Bishop Hill Diversionary tactics
Feb 22, 2011 Climate: Ward A truly Wardian performance by the LSE man at the Grantham Institute site today, taking a pot-shot at Christopher Booker because of his (entirely correct) observations about the inaccuracies in the science in Sir Paul Nurse's Horizon programme. No true statement should ever go unchallenged it seems:
Dr Bindschadler indicated that human activities emit the equivalent of about seven billion tonnes of carbon into the atmosphere each year, whereas natural sources, such as volcanoes, only produce about one billion tonnes. Christopher Booker, whose weekly column in The Sunday Telegraph regularly recycles the content appearing on 'sceptic' blogs, attacked Dr Bindschadler's statements, describing them as "mind-boggling" and "a grotesque misrepresentation". Mr Booker claimed that natural sources account for more than 96 per cent of annual emissions of carbon dioxide. So who is right? With a typical flourish, Ward then proceeds to avoid the question he has just posed and embarks on a lengthy discussion of various aspects of the carbon cycle, but one that never quite gets back to the ratio between human and natural carbon dioxide emissions. As readers here know, Bindschadler got it wrong and Booker was right. The ratio is nothing like 7:1. Unfortunately, Ward just can't quite bring himself to say that truth.
Reader Comments (176)
"Oh, I see. And perhaps it is the little fairies that tell the trees which is which? Have you ever studied ANY science? Incredible!"
Feb 22, 2011 at 7:47 PM | Don Pablo de la Sierra
Well that's certainly a very aggressive and rude comment directed towards Paul B. You must be very certain indeed of your facts to state this with such dismissiveness. Well, let's have a quick look on Google and see what we can find...
Oh look, loads of papers. The first one I looked at is called 'Stable carbon isotope variation in C3 and C4 plants along the Amazon River' by Martinelli et al dating all the way back to 19991. It clearly talks about plant's preference for certain carbon isotypes.
Seem's that you're just plain wrong DPdlS. There are also several other papers on the same subject.
You owe Paul an apology.
I notice once again, that at the time of posting, no other commentors have seen fit to point out your error or take issue with your offensive tone. Proving once again that any claims this site makes to true scepticism, or sometimes even to reasonable discourse, are just a farce.
Paul B
Good to 'see' you again. Seriously.
Zed
Calm down dear. You are sounding a bit OTT.
Paul
WRT nuclear etc and decarbonisation pathways, we are in agreement. Thank you for answering.
Snotrocket
To avoid going any further down a rather repetitive route (since all we can do is repeat what we've already said) I'm sure you'd at least agree that our interpretation of what Nurse and Bindschadler said or meant is heavily coloured by our preconceptions.
Thanks yourself. I wish I had time to participate more often. But, in any case I'm going to retire from the fray soon to watch Maxine Peake in "Silk"...
ZedsDeadBed
Thanks for your support. It would, I must say, be very interesting to know how much science "Don Pablo de la Sierra" has studied.
Given DP's grasp of reality, I'm not sure an apology would carry very much weight!
Zed
I left it up to Paul B - who clearly knows his onions - to respond to Don Pablo. Simple courtesy.
Personally, I find this harsh.
ZDB
Oh look, loads of papers. The first one I looked at is called 'Stable carbon isotope variation in C3 and C4 plants along the Amazon River' by Martinelli et al dating all the way back to 19991. It clearly talks about plant's preference for certain carbon isotypes.
Drop the faux outrage and try to be a little helpful. Since you're not in a helpful mood (you never are, BTW), I googled the paper you mentioned and came up with this abstract at Nature:
I don't speak wizardese. Can anybody tell me if this abstract means to say plants enjoy natural CO2 more than anthropogenic CO2?
Nature recycles. 13C/12C ratios get mixed up in the process. The paper cautions against underestimating the complexity of the ecosystem, particularly if you are
Which is interesting.
sHx
"Can anybody tell me if this abstract means to say plants enjoy natural CO2 more than anthropogenic CO2?"
I think it means to say the opposite. Plants prefer Carbon12 to Carbon13, so they will enjoy CO2 that has passed through other plants (even if they have spent some time as coal).
Seriously though, the most interesting part of the abstract is the last sentence, which warns that you need to know whether your preserved plant material came from the forest floor or the canopy before drawing conclusions about the composition of ancient atmospheres.
