NS climate myths guide

The Nude Scientist has produced a Climate change: A guide for the perplexed with some common myths explained, correctly as far as I can see. There is also a blog on it which has already degenerated into the usual rubbish, ho hum.

Comments

  1. #1 mugwump
    2007/05/17

    Plenty of the usual alarmist nonsense. Eg,
    Climate myths: Polar bear numbers are increasing

    …followed by…

    “the truth is that no one can say for sure how overall numbers are changing”

    So the myth could just as easily have been “Polar bear numbers are decreasing”, but that wouldn’t be anywhere near as alarming, would it?

  2. #2 guthrie
    2007/05/17

    Ahh, you learnt your style from Creationists.

    Basically, the point with Polar bears is that we have definite evidence that climate change is bad for many of them. THe two populations in question have shown decreases in numbers, due to a large extent to the loss of sea ice. This therefore is a pointer to how things will progress in the future. For denialists to start saying “but polar bears are increasing in numbers” ignores the complexities of the situation.

  3. #3 mugwump
    2007/05/17

    “”but polar bears are increasing in numbers” ignores the complexities of the situation.”

    Ah, so sceptics who point to increases in polar bear numbers are “ignoring complexities” but alarmists who say “polar bear numbers are decreasing” or “polar bears will be extinct in 25 years” [Tim Flannery] are reflecting all the subtleties of the situation.

    Silly me, why couldn’t I see that for myself?

  4. #4 mugwump
    2007/05/17

    I am perplexed. Maybe readers of this blog can help me out. If you look carefully at the bottom figure in this plate from the NS article, you’ll see that nearly all the temperature reconstructions fail to match the instrumental record of the last 100 years (they are off by a wide margin).

    How are these “scientists” justified in projecting their reconstructions 1000 years into the past if they cannot even match the known temperature record? Or am I missing something obvious here?

    Is this a new kind of logic only climate scientists get to use? Does the polar bear talk give us a clue: “decreasing polar bear numbers” is the same as “increasing polar bear numbers”, hence “disagreement between record and reconstruction” is the same as “agreement between record and reconstruction”?

    Please help me. This is confusing. I do not have the advantage of living in wonderland.

  5. #5 SteveF
    2007/05/17

    To me they look pretty comparable. Indeed you can’t actually see the instrumental record in places because the proxy reconstructions overlie it.

    But then as you cleverly called scientists, “scientists” you must be right.

  6. #6 guthrie
    2007/05/17

    Not that I have read any flannery, but i assume he was extrapolating from the evidence available for the decreasing populations. AS such he was overstating things.

    Anyway, I’m sure that doesnt change your conviction that everything is hunky-dory.

    Regarding the reconstructions, I thought you understood that different ones use different proxies, and therefore will get slightly different results, depending on a variety of factors.

  7. #7 uBeR
    2007/05/17

    Pretty good article. A few things could have been handled better, but was a good, simple overview.

  8. #8 mugwump
    2007/05/17

    That should have read:
    “nearly all the temperature reconstructions fail to match the instrumental record of the last 10 years”

    (not “100 years”, which as has been pointed out you cannot see from the graph).

    Presumably, if these reconstructions are valid, they would accurately reflect the warming of the last decade. They don’t, therefore the reconstructions are invalid. “scientists”. QED.

  9. #9 SteveF
    2007/05/18

    It looks to me that often they don’t reflect the warming of the last decade because they don’t attempt to reconstruct the last decade. The instrumental record stretches beyond the reconstructions which mostly seem stop a bit before 2000 (roughly speaking). This is to be expected from Jones 1998, what with Jones 1998 having been published prior to the last decade of warming. I imagine a similar situation exists for those papers published early in the 2000s, which will be using data that stops a while ago now.

    For the three most recent papers, rather than simply eyeballing the graph I checked them out. To quote from the Oerlemans (2005) paper:

    “The global mean temperature shown in Fig. 3A is a weighted mean for the period from 1834 to 1990.”

    In the Moberg et al (2005) paper, the low resolution proxies mostly finish in the middle of last century, with one (from GRIP) going up to 1996. From my quick scan of their paper, it seems that they take their reconstruction up to around 1990. It is also worth pointing out that the Moberg paper, which is often cited by sceptics as evidence for greater natural vairability than MBH 1998, is the reconstruction which fits the instrumental record over the 20th century least well (this is not to say their main conclusions about natural variability are wrong).

    I also checked out the D’Arrigo paper which does note that divergence between proxy (tree rings in this case) and instrumental data takes place more recently. This follows excellent agreement over the 20th century. In this particular instance, the authors note the evidence and seek to find ways to explain it (it has also been noted by some other tree ring people). Almost, you might say, like scientists would do.

