Bishop Hill Me and the NAS
Jan 6, 2012 Climate: MWP In the comments to the last thread, Richard Betts is amazed by my statement that the NAS panel's version of events is closer to the truth than the IPCC's and wonders if I now accept the Hockey Stick.
I'm not sure why. The NAS's idea that it is "plausible" that modern temperatures are warmer than medieval ones is surely unarguable. Nobody is suggesting that such a thing is implausible, just that there has been no demonstration that it is the case.
Saying that it is plausible that modern temperatures are unprecedented is therefore essentially to say nothing very much, and is clearly much less objectionable than saying that modern temperatures are "likely" unprecedented.
That said, the NAS panel did still conveniently fail to report the use of bristlecones in most of the temperature reconstructions they discussed, despite North apparently being aware that at least some of them did so. For him to argue that these studies in some way justified the Hockey Stick seems, ahem, less than than straightforward.
In some ways, I think Richard and I are getting caught up in the backdraft from all the spin that went on in the wake of the NAS report. When journalists present the word "plausible" as exoneration of the Hockey Stick, you can end up talking at cross purposes.
Bishop Hill
A later thought - does the word "likely" have any place in civilised discourse on the state of our knowledge of temperatures of the last millennium?
Reader Comments (73)
Hi Bish
Thanks for clarifying. It was more that you now seem happy with the NAS conclusions whereas in HSI even that didn't seem to be the case.
So the bottom line is that you are happy with NAS but less so with AR4 (due to the stronger statement with "likely"), correct?
Cheers,
Richard
Richard, if you (1) replace all occurences of "likely" by "plausible", and (2) restrict discussions to the last 400 years, and (3) refrain from any unwarranted implication that the possibility that Mann might not have been completely wrong on the facts in any way justifies his appalling methodological blunders, then I think you might be able to get widespread agreement.
I have asked the Met Office to explain Professor Slingo's comments.
Holding email from MET received (below).
Can I suggest that others who have reservations about Professor Slingo's comments and would wish for a clarification to ask also?
Dear Don ,
Thank you for your email in connection with climate change.
The Met Office welcomes enquiries and feedback, and in the context of climate change these items nearly always require a certain amount of research to fulfil a suitable reply.
All enquiries/feedback is recorded and the reference number for your enquiry is REF:0015820
If you have asked specific questions or for further information, please be assured that we are working towards an answer for you. Given our research workload we cannot always ask our Hadley Centre scientists to deal with feedback as quickly as we would wish. In addition to this, due to work loads, we are unable to provide point-by-point answers to particularly long enquiries, and we cannot to enter into ongoing debates. Nevertheless, we aim to respond to every query put to us where necessary and aim to respond within 28 working days.
If you have written to express an opinion, all opinion is reviewed by our scientists and we thank you for taking the time to get in touch with your point of view.
If you have any further queries or need additional information, please contact our Weather Desk on 0870 900 0100 where one of our advisors will be happy to help. The number is open 24 hours a day, every day of the year and it will help us if you can quote the reference number given above.
Yours sincerely,
Sara-Jane
@Richard Betts
Your conclusion that the Bishop is now happy with NAS, or that he now accepts what they said about the HS, doesn't seem to me to fit at all with what he actually wrote in the post above, but perhaps I'll leave it to him to reinterpret it.
Richard Betts
Please tell us your views on the use of Bristle Cone pines in the Hockey Stick?
So here's the double standard. Slingo et all dismiss the inconvenient MEEP by saying that only some parts of the world were likely warmer today and that there isn't enough data for the rest of the world to come up with any conclusions YET these same scientists are more than happy to use the limited weather stations around the world that may show some warming and then "smooth" those temperatures around that rest of the planet Nd then say they are absolutely certain the planet is unprecedentedly hotter today without a word of doubt?
Gee, wasn't that long ago when a denier would have been someone who doubted the existence of the MEWP
Mailman
"Happy" would be going too far. It was better than AR4.
The panel recognised that the data and methodology used in MBH98 were inappropriate. They therefore had an opportunity to put some distance between the reputable science and Hockey Stick - they simply had to say so clearly. They refused to do so and tried to spin the report sufficiently to allow Mann and the IPCC to save face (we see concerns re consistency between the two reports in the climategate emails).
