Tom Nelson spots a gem in the Climategate 2 emails:
Hockey stick co-author Ray Bradley:
“it may be that Mann et al simply don’t have the long-term trend right”;
“I hedge my bets on whether there were any periods in Medieval times that might have been “warm”, to the irritation of my co-authors!”
…
Sorry this kept you awake…but I have also found it a rather alarming graph. First, a disclaimer/explanation. The graph patches together 3 things: Mann et al NH mean annual temps + 2 sigma standard error for AD1000-1980, + instrumental data for 1981-1998 + IPCC (“do not quote, do not cite” projections for GLOBAL temperature for the next 100 years, relative to 1998. The range of shading represents several models of projected emissions scenarios as input to GCMs, but the GCM mean global temperature output (as I understand it) was then reproduced by Sarah Raper’s energy balance model, and it is those values that are plotted. Keith pointed this out to me; I need to go back & read the IPCC TAR to understand why they did that, but it makes no difference to the first order result….neither does it matter that the projection is global rather than NH….the important point is that the range of estimates far exceeds the range estimated by Mann et al in their reconstruction. Keith also said that the Hadley Center GCM runs are being archived at CRU, so it ought to be possible to get that data and simply compute the NH variability for the projected period & add that to the figure, but it will not add much real information. However, getting such data would allow us to extract (say) a summer regional series for the Arctic and to then plot it versus the Holocene melt record from Agassiz ice cap….or….well, you can see other possiblities.
[……At this point Keith Alverson throws up his hands in despair at the ignorance of non-model amateurs…]
But there are real questions to be asked of the paleo reconstruction. First, I should point out that we calibrated versus 1902-1980, then “verified” the approach using an independent data set for 1854-1901. The results were good, giving me confidence that if we had a comparable proxy data set for post-1980 (we don’t!) our proxy-based reconstruction would capture that period well. Unfortunately, the proxy network we used has not been updated, and furthermore there are many/some/ tree ring sites where there has been a “decoupling” between the long-term relationship between climate and tree growth, so that things fall apart in recent decades….this makes it very difficult to demonstrate what I just claimed. We can only call on evidence from many other proxies for “unprecedented” states in recent years (e.g. glaciers, isotopes in tropical ice etc..). But there are (at least) two other problems — Keith Briffa points out that the very strong trend in the 20th century calibration period accounts for much of the success of our calibration and makes it unlikely that we would be able be able to reconstruct such an extraordinary period as the 1990s with much success (I may be mis-quoting him somewhat, but that is the general thrust of his criticism). Indeed, in the verification period, the biggest “miss” was an apparently very warm year in the late 19th century that we did not get right at all. This makes criticisms of the “antis” difficult to respond to (they have not yet risen to this level of sophistication, but they are “on the scent”). Furthermore, it may be that Mann et al simply don’t have the long-term trend right, due to underestimation of low frequency info. in the (very few) proxies that we used. We tried to demonstrate that this was not a problem of the tree ring data we used by re-running the reconstruction with & without tree rings, and indeed the two efforts were very similar — but we could only do this back to about 1700. Whether we have the 1000 year trend right is far less certain (& one reason why I hedge my bets on whether there were any periods in Medieval times that might have been “warm”, to the irritation of my co-authors!). So, possibly if you crank up the trend over 1000 years, you find that the envelope of uncertainty is comparable with at least some of the future scenarios, which of course begs the question as to what the likely forcing was 1000 years ago. (My money is firmly on an increase in solar irradiance, based on the 10-Be data..). Another issue is whether we have estimated the totality of uncertainty in the long-term data set used — maybe the envelope is really much larger, due to inherent characteristics of the proxy data themselves….again this would cause the past and future envelopes to overlap.
