I disagree. But if you want to debate it, please start another thread. I promise I will participate.
I’m not a trained climate scientist. But I’m intelligent enough to understand these arguments and consider them. So I don’t see why it requires a scientist to respond to these arguments.
Especially since debates over the hockey stick have taken place all over the internet. How hard would it be to “mine” for a response to these arguments; study them until you understand them; and then post them here?
Or, if there is no good response, maybe you should consider the possibility that the hockey stick is BS.
It’s a lot more serious than that. The objections I raised each cast a lot of doubt on the hockey stick.
Here’s an analogy: Suppose I claim that I’ve built a free energy/perpetual motion machine. You respond to my claim by explaining how the laws of physics make such a machine impossible. I respond by saying that “there will always be some mysterious that cannot be explained within the current theory.” Is that a strong response? Of course not.
I haven’t disputed this. But like I said, they could have made the same point even if Mann’s paper had been based on tea leaf reading.
It’s unfortunate that you decided to attack a straw man here.
I have never claimed that the NAS said such a thing.
But they did say that “‘strip-bark’ samples should be avoided for temperature reconstructions”
And yet, according to some skeptics, certain pro-AGW researchers continue to rely on such samples.
Why would those researchers do such a thing?
Did the NAS essentially endorse the hockey stick? I don’t think so. At most, they agreed with certain aspects of it.
Anyway, this is not a debate about what the NAS actually said or meant. This is a debate about whether the hockey stick is legitimate.
If you think that the NAS has satisfactorilly rebutted my arguments, by all means quote and summarize them.
While this paper was “published”, it was not published in a serious refereed scientific journal. Rather, it appeared in Energy and Environment, which you can read about here:
I can’t find much discussion of this particular paper, which is not surprising given the reputation of the journal that it was published in and the fact that it was just published this month. However, here is a brief discussion of one of Loehle’s previous papers. It is always dangerous to put much stock in any one paper but doubly dangerous to do so before the paper has been in the public sphere long enough to be reviewed by other scientists, triply dangerous when the paper is not published in a real scientific journal and perhaps quadruply dangerous when the author works for an organization that has a nice astroturf-sounding name (The National Council for Air and Stream Improvement) but is self-described by
That may be so. But as I said earlier, motivations are interesting but less important than substance. (By the way, I would say it’s also dangerous to put stock in a scientific paper where the researcher resists disclosure of his or her underlying data.)
If Exxon makes a compelling argument against the hockey stick, it’s still a compelling argument. If the IPCC makes a poor argument in favor of the hockey stick, it’s still a poor argument.
So let’s talk substance: Do you agree that some proxies are more hockey-stick-prone than others?
Yes, but since none of us is really qualified to evaluate the substance then we have to note the facts so far which, as I noted, are that we have a paper that was just recently published in an nth-rate journal that has essentially no peer-review and has several other strikes against it. Its substance will become apparent over time when other scientists in the field have had the chance to consider it.
I don’t know what sort of paper you are talking about. What Mann resisted disclosing (although he eventually did disclose) was his actual computer code, which is his intellectual property in the eyes of the NSF who funded his research and whose non-disclosure is in fact in line with what is done across most of the physical sciences.
I believe Moberg et al. also didn’t use any tree rings for their reconstruction (or at least the low frequency part of the reconstruction) and, while they did find a more pronounced MWP and LIA than Mann et al. did, their MWP was essentially no warmer than what Mann et al. found.
Actually, it is rather difficult since scientists tend not to spend a lot of time responding to arguments in the popular press on the web as they are more concerned with discussing their findings with other scientists in the field. This is something that creationists were very adept at taking advantage of. Eventually, sites like talk.origins sprung up to try to deal with these arguments in the creation/evolution debates and there are now a few sites such as RealClimate in the climate science sphere. However, there is only so much these sites can do.
And, this is analogous to this situation how?
Well, since both the NSF and the recent IPCC report weighed in on these issues, what they actually said or meant is rather important since it represents the views of people who are well-qualified to come to conclusions on these issues and who are speaking through the processes set up in the scientific community to weigh in on these issues.