    This to me implies that proxies are imperfect (gasp!). What do we do with this nugget of information? Throw the baby out with the bath water and basically accuse palaeoclimatologists of being charlatans? Or perhaps we recognise that in the main the proxies are doing a decent job, capturing the trends observed in instrumental data, but that further work is required to refine them and explore the limits of their capability. In this regard, the D’Arrigo paper presents a different method of statistical analysis which, looking at the paper, is an improvement on previous efforts for the troublesome recent period.

    It is also worth pointing out that in the D’Arrigo paper, they note that their results suggest “that MWP conditions were nearly 0.7 degrees cooler than those of the late twentieth century. These results suggest how extreme recent warming has been relative to the natural fluctuations of the past millennium.” However, they go on to qualify this statement for the reasons outlined above and note the need for caution. This reasoned approach is completely counter to the way you have presented research in this community. Still, I doubt they give a toss what you think about them.

    Having said all that, it’s good to see you admit that before this they are in pretty decent agreement and that your original point was completely wrong.

    [Agreed; most recons end about 1980 -W]

  10. #10 mugwump
    2007/05/18

    The problem for the paleoclimatologists is “the troublesome recent period” is not only the most significant feature of the instrumental temperature record, it is also precisely the period that supposedly establishes the AGW hypothesis. If you can’t reproduce that your whole technique is pretty questionable (or maybe the instrumental record is questionable – there’s so much secret ad hoc adjustment to the record by GISS and HadCRU that it may just be the reconstructions are right and the “instrumental” record is wrong.)

    And I don’t agree the reconstructions are in “pretty decent agreement” over the rest of the instrumental record. It is so short and there are so few significant features in that record that I’d be very suspicious of overfitting.

    These guys may be great lumberjacks but they are lousy statisticians.

  11. #11 SteveF
    2007/05/18

    Interesting. Apparently the reconstructions (referring to all of them – a position I have demonstrated to be false) don’t match the instrumental record. On being pointed out that they do (the recent period in one reconstruction aside), the argument then shifts to the instrumental record is too short and has too few significant features. Isn’t that what they call a bait and switch. Or shifting the goalposts. Or a load of old bollocks as my dear old grandfather would say (sniff).

    So anyway, despite this good agreement, the whole reconstruction technique is questionable? Well, this is a somewhat silly remark, unless of course, you are the kind of person who thinks that science is a simple, neat process that produces perfect results every time. Apparently you are such a person. Those of us who actually handle data day in day out, know that isn’t the case.

    What is really happening is that in some tree ring results, there is a recent discrepancy. This is acknowledged by the palaeoclimatologists, is being investigated and is taken into account when making conclusions (as I demonstrated from the D’Arrigo paper). In other words, many of the accusations you have been levelling at the “scientists” are in fact complete and utter bullshit.

    Still, I’m sure they’ll cope with an anonymous internet commentator making such statements. Next thing you know, we’ll be hearing about how Mann withheld data……..yawn.

  12. #12 guthrie
    2007/05/18

    Yes yes, so much secret adjustment to Hadcru etc that actually we don’t know about it…

    Anyway, what is interesting about the new scientist thing is the way it has filled up with a species of commenter who are related to little englanders. They distrust the gvt, big business, and anyone who claims to know more than them, unless of course the supposedly knowledgable one is agreeing with them. Hence having Tony Blair try and make climate change one of his legacies does not help, since these people sit moaning about the politians and how they are manipulating things for their own benefit.

    Also, it is amazing how many are so narrowly socialised that they think climatologists will get big money if they endorse global warming.

  13. #13 mugwump
    2007/05/18

    SteveF, can you point me to the dendro studies showing good agreement with the recent warming? Also, can you point me to the archives of HadCRU that can be used to reproduce their global temperature records, including their work on UHI?

    Thanks in advance.

  14. #14 guthrie
    2007/05/18

    Someone else has already been demanding all the Dacru data, I think I saw it at Deltoid. Do you guys have nothing better to do than demand stuff you show no ability to comprehend?

  15. #15 SteveF
    2007/05/18

    Did I say there were dendro studies in good agreement with the most recent warming? No. In fact I noted disagreement. Twice. Maybe you missed this. I said there was generally good agreement with the 20th century instrumental record. There is. The D’Arrigo paper is one such example. If you read the paper, there is a nice colourful graph which should help you to grasp this.

    You appear to want me to follow you down the rabbit hole and into a never ending spiral of extremely tedious discussion of climate data and associated conspiracies. No thanks. Pointing out your errors and bait and switch have been enough for me. Toodle pip.

  16. #16 mugwump
    2007/05/18

    Where are my errors and bait-and-switch? We have no agreement between dendro reconstructions and the most significant feature of the instrumental temperature record. The prosecution rests.

    It is astonishing to me that any scientist would defend witholding of data, but in climate science it is apparently the MO. Believe me guthrie, if they’d give us the data I sure would know what to do with it. What are they afraid we’ll find?

  17. #17 SteveF
    2007/05/18

    Documented. Waste of time. Tedious.

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