…Ray [Bradley]
At 01:34 PM 7/10/00 +0200, you wrote: Salut mes amis,
I’ve lost sleep fussing about the figure coupling Mann et al. (or any alternative climate-history time series) to the IPCC scenarios. It seems to me to encapsulate the whole past-future philosophical dilemma that bugs me on and off (Ray – don’t stop reading just yet!), to provide potentially the most powerful peg to hang much of PAGES future on, at least in the eyes of funding agents, and, by the same token, to offer more hostages to fortune for the politically motivated and malicious. It also links closely to the concept of being inside or outside ‘the envelope’ – which begs all kinds of notions of definition. Given what I see as its its prime importance, I therefore feel the need to understand the whole thing better. I don’t know how to help move things forward and my ideas, if they have any effect at all, will probably do the reverse. At least I might get more sleep having unloaded them, so here goes……[Frank Oldenfield]
==============================================================
But wait, there’s more
Hockey stick co-author claims that after 1850, critical trees lost their alleged ability to record temperature
If you examine my Fig 1 closely you will see that the Campito record and Keith’s reconstruction from wood density are extraordinarily similar until 1850. After that they differ not only in the lack of long-term trend in Keith’s record, but in every other respect – the decadal-scale correlation breaks down. I tried to imply in my e-mail, but will now say it directly, that although a direct carbon dioxide effect is still the best candidate to explain this effect, it is far from proven. In any case, the relevant point is that there is no meaningful correlation with local temperature. Not all high-elevation tree-ring records from the West that might reflect temperature show this upward trend. It is only clear in the driest parts (western) of the region (the Great Basin), above about 3150 meters elevation, in trees old enough (>~800 years) to have lost most of their bark – ‘stripbark’ trees. As luck would have it, these are precisely the trees that give the chance to build temperature records for most of the Holocene. I am confident that, before AD1850, they do contain a record of decadal-scale growth season temperature variability. I am equally confident that, after that date, they are recording something else. [Malcolm Hughes]
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
davidmhoffer says: December 24, 2011 at 10:38 am
“This makes criticisms of the “antis” difficult to respond to (they have not yet risen to this level of sophistication, but they are “on the scent”). ”
—————-
There’s the money quote right there. They are wrong, they know they are wrong, and that it is only a matter of time before they are caught.
Well said David. Also I wonder if some of them saw this originally, then worldly temptations proved too great and they passed into denial of “knowing” they are wrong – and this repressed denial is a big reason they scapegoat us using that word.
As I pointed out previously somewhere, tree rings grow most when there is both warmth and wet but those two features only coincide at one narrow sweet spot as the climate zone overhead moves to and fro latitudinally. Such cycling latitudinally overhead is constant but erratic on a timescale matching the climate swings from MWP to LIA and LIA to current Warm Period.
Thus if the climate zone in which the species is most successful moves too far north warmth may increase but growth will slow due to drought.
If the climate zone in which the species is most successful moves too far south precipitation might increase but growth will slow due to cold.
So growth declines in BOTH cold and warm periods and is at maximum in between. Maximum precipitation is always found in the narrow bands closest to the boundaries between air masses of different types such as near the jet stream tracks.
So all that the tree rings tell us is when the trees are under that latitudinally narrow climate sweet spot with enough of both warmth and water for the particular requirements of that specific species.
Maximum growth fails to correlate with maximum warmth because drought soon intervenes and maximum growth does not correlate with maximum precipitation either because cold soon intervenes.
Minimum growth correlates with BOTH maximum warmth and maximum cold.
Indeed, they are wholly useless as a climate proxy and ALL reconstructions based on them must be scrapped forthwith.
“Unfortunately, the proxy network we used has not been updated, and furthermore there are many/some/ tree ring sites where there has been a “decoupling” between the long-term relationship between climate and tree growth, so that things fall apart in recent decades….this makes it very difficult to demonstrate what I just claimed.”
I suggest that the answer to that conundrum is that the climate zones drifted more poleward during the period in question such that drought started to intervene causing a reduction in growth despite the increasing warmth.
Juraj V. says:
……………..
Let see if I can get this right, ah yes I got it, you mean the broken Hockey Stick.
http://www.vukcevic.talktalk.net/CET-100-150-100.htm
Done some time ago, I was just trying to be nice to Mr. Man, or was it Mann.
Lucy Skywalker says:
………………
Hi miss Skywalker, it is part of an article just finished, which may throw more ‘sunlight’ on the whole affair, but at the moment I am trying to amuse myself.
I did post similar graph on the RC
http://www.vukcevic.talktalk.net/CET-GMF.htm
it shows good example of ‘curve-fitting’ but true. It is a ‘non-stationary’ correlation, it drifts back and forth, not a surprise when you think how many factors affect the CET including volcanic eruptions, the North Atlantic SST changes, as well as the atmospheric pressure variations as expressed in the NAO (North Atlantic Oscillation) index.
Have a nice holiday.