The NSF panel was not set up to rebut arguments found on skeptics websites (and particularly arguments made after their report appeared). It was set up to weigh in on the controversy surrounding the temperature reconstructions, which it did, and I have extensively quoted their conclusions above which, I think, pretty much speak for themselves. They are not a complete endorsement stating that they believe that the hockey stick is perfect in all respects nor are they a discrediting of it; rather, they explain the confidence with which they believe each of the conclusions in that original work can be supported and discuss what research in the future would be most useful in settling the outstanding questions and sources of uncertainty that remain in the field.
Speak for yourself. If you feel unqualified to evaluate the substance of the science, then I question why you bother to make scientific arguments.
Start the thread on motivation and ask me there. I promise I will try to answer.
Does that mean “yes” or “no”?
And what does “more pronounced” mean – longer? Can you give me a link? Thanks.
And my earlier question stands: Do you agree with the charges of some skeptics that some researchers continue to use proxies that the NAS panel said should be avoided?
And do you agree that the Osborn & Briffa paper you cited doesn’t seem to show a hockey stick?
If you go to climateaudit.org, there is a discussion right now about the Loehle paper I linked to. One person who has criticized the paper is a geniune scientist who is working with Michael Mann.
Anyway, it’s not like I’m raising obscure objections. There is a lot of discussion out there about the “splicing” problem; the “bristlecone” problem; and the “divergence” problem.
If nobody has bothered to respond to these objections satisfactorilly, that’s a serious blow to the hockey stick.
In general it’s a cop-out to respond to mounting indications that a hypothesis is wrong by stating “well, maybe there’s something out there that we just don’t know.” Which is basically what you stated.
It may be interesting, but it’s not determinative. Anyway, the NAS panel clearly did not “bless” the hockey stick. So it’s not reasonable to assume that it must have considered the objections I have raised and not even bothered to discuss those objections.
Well, I personally feel more qualified to evaluate the substance of some papers than others. Since the proxy temperature reconstructions area hinges almost entirely on rather technical issues involving the data and I haven’t spent the time to try to understand in detail all the temperature proxy data out there, it is one area where I am generally less confident.
The Moberg reconstructions one of the ones shown in that plot of the various temperature reconstructions which is shown on the Hockey Stick Controversy page in Wikipedia that you linked to. (Mann et al., by the way, have an argument as to why they think the Moberg reconstruction might exaggerate the variability of the temperature over centennial scales, see pp. 4103-4 of the paper Mann, M.E., Rutherford, S., Wahl, E., Ammann, C., Testing the Fidelity of Methods Used in Proxy-based Reconstructions of Past Climate, Journal of Climate, 18, 4097-4107, 2005 available here.
Well, since the NAS report came out fairly recently (2006), I am not sure many papers on temperature reconstructions have been written since it appeared. I am also not sure which tree ring series use strip-bark trees or even if the data collection methods for the various tree ring data have always noted whether the trees were strip-bark or not.
I don’t understand how that question even makes sense given that Osborn and Briffa don’t actually reconstruct a temperature scale. What they do is look at various proxies that have a not-too-small positive correlation with temperature and then ask questions about the statistics of these series over time and what they find is that the late 20th century is the most anomalous in the warm direction, as I have noted. However, their method does not allow them to directly reconstruct exactly what the temperature was at any time…which has some disadvantages (in not yielding anything so simple as a nice plot of temperature vs. time) but also has some advantages (as it is free from the various data manipulations that must be done to coax out a temperature record from these proxies). In that sense, it is a nice complement to the methods of Mann and others.
I’m a little confused. Are you qualified to evaluate scientific arguments in this area or not? Simple yes or no question. Earlier, you said this:
Seems like you feel you are unqualified. Right?
THank you. I will check it out. What does “more pronounced” mean? And do you agree that some proxies are more hockey-stick-prone than others?
Fair enough - it will be interesting to see how people react. In any event, I think you need to concede that it is dangerous to put stock in a temperature reconstruction that relies – in whole or in part – on a proxy that the NAS says should be avoided.
In that case, do doubt the claims of skeptics on this point?
Think back . . . my claim was that the elbow of the hockey stick would seem to be more an effect of splicing of data sets rather than any historical change in temperature. It looks like the Osborn and Briffa paper you cited doesn’t undermine that claim.
I suppose I will answer my own questions:
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In my opinion, lack of advanced and/or formal training does not disqualify anyone from being able to evaluate a scientific argument. “You’re not qualified” would seem to be a rhetorical refuge of people who are having difficulty responding to an argument on its merits.
