Replies

"I didn't see you address the issue of Mann's deducing temperature from ice cores, tree rings, etc for the 1000 to 1900 part of the graph and using measurements for 1900 onwards"

Give me a break!! I am only one person and each of my replies is composed by me (except as noted). This is more time consuming than just cutting and pasting from a website. For example, post number 83 is a cut and paste directly from CO2 Science. I had to actually try to dig out the paper and when that failed I had to try and see what other work the authors had done so I could get an idea of what they said as opposed to how CO2 Science put the spin on it. Going back to source papers is time consuming but I like to do my own thinking.

In regards to Mann, the way he matched up the records was (and this is a direct quote from Mann's paper):

"We first decompose the twentieth-century instrumental data into its dominant patterns of variability, and subsequently calibrate the individual climate proxy indicators against the time histories of these distinct patterns during their mutual interval of overlap."

The method he used to decompose the instrumental data is the Principle Component Analysis (that is the current area of discussion between McKitrick and Mann). Again, from the paper:

"We isolate the dominant patterns of the instrumental surface temperature data through principal component analysis (PCA). PCA provides a natural smoothing of the temperature field in terms of a small number of dominant patterns of variability or ‘empirical eigenvectors’."

I do not agree with your last comment. TO me (from what I understand) it looks like fairly solid science to me. However it does appear (to me anyway) to be fairly complex. You might have the math necessary so that this appears simple, I do not. However I am always willing to learn.