SPM and Proxies

Obviously my main scientific interest in the SPM is their handling of proxies. Here there was one rather big surprise and it wasn’t what you might think. (I’m not saying that this is necessarily a very important section of the report; it just happens to be an area that I know well, am interested in and can appraise.)

realclimate were very content of the SPM’s take on HS matters:

Given all of the hoopla [referring to the NAS Panel] since the TAR, many of us were curious to see what the new report would have to say about paleoclimate reconstructions of the past 1000 years. Contrarians will no doubt be disappointed here. The conclusions have been significantly strengthened relative to what was in the TAR, something that of course should have been expected given the numerous additional studies that have since been done that all point in the same direction. The conclusion that large-scale recent warmth likely exceeds the range seen in past centuries has been extended from the past 1000 years in the TAR, to the past 1300 years in the current report, and the confidence in this conclusion has been upped from “likely” in the TAR to “very likely” in the current report for the past half millennium.

Given that Keith Briffa was Lead Author of the HS section, a Hockey Team POV was already taken in the First Draft and Second Draft and is hardly a surprise. The Summary of chapter 6 Second Draft said:

However, it is very likely that average Northern Hemisphere temperatures during the second half of the 20th century were warmer than any other 50-year period in the last 500 years. It is also likely that this was the warmest period in the past 1000 years and unusually warm compared with the last 1300 years. …

Some of the post-TAR studies indicate greater multi-centennial Northern Hemisphere temperature variability than was shown in the TAR, due to the particular proxies used, and the specific statistical methods of processing and/or scaling them to represent past temperatures. The additional variability implies mainly cooler temperatures (predominantly in the 12th-14th, 17th and 19th centuries) and only one new reconstruction suggests slightly warmer conditions (in the 11th century), but well within the uncertainty range indicated in the TAR.

This is tracked quite closely in the SPM which said:

Average Northern Hemisphere temperatures during the second half of the 20th century were very likely
higher than during any other 50-year period in the last 500 years and likely the highest in at least the past
1300 years. Some recent studies indicate greater variability in Northern Hemisphere temperatures than
suggested in the TAR, particularly finding that cooler periods existed in the 12 to 14th, 17th, and 19th
centuries. Warmer periods prior to the 20th century are within the uncertainty range given in the TAR. {6.6}

In arriving at this conclusion, the WG1 report has a little squib on M&M controversies, in which they mischaracterized our findings – compare the Second Draft characterization to our abstracts. I commented on this mischaracterization, but hold out little hope that it changed in the WG1 Report. One of the nice things about the NAS Panel was that they, at least, did not mischaracterize our work.But what of the stadiums full of reviewers that have supposedly considered and endorsed Briffa’s take? Well, 99.99% of the reviewers paid no attention whatever to this section. I actually checked this. Under IPCC rules, reviewers were entitled to see all other comments. So, after the First Draft, I requested a copy of all comments on the First Order Draft, which they annoyingly sent me in a printout rather than digitally. The number of commenters on the Hockey Stick section was very small and consisted to a considerable extent of the players in the game: Esper, Mann, McKitrick, me, etc. As a process, this is not an independent verification of results – as most people in the public assume, but to a large extent, the Team taking in one another’s laundry.

See below for a couple of other takes.

The Surprise

In the TAR SPM, the HS had pride of place on the right hand side of the throne. While it is still honored in the SPM$, it does not have pride of place. Paleoclimate was reduced to a rather small box, but was not otherwise dishonored.

Here’s the surprise. The SPM stated:

Studies since the TAR draw increased confidence from additional data showing coherent behaviour across multiple indicators in different parts of the world.

Readers of this blog are, if nothing else, familiar with the incoherent behaviour of proxy data, even between (say) Briffa’s Yamal version and the Esper’s updated Polar Urals series; or between Keigwin’s Sargasso Sea SST estimate and the Arabian Sea upwelling indicator (G Bulloides). What data could they conceivably had in mind when they said this?

I searched through chapter 6 of the Second Draft and could only find one use of the adjective “coherent” and this was in an unrelated context. I can think of only two explanations for this particular language: first, it could have been inserted in the Final Draft (which I haven’t seen). If so, people should recognize that this particular claim was not itself reviewed within the four corners of IPCC review, but was inserted by the Lead Author (Keith Briffa someone who has an active POV) after the Second Draft. Secondly, the language could have been inserted by the SPM drafters whoever they are or during the Paris excitement.

The drafters of this section probably assumed that the various strands of the spaghetti graph were new data and that journals would not simply publish permutations of heavily overlapping data sets as new studies. Of course, things like Hegerl et al 2006; Osborn and Briffa 2006 etc. simply recycle the same data over and over. I’d sure like to see something simple like (say) a list of the “additional data showing coherent behaviour across multiple indicators in different parts of the world”. I wonder who I could get such a list from.