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It would appear that the handle of the “hockey stick” is based in large part on proxies of questionable value.
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The elbow of the hockey stick seems to be more a result of splicing than anything else.
My conclusion is that the hockey stick is BS.
Great, why don’t you publish?
Lol. I just did. 
It looks to me like the “elbow” of the hockey stick is present in the instrumental record as well: http://upload.wikimedia.org/wikipedia/commons/f/f4/Instrumental_Temperature_Record.png
The “elbow” in these other temperature records appears to be at around 1900 too: File:1000 Year Temperature Comparison.png - Wikipedia
Are you talking about a different “elbow?” The “elbow” is the part where the straight portion of the stick meets the blade, right?
I don’t think so - not if you look at that graph at the same scale as the hockey stick. If you look at that graph at an even closer scale, you can find multiple elbows. Unfortunately, the instrumental temperature record does not go back 1000 years.
That temperature reconstruction is spliced. The black line is instrumental.
Essentially, yes.
Thanks for breaking the suspense on what you conclude. We have been waited with baited breath and had absolutely no guess as to where you were going to come down on this.
So, in other words, you will call anything you want an elbow now that someone has pointed out that the instrumental record and the proxies actually overlap for an approximately 50 year period (~1850 to 1900) before a significant rise in temperatures begins.
Why does everything have to be binary “yes-no” with you? There are degrees of qualification. Clearly, the people who are most qualified to evaluate it are people in the field like the NAS committee or the IPCC. I am not completely unqualified to discuss it because I have read a fair bit about it…but I haven’t followed it in detail so if my assessment disagreed with the assessment of people who clearly have better qualifications, you would do well to be skeptical of my conclusions.
Well, of course that is true. A given proxy only gives an estimate of the temperature in a particular location. Although the different results also have to do with the way the proxies are combined together. Some people argue that Mann et al.'s way of doing this tends to artificially dampen out the multicentennial signal while Mann et al argue that Moberg et al.'s way of doing this tend to artificially amplify it.
It is dangerous to put too much stock in any one study which is why it is important to look at the entire body of evidence in a field. One can always identify potential weaknesses of any particular study.
The point is that the Osburn and Briffa paper shows that even if you study the proxies in a way that is very different and makes all these concerns irrelevant, you still come to the same conclusion regarding the extent of the late 20th century warming being anomalous.
Believe it or not, I have an open mind. That’s how I ended up changing my mind on the whole AGW debate.
Not necessarily: My point is that you can find an elbow if you look at a temperature curve on a close enough scale.
I don’t see how this affects my basic point, which is that the hockey stick seems to have a big inflection point right where you switch from proxies to instrumental data.
I’m not sure if that’s correct. Do an image search for “Mann Hockey Stick.” The red part (which represents intstrument data) seems to start at around 1900. What chart are you looking at and how is it smoothed and scaled?
Not everything has to be “yes-no,” but I find it’s an effective way to deal with people who are weaseling.
Do I need to remind you about what you said earlier?
The skeptics seemt to be saying that a lot of studies rely on the same flawed proxies. You don’t seem to dispute this.
Perhaps (and perhaps not), but that’s a much weaker conclusion than what is suggested by the hockey stick.
If you look at this page, you need to not just look at the pictures, but to also look at the text below it. The reason there are a whole bunch of different lines is because different researches independentally tried alternate methods to determine historic temperatures and/or to see if past results were replicable. Arguing over bristlecones is silly when 10 studies come to the same results using methods that were in majority probably not reliant on bristlecones. For instance, #10 is based on glaciers, #8 is based on boreholes and meteorology, #5 on tree rings, etc. Studies have been done on coral and lake sediments as well, though I’m not sure if those are included in the picture.
Science doesn’t assume fact unless different sources and methodologies come to the same result, and the results of others can be replicated if one uses the same methods.
You just aren’t going to get similar looking graphs if the same thing isn’t being measured. So if you are worried that proxy data is “diverging” from real world data, my only guess would be that this effect is being overblown since the only other option would be that all proxy sources are all giving us back something else that isn’t temperature, because certainly they are all giving us back a look at a single something or, as said, they wouldn’t appear similar through history.
Mann’s data can entirely be trashed and there would be no difference in outlook.