Bishop Hill Dr Wilson, I presume
Feb 26, 2011 Climate: MWP I very much enjoyed last night's lecture by Rob Wilson and it was good to have a couple of chats with him, both before and after the talk. I found him both charming and very engaging. He even gave my own lecture a plug, which was very kind.
Although aimed at a lay audience, Rob managed to squeeze a lot of science into the talk, and I particularly enjoyed the bits about non-climatological uses of tree rings, which is not an area I knew much about.
My abiding impression was one of balance - this wasn't a standard "we're all going to fry" talk, but a much more nuanced look at the field. There was discussion of some of the difficulties of standardisation of tree ring series and the discrepancies between models and paleo work, which I felt left the listener with a reasonable impression the science not being settled.
There was one nice moment where we were shown the AR4 spaghetti graph, which Rob said "could lead you to conclude that current temperatures are unprecedented", or words to that effect. I thought this was a very considered way of putting it and I asked him about his choice of words in the Q&A session. He said that he did think that the IPCC's 66-90% certainty overstated things. 50:50 was mentioned as a possibility.
Another bit that made me laugh was when he talked about the equipment needed to core trees and showed everyone a tree corer. It was hard not to be reminded of the "heavy lifting" equipment that some people in the field have claimed is required for this kind of thing.
Rob's own work involves trying to create a long pine chronology for Scotland - I've often wondered why one hears so little of tree ring series from this part of the world, given that the northern tree line is within fairly easy reach of major population centres. Rob reckons an 8000 year chronology is possible, although a long way off. It was amusing to hear that sampling work has to stop in the summer so as not to disturb the tourists. It must require a certain dedication to one's science to wade around in Scottish lochs outwith the summer months.
Reader Comments (35)
Good to see a lay-directed lecture which is giving a balanced view of science -- this science especially. Hopefully it could be the start of a trend.
The tourists he is referring to are the midges !!!!
They may be native but.
Rob used to post at CA, eg:
http://climateaudit.org/2008/10/15/the-silence-of-the-lambs/#comment-166101
I always wondered, could volunteers help out with tree coring, in the same way that volunteers helped with the SurfaceStations project?
Interesting comment from Rob at CA. I admire the high signal-to-noise ratio.
Why don't tree branches yield any information? The silence of the limbs?
Dearieme - I think you should take a bough for that one.
Or maybe their bark is not as loud as their bite.
I'm getting very cored of these dreadful puns ...
Pointman
Because they are pining for the fjords? To take a leaf out of Monty Python's book?
Or trunkating their data,
If we carry on like this we'll soon get to the root cause. And it will all Fall into place.
Dearieme-
Look what you've started...one after another, like boling puns.
But getting back to Dr Wilson: I recall a blog comment in recent months -- I can't seem to find where -- that reconstructing temperatures from tree ring widths has given way to reconstruction using the isotopic composition of oxygen in the wood, with the tree rings used just for dating. Did Dr Wilson mention this in his talk? And does anyone else recall such a reference, or have further information on the topic. It seems that, unlike tree ring widths which have strong dependencies on many factors other than temperature, a method based on isotopes would provide a clearer picture.
If everyone were to take the Rob Wilson approach (state your conclusions, don't treat others like idiots), the raison d'être for climate scepticism would cease.
That would be a natural trick to create a decline.
Dearieme, that's another branch of the science, isn't it?
Just wonder which pub you all have been visiting? Sounds like quite a party. :)
C'mon you guys, leaf it alone!
Ah begorrah tis da Tree Fellers Arms to be sure Don Pablo.
Get Smart Rick Bradford..you and your cone of silence.
Hmmm, that's the second "non-denier" within the last day or so that thinks the IPCC overstated the certainty of the "unprecedented" results of the paleo studies.
http://rankexploits.com/musings/2011/agreeing/
"Recent warming is unprecedented over the past millennium" is in the "More Likely than not (50-66%)' bucket.
Zeke and Rob, considering who wrote those paleo conclusions, better watch your backs....
Oh...mandatory pun:
Yeah, I miss my Mustang too.
Oh Shoot
Andrew
I've corresponded with Rob Wilson from time to time over the years and find him a thoughtful and serious commenter. Our discussions have always been very civil. Merely by being civil, he has done more than his share for "reconciliation". For this, he's been subjected to a considerable amount of criticism from the Team - something that I regret.