Other Takes (Sunday)

Andrew Dessler observed of the above HS statement:

I’m somewhat surprised at this no-holds-barred endorsement, particularly since a National Academy of Science panel that reviewed the science of the hockey stick in 2006 explicitly did not make such a strong endorsement.

about which, Mann observed at realclimate:

Nonetheless, the NRC report was a rush job, was forced to ignore key papers in the pipeline, and had limited representation of experts in paleoclimatology (perhaps seeking breadth but sacrificing depth in this key area in their selection of panel members). By contrast, the IPCC was a long, careful, deliberate process, based on several years of thorough assessment of the literature, the IPCC paleoclimate chapter was written by leading experts in the field of paleoclimatology, and input was solicited from essentially every leading expert in the field. It should be unsurprising that they came to a somewhat different (and in my view, more accurate) bottom line.


25 Comments

  1. Posted Feb 3, 2007 at 4:54 PM | Permalink

    The IPCC folks still have 3 months to cook a coherent pasta soup. If each author of a pasta graph agrees that he made errors equal to His_i – Average_i, they may eventually get identical and coherent results, reinforcing the consensus even more than ever before.

  2. Gerald Machnee
    Posted Feb 3, 2007 at 10:50 PM | Permalink

    How do I explain to my neghbour over breakfast that 2000+ scientists did not come up with a unanimous conclusion?

  3. Kevin
    Posted Feb 4, 2007 at 7:10 AM | Permalink

    Just remind him that 2000+ people have never come up with a unanimous conclusion about anything, Gerald. But I know how you feel.

  4. jae
    Posted Feb 4, 2007 at 8:38 AM | Permalink

    I am confused as to how a group of sciences dealing with climate could allow themselves to be so manipulated by political interests. I can understand that type of thing under a regime such as the USSR (Lysenkoism), but in the freer climate of the west it is almost inconceivable. ( I know, the word does not mean what I think it means.)

    (Sigh) Be very very worried about the “free world” especially when the UN gets involved.

  5. jae
    Posted Feb 4, 2007 at 8:47 AM | Permalink

    Steve M. I think your work is highly respected by those that have taken the time to study it (even by HS people, I’ll bet, even though they can’t admit it). Therefore, the treatment of the spagetti graphs in 4AR shows clearly how flawed the IPCC process is. This will not go unnoticed.

  6. Steve McIntyre
    Posted Feb 4, 2007 at 8:49 AM | Permalink

    Andrew Dessler observed of the above HS statement:

    I’m somewhat surprised at this no-holds-barred endorsement, particularly since a National Academy of Science panel that reviewed the science of the hockey stick in 2006 explicitly did not make such a strong endorsement.

    about which, Mann observed at realclimate:

    Nonetheless, the NRC report was a rush job, was forced to ignore key papers in the pipeline, and had limited representation of experts in paleoclimatology (perhaps seeking breadth but sacrificing depth in this key area in their selection of panel members). By contrast, the IPCC was a long, careful, deliberate process, based on several years of thorough assessment of the literature, the IPCC paleoclimate chapter was written by leading experts in the field of paleoclimatology, and input was solicited from essentially every leading expert in the field. It should be unsurprising that they came to a somewhat different (and in my view, more accurate) bottom line.

    One Mann’s “leading expert in the paleoclimatology” is another man’s member of the Hockey Team, I guess.

  7. Joe B
    Posted Feb 4, 2007 at 10:20 AM | Permalink

    Re Kevin

    In regards to “2,000 scientists completing the IPCC,” Roger Pielke Sr. recently hadf this comment on his blog:

    “the answer is that the same relatively small group are selecting, writing and reviewing the assessments. The process has become so inbred that I do not think many of the IPCC scientists even realize the blatant conflict of interest that exists. This has prevented truely independent assessments of the role of human climate”

  8. Steve P
    Posted Feb 4, 2007 at 10:24 AM | Permalink

    I am confused as to how a group of sciences dealing with climate could allow themselves to be so manipulated by political interests. I can understand that type of thing under a regime such as the USSR (Lysenkoism), but in the freer climate of the west it is almost inconceivable. ( I know, the word does not mean what I think it means.)

    Although it’s amusing to see this begin to backfire on the alarmists; there’s already plenty of noise from the NGO’s and their journalist fellow travelers that the report understates the risks.

    And wait til they try and really engage the Chinese. The Chinese press is already positioning the report as indicating the AGW risks are smaller than thought. The Chinese were of course happy to have the Europeans and Japanese damage their economies by signing Kyoto, and they’d love to see the US economy debilitated. But it’s inconceivable that they’ll agree to anything that slows their own economic growth.

    It appears that these days it’s only the Europeans that despise Western industrialization and promote AGW alarm as an excuse to slow or reverse its growth. Fortunately, the influence of such misanthropic ascetic religionists will decline as their own economies do.

