Lots of people are asking me about Douglas Keenan’s challenge to identify which time series meets a certain criterion. If our betters are as good as they say at identifying signals in temperature time series, challenges Keenan, they ought to be able to tell signal from noise.
There have been many claims of observational evidence for global-warming alarmism. I have argued that all such claims rely on invalid statistical analyses. Some people, though, have asserted that the analyses are valid. Those people assert, in particular, that they can determine, via statistical analysis, whether global temperatures are increasing more than would be reasonably expected by random natural variation. Those people do not present any counter to my argument, but they make their assertions anyway.
In response to that, I am sponsoring a contest: the prize is $100?000. In essence, the prize will be awared to anyone who can demonstrate, via statistical analysis, that the increase in global temperatures is probably not due to random natural variation.
Keenan asked me for comments on his column before he released it, and I’m sure he won’t mind me telling you what I told him:
I think the offer will be ignored, but it’s a good tactic. You know James Randi? Before he lost his mind he offered a million bucks (or whatever) for whoever could demonstrate psychic abilities under controlled conditions. Some no-names took the challenge and lost, but the big boys sniffed that it was beneath them.
The real reason for their refusal is obvious, as it will be for your challenge. But it will be great fun doing it! It will highlight the main point you made at the end: these people have no idea what they’re doing.
Incidentally, my prediction has already come to pass. Yesterday, a major figure in the doom camp sniffed that Keenan’s challenge had nothing to do with climate. (I was in an email chain where I learned of this.)
You have to honor a man who is willing to put up a choking wad of his own simolians to back a boast. Spread the word and help Keenan get some well-deserved publicity. (I’d do something similar, but all I could offer is an old lottery ticket that I’m fairly sure is out of the money but which I haven’t yet checked.)
Now randomness. Some folks over at Anthony Watts’s place were discussing the challenge and, with the prime exception of one MattS (intelligent fellow), were misunderstanding randomness. We’ve talked about it many, many, many times, but here it is once again, with respect to Keenan’s challenge.
I have no idea—I didn’t ask, and Keenan didn’t explain, plus I don’t want to know—how each of the series in his file were generated, but generated they were. Caused to be is another phrase for generated. Some mechanism caused each value. A popular mechanism is called a “pseudo-random number generator”, in which pseudo-random means known. Random, of course, means unknown, and nothing else. There is no such thing as real, objective, or physical randomness.
So this known-number generator (if it was used) made numbers according to a known formula, where the numbers are as determined as death and taxes. One number follows another with perfect predictability—if one knows the algorithm, of course.
It appears Keenan used three different algorithms, one which added positive numbers according to some similarly determinative scheme to a base scheme, one which added negative numbers to a base scheme, and a base scheme. The base scheme is the known-number generator.
Of course, I’m guessing. I don’t know. But this procedure is certainly common enough under the term simulation. Problem is, too many people (not Keenan) think simulations are semi-magical, claiming they have to be fed with “random numbers.” That makes no sense, because random means unknown, and you can’t feed an algorithm with unknown numbers. More detail is here.
Anyway, this is all beside the point. Keenan asks which of the three types of generated data each series is. Now we’re into the realm of modeling. Modeling? The process of collecting premises which come as close as possible to identifying the causes of the data and which describe our uncertainty in observables.
Now…but, no. That’s all I’ll say. I’ve already given information sufficient to deduce the methods Keenan used, accepting only that he used one of the known generators. Sufficient in theory. Practically? God bless.
I stop because I don’t want the fun to end and because it is besides Keenan’s main point, which is the methods climate scientists use (and everybody is a climate scientist these days) are crap. Amen to that with bells on. Follow the “many, many, many” link above for why.