Fundamental Differences between Bob Tisdale and Reality

I guess Bob Tisdale didn’t like my pointing out that when revision goes his way he heaps praise on it, when it goes the opposite way he denegrates it. In an attempt to save face he has posted about what he calls “fundamental differences” between the updates. He only ends up proving my point — but WUWT readers don’t get to see that, because of the data he doesn’t show.

Here’s his “money graph” about the sea surface temperature data update from NOAA:


Here’s what he has to say about it:

But the short-term warming rate of the new NOAA ERSST.v4 data during the global warming slowdown is much higher than the HADNMAT2 data. See Figure 1, which was first presented in my open letter to Tom Karl. That graph serves as the basis for my statements (1) that the recent update to the NOAA sea surface temperature data cannot be justified by the dataset that was used a reference for those adjustments, and, in turn, (2) that the NOAA adjustments are overcooked.

Yes, his sole reason is that the ERSSTv4 data has a different trend estimate than the NMAT data since 1998. He calls one “much lower” and the other “much higher.”

I can make graphs too. Here’s one, using only data since 1998:


It’s not exactly the same as Tisdale’s, it seems we’re using different baselines — but that really doesn’t matter.

What matters is what Tisdale doesn’t show. Here’s another graph with data since 1970:


That certainly destroys the impression from Bob’s cherry-picked graph. But wait — is the NMAT trend estimate “much lower” and the ERSSTv4 trend estimate “much higher”? Well, that from NMAT is 0.0116 deg.C/yr, from ERSSTv4 it’s 0.0117 deg.C/yr. [sarcasm] Big difference! [\sarcasm]

What did Bob Tisdale show you of this part of the data?


I guess Bob Tisdale wants us to compute whatever revision prevents the since-1998 trend from getting any higher, no matter how it affects the rest of the data.

If you don’t think Tisdale explicitly accuses NOAA of wrongdoing, consider what he said in his “open letter” to Tom Karl:

The results of the statistical methods used on the earlier version of the NOAA sea surface temperature data (ERSST.v3b) did not provide the results NOAA was looking for now, so NOAA/NCEI, under your direction, mixed and matched methods until they found the results you wanted (ERSST.v4).

Oh, the irony.

27 responses to “Fundamental Differences between Bob Tisdale and Reality

  1. Dan Andrews

    Ugh. That man (Bob) has a serious case of Dunning-Kruger, completely unable to assess his own (in)competence and unable to recognize real competence in others.

    • Well, he knows enough to construct a cherry-pick at least. Or maybe not?–1998 is a cliche in denialosphere, after all.

      These guys write “With false self-deceiving tears,” as William Blake once put it.

  2. harrytwinotter

    Bob Tisdale and his friends have no shame. His articles show they are trying to deceive people.

  3. WUWT is an asylum for some of the worst sufferers of Dunning-Kruger I’ve ever encountered, Watts among them – and no one is getting help.
    Tisdale, Eschenbach, et al are all so convinced of their own brilliance and just how stupid all the people with actual training, experience & dedication are.

  4. Tamino, OT, but I saw a graph that seemed like a bad example of how to look at data

    The graph under this section “Number of Complaints Submitted to the New York City Taxi and Limousine Commission”- just struck me as “funny” in terms of how it seemed the argument was just draw a line on the graph for a change in trend. I suspect it would lead to eye rolling. What was i=obvious to me was seasonal trend in data that probably could have been dealt with.

    My on topic comment is that Tisdale is a pathetic figure.

  5. “17 years ago” obviously is the new “6000 years ago” in the small minds of a certain type of people – nothing obviously ever happened before that…

  6. Everett F Sargent

    “The intent of this letter to present when and how the new NOAA sea surface temperature data differ during the hiatus from the night marine air temperature data, upon which it is based, which are used for bias adjustments over the term of the data.”

    The words “upon which it is based” have been crossed out at both BT’s and WUWT websites showing the “open” letter to Dr. Karl.

    BT got so caught up in assuming that NOAA used the HadNMAT2 dataset, when NOAA actually didn’t, that anything he said after that faux pas is an abject non sequiter.

    Willard The Insult Climate Dog and The Three Stooges (Monkers as Moe, Willis as Larry and Bob as Curly). What a bunch of morans.

  7. Lars Träger

    There is one reason why Tisdale will forever love HADNMAT2 – it ends in 2010, and that’s what “now” will for ever be in his comparison.

  8. In a bizarre word salad Anthony attempted a comment in support of Tisdale by being gratuitously nasty about Tamino.

    Closet human being calls other people gutless.