James Sexton says:
December 24, 2011 at 8:52 am
Very well said. These Climategaters provide powerful evidence that tree ring width is worthless as a proxy for temperature.
Now, there is the question of why they were not truthful about their own evidence. But there is no question that they failed their duty as scientists, the duty to report all the evidence whether positive or negative. This is “hide the decline” all over again.
I sure hope someone is writing a screenplay of this non-science. Someone with the talent to write such a script could make millions.
Just an idea. I don’t have said talent.
@dizzy,
Michael Mann is a real scientist? You have to be joking!!
Thank you!
And I wish everyone, no matter what your opinion on the subject of climate change, a very happy Christmas and a healthy and prosperous New Year.
Personally, I am hoping for a preposterous New Year, but then I tend to be an optimist.
dizzy says:
December 24, 2011 at 10:02 am
Your post is a Red Herring. In the material you quote here, Bradley does not address in any way the question that was raised by his email which we have been discussing. Please stop trying to covertly change the topic.
I suppose what bothers me is the extent to which the IPCC is cited in papers. For example:
The IPCC is so fundamentally discredited on so many issues, I can’t see how anyone can cite their work.
Steve Garcia says:
December 24, 2011 at 1:24 pm
“The Divergence Problem is a BIG deal. A really big deal. It is VERY important if the instruments in the last 70 years – the best documented, most precisely measured, most widely dispersed period – agree with the tree-rings. And to find out that it wasn’t just “after 1960″ that the decline was happening – holy cr*p, Batman!…
The simple explanation is that tree0rings simply aren’t proxies for temperature. But no one wants to be the one who points out the Emperor has no clothes. So they discuss that it exists, while still using the data – the data that isn’t telling them what they think it should. But they carefully mask the full impact of it.”
I have been harping on this since the publication of CG1. Tree ring width is worthless as a proxy for temperature. I have also been harping on the fact that “hide the decline” shows in spades just now non-empirical or anti-empirical The Team have been. Of course Steve McIntyre has been writing about this for years. He has some fine discussion of Briffa’s work that fed into “hide the decline.”
I think that over the years we have learned to be better analysts of emails, scientific method, and The Team’s scientific claims. We have benefited from great guides in McIntyre, McKitrick, Watts, and others. There is more to be mined from the emails.
Andrew says:
“Has anybody mentioned the how Global Warming extremists have a lot in common with Progressives eugenics movement from the 1930?s?”
Answer: Yes. Michael Crichton in ‘State of Fear’ see Appendix 1 Why politicised Science is dangerous.
crosspatch says:
December 24, 2011 at 11:04 am
This just blew me away. I hadn’t connected the dots on this one, and since I live in a fairly mountainous area (I’m in a “valley” at 4850 ft. with mountains around me in almost all direction) and have spent a lot of time in the mountains around me, I can’t figure out how measuring growth for just 15% of the year translates into average global temperature. (I’ve seen cold winters follow hot summers, and warm winters follow cool summers, and every combination inbetween.)
What a disconnect in logic! Mann certainly has some ‘splaining to do.
Climastrologists.
Ill bet Mystic Meg could do a better job.
Lucy Skywalker;
Also I wonder if some of them saw this originally, then worldly temptations proved too great and they passed into denial of “knowing” they are wrong – and this repressed denial is a big reason they scapegoat us using that word.>>>
As in all complex matters, I think there is more than one driving factor and the answer probably varies by individual.
That said, my own pet theory is that they got way down the road with this and were over their heads in a hurry without knowing it. They started with confirmation bias. They weren’t looking for data upon which to build an informed opinion. They had already made up their minds that CAGW was “reall” and went looking for data to support it. They more than likely tried multiple methods, and at some point hit on tree rings which, based on their initial results, seemed to say exactly what they were expecting them to say. When data started showing up that didn’t correlate, they were already to invested in their belief system to even ask themselves if the initial correlated data was coincidence or not. They just kept looking for the “right” data and discarding the “wrong” data.
But by being over their heads, I mean something well beyond confirmation bias. How many of these scientists are arborists? Biologists? Farmers? Agricultural engineers? Crop specialists? Chemists working in the fertilizer or pesticide industries enhancing crop viability and production? Geneticists?