EM Smith had an interesting article up about C12/C13 isotope ratios up a while back:
http://chiefio.wordpress.com/2009/02/25/the-trouble-with-c12-c13-ratios/
Thanks, guys. That was an honest question, BTW. I really wanted to know whether plants can distinguish between the two types of CO2 according to their isotope signatures. I was preparing myself for a barrage of abuse and deliberate obfuscation especially from ZDB. It's been one hour since I posed the question but both Paul B and ZDB seem to have gone AWOL after creating a ruckus.
Maybe they (ZDB and Paul B) will come back tomorrow and inform us further on plants' eating habits. Maybe plants like eating cake more than bread.
This somewhat prophetic bit from Christopher Booker's article:
"One may argue about the “carbon cycle” and how much CO2 the oceans and plants reabsorb. But, as baldly stated, the point was simply a grotesque misrepresentation, serving, like many of the programme’s other assertions, only to give viewers a wholly misleading."
If only Paul B had been on the programme!
"impression"
Why didn't that bit copy over from the article? I blame Paul B.
sHx (Hey, I said somewhere upthread I'd left to watch a TV programme!)
Plants prefer "light" carbon (12C) over "heavy" carbon (13C). In places like the Amazon, carbon which has been converted into plant material (ie it is depleted in 13C because of that preference) gets respired when the plant dies, then is taken into more plant material before it gets the chance to re-equilibrate with the atmosphere. So it becomes even more depleted in 13C. The paper says there are various gradients of increasing ratios of 12C/13C which depends on how often the carbon has been recycled through different plants. Its not easy to understand, even for scentists, but it isn't "wizardese".
But it isn't the case that 12C is "anthropogenic" carbon while 13C is "natural" carbon. There's always much more 12C than 13C (about 99:1). But in fossil fuel carbon there's slightly more 12C than there is in "natural" carbon. So you could (if you were so inclined) argue that plants prefer an atmosphere with more anthropogenic carbon (which is what Dreadnought just said). But actually the difference is so small that it makes no detectable difference to rates of plant growth.
woodentop
If you look at Francey et al 1999 in Tellus:
http://onlinelibrary.wiley.com/doi/10.1034/j.1600-0889.1999.t01-1-00005.x/abstract
you'll find it gives a very clear picture of a distinct trend to lighter carbon in the atmosphere since about AD 1800 (not sure if the PDF is available of course). You'd have to be very perverse to argue that that was not the signature of fossil fuel emissions.
EM Smith raises many complexities in his piece, but does not address the very clear trend shown in the Francey et al paper. He needs to do that if he is to convince me that the complexities he describes are significant in the context of the overall trend.
It is a mistake to regard the anthropogenic/natural carbon isotope signature using the ratio C13/C12 as clearcut, well understood and definitive, quite apart from uncertainty in gross estimates and multi-temporal oscillations. There is a very informative but technically challenging debate in the comment thread below a blog post by Roy Spencer in the following link, where the comment thread demonstrates the complexity and uncertainty at present levels of knowledge. Interesting to see Paul Dennis joining in at 6:11 am January 30, 2008 for example.
http://wattsupwiththat.com/2008/01/28/spencer-pt2-more-co2-peculiarities-the-c13c12-isotope-ratio/#comment-4793
Bishop I disagree with you completely, and so does Ferdinand Engelbeen and Peter Dietze, and 99% of the lukewarmers.
The tricky bit is the NET flow of CO2, My Guineapig has a huge CO2 turnover, yet my guinea pig is a net CO2 sink because during its life time it grows and I'll bury it when it dies. The exact amount of the gross troughput of carbon through my guinea pig doesn't matter at all for the increase of CO2 in the atmosphere, the net storage, however, does.
So man is fully 92% responsible for the increase of CO2 in the atmosphere (the 8% is volcanoes and temperature related outgassing). Yes there is a hockeystick in CO2 and it's man made. Temperature is not though.
All this stuff about CO2 and its origins!
Ask Bob Ward, he is the (self proclaimed) authority
Midnight news on UK BBC Radio 2.
Extra £100m to repair potholes in roads. Apparently these were caused by cold weather, and global warming was not mentioned.
Stunning
"What Ward wishes Bindschadler had said is that human contributions to CO2 emissions outside the natural Carbon Cycle are seven times as great as those from other sources (including volcanoes)"
Do you seriously expect anyone to believe that volcanoes are "outside the natural carbon cycle"? Surely, only those emissions that are from non-biological anthropogenic activity are "outside the natural carbon cycle" - of course, that renders any statement rather meaningless, as in "100% of non-natural CO2 emissions are non-natural".
