Friday, March 03, 2006

Fascinating new results on global warming

As those of you following the debate about global warming will know, the National Academies of Science are currently running a symposium to evaluate the results of Mann et al, and the criticisms of McIntyre and McKitrick.

David Stockwell has published preliminary results of his new study, applying the methods of Mann et al to the same surface temperature data, but using other associated data.

A graph of Stockwell's results:



As can be seen, this is very strongly similar to the "hockey stick" graph of Mann Briffa et al.



What's interesting about Stockwell's results is this: his associated data is not real observational data, but "red noise": "1000 sequences of 2000 random numbers containing red noise generated with a multiple time scale fluctuation approach."

What is "red noise"? Random numbers. Specifically, red noise is a random signal in which the amplitude decreases monotonically as the frequency increases.

Reproduced from Stockwell's initial paper (in submission), here is his conclusion:
The resulting reconstruction is very similar to published reconstructions (e.g. see [1]), exhibiting a gradual decline in temperatures from an apparent Medieval Warm Period (MWP)), and an anomalous 20th Century warming popularly known as the ’hockey-stick’ [4] Clearly the ’hockey-stick’ pattern is easily produced by selecting those random series that correlate over the period of the calibration temperatures (producing the blade) and revert to randomness elsewhere (producing the handle). The apparent height of the MWP is an function of the arbitrary zero calibration point. Thus all the salient aspects of past climate usually associated with millennial reconstructions are essentially already encoded into the methodology, so that a ’hockey-stick’ shape is inevitable on any data resembling natural LTP series.


Emphasis mine.

[Updated with second graphic, and corrected authors.]

9 comments:

Rick Ballard said...

If I understand this correctly, had Mann played a bit more with the numbers I might very well have burst into flames 13 minutes ago?

What a dangerous man. All due to too much sap in the tree rings.

Charlie Martin said...

Yeah, pretty much. Basically, what it means is that there's no information content in the "hockey stick": applying the Mann et al methodology to any data produces a hocket stick. Thus there is no "surprise" and no information.

Rick Ballard said...

Of course, that's no reason not to cripple worlwide economic activity. After all - it's for Gaia. Ask Kofi.

Barry Dauphin said...

And just tonight NBC ran the usual global warming puff piece in which some "scientist" from an environmental action group said that we've only got a few years left until it will be too late to make changes, and that the changes have to take place in the US. These groups need to start practicing disclosure. I'd love to see what other political organizations some of them belong to or have supported in the past. The communists didn't die off, they moved into global warming research. Maybe they're nostalgic for Siberia.

Barry Dauphin said...

Also check out this comment from Spence_UK in the comments section of the link: "...Of course since the temperature reconstruction folk don’t even archive the sites they do use, let alone the sites they don’t use, so the opportunity to work out whether or not the sites they have found are actually useful has been lost."

I know those tree rings must be around here someplace.

Morgan said...

They can have my SUV when they pry it out from under my extremely warm dead butt.

cf said...

Seneca, if you can add some paragraphs explaining this better for an ordinary reader, you can do a great service..send it to the American Thinker..(It wouldn't take more than a graph or two to what you've already written)

Unknown said...

I have never yet met a global warming hysteric who was willing to change their own lifestyle one iota.

It is either the nasty corporations or perhaps a desire to keep the third world in pristine poverty that attracks their attention. The idea that old number one might have to start washing his/her clothes on a rock never enters their minds.

cf said...

BTW, Seneca, I think AT can now do graphics..