There seems to be some confusion about McKitrick's latest attempt to refute global warming. For instance, Andrew Sullivan thinks that McKitrick's famous degrees-radians screw up is part of this latest attempt. However, McKitrick claims to have refuted global warming in several different ways and the degrees-radians screw up was a in a different paper to his latest one. I decided to draw up a table to help folks sort them out.
| Authors | Summary | Consequences if he is right | Status |
|---|---|---|---|
| Essex and McKitrick | There is no physical basis to average temperature. | No global warming because there is no such thing as global temperature. | Failed---the whole field of thermodynamics has not been thrown out. |
| McKitrick and McIntyre version 1 | The hockey stick graph was the product of "collation errors, unjustifiable truncations of extrapolation of source data, obsolete data, geographical location errors, incorrect calculations of principal components, and other quality control defects." | The global warming we are seeing might be natural. | Mann et al publish a correction to the supplementary information for the hockey stick graph. They say that the errors do not affect their published results. |
| McKitrick and Michaels | Surface temperature record is contaminated by economic influences. | No evidence that there is global warming going on | Results go away after errors such as confusing degrees with radians are corrected. |
| McKitrick and McIntyre version 2 | hockey stick is the product of improper normalization of the data. | The global warming we are seeing might be natural. | Jury is still out, but it does not look promising for McKitrick |
Meanwhile, James Annan agrees with Connolley's concerns about M&Mv2:
Having had a quick glance at this and their papers, I think I agree with you. In fact it appears that we can add not knowing the difference between multiplication and division, to the already impressive list of blunders that M&M have made. They even seem to talk about adding the mean to the time series rather than subtracting it too. I might check this more carefully over the next few days if no-one else beats me to it.
Brad DeLong also seems to agree.
But Connolley argues---I think correctly---that McKitrick and McIntyre are simply confused: the normalizations diminish the influence of series that show a recent uptrend.
More like this
Hockey stick wars, the story so far: McIntyre and McKitrick (M&M) first claimed that the hockey stick graph was the product of "collation errors, unjustifiable truncations of extrapolation of source data, obsolete data, geographical location errors, incorrect calculations of principal…
Realclimate has a good explanation of the latest battle in the hockey stick wars. It looks to me like McIntyre & McKitrick's claim (that the hockey stick is the product of an erroneous calculation) is not correct. That doesn't mean that the graph is correct of course…
In this column, Richard Muller claims that McKitrick and McIntyre have shown that the hockey stick graph is an "artifact of poor mathematics". If you have been following the global warming debate this claim should look familiar, because McKitrick and McIntyre made the same…
In a comment to post on the Barton letters, Ed Snack claimed that
Michael Mann made an error in MBH98, he confused the square root of the cosine of the latitude with the cosine
Now if you look at MBH98, cosine latitude is only mentioned here:
Northern Hemisphere (NH) and global (GLB) mean…
I heard that Steve McIntyre had a paper called "Verification of multi-proxy paleoclimatic studies: a case study" that he was going to present at the AGU fall meeting. I did a search of the AGU site and found the paper listed in one area but it did not come up in the program listing. Where it was listed there was a link to McIntyre's site.
So I went to McIntyre's site but could not find or any reference to it there or at McKitrick's site. I am only guessing but is it possible he has withdraw it?
Just checked his site again and the paper is there now! So he has not withdrawn it (yet) ;-)
Averaging or manipulating measurements of physical objects without weighting, or linking, those measurements to the objects those measurements are associated with, lead to serious errors which we in the mining industry learnt at great cost decades ago.
I hope the climate types might learn from our experiences rather than repeat it by implementing the Kyoto Protocol.
I feel sick...I should take my temperature.
Oh, wait: Louis says I have to link the thermometer to...to...hmmm...cr*p. Soemthing or other.
Well!I can't tell if I have a fever now. Where's that linking thingy? Dangit. Well, I certainly shouldn't take any medicine - I can't trust the thermometer!