Hans Erren,
Your guinea pig is not a CO2 sink. It is a wash. Its carbon comes from the biosphere and returns to the biosphere. After it dies (and they die so easily, sad to say) all of its carbon, even what you bury, gets re-upped into the biosphere.
Paul B
I have a Ph. D. from Cornell University in Physiological Psychology, with a major in Physiology, and minors in Computer Science, Biochemistry and Statistics. I also have a very firm grip on reality. I can read scientific papers and know how to interpret them.
Now that you know my credentials, what are yours? Fair is fair, is it not?
The paper ZDB points to and which the abstract was reproduced by sHx @ Feb 22, 2011 at 9:09 PM does say that C13 is slightly discriminated against in plants. The paper does not say why. Having studied biochemistry, which is basically physical chemistry, I would argue that is due physical chemical processes present in all chemical reactions, biologic or not.
I might point out that C14, which is radioactive, is also present in all living materials. In fact there are a number of isotopes of carbon, according to my CRC handbook of Chemistry and Physics, so yes, I am well aware of the various isotope ratios used for dating materials and such. My argument is with your statement that plants can selectively, magically sort the isotopes. Variations do occur, but not for the reasons you argue.
However, as woodentop points out at Feb 22, 2011 at 10:22 PM there are lots and lots of problems with C12:C13 ratios. And there is nothing to suggest that it is anything but the physical chemistry involved at the time.
In fact, if you go to the university library, or like me have access to the Science online, go look up
Craig, H: Carbon-13 variation in Sequoia rings and the atomosphere Science 119 141-143, 1954
What Craig did was to measure the C12:C13 ratios from the same Sequoia trees using rings 50 years apart and found that they differed. The conclusion was that there were atmospheric issues causing the changes.
So it sounds like plants eat what they can get, just like us.
Sorry, I can not retract my statement, although like many others on this blog, I have enjoyed your postings. Please do come back and let's discuss. Perhaps ZDB will learn some manners from you. You are a delightful change.
John Shade, ROFLMAO!
I really must be getting old.
I have been studying climate matters for several years now.
It has just suddenly dawned on me that we have been shying at shadows.
Here is the picture as I now see it.
CO2 is a trace gas, even amongst greenhouse gasses, a trace hothouse gas.
Water vapour makes up by far the major part.
Now are we are fearful about the terrible consequences of increasing the amout of these gasses:
From a naturally occurring almost zero to 4% of the atmosphere
to a maximum of say 4% plus say 7/100 of a small fraction of 4%.
Am I correct?
If so I can "Really" see why we should be afraid, really afraid of the big bad wolf,
knowing well, that the wolf is really a very well trained guide dog.
"So man is fully 92% responsible for the increase of CO2 in the atmosphere (the 8% is volcanoes and temperature related outgassing). Yes there is a hockeystick in CO2 and it's man made. Temperature is not though." - Hans Erren
I'm sorry Hans but I dont follow you here. Clearly Man has increased his CO2 output over the last 100 years, no problem with that. But you seem to be saying that volcanoes have increased their CO2 output by 8% over the same time frame. What is the evidence for that?
TIA
Don Pablo de la Sierra
OK you seem to be better qualified than I originally thought, so apologies for any hasty response … but I think you might agree, looking back at it that your original response was a bit flippant and could easily have been misunderstood!
I don't think I made any argument about how plants fractionate carbon.
I did say this
which might have given you the impression that I think the plants are somehow 'selecting' one form rather than another. Of course they don't. But its a form of words that is often used in this context and the end result is the same.
From the point of view of detecting the atmospheric fingerprint of plant derived carbon, all that matters is that they do fractionate, and that enough extra plant derived carbon gets into the atmosphere for it to be detected. The data in the Francey et al 1999 paper that I referenced (derived from Antarctic ice cores) are very compelling, and if you are going to argue that there is no atmospheric signature of carbon from fossil fuels, you need to find some other explanation for the trend shown in that paper and in other studies of atmospheric and marine carbon.
None of this is to deny the many complexities in the physiological responses of plants and animals to different types of carbon, some of which impact the scientific work I do myself.
@Hunter
So my guinea pig is a wash, even more reason to ignore the 90 Gt of oceanic Co2 turnover, which doen't NET add to the CO2 level in the atmosphere.