  9. is the difference in the trends for ERSSTv4 and NMAT2 (c. 0.04C/decade), which Bob seems to think are “so different” for the period 1998-2010, even significant? maybe this is an easier way to see if Tisdales “much higher” and “much lower” are even justified statements

  10. Bob Tisdale: “the recent update to the NOAA sea surface temperature data cannot be justified by the dataset that was used a reference for those adjustments

    Someone who knows more about ERSSTv4 may correct me, but as far as I know the Night Marine Air Temperature (NMAT) is not used as a “reference”. At least not in the sense of comparing NMAT with Sea Surface Temperature (SST) to find data problems in the difference series, like is done in the homogenization of station data. This is because only a part of the ships report NMAT. I think NMAT data is used to estimate which fraction of ship use buckets to measure SST.

  11. Victor you are correct. Bob has it all wrong in his now umpteenth post about this. HadNMAT2 is used to correct a bias in ship sea surface temps only. For the period he’s looking at (in fact since the early 1980s), they only comprise 10% of the observations. The rest of the data is from buoys, and HadNMAT doesn’t apply to them. They are much more accurate than ship data anyway. So much so that if ship and buoy data are together, the buoy data is given six times the weighting of ship data. So the comparison Bob thinks he’s making is completely and utterly wrong. And not just because the trends is actually quite close. He is not comparing what he thinks he is comparing.

    I got sick and tired of Bob’s articles about this. He keeps insisting on making the same huge error over and over and over again. He’s repeating himself twice a day now, with yet another article hot on the heels of one just a few hours earlier. After reading lots of papers on the subject – if Tamino doesn’t mind, I wrote about it:

    I’ve also done the unthinkable (only if you’re a WUWT denier) and checked it out with one of your colleagues and co-authors of Huang15, one of the main ERSSTv4 papers.

    • Nice article, Sou. One learns a little about Bob Tisdale and a little about how sea surface temperature trends are estimated.

      So Bob Tidale has been blogging on sea surface temperature for years, but somehow I know better how the SST is computed? I will leave it to the reader to draw conclusions from that.

      (And maybe it sounds close to outsiders, but the land temperature computed from station measurements and the sea surface temperature from marine observations are two completely different communities and the data problems are removal methods are completely different.)

  12. Hello Tamino.
    Ive always liked the way you
    explain your stats clearly.
    I ask a favor.
    Could you explain why the lowest part
    of Tisdales wiggly line falls below 0
    whilst your lowest part is around .2?
    I note you did mention something about
    different baselines and im guessing this
    is related to my query.

    • The text states just below tamino’s graph:

      “It’s not exactly the same as Tisdale’s, it seems we’re using different baselines — but that really doesn’t matter.”

      • Yes. Thanks. Id noted that id
        seen that about baselines and
        considered it probably relevant.
        Im guessing ( until otherwise told ) that base line is the 0 on the y axis.
        Both Tisdales and Taminos charts dont seem to give whys and wherefors for this placement.
        To be fair, niether does any chart ive ever seen on anomolies.
        Such issues may not matter in terms of the comparisons Tamino is doing with Tisdale and visa versa , but im just requesting clarity on it. To learn.
        One obviously needs a y axis in a chart, with graduations marked,
        but , at least in this case, a starting point, a zero, seems irrellevant.
        If you or anyone could direct me to a website that makes things clear i would appreciate it.
        I do understand people have busy lives. Lucky me is on a brief holiday.
        Thanks again.

      • “Baseline” is customarily defined for a given span, usually 30 years, and different data sets use different definitions. It’s not a big deal, since one can be converted to another by simply adding or subtracting the appropriate offsetting value–say, 0.2 C.

        Hope that isn’t explaining the part you already understand….

        Im slowly getting my head around
        it, but still unsure why its sorta not compulsory to define a baseline on a chart.
        There seems to be some standards and the reader must
        ASSUME the standard is being met. Which seems a bit bodgy and open to abuse or misinterpretation.
        If the very next chart i look at is about anomolies in say, gazelle
        populations, and its baseline isnt
        defined either, which would be pretty likely, i just gotta trust the
        gazelle statistition is doing his/her
        very best to make it relevant.
        By way of thanks to doc snow,
        jgnfld, and tamino, i found an article
        on the subject, which may be
        of interest.
        Li D

      • I agree that charts really should specify baseline, in general–even if only indirectly in their specification of data used. The datasets always do tell you, somewhere, what their period of reference is, and FAQs may also give conversion factors. For examples:

  13. Horatio Algeranon

    This is not the first time Watts and Co have accused NOAA of wrongdoing.

    Not a good idea to piss NOAA off.

    I bet that when the flood finally comes, NOAA won’t be too keen to let Watts and Tisdale on the ark — even if a “pair of clowns” is on the list.

  14. turboblocke

    Lol, …pair of clowns on the list. I like that.