  9. JMS
    Posted Feb 4, 2007 at 11:49 PM | Permalink

    I am not so sure. The fact that observational data were given such a prominent role — attributing recent extreme weather events to AGW — seems to validate the view that AGW is having a noticable effect on the climate.

    Here in Bozeman, I joke with friends about global warming, but I am starting to think that the oddly warm weather we have been having for the last few years is an effect of the change in climate. It was 50 here today, extremely warm for MT in February. I havent had to put my snow tires on for 3 years. We are in the 7th (or is it 8th) year of a drought (D0 right now, merging into D1 areas). Things have changed noticably over the last few years, especially in the summer. The lack of rain and runoff in the summer has led to many summer fishing closuers because of high in stream temps.

    The problem is that this is what the GCMs predict as a likely change in precip for this region. Drier summers and not that wet winters. For all of you doubters about the veracity of GCMs, this is what the models say might happen. Even GISS Model II from ’88 got a lot of this right. Play with EdGCM if you want a feeling for how an old model works. The newer ones (Model E, for instance) are better.

    Finally, as far as I can tell, the paleo evidence is pretty well wrapped up. MWP was close to (+/-) the 20th Century mean. It also looks to be a regional effect. MBH99 did not get rid of the MWP; there was a lot of argument in the climate science community in the early ’90s as to whether it was a regional or global effect. Google Michael Tobis to get a sense of what the argument was about on USENET during that time period. MBH98 and 99 did not get rid of the MWP; they just confirmed the view of the anti global MWP people.

    As Steve has pointed out — and as co2science has tried to prove — there were MWP episodes all over the world. The problem is that they were not concurrent and they were not, as Steve and others here want to belive, benign. In the Four Corners area of the US the MWP seems to have occured around 1200 AD and lead to extreme drought. This caused the Anasazi (think Mesa Verde) to die off. Climate change, not good. In Northern Europe, it resulted in longer growing seasons about 200 years earlier — things were good for them. We just do not know with any degree of certainty what might happen in a warmer world (the SPM does give some estimates of what might happen), but it does appear that it will not be pretty.

    Do you really want to make your grandchildren pay for our folly?

  10. Posted Feb 5, 2007 at 12:03 AM | Permalink

    JMS, if Global Warming(tm) is causing the oddly warm weather you are having in Bozeman, what’s causing the oddly cold weather we’re having here?

    Let me guess.. Global Warming(tm)?

  11. Michael Kozuch
    Posted Feb 5, 2007 at 7:03 AM | Permalink

    Nicholas, JMS

    I’m in Chicago, and it’s been around minus twenties Fahrenheit wind chill for a few days, and it will be today. It’s the coldest extended weather that I can remember for around 30 years. It doesn’t seem like Global Warming to me.

  12. Paul Linsay
    Posted Feb 5, 2007 at 7:49 AM | Permalink

    #12, Michael. You should have been in Chicago during Global Cooling. I remember the winter of 1969 (1970?) when the daytime high for one week was -25F(-32C), without windchill.

  13. Michael Jankowski
    Posted Feb 5, 2007 at 7:50 AM | Permalink

    was forced to ignore key papers in the pipeline

    Isn’t every summary “forced to ignore key papers in the pipeline?” What makes the NAS report any different from IPCC in this sense?

    I also find it a funny comment from someone who uses rejected papers as supporting references.

  14. Michael Kozuch
    Posted Feb 5, 2007 at 8:37 AM | Permalink

    #13 Paul

    It might have seemed that cold to you, but the records don’t show it.

    From Wikipedia

    The coldest temperature ever recorded in Chicago is -27°F (-33°C) on January 20, 1985. On December 24, 1983, the high temperature at Chicago reached only -11°F (-23°C), and on July 30, 1916, the low temperature sank to only 84°F (29°C), both of which are records.

  15. Posted Feb 5, 2007 at 9:10 AM | Permalink

    Michael : Funny you should say that. This last six months in Sydney has been a bit odd. Winter seemed to stay late, there was barely any spring, and the summer is only just now getting hot, when usually it’s pretty hot earlier than this. I believe this last Christmas was the coldest recorded in Melbourne yet, and it wasn’t that warm here either.

    Yet I had somebody on another web site tell me, when I mentioned that this year was a fairly cool, that I was wrong – this summer was hot for Sydney – despite the fact that I live here and he does not! I find it odd that many of my friends agree with me that this has been a cool time, yet temperature records don’t seem to reflect that. Why is that? Either my experience is somehow wrong, or else the record is, I guess. How do I tell which?