Both Paul Nurse and Bob Ward have misrepresented the facts over CO2 emissions in order to indulge in alarmism.
There were no concerns expressed about getting the science right in order to inform the public in this debate, none at all. Indeed we see Bob Ward twisting himself into knots in order to support Paul Nurse's gross misrepresentation (or is that net?) .
Simply put the viewers of BBC's Horizon programme were lied to, and deliberately so.
Would you buy a used car from Paul Nurse after that performance? I don't think so.
Pushing junk science to induce an alarmist response is irresponsible.
AusieDan
"From a naturally occurring almost zero to 4% of the atmosphere"
Do you mean 0.04%? It hasn't been 4% for a very long time (although even that didn't appear to induce thermal runaway).
What I would like to know is what the surface temperature would be without any CO2 in the atmosphere*, as without a well-researched value for that, any speculation over the effects of any increase are just that: speculation.
*33 degrees cooler is often quoted, but I find it hard to believe that such a minor component could have such a large effect.
Roger Tolson
"When I ask people what the CO2% content of the atmosphere is they say anything from 20 to 90%"
Quite so, but it's hardly surprising when so much is alleged about the damage it does. I would love to hear a radio or TV interviewer ask an AGW supporter the same question - if they didn't know the answer (quite likely) they would look foolish, and if they did know, they might find it difficult to articulate...
Paul B
"... plants preferentially take up one form of carbon rather than another ...
which might have given you the impression that I think the plants are somehow 'selecting' one form rather than another"
That is what 'preferentially' means, surely? I realise this is a tricky area, but you are tying yourself in knots trying to convince us that anthropogenic CO2 is somehow treated differently in the carbon cycle.
That's the sort of thinking that led the EPA to brand CO2 as a dangerous substance!
@JamesP
In the context of stable isotope science, it would just be taken to mean that plant carbon is richer in 12C than atmospheric carbon due to an internal physiological mechanism. I think the general public would also see it in the context of a physiological response, rather like plants "preferentially" turning toward the sun.
Well I would be if that was what I was trying to convince you of, but I'm not. I'm just saying that changes in the stable carbon isotope signature of atmospheric carbon since industrialization show that the proportion of plant derived carbon has been increasing over the past 200 or so years.
Re your question to AusieDan about the background greenhouse, that figure of 33C is not due to CO2 alone (which is, as you say, about 0.04% of the atmosphere). Here's what it says in wikipedia:
Paul B
"Naturally occurring greenhouse gases have a mean warming effect of about 33 °C (59 °F).[33][C] The major greenhouse gases are water vapor, which causes about 36–70 percent of the greenhouse effect; carbon dioxide (CO2), which causes 9–26 percent; methane (CH4), which causes 4–9 percent; and ozone (O3), which causes 3–7 percent.[34][35][36] "
That's a whole load of uncertainity in the greenhouse effect, ranging from 52% to 112% of causation.
On a par with Met Office forecasts and overlapping probabilities.
Mac
Well obviously total causation will be 100% and I suppose the percentages for each gas would vary within the bounds indicated, but they'd still add up to 100%
I suggest you follow up the references, and see where those numbers come from. Its only Wiki after all.
I see that someone called ScientistForTruth challenges my 'business income' analogy very confidently and aggressively on the basis that 'income' can only possibly mean 'gross income'.
I can assure him that this is not the case. But if he doesn't want to take my word for it, he can Google 'business income definition'. One of the top results is a dictionary of business terms, which gives the following four definitions of 'income':
1. money earned during an accounting period that results in an increase in total assets.
2. items such as rents, interest, gifts, and commissions.
3. revenues arising from sales of goods and services.
4. excess of revenues over expenses and losses for an accounting period (i.e., net income).
It will be seen that definitions 1 and 4 are 'net' , 3 is 'gross', and 2 seems to be a specialised usage (if these items are distinguished from other forms of revenue).
Whether any particular usage is likely to be misleading can only be determined from the context.
Paul B
No, the plants are not "Fractionating" carbon by isotope number. That is exactly what I was poking fun at. There is no known enzyme at will select C12 over C13, or at least that I was able to find in the literature on line. I did, however, find the Craig paper from over 50 years ago that shows pretty conclusively that the ratios of C12:C13 varied with time in the same plant. Since the major intake carbon source, but not only source, is atmospheric CO2, then it would appear that what we are looking at are carbon samples taken from material laid down while the ratios of the isotopes varied naturally in the air the plants ingested. This is Craig's conclusion. It is also pretty damn obvious.