I would suggest that a more reasonable report might have been structured as follows:
1. MBH data and method inappropriate
2. Many other studies use same data
3. Non-bristlecone studies are probably unreliable too (divergence, lack of verified model of tree growth)
4. Non tree ring studies
5. We don't know very much about temperature history.
"Likely", could, maybe, possibly, there is a chance," are not terms that should be found in a science paper destined to influence idiots into making really stupid investments with taxpayer's money. Full Stop. Anyone who now offers any credibilty to Michael Mann's hockey stick, after all the analysis thgat has been done and after reading Lamb's work should be working in a scientific endeavour. In my opinion.
Speaking as a reader of both the book and this blog, to me Richard Betts seems to be implying is that there was some sort of authorial voice in the HSI that showed "unhappiness" with the NAS report, and that is now contradicted by the Bish saying he is wildly "happy" with it now on this blog ;)
One of the things I like about the book was its forensic detailing of the issues that let the actions and conclusions speak for themselves. The nearest to an authorial conclusion I can see looking through it now
I have lived more than half my life in times of supposed 'unprecedented warmth'. And I can detect no major difference in the climate overall now than when I was a kid in the 1960s.
So even if it is on average 0.2C hotter now than it was in The Summer of Love, can anyone explain why this passes the SFW test? Because I've been bombarded for years with predictions of dire and readful consequences of global warming. And each year I look, they don't happen yet.
Actuaries tell me that I should have about 30 years left. Will I live long enough to see any of the actual dire consequences? Or are they reserved for another 50 to 100 years ahead?
North?
Maybe you should use full names to save on confusion. (Well, mine)
The proper interpretation of NRC2006 was made clear in oral and written statements made by North and others on the record and under oath to the Barton Committee. They agreed that Wegman's Report was credible and said that their Report said much the same on the statistics. "Plausible" was used specifically because they did not believe it was possible to put a statistically valid numerical certainty to any estimate of earlier temperature prior to 1600 AD in comparison to recent times. They did not stand up the "hockey stick" it was merely plausible.
(sorry, access to proper keyboard now)
So here's the double standard. Slingo et all dismiss the inconvenient MEWP by saying that only some parts of the world were likely "warmer" than today and that there isn't enough data for the rest of the world to come up with any conclusions YET these same scientists are more than happy to use the limited number of weather stations around the world that MAY show some warming and then "smooth" those temperatures around that rest of the planet that have no weather stations and then say they are absolutely certain the planet is unprecedentedly HOTTER today without a word of doubt?
Gee, it wasn't that long ago when a denier would have been someone who doubted the existence of the MEWP
Mailman
Dramatis personae :
The NAS panel was headed by Gerald North
Likely has no place.
Consider that when you toss a coin it is "likely" you will get heads.
"Likely", could, maybe, possibly, there is a chance," are not terms that should be found in a science paper destined to influence idiots into making really stupid investments with taxpayer's money. Full Stop.
So a vaccine that would only "likely" cure AIDS should be denied funding, because the result is not certain?
A method of "likely" improving extraction of shale gas should be not pursued?
Your statement is so basically ridiculous.
Consider that when you toss a coin it is "likely" you will get heads.
Do you insure your house? I do. Even though it is extremely unlikely to be burnt down or otherwise damaged.
Governments need to consider the consequences of possible events. That is not to defend the ridiculous extent the "precautionary principle" can be stretched to, but it would be extremely unwise of a government to only stick to the likely.
There is some difference between something which is likely to produce a result and a result which is likely to be correct. In the former, nothing much may be lost but in the latter, a great deal may be.
Geckko
It is equally likely you will get tails, which effectively negates the 'likelihood' of your getting heads.
It is possible but unlikely that the coin will fall on its edge and stay that way. It is almost certain that it will come to rest showing either obverse or reverse face but either option is equally likely.
Chambers has both 'probable' and 'credible' as definitions but my own view is that the use of 'likely' in this context was intended to convey the former meaning and was used precisely because there was no firm evidence that could be cited for anything more positive than a bit of handwaving.