I am not as negative on dendro data sets as many readers.(That doesn't mean that I support how the data sets are handled by the Team - a different issue.) They are cheap to collect and they have the great advantage of being well-dated.
I had lunch with Rob at AGU one year (Dec 2006, I think). As we were walking back, Michael Mann was walking down the street the other way. I'd met him once before - at the House Energy and Commerce Committee hearings in July 2006 - and said hello. Mann physically averted his gaze, ostentatiously looked the other way and bulled along the sidewalk. Afterwards Wilson cringed, not because of Mann's rudeness, but because he had been spotted talking to me. He said that he expected lots of trouble. .
The original approach to identifying climate signals from tree rings was to use the rings for dating and isotopic ratios to determine climate.
See for example
Libby, L.M., Pandolfi, L.J., 1979. Tree thermometers and commodities: Historic climate indicators. Environment International 2: 317-333
The abstract reads
In four modern trees, hydrogen and oxygen isotope ratios track the modern temperature records.
In a 2000-yr sequence of a Japanese cedar, there are the same periodicities of variation of D/H and
O18/O 16 as have been found in O18/O 16 in a Greenland ice well.
The same periodicities are found in uranium and organic carbon concentrations versus depth in a sea
core from the Santa Barbara Channel, and in carbon-14 variations in a sequence of Bristlecone pine from southern California.
In a 2000-yr sequence of Japanese cedar and in a 1000-yr sequence of European oak D/H and O18/O 16 are related to each other by a slope of 8, just as they are in world-wide precipitation.
In a 72-yr sequence of Sequoia gigantea, measured year by year for its oxygen isotope ratios, the
10.5-yr cycle of sunspot numbers found, but not the 21-yr cycle of sunspot magnetism; this we believe
indicates that the sun is affecting the earth's climate with non-magnetic particles, probably photons.
All these phenomena are related to periodic changes in sea surface temperature caused by periodic
changes in the sun.
Steve McIntyre
An insightful anecdote re getting the cold shoulder from Mann - and Wilson's nervousness at being seen talking to you.
Willem de Lange
Interesting. Thanks for this. I'm having one of those days generally when I keep discovering that I know less than I thought I did. ;-)
I diodn't know you guys were having a pun party, honest. I just innocently transcribing from the CA thread to Rob Wilson:
"When it comes to Dendros, their Bark is worst than…..???"
Steve McIntyre
Posted Oct 15, 2008 at 7:26 PM
their pith?
re. Bernie says:
Your forceful tone seems warranted but I am less certain that it will have the desired effect.
I.e. Pithing into the wind?
Yew lot seem very cherry tonight, all this cheeking your elders, you won't be very poplar with the Bish when he gets back.
cumbrian Lad,
Is he away?
I hadn't noticed!
C'mon boys, let's party party party.
Drinks on the Don
thanks for the feedback Bishop
re - "I've often wondered why one hears so little of tree ring series from this part of the world, given that the northern tree line is within fairly easy reach of major population centres. Rob reckons an 8000 year chronology is possible, although a long way off"
I also wonder why (am interested in history/climate/ecosystem) of my country, this seems a logical study for Rob, so why is it "a long way off"
maybe Rob can comment on his priorities/funding issues etc (as others note he posted at CA a few times).
Steve McIntyre, you wrote QUOTE
I am not as negative on dendro data sets as many readers.(That doesn't mean that I support how the data sets are handled by the Team - a different issue.) They are cheap to collect and they have the great advantage of being well-dated.
UNQUOTE
I see two problems with using tree rings and also other non instrumental temperature proxies:
The first is the difficulty of assigning a definite numerical value to be compared with instrumental readings. I can accept that could be possible to say that it was warmer at certain times and cooler in others, but how to get definitie values without very large error numbers, just escapes me.
The second is the very sparce, fragmented, scatterned but not randomly located locations.
I cannot see how data, even if valid and with usably useful narrow error margins can be accumulated into a valid global index to compare with the modern global indexes (even accepting that these are fair dinkum - itself a big ask.)
If for example someone took good measurements from a location in the north of Scotland, how can that be compared with the NCDC global index of land and ocean temperatures?
I would think all you could compare it with would be thermometer records taken in EXACTLY the same place (temperature being very susceptable to changes in location of a few hundred metres in my experience).