You are quite wrong in your statement. The plants are simply eating whatever carbon dioxide available at the time, and they are not fractionating.
What you posted yesterday may have appeared to be "scientific fact" to you, but it was in the same category of "scientific fact" as polywater and cold fusion. I suggest you look both up.
As noted earlier, you are a welcome change from the usual troll who wanders through here from time to time. And I agree with BBD that you are interesting. However, be aware that this blog has attracted a large number of very, very well qualified scientists, such as Phillip Bratby and Atomic Hairdryer, just to name two. All are better qualified than I, so while I may be a sharp knife, there is a large drawer full of very keenly honed razors here as well. So my advice to you is be aware of them.
And as anyone, including ZDB, who has posted here regularly knows, I am reasonably knowledgeable in many areas of science, Irish history and Irish Fairy tales. And that I can be an cantankerous curmudgeon.
And, for the record, I did find your comment:
both snarky and offensive.Finally, I am still waiting to see your list of impressive academic and scientific credentials. From what I have seen from your grasp of biochemistry, they are not that strong. Hence my original statement.
That said, welcome. I do hope to see you post some more. Like you, I prefer to hear other view points. I know that BBD clearly enjoyed yesterday.
"Here's what it says in wikipedia:"
Aka, William Connelly's Big Book.. :-)
As Mac points out, there's a lot of uncertainty there, but taking a median figure, one might suppose that no CO2 would reduce the surface temperature by 5 or 6 degC. It still sounds a lot to me for a gas that constitutes less than 1 in 2500 molecules, but even if we accept it, the effect is still a lot less than the unrelated natural swing between ice ages and interglacials, over which we have no control whatsoever.
IIRC, there was an ice age in the Ordovician period, some 450m years ago, when the CO2 content of the atmosphere was around 4%. Of course, it wasn't that nasty anthropogenic stuff... :-)
"1. money earned during an accounting period that results in an increase in total assets."
With due deference to our host, only an accountant would define 'income' that way. For normal folk, it's what you earn, which is invariably expressed as a gross figure, e.g. £30k, or £400 a week, etc.
Taxation muddies the waters horribly, which is why we have accountants and PAYE, but if you ask most people what they earn, they will state the gross figure, as it's the only one that makes sense!
Paul B
How do they add up to 100% causation???????????????
You seem unsure yourself.
James P
A median figure on causation?
Crikey!
I think Craig did not discrminate between types of wood. See Wilson and Grinsted, Nature 1977
For a more up to date analysis, see McCarroll and Loader, 2004, Quaternary Science Reviews:
Well if you must know, biochemistry obviously isn't my primary field, but I have a PhD in an area related to proxy archives of the marine environment and I've had 4 papers published. So I'm sure I'm quite capable of holding my own with Messrs Bratby and Hairdryer
Paul B
"the proportion of plant derived carbon has been increasing over the past 200 or so years"
That sounds rather likely. Is it significant?
@James P
The temperature/greenhouse gas feedbacks in the ice age cycles also involve water vapour. In fact the temperature difference is about 10C and the CO2 concentration varied by about 100 ppm, so you'd need other greenhouse components to explain the amplitude.
But the sun was significantly weaker then. Apparently you got glaciation if CO2 fell below 3,000 ppm.
http://www.skepticalscience.com/CO2-was-higher-in-late-Ordovician.htm
Significant enough to be recorded in Antarctic ice cores and Caribbean sponges as a very noticeable change from the background level.
http://www.ferdinand-engelbeen.be/klimaat/klim_img/sponges.gif
According to a paper, referenced here, about 99% of airborne CO2 has the C12 isotope: http://www.co2science.org/articles/V12/N31/EDIT.php
The same link has this:
"In a paper recently published in the international peer-reviewed journal Energy & Fuels, Dr. Robert H. Essenhigh (2009), Professor of Energy Conversion at The Ohio State University, addresses the residence time (RT) of anthropogenic CO2 in the air. He finds that the RT for bulk atmospheric CO2, the molecule 12CO2, is ~5 years, in good agreement with other cited sources (Segalstad, 1998), while the RT for the trace molecule 14CO2 is ~16 years. Both of these residence times are much shorter than what is claimed by the IPCC. The rising concentration of atmospheric CO2 in the last century is not consistent with supply from anthropogenic sources. Such anthropogenic sources account for less than 5% of the present atmosphere, compared to the major input/output from natural sources (~95%). Hence, anthropogenic CO2 is too small to be a significant or relevant factor in the global warming process, particularly when comparing with the far more potent greenhouse gas water vapor. The rising atmospheric CO2 is the outcome of rising temperature rather than vice versa."
