I'd like to apologize. I can't though. I don't feel bad about what I did. I intentionally deceived people, but I did it in a way people wouldn't be fooled (at least, not for long). You see, I knew what I said in this fairly visible post at Watts Up With That? was wrong. I knew what I said in post here a few days ago was wrong. I said it anyway.
You see, for the last couple years I've tried to draw attention to a number of problems with the BEST temperature record. It didn't work. I couldn't get anyone at BEST to care, much less to acknowledge the problems. I won't rehash the whole history here. Suffice to say I've tried talking to BEST members Steven Mosher, Zeke Hausfather and Robert Rhode about some issues that are pretty much indisputable. Zeke was friendly but didn't know enough to answer, Rhode didn't respond and Mosher was... well, Mosher. I think it'd be best if I don't say more.
The point is I've been unable to get meaningful responses to simple points for over two years now. It's been said insanity is doing the same thing over and over expecting different results. That was on my mind when I discovered some new problems with the BEST temperature record. I considered writing those last two posts about BEST in an accurate way, but I knew I'd just get ignored if I did.
So I decided to play a trick. I knew BEST members would just ignore me if I pointed out these problems in a normal fashion. I also knew at least one BEST member, Mosher, would quickly respond to me if I made a bad argument he knew he could rebut. The solution was obvious. If I wanted a response to my valid points, all I needed was to make my valid points in a bad argument.
So that's what I did. I had three problems I wanted to highlight. First, BEST fails to recalculate its breakpoints during its jackknifing calculation, causing its calculated uncertainty to be too low. Second, BEST's choice of baseline period in its uncertainty calculations screws with those calculations. Third, BEST's results are unduly influenced by a handful of stations in Antarctica, including a number of stations whose record in the BEST data set have problems (such as one station appearing at least three times).
The third problem was responsible for a step change in BEST's uncertainty levels. I knew this because it was discussed in one of their papers which I had reread when examining the other two problems (which is what made me even look into the issue). I also knew that step change coincided fairly closely with the timing of one of the other problems. That gave me the idea of conflating the two issues.
I figured if I blamed this step change in uncertainty levels on the choice of baseline period in BEST's uncertainty calculations, I would look like a fool to the people at BEST. Thinking me a fool, they would consider me an easy target and would respond to say I was wrong about the effect of the problem. But to say I was wrong about the effect, BEST would have to say what the actual effect was.
It worked. The three BEST members I've tried talking to before quickly responded to tell me I was wrong. In doing so, they confirmed the problems I had found. The choice of baseline in uncertainty calculations was acknowledged to influence those calculations:
2) In the statistical calculation, the choice of a 1960-2010 baseline was done in part for a similar reason, the incomplete coverage prior to the 1950s starts to conflate coverage uncertainties with statistical uncertainties, which would result in double counting if a longer baseline was chosen. The comments are correct though that the use of a baseline (any baseline) may artificially reduce the size of the variance over the baseline period and increase the variance elsewhere. In our estimation, this effect represents about a +/- 10% perturbation to the apparent statistical uncertainties on the global land average. Again, this is completely separate from the large step-increase in uncertainty associated with the absence of Antarctic data.
As far as I've been able to tell, BEST has never disclosed this issue before. It's unlikely they would have if I had continued raising issues in the normal fashion. It was only because I created my strawman that I was able to get BEST to acknowledge this problem. Similarly, for the issue of not rerunning its breakpoint calculations, BEST has now said:
3) With regards to homogenization, the comments are only partially correct. The step that estimates the timing of breakpoints is presently run only once using the full data set. However, estimating the size of an apparent biasing event is a more general part of our averaging code and gets done separately for each statistical sample. Hence the effect of uncertainties in the magnitude, but not the timing, of homogeneity adjustments is included in the overall statistical uncertainties.
I've always been told there are no adjustments to the BEST data so there wouldn't be any need to estimate the size of them, but now I'm told otherwise. I'm not sure what ot make of that. What I do know, however, is BEST has confirmed my point that they do not estimate the uncertainty introduced by their homogenization.
Finally, I got BEST members to raise the issue of the importance of data in Antarctica for me. This is the real source of the step-change I highlighted. Here are a couple comments from BEST members on it:
Prior to 1960 there is no data at all in one of the world’s continents, Antarctica, which significantly increases the uncertainty in the global reconstruction.
1) First off, the step-wise shift in uncertainty has nothing to do with normalization or data processing issues. The large increase in uncertainty prior to about 1950 is a simple consequence of the complete absence of weather stations in Antarctica prior to the 1950s.
It is trivially easy to see neither remark is true. I was able to quickly respond showing there was data prior to 1950 because I had spent time studying the BEST data for Antarctica prior to writing either of my posts. That's why I knew there are actually ten BEST stations available for Antarctica before 1955 (actually eleven, but one is a duplicate of another).
This let me raise a point I find amusing. Two of those stations get their early portions discarded by BEST because BEST found "empirical breakpoints" in them. Empirical breakpoints are found by comparing stations to their neighbors. That means BEST is simultaneously claiming there is not enough data to estimate temperatures in Antarctica before ~1960, but there is enough data to tell when stations measuring those temperatures are wrong!
So do I owe anyone an apology? I'm not sure. Regardless of my intentions, I did intentionally mislead readers. On the other hand, I misled readers in a way I knew would be easy to correct. I would have written a correction myself if nobody else had done so. That means there was really never any harm to my deception. This is unlike the deception BEST pulls when it releases reports showing things like:
Even though the responses to me show BEST knows there are problems with its uncertainty calculations which means it cannot possibly achieve the precision it claims to have, and that its "95% confidence limit" is actually lower than 95%. I know, "He did it first" isn't a good justification for anything, but if BEST is going to knowingly deceive people about its results, I can't feel bad about using tricks to get them to admit their knowledge of their deception.
Of course, I could be lying about all this. I might have just made a boneheaded mistake in my posts which correctly identified two undisclosed problems with the BEST methodology. I might have just inadvertently got BEST to admit it knows the precision it gives for its results is exaggerated. It might just be chance this is the only time BEST has acknowledged any of the many issues I've raised with its work.
That'd be a heck of a coincidence though.