And this medicine...hmmm...it's development was funded! Gosh. The scientists making it must be biased. Heck with it. No medicine. And I'm not feverish: that thermometer can't be trusted!
Thanks, Louis, for setting me straight. Say, you don't have any land you want to sell me, do you?
D
Since Louis likes to namedrop the mining industry all of the time, it seems appropriate to point out that the majority of the mining giants are up on their science, and consequently have a view on global warming directly in contradiction to Louis.
In fact, it would be interesting to see if Louis can name even one significant Australian mining company which agrees with his point of view.
Neither of you answered the initial question.
Louis: What was the initial question? If it was your comment about averaging or weighting of measurements then I think it is done. If it was something else, then what?
Usually, when asking a question, one uses question marks.
It omits any sort of, like, confusion for people who may not know one's prodigious wit and intellect.
D
So that would be a no, to the presence of "one significant Australian mining company which agrees with his point of view".
Tim,
in the comments to this post by Steve McIntyre, you repeatedly claimed that you "correct the misconception that you [McIntyre] were involved in McKitrick's error" in this post.
Um, I'm not seeing any correction here.
Please explain?
Chris, I wrote this:
And the table makes it clear that the degrees/radians error was in McKitrick and Michaels, not McKitrick and McIntyre.
No. Not even close. That's not correcting the misconception, that's providing information and carefully not pointing something out a non-obvious consequence.
However, I note that you have corrected the misconception -- in an editorial amendment buried inside this comment,
with an interesting use of the passive voice.
Of course, that did not stop a later commentator from claiming that the degrees-radians bug invalidates all the McKitrick and McIntyre work!
Sure Chris, what do you think in a different paper means? And the later commenter did not say that the error invalidates all of McKitrick and McIntyre's work -- you made that part up.
Whoops - "something" is wrong: that should be "not pointing out a non-obvious consequence".
Which leads me nicely to a more important point: how a person deals with his-or-her mistakes is (at least) as important as the initial mistakes. Judge Posner's brilliant New York Times essay
compares corrections in the blogosphere to corrections in the main-stream media.
(I'm a computer programmer, so dealing with my own mistakes is a constant preoccupation.) In this context, it is interesting to note that McKitrick and Michaels did not "confus[e] degrees with radians", but rather assumed that the cosine function in Shazam used degrees (like most people do) when it actually used radians (like the people who wrote the cosine function do). I can assure you that it's an easy mistake to make. Fortunately, in my case, it produced obviously wrong numbers ...
In fact, McKitrick did confuse degrees with radians. He did not notice that his latitudes were in degrees while Shazam, like pretty well every other computer program out there, uses radians.
And it should have been obvious that it produced wrong numbers. The goodness of fit went way down, but the strength of the economic effects increased significantly, so the results were "better" for him and he was too eager to accept them.
Since this has picked up again here, a few comments wrt to averaging. Essex and McKitrick (mostly McKitrick), make some false claims. In general the arithmetic mean is pretty robust, but there are problems with geometric, root means square and others which McKitrick has done his best to ignore.
Most of these have to do with the issue of where the zero of the scale is. For geometric averages if there is a single zero in the record, the average is zero no matter what the data. The sign of the geometric average depends only on whether one has an even or odd number of negative values, which obviously depends on the choice of zero. Pretending that the geometric average is useful in such a case as McKitrick does is arithmetically (or should I say geometrically) ignorant.
For a vector average (or root mean square) average the values 5 and -5 have the same contribution, so obviously that is going to be a problem and this is not a sensible method.
For a harmonic average, any zero makes the average undefined. And so on.
One could, in principle avoid these problems by using a scale with zero much less than any observed value (such as absolute zero), however, in the case of global temperature measurements this does not work.
In order to compare trends in different places, one looks at the average temperature over a period in some location, and then takes the difference between that and the temperature at any time to form a temperature anomaly. The anomaly at one location is compared to that at another. Thus the problem of zeros remains if one is looking at comparing temperature trends and the only usable common average is the arithmetic.