Michael Mann, bless him, attempted the impossible, bless him, of compiling a large scale conglomination I will call it, of numerous proxy readings.
Even allowing that he might have made, what I will call one or two, not completely trivial errors, well what would we have had if he had done it quite perfectly and got high praise from yourself (am I dreaming?).
Well it would still be a mish-mash I would claim, not worth a row of beans unless they were magic beans a la Jack the giant killer, if you get my meaning.
This despite my frivolity, however is a serious question.
I almost forgot - all these reconstructions seem to forget that there is a second, lower order hemisphere to the earth, here down south, that seems to be always forgetten in these matters.
Does that rather mess up comparisons?
Is this the hottest period for the last 1000 years?
I claim the answer is both unknown and unknowable.
Yesterday:
I've corresponded with Rob Wilson from time to time over the years and find him a thoughtful and serious commenter.
Four years ago:
Here’s something amusing in the New Scientist article, which includes a defence of the Stick. Their jpg is compiled by one Robert Wilson of the University of Edinburgh, who includes the reconstruction from Juckes 2006. Has Juckes been accepted or doesn’t this matter any more?...If you cherrypick from red noise series using 20th century trends as a criterion, you can produce stuff like this....
Joshua --
Your "four years ago" quotation comes from here. The "cherrypick" sentence does not relate to Dr Wilson, who compiled the graph but did not originate the reconstructions depicted. [He also was not an author of the article.] Could you please elucidate the point you are trying to make with the juxtaposition of the two quotations?
Harold -
It seems to me that if someone uses a graph with "cherrypicked" data, and if a scientific article they write is "amusing," then he isn't a very good scientists nor particularly "serious" or "thoughtful."
Except, of course, if the way you make those judgements about his character and/or the product of his work is driven by whether his opinion on one particular question jibes with your own.
Actually, Harold - an apology is in order. I read down further in the thread and saw that Wilson said that he "readily" admits to cherrypicking (read the thread for context). Still, the juxtaposition of the attributes "amusing" and "serious" are interesting - although "amusing" was directed at the paper and "serious" was directed at Wilson's character - a relevant distinction.
Joshua,
The World since 2007 is frozen in time? Cetainly, words written in 2007 can be put into the context of subsequent events.
One would think "over the years" includes the years since 2007.
Joshua -
I found the discussion between McIntryre & Wilson on that 2007 thread to be quite in accord with McIntyre's description of "thoughtful and serious." It was a collegial exchange of clear information, civil and without any obfuscation or misrepresentation. He did not indicate his 2007 view of the significance of the spaghetti graph, at least not on that thread. His current opinion as given in the original post -- "could lead you to conclude that current temperatures are unprecedented" -- seems appropriately measured.
BBD
"I'm having one of those days generally when I keep discovering that I know less than I thought I did. ;-)"
All my days are like that - my science definitely isn't settled yet.
As for the puns today - I've only just twigged what they were on about.
And I have always thought that "Dendrochronology" had a nice ring to it!!!
Greetings Bishop Hillites,
A friend just e-mailed and said that there was some activity here that I should read w.r.t. my seminar last Friday.
I do not really follow the blog world anymore. I used to dip into Climate Audit but posting is generally too time consuming as there are often way too many replies. So – please do not feel offended if I do not post again after this.
Just a few brief comments:
1. W.r.t stable isotopes in tree-rings, I urge those interested to read the following paper:
McCarroll, D. and Loader, N.J. (2004). Stable isotope Dendroclimatology. Quaternary Science Reviews 23(7-8) 771-801.
http://www.st-andrews.ac.uk/~rjsw/papers/McCarrollandLoader2004.pdf
There has been a whole flurry of work over the last 5 years or so as the measurement techniques are getting quicker and cheaper and finally the dendrochemists can measure multiple samples. A weakness of the early studies was that they focussed on only a few trees.
2. re. my work in Scotland. Well – I try and keep the following project web page up to date.
http://www.st-andrews.ac.uk/~rjsw/ScottishPine/
w.r.t. sampling in lakes – I made a flippant remark about not being able to sample due to the tourists. This is actually only part of the story as the main reasons are that we cannot disturb mating/breeding dragonflies, Capercaillie etc etc. Most of the fieldwork is done in September although we are now hoping to get in during March before the summer lock down.
Rob