MBH98 has been effectively debunked not only by McIntyre and McKittrick but, according to the Climategate 2 emails, by most other members of the team as well and I come back to Ed Cook's comment "what we do know is that we know f*** all".
So given the conflicting evidence from an assortment of sources (reputable and otherwise) let's stop pretending that we have the faintest idea whether MWP was warmer or cooler than 1975-2000 and can we also stop pretending it matters.
Mooloo, you are confusing past - which is fixed - and future - which may happen.
There is no place for using 'likely' when referring to the past unless you are so unsure of the facts that you are making a speculation of what you think - or want - to have happened.
The examples you give are about events that are in the future and are therefore unknown and hence likely.
Mooloo
As usual you have completely misread even the most basic of english, perhaps because it is not your mother tongue.
Try again. are not terms that should be found in a science paper destined to influence idiots into making really stupid investments with taxpayer's money. Full Stop.
Mooloo
It is the imprecision of the word 'likely' in a scientific report that people are objecting to - both its meaning (somewhere between 50 and 90%) and how it is determined
Mooloo
Got it??
It's pretty obvious that most reconstructions show that the MCO is at least as warm as the recent past. The only wan to change this is to use "Mike's Nature trick." and that's a crock
Insurance is a good example of the appropriate application of precaution. It is "unlikely" but not impossible that your house will burn down. Your insurance company is well aware of the overall probabilities and will charge you a premium based on that, you will see that the premium is relatively small compared to the potential loss and will agree.
Governments do indeed need to consider the probabilities of unlikley events and take appropriate precautions, the investment in the Thames Barrier is one such example. However, it is not just the liklihood of an event that matters but the relative costs of the consequences vs the protective measures necessary. For example the liklihood of the earth being impacted by a near earth object in the forseeable future is positive band the potential consequences devastating but we do not see investment by governments in the necessary protection systems becasue the cost would be so great.
So the bottom line is that you are happy with NAS but less so with AR4 (due to the stronger statement with "likely"), correct?
Cheers,
Richard
Bish
Now that would really offend me. Maybe I'm easily offended but I could find nothing in what you wrote that would permit someone to arrive at that conclusion.
The IPCC's use of the word "likely" has no place in science. When we talk about what is known scientifically, we never say that two flipped coins won't both come up heads. We are fairly confident 5 flipped coins won't all come up heads (p 0.03), so we will put that conclusion in the abstract of a scientific paper, but we have greater confidence in 7 coins (p<0.01) or more (p<0.001). Before approving a new drug, we usually demand TWO clinical trials with the probability of chance having produced the apparent beneficial effect being equal to that of getting five heads from each trial. Before CERN will definitively announce the existence of the Higgs boson, they want chance reduced to 5 sigma or about 12 flipped coins.
Policymakers, on the other hand, may be interested in the IPCC's version of "likely". If either of two flipped coins coming up heads could produce a $1M disaster, should we tell them that a disaster was "likely" (or more likely than not = one flipped coin). Why not? Perhaps this knowledge will enable them prevent the disaster by spending $10-$10,000. If avoiding CAGW were a reasonable cheap option, the IPCC's abuse of the term "likely" wouldn't matter so much. With little understanding of the magnitude and cost of a possible disaster 50 years from now and cost of insuring against the possibility of disaster hidden by cap-and-trade and phony emissions offsets from the third world, it isn't obvious whether society should purchase insurance against possible disaster.
Moolook,
The meme has long been changed by the IPCC et al from "Global Warming" to "Climate Change". Accepting that at face value, this means the climate can "change" by warming AND cooling, otherwise they would have stuck with Warming (can't have it both ways). It follows that governments shouldn't be trying to change the climate but to adapt to any change forthcoming. It would be extremely foolish for a government to do anything else but.