    Of course this is all just weather. But that’s the reason I’m pointing it out. If someone can argue that AGW is real just because it’s been hot lately, then why can’t I point out that it isn’t because it’s been cool lately? Seems like a poor line of reasoning to me. I’m just trying to show how silly it is. But in doing so, it’s made me worry about the accuracy of temperature records. Recent weather seems to me to be pretty much as it’s always been, and if average temperatures have risen, what, 0.2 degrees or so in the last couple of decades (=most of my life) would I even be able to notice that difference? Seems unlikely to me. Which is why I think when we notice how hot/cold/wet/dry it is lately, I don’t think we can infer much from that, and we certainly can’t make any determinations as to the cause without further information than just the temperature.

  16. TonyN
    Posted Feb 5, 2007 at 9:38 AM | Permalink

    The IPCC’s press release before the launch of the SPM proclaims that “There will be a chapter assessing the palaeoclimate perspective’. And there is; the shortest in the report.

    On RC, The Group got into a spot of bother with their devoted readers by closing their summary of the SPM with the words: “We will address some of these issues and how well we think they did in specific posts over the next few weeks. There’s a lot of stuff here, and even we need time to digest it!’ Someone seemed to find the “even’ a little bit arrogant, but I wonder if it really was?

    Palaeoclimatology was the “main event’ in the TAR. This time it’s a “sideshow’ that seems to have only been included to avoid all the questions that would have been asked if it had been left out. Saying that “the warmth of the last half century is unusual in at least the previous 1300 years’ isn’t really saying anything very much at all. It doesn’t sound very scientific either. Attaching a confidence of “likely’ to this claim in the next paragraph is rather less than a ringing endorsement. Reconstructions that show that the last half-century has been “the warmest in the last 500 years’, only rate “very likely’, and most people knew that from the documentary, archaeological and instrumental (CET) records anyway.

    Might The Team suspect that their chapter was included to save face and avoid hurt feelings? Even they would need a bit of time to digest that. Anyway, reconstructions seem to have suddenly gone out of fashion.

  17. Brooks Hurd
    Posted Feb 5, 2007 at 11:22 AM | Permalink

    JMS,

    Indications of temperature stations here on the Central Coast show a cooling over the past 5 years. However, no one location is indicative of global temperature.

    I just spoke to some friends in northern Norway who said that the winter this year was quite warm but now is what they remember form the past.

  18. Brooks Hurd
    Posted Feb 5, 2007 at 11:29 AM | Permalink

    The SPM is still bringing up the issue of increased TC numbers and intensites, when most scientists who study this issue agree that the changes in data quality over the past 50, 100, and 150 years make such a statement inconsistant with good science.

  19. Dave B
    Posted Feb 5, 2007 at 11:42 AM | Permalink

    #10, JMS…

    don’t worry. you are supposed to get precipitation tomorrow, and temps decreasing to below seasonal averages by tomorrow night…

    http://www.wunderground.com/US/MT/Bozeman.html

    click the “scientific forecaster discussion” for lots more info.

  20. Steve Sadlov
    Posted Feb 5, 2007 at 12:33 PM | Permalink

    RE: #16 – Simple answer for me is, surface measurements are complete shy##.

  21. Paul Linsay
    Posted Feb 5, 2007 at 1:24 PM | Permalink

    #15, Michael, thanks, must be my failing memory. I looked it up here and January 1970 had two weeks at -10F.

  22. bruce
    Posted Feb 5, 2007 at 11:28 PM | Permalink

    Re #16, 21.

    I too live in Sydney, and have enjoyed what I have experienced as a relatively cool and pleasant summer. However, my wife has continually complained about how hot it is. This could be something to do with her stage in life, but it could also be to do with the relatively high humidity that we have experienced most days. Our human experience of temperature is strongly affected by humidity. This is well accepted, and explained here: http://www.bom.gov.au/info/thermal_stress/

  23. DaleC
    Posted Feb 6, 2007 at 4:06 AM | Permalink

    For weather anecdotes, the catalog at http://www.iceagenow.com/Record_Lows_2007.htm is always interesting.

  24. Tomas Szabo
    Posted Feb 6, 2007 at 12:21 PM | Permalink

    (hello climateaudit this is my first post here)

    Weather where I live (sweden) has been unusally mild early this winter up until january when winter finally arrived, now it is pretty much what you would expect it to be. But this is pretty much expected thanks to our friend ENSO I guess.

  25. Tom Brogle
    Posted Feb 9, 2007 at 5:58 AM | Permalink

    Re 16
    I have made a study of Australian Temperatures and have come to the conclusion that the Board of Meteorology has succeeded in adding more UHI effect to UHI effect to get a temperature rise of 2 degrees C in the last 90 years.
    It is done like this they have a station at a
    Post Office which becomes a town then they move it out to the airstrip which eventually becomes an airport.
    There are apparently no corrections for the UHI effect in the BOM figures unlike those of the USA which has had a temperature rise of 0.3 degrees C in the same period.

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