The global surface temperature average (land and sea) for 2014 was nominally the warmest since the global instrumental record began in 1850; however, within the margin of error, it is tied with 2005 and 2010 and so we can’t be certain it set a new record.
Out of habit, I decided to verify this by checking their data. I went to their data page and clicked on "Summary Page" in their All Land category. There, I found this graph:
They have another reconstruction including ocean data. I haven't looked into that one yet since it is relatively new and isn't comparable to their previous results (and has never been published in any literature). Given those confounding factors I figured I'd just look at the land record as a simple check. As long as nothing seemed out of place, I'd stop there.
I found something out of place as soon as I opened the data file for the graph. I wanted to just plot the graph myself and verify it was accurate. When I did, I immediately saw the line:
This analysis was run on 12-Oct-2013 00:45:15
BEST just told everybody 2014 is tied for the hottest year in its record. It is not okay to do that when showing people work done in 2013. Results which end in September 2013 cannot back up conclusions about how hot 2014 was.
Perturbed, I went to their Findings Page, clicked on Summary of Finding and checked the graphs there. I recognized them as the same graphs BEST has had for their summary since 2012. About to give up, I saw a link under one of them said, "More recent data." I checked the other images, and it turns out all four images link to the same two data files. Confusingly, neither data file actually contains the data shown in two of the four images. Regardless, the "More recent data" file contained the line:
This analysis was run on 21-Aug-2014 03:12:47
Which is more recent than the data file I found on the summary page linked to on the Data page. It's not clear to me why both of these files are available on the website at the same time in different locations. Confused, I went back to the Data page and found the newer results by clicking on the link directly below the one I had used before.
That means underneath "Summary Page" is a line which says "Monthly Average Temperature" that uses different results, and neither link goes to results which support BEST's claim 2014 is tied for the warmest year in their record. I find that incredibly baffling. I was under the impression when you publish results for people to see, you should publish the data used to come up with those results.
But what I find more baffling is BEST's decisions regarding what results files to link to. I don't understand posting images with links to data files that don't contain the data shown in the images. I don't understand having linking to two different sets of results on the very same page with no warning, much less explanation, of the difference.
But what I really don't understand is why these different results files can change without any record being kept. You see, I happen to have kept copies of results files for BEST's global temperature record. I did it for convenience as I wanted to have the data on my computer. When I looked at the previous copies, I found I now have four different versions. Well, I actually have five. There were two versions of their global land record published on their website at the same time, both said to have been calculated at the same time. They're not identical, but they're similar enough I won't count them separately.
The other four are not so similar. To show this, I decided to create a .gif showing all four (with a 10 year running average applied):
The differences are significant. They are also largely limited to the past. One could easily think this means they aren't relevant to BEST's claims about record temperatures. One would be wrong. BEST, like all temperature constructions, picks a time period where it "aligns" its data. The effect is to make all of its data match as best it can in that period.
That inevitably makes the data match better in the calibration period than anywhere else. It also means changes in its data will tend to manifest more greatly outside the calibration period than inside it. Since BEST calibrates its data to a modern period, the past will necessarily vary more from version to version than the present will.
That gives the impression our certainty of recent temperatures is greater than it actually is. The reality is the choice of calibration period is largely arbitrary. Were a different one used, modern temperatures might have varied more from version to version.
Incidentally, BEST claims:
Numerically, our best estimate for the global temperature of 2014 puts it slightly above (by 0.01 C) that of the next warmest year (2010) but by much less than the margin of uncertainty (0.05 C). Therefore it is impossible to conclude from our analysis which of 2014, 2010 or 2005 was actually the warmest year.
It's difficult to see why anyone would take uncertainty estimates calculated to the hundredth of a degree seriously given the differences in the various results BEST has published. BEST has never compared the various results its published, but if it had, it'd find the different versions often don't lie within each other's uncertainty ranges in modern times.
January 1st, 4:16 AM Edit: I've confirmed there is at least one more version of the BEST global land record which preceded any of the ones I've shown in this post. I'll have to see if I can dig up a copy of it somewhere.