were relevant to what I have been looking at. They have been running a Steig Corrigendum thread concurrent with ours and I have followed it […]

More on Voodoo Correlations

Mann said: Although 484 (~40%) pass the temperature screening process over the full (1850–1995) calibration interval, one would expect that no more than ~150 (13%) of the proxy series would pass the screening procedure described above by chance alone. Reader DC said: Of the 484 proxies passing the 1850-1995 significance test, 342 also passed both […]

Caspar Ammann, Texas Sharpshooter

The Texas Sharpshooter fallacy is a logical fallacy where a man shoots a barn thirty times then circles the bullet holes nearest each other after the fact calling that his target. It’s of particular concern in epidemiology. Folks, you are never going to see a better example of the Texas Sharpshooter work itself out in […]

Data Smoothing and Spurious Correlation

Allan Macrae has posted an interesting study at ICECAP. In the study he argues that the changes in temperature (tropospheric and surface) precede the changes in atmospheric CO2 by nine months. Thus, he says, CO2 cannot be the source of the changes in temperature, because it follows those changes. Being a curious and generally disbelieving […]

What other data series could be plugged in?

I recommend that CA readers visit UC’s blog for some interesting discussion. (BTW UC visited Toronto recently and we had a nice dinner.) UC posted the following interesting figure on Unthreaded as follows: BTW, got interesting result when I replaced Temperature PCs with solar in MBH98 algorithm. Similar RE values as in the original, and […]

Mann's New Divergence "Theory": A Smoothing Artifact

Over at realclimate, Mann has advocated a new “explanation” of the Divergence Problem raised by one of their readers in connection with IPCC AR4 Figure 6.10. Mann says that there is no Divergence Problem; he blames the reader for failing understand boundary constraints in smoothed series. Raising the Divergence Problem at realclimate was so blasphemous […]

Juckes – Meet the Durbin-Watson Statistic

When one looks at the plots of the various Juckes proxies against gridcell temperature, the possibility of spurious regression must come to mind. “Spurious regression” has been discussed on this blog from time to time and tries to provide a statistical framework for seemingly high correlations between unrelated series – things like Honduran births and […]

Bürger and Cubasch Discussion

I hope that you are following the lively discussion about Burger and Cubasch at Climates of the Past here , where Mann aka Anonymous Referee #2 is carrying on in a quite extraodinary way. I’ll probably try to weigh in over there at some point. The dialogue has exploded fairly quickly and I’ve collated some […]

Predict future climate change!

[Steve: Editorial comment] – This is John A’s post. I do not agree with his editorial flourishes linking this to models. I view the following as illustrating the defects of sole reliance by multiproxy reconstructions on the RE statistic – a statistic for which there are no distribution tables and which is little known or […]

A new reconstruction of past climate

While Steve is away, and in honor of the NAS Panel which is so convivially considering the question of the reconstruction of past climate, Dave Stockwell decided to do his own reconstruction using exactly the same methodology as the Hockey Team. As you can see, his results are clearly consistent with the results of the […]