I don’t know the answer, but I’m guessing zero. They went straight from the assumptions they’d made about the physics to looking for a proxy to confirm their assumptions. But they don’t seem to have a shred of expertise required to connect (or not) the proxy to the physics.
I suspect Michael Mann may know the hard cold truth, why else would he fight so hard to keep his data, his methods, and even his casual emails to colleagues from the public eye? Bradley certainly has his doubts based on this email, but note that he never ventures into WHY the numbers don’t work right. He mentions the failure of the data to match the temperature record, theorizes that the trees are measuring something else, but doesn’t even venture a guess as to what it might be. Clearly he has no experience growing things from a vegetable garden to an orchard, or anything in between.
Over their heads and in so deep they don’t even know they are drowning.
davidmhoffer says:
December 24, 2011 at 4:16 pm
Well said. I think that some of them set out to find some data, any data, that could serve as an argument for CAGW. The very idea that there is a geographic “sweet spot” for data reeks of cherry picking and rationalization after the fact. I can assure you that no one has done empirical research to provide evidence for the claim that there is a geographic “sweet spot.” Climategaters just never were that “into” empirical research.
Merry Christmas and a Happy New Year to Anthony and all of his elves that work behind the scenes to make this forum possible.
James Sexton says: December 24, 2011 at 8:52 am writes “It is time to move all of that literature to the science fiction area of the library.”
James, I reached that conclusion 18 months ago. I’d also read the Ray Bradley piece in CG1. The copied recipients (alverson@pages.unibe.ch, jto@u.arizona.edu, k.briffa@uea.ac.uk, mhughes@ltrr.arizona.edu, pedersen@eos.ubc.ca, whitlock@oregon.uoregon.edu, mann@multiproxy.evsc.virginia.edu) do not appear to have acted rigorously to investigate and correct the problem since this email of Mon, 10 Jul 2000.
If it is correct that dendro suffers a major calibration problem since 1859 (Malcolm Hughes), by simple logic one cannot assume that the calibration worked before then, when there is very little instrumental recording against which to calibrate.
If all of the above holds, this leaves us with essentially no fruitful way to use dendro except for counting the passing years. Someone please tell me this is wrong, because the science world needs as many valid proxies as can be found to be reliable.
Steve Garcia says:
December 24, 2011 at 1:24 pm
@Bob_L December 24, 2011 at 12:11 pm
Bob, the thing is, I never thought that I would come to the point of doubting tree-rings as proxies for temperature. It seems such an entrenched idea, and I had always thought, “Well, the dendrochronologists have all this worked out, don’t they?”
Exactly: thinking that hundreds of modern ipcc scientists must have had CO2 = CAGW pretty much “worked out” was the most basic presumption made, probably for most of us knowing something about the way real science works. To think otherwise would have been nearly impossible, at least for me. Until I looked. But I got one red flag by coincidence almost immediately, because I just happened to start looking at AGW about 6-8 months before the TAR was finally published: the Summary of the science behind the TAR, came out before the science. I’d never even heard of that in the case of such a presumably well worked out area of science. Then the alleged science didn’t come out for so long that I even stopped looking for it, but I was still very irritated. As they say, the rest is history. And it still just keeps getting worse.
People trying to regress me back to the womb is bad enough…but to the Stone Age?
Dendrochronology’s use as a thermometer (or attempted use thereof) is relatively new. In the past it was generally mainly a precipitation proxy (you could tell droughts from periods of adequate or abundant rainfall by ring width). It would be rather difficult to find trees where temperature was the dominant constraint on growth. Maybe right at the edge of a treeline.
Geoff Sherrington says:
December 24, 2011 at 5:50 pm
“Someone please tell me this is wrong, because the science world needs as many valid proxies as can be found to be reliable.”
Sorry, but it is not wrong. The problem is systemic. People who use tree ring width proxies have not done the empirical research to determine whether the proxy actually track the variable in question, temperature in this case. If one is serious about using proxies, one must identify the environments in which they will be used and then experiment to determine how they change as the important factors that contribute to growth change.
Some simple minded people will tell you that you can just trust that tree ring width tracks temperature. They will assure that you can cut the trees, measure ring width, and read temperature from the rings. It never occurs to them that they are assuming that temperature is the one factor that affects tree ring width. Such an assumption goes beyond the anti-empirical to the colossally stupid. If you want to use tree rings as proxies, you must provide empirical evidence, preferably from active experiment, to show that temperature has an affect on tree ring width that can be given unique specification.
