Mike Jonas mellows some

Mike Jonas says:

Let me go back to Craig Loehle’s statement a while ago “we assert that the linear warming from 1850 forwards is part of some long-term pattern which we do not choose to characterize“.

You have got an apparent approximately cyclical pattern over 100 years, in which you are able to identify 1 1/2 cycles only. You have no mechanism for the pattern, and you guess at what cycle periodicities to map to it. Having curve-fitted to the pattern, you have not tested it against any adjacent period or in any other way. In all logic, you simply are not allowed to draw any conclusions from any projection of that pattern.

It is perfectly legitimate to devise patterns like that, and sometimes they can lead to new ways of investigating the underlying phenomena, but you can’t draw any conclusions until you have a mechanism or some kind of independent validation.

In your particular case, the data following the fitted period diverges immediately. By far the simplest explanation is that your fitted pattern doesn’t work. In the absence of any mechanism or independent validation of your pattern, you quite simply cannot go against that explanation.

Your pattern was attempting to map global temperature against time, based on some abstract notion of uncharacterised solar cycles, and you only had what appeared to be 1 1/2 cycles to go on. I say “appeared to be” because you can’t be sure that you were indeed looking at 1 1/2 cycles. Look at the data again – the idea that it is 1 1/2 cycles is dependent on the shape of the data prior to 1850. If the temperature was rising prior to 1850 (and you have no clue as to whether it was or not) then you don’t have 1 1/2 cycles. In fact you probably don’t have cycles at all.

Just look at the difficulty that solar physicists have in predicting solar cycles. We’re on cycle 24 now – not cycle 2 1/2 – and the solar physicists were all over the shop trying to predict it, in terms of when it would start, how high it would get, and how long it would last. As the supposed due date for cycle 24 approached and passed, the predictions were revised over and over again and even now no-one has a clue as to whether any predictions are likely to even come close. In other words, even if you’ve got a whole series of cycles to go on, without a mechanism you can’t make ANY meaningful predictions.

I apologise for using rather strong language at first, but I was absolutely gobsmacked at your paper and stunned that it could have got through any kind of peer-review. IMHO you had no scientific (or mathematical) basis whatsoever for any of your conclusions.

Filed under: In other online forums,Natural Processes — by Richard Holle @ 8:30 am on July 26, 2011

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