BH must be right to say that the "idea that it is plausible that modern temperatures are warmer than medieval ones is surely unarguable." The same point is found in Ljundquist's paper, "the controversial question whether Medieval Warm Period peak temperatures exceeded present temperatures remains unanswered". On the other hand, it also seems pretty plausible that even recent reconstructions underestimate past variability - see Ljundquist's conclusions. Even more impressively, try section 4.3 of http://www.physics.mcgill.ca/~gang/eprints/eprintLovejoy/neweprint/Emergence.climate.merge.25.10.11.pdf, especially figures 9 and 10. The anomalous scaling behaviour of the Hockey Stick argues strongly against it's validity. Even for the later reconstructions, the scaling suggests that the amplitude of the variability remains too small.
Scott: Durban decided to reduce CO2 levels to 210 ppmv.
The intention is to take us one third the way to the next ice age.
Mooloo
"
"Likely", could, maybe, possibly, there is a chance," are not terms that should be found in a science paper destined
to influence idiots into making really stupid investments with taxpayer's money.Full Stop"
So a vaccine that would only "likely" cure AIDS should be denied funding, because the result is not certain?
A method of "likely" improving extraction of shale gas should be not pursued?
Your statement is so basically ridiculous.
"
Well a potential vaccine would be based on some observation of effect either epidemiologically or via experimentation. Both of which would carry estimates of uncertainty and significance.Improvement of an engineering process would result from analagous activities in process monitoring or workshop design.
In terms of completely original 'eureka' invention in either field, denial of funding is depressingly common. Because 'may' and 'possibly' are an obstacle to the investment that would result in 'likely' let alone the pilot work that would yield actual numbers and calculated returns (both human and financial).
"A later thought - does the word "likely" have any place in civilised discourse on the state of our knowledge of temperatures of the last millennium?"
Given the state of large swathes of the temperature network, and all the adjusting fiddling and fudging that goes on, sometimes wonder if 'likely' has any place in civilised discourse on the state of knowledge of temperatures. :-)
As far as the last millenium and the Hockey Stick, isn't the last word still with McShane & Wyner i.e the uncertainty in the proxy source data invalidate the conclusions drawn.
Do trees make good thermometers?
Are trees likely to be thermometers?
Is it plausible that trees record temperature in any meaningful way?
Now considering all the natural background noise in wild woods and forests, the fact that scientists have been caught mining for data that fits a narrative, the all-to-obvious divergence problem, etc; I would say that temperature reconstructions based on in full and in part on trees are flawed to the point that the results are neither robust nor reliable.
Mac: tree rings are a proxy for rainfall, not temperature.
Is it likely that Slingo misrepresented the view of NAS?
Yes!
Is it plausible that NAS got the hockey-stick science wrong?
Yes!
Mac and others,
The NRC Panel members did not get the "hockey stick" science wrong. They identified the problems in the maths and in the data. With the exception of John Christy, they simply could not bring themselves to call a spade a spade. In my paper I quote what Gerry North had been reported as saying previously in Science:
He also said,
Panel member, Kurt Cuffey, had said in the San Francisco Chronicle of 9 October 2005,
I'm sure if we look hard enough we could find similar quotes for the the rest of the Panel apart from John Christy.
Accept the Hockey Stick?
1527.txt: Dendrochronologist Rob Wilson writes: “ There has been criticism by Macintyre of Mann’s sole reliance on RE, and I am now starting to believe the accusations. ”
4241.txt: Rob Wilson again: “ The whole Macintyre issue got me thinking…I first generated 1000 random time-series in Excel … The reconstructions clearly show a ‘hockey-stick’ trend. I guess this is precisely the phenomenon that Macintyre has been going on about. ”
4369.txt: Tim Osborn says “ This completely removes most of Mike’s arguments… ” and Ed Cook replies “I am afraid that Mike is defending something that increasingly can not be defended. He is investing too much personal stuff in this and not letting the science move ahead.”
3 from many Richard! Accept the Hockey Stick indeed!
This is not about a new interpretation of the hockey-stick data but a deliberate misrepresentation by Slingo of a NAS review into a manipulation of the hockey-stick science by Mann to suit the AGW narrative. The science was manipulated to get rid of the MWP (NAS - less confidence) but still to show the LIA (NAS - more confidence).
Is it likely that Slingo misrepresented the view taken by NAS intentionally?
