For all the hubub surrounding Dr. Michael Mann’s hockey stick, the MWP, and throwing out data past 1960 because it didn’t seem to calibrate against the instrumental