The same reasoning applies to all proxies. It seems to me that all existing proxy records are in just as bad shape as tree ring proxies. There might be some exceptions. Perhaps the physical theories that partially explain sunspots make them an exception.
Science must learn once again that its bread and butter is the empirical.
John Daly (RIP) pointed out what a load of bull treemometers are many years ago. McIntyre and others have been demonstrating for years just how dodgy this anabranch of ‘climate science’ is, by analysing the data. Anecdotally, I have a few friends with degrees in Forestry (and yes, they do hard science in order to graduate) who have been baffled as to why anyone would take this stuff seriously.
Wile E. Coyote ran off the cliff quite a while ago, and has been hanging in the air. We are just waiting for the moment when he looks down, or the time allotted for the cartoon runs out. On past performance, the latter looks more likely.
I am still trying to wrap my mind around the concept of how a marker could measure something for a certain period of time, and then stop measuring it and perhaps be measuring something else. You have to be a post-normal scientist to grasp this, evidently, as it is way beyond the ken of plodding slaves of fact like yours truly.
Stephen Wilde says:
December 24, 2011 at 2:11 pm
“I suggest that the answer to that conundrum is that the climate zones drifted more poleward during the period in question such that drought started to intervene causing a reduction in growth despite the increasing warmth.”
Before we can know, someone has to do the necessary empirical research on the selected variety of tree ring in the environments under study. As long as no one knows the relative contributions of temperature, moisture, sunshine, and you-name-it to growth of that variety of tree in the selected environments, no value can be assigned to temperature or any other variable. Once these matters are settled then your hypotheses can be assessed.
davidmhoffer says: December 24, 2011 at 4:16 pm
[An eminently plausible theory and concludes:]
Or in other words … the ice, on which The Hockey Team has been skating, is getting thinner by the day. 😉
OK, I’ll get my coat!
I’ve got a stand of oak trees in the yard behind my house. I’ve lived there for over 20 years, and as far as I am concerned, just my observations about those trees alone debunks tree rings as thermometers (for me at least)
1. There are acorns every year. But every few years there’s a bigger than normal production of acorns, probably 5X. I don’t know exactly what the cycle is, but there is one. In those years it is clear that the trees are putting maximum resources into acorn production rather than growth. How can Mann et al know centuries later which years those were?
2. One spring there was a late killing frost (early 90’s). Oak trees cannot “re-bud” if their leaves are killed by frost (most trees just shed the dead leaves and start again). If oaks lose their leaves entirely, they die. The oaks close to the house and garage were in poor condition, but got enough shelter that they retained about 1/2 of most of their leaves. At the very back of the yard though was a single tree with nothing close to it. It lost at least 90% of each leaf and I was sure it would die. It took 5 years of that tree just hanging on for it to recover. A few centuries from now, how would anyone know that the tree had stunted growth for 5 years due to one day of frost?
3. That stunted oak tree is close to a stand of aspen. At the time, the aspen were perhaps 3 feet or so while the oak was more like 60 or 80 feet. In the 5 years that oak hung on for dear life, the aspen grew enough to compete with the oak for both water and sunlight. Today the aspen tower above that oak. But the oaks close to the house? They make the aspen look like midgets because they just kept on growing and are now far taller than any aspen I’ve ever seen. The shade from those oaks is so deep that even grass won’t grow for lack of sunlight. Those oaks are too tall for aspen to compete with them for sunlight, and because the aspen seedlings cannot get started in the shade of the oaks, they don’t compete for water either. But that poor oak in the back does. A few centuries from now, how will anyone know this?
4. Over the last 20+ years, we’ve had several outbreaks of tent caterpillars. In the really bad years, if it were not for insecticide, they would have cleaned the trees of leaves entirely, and if they didn’t die, they would certainly have had a stunted year growth wise. Centuries from now someone can look at the tree rings and know that the thin years were due to pestilance?
5. There are a lot of deer in the area. They love to harvest my garden for me and they can leap an 8 foot fence without bothering to take a run at it. I gave up competing with the deer for the produce and just quit gardening. Less deer in my yard….and less deer…uhm….fertilizer… left under the oak trees. They’re going to know that a few centuries from now?
Tree rings as a proxy for any single factor is just hokum. And that’s putting it politely.