Yes!
Is it plausible that Slingo misrepresented the view taken by NAS unintentionally?
Yes!
If the original NAS panel were reconvened today would they express more or less confidence in the hockey-stick science? I would argue they would report less confidence.
'plausible' is a satisfactory word in the context of philosophy. I doubt whether users of the word in science would be too enamoured with many dictionary definitions though:
1. Superficially fair, reasonable, or valuable but often specious: 'a plausible pretext'
When used to describe persons, it is rather worse:
1. Superficially pleasing or persuasive: 'a swindler…, then a quack, then a smooth, plausible gentleman — R. W. Emerson'
2. Apparently, but often deceptively, worthy of confidence or trust: 'a plausible commentator'.
3. Using specious arguments in discourse that sound likely but are intended to deceive: 'a plausible speaker'.
Antonyms: honest, sincere.
It's a common feature of the dogmatic/fanatical, on any subject, to assume that anyone questioning their dogma is equally dogmatic/fanatical.
It's a common feature of true believers to claim that if there is a gap in knowledge then their complete made-up implausible b*llocks is a more valid way of filling the gap than simply saying "we just don't know (yet)".
Both of the above features seem to be common amongst believers in CAGW.
Jan 6, 2012 at 11:27 AM | Pete H
Sure, I didn't think BH accepted the Hockey Stick specifically, just that he'd accepted the NAS conclusion more than I previously thought he had. BH has clarified his position (which appears to be somewhere between my interpretations of his position in HSI and his current one) which is fine.
I must admit I did send a slightly mischievous tweet to both Mike Mann and BH which is possibly why BH thought I was saying he'd back-tracked on the Hockey Stick. Shouldn't have done that, bit naughty, sorry... :-)
Twitter gets us all in trouble eventually :-)
I don't want to muddy the waters even more, but I must say that "likely" has a very different nuance in American English from its uses in British English. AIUI it is used to convey "highly probable"- and as, by now, several generations of younger scientists speak International English (deriving much more from the American than the British variants), that may explain a lot of the confusion.
In a similar vein, I think the use of "plausible" in a scientific context is more akin to the "philosophical" usage than to the pejorative dictionary definitions listed above, which I suggest users of International English would consider archaic if they were aware of those uses at all.
Jan 6, 2012 at 8:48 AM | Jack Cowper
Not being an expert in palaeclimate reconstructions I defer to others on that point. I am aware of the arguments of why they are considered unreliable as indicators of temperature.
For my IPCC AR5 writing I'm interested in tree ring records as an indicator of vegetation growth in itself (ie: not as a climate proxy). I'm on the Working Group 2 chapter on Terrestrial and Freshwater Systems, and we are looking at the literature on all sorts of indicators of ecosystem change (or lack of it) from whatever cause (climate, CO2, ozone damage, etc etc). Much of the literature focusses on phenology, but tree rings are another potential source - although one has to be careful about the fact that many sites are chosen specifically for their sensitivity to climate, so may not be representative of ecosystem responses as a whole.
The "divergence problem" is very interesting in this regard, as it may represent changes in the relative importance of different drivers of change (still reading the latest on that).
If anyone knows of any useful papers here then please let me know.
Thanks!
Jan 6, 2012 at 12:53 PM | Skeptical Chymist
Thanks, interesting!.
"likely" has a very strict definition in IPCC terminology - it is defined as "a greater than 66% chance".
If i recall correctly, there was a press conference when the NAS report was released. There were numerous comments at the press conference which were different from the written report, and which were used extensively at the time in coverage of the report. it wouldn't surprise me if there was a "likely" quote from the press conference.
per
Richard:
I really do enjoy your comments and your playful sense of humour in a field that has its share of curmudgeons.
That said, the IPCC may well have defined "likely" as greater than 66% - but that just begs the question as to how "strictly" or "precisely" one can measure 66%. I remain unconvinced that the state of knowledge admits such efforts at definitiveness without an established track record that shows that such odds makers know what they are talking about.
... though why you would pay attention to someone who can't even do a copy and paste properly I can't imagine.
I am not having a good day, guys!