The evidence that CO2 is in some sense a 'driver' of climate remains very weak. The long reconstructions from geological research show it more as an 'effect' of temperature rises, than as a 'cause'. The behaviour of temperature variations in the 19th, 20th and 21st century is also as if increased CO2 was of negligible importance in influencing them. The informal null hypothesis of 'business as usual' for our climate retains credibility over any alternative, not least the notion that rising CO2 is extremely influential. Only in computer models adjusted to provide what-if illustrations of the effect of an associated, and hypothetical, positive feedback, do we get alarming results. Such results should be no more than a source of curiosity in academic circles, and a spur to more research and more detailed observations. They have no proper place in forcing massively important policy and lifestyle decisions. Not in the hands of responsible adults, anyway.
Paul B
I call that Cherry Picking. Seem to remember someone picking through tree rings as well to get his desired result -- a Mann made result. Of course that seems common in research on "proxy archives of the environment".
And just what is this wonderful mechanism that magically removes C13? I proposed the Fairies. That appears as scientific as anything proposed as yet. Perhaps there is a enzyme Carbonisotopicselectase. . If so, it would be worth billions.
And where in ANY of this literature did they do a temporal longitudinal study of the same plants, except Craig 1954?
Finally, has ANYONE bothered to measure the actual C12:C13 ratio from air in the area they collected their data? Craig suggests that it was due to atmospheric variation. I tend to agree. The carbon isotopic ratio varies all over the place and has been known to do so for at least 60 years. There is no way one can assume that it is constant for more than a few minutes. At least Craig was able to show temporal variability.
No, there is no evidence here of anything but what Craig suggests until someone does a rigorous study. Magical biological mechanisms that remove C13 selectively have not yet been explained. It is far easier to explain it with variations in atmospheric content ingest by the tree. Look up Occam's Razor.
And good luck with Phillip Bratby and Atomic Hairdryer. :) I wouldn't take them on, myself, although I do tease them about the Standard Model of Quantum Mechanics being wanting by not explaining Gravity except with a magical Higgs Field, which might actually exist, but still has not been shown.
But I will be the first to agree that the Standard Model is the best we have today and that the billions spent on the Large Hadron Collider in Cern are well worth it.
I suggest strongly that you pick up some in-depth training in biochemistry. Your present level of knowledge is very, very poor. It shows.
Paul
"Apparently you got glaciation if CO2 fell below 3,000 ppm."
But it didn't fall below 3000 until after the ice age was over!
According to the 'skepticalscience' website, "the CO2 record over the late Ordovician is entirely consistent with the notion that CO2 is a strong driver of climate" although the long-term (600m years) records of temperature and CO2 show practically no correlation at all! Mind you, both have dropped a bit in the last 50m years, but that's still a short time geologically speaking, and since it was a good 10 degC hotter then, I don't really see what the worry is.
"Significant enough to be recorded in Antarctic ice cores and Caribbean sponges as a very noticeable change from the background level."
When I asked about significance, I meant (politely), so what? I've no doubt that industrial activity, including CO2, can be detected, but unless it is shown to have a significant effect, then it is no more than a curiousity. I've worked, quite happily, in greenhouses with an artificially raised CO2 level of around 1200ppm and all I noticed was that the plants seemed to grow rather well...
'curiosity' - sorry.
Don Pablo de la Sierra
See (again) the McCarroll/Loader paper that I mentioned in my previous response to you.
D. McCarroll, N.J. Loader / Quaternary Science Reviews 23 (2004) 771–801
See (for example) Gagen et al Chemical Geology 252 (2008) 42–51 "Do tree ring δ13C series from Pinus sylvestris in northern Fennoscandia contain long-term non-climatic trends?"
There are many other such studies
Thanks. You're very kind! But the fact is that there is so much specialist research going on now that most scientists in-depth knowledge of fields other than their own is very poor. That's why we rely on peer review. So (for example) I wouldn't presume to challenge Phillip Bratby and Atomic Hairdryer in their expertise about Quantum mechanics, if that is indeed their specialist field. And if they want to challenge me in my field, that's fine, but I wouldn't necessarily assume that they knew any more about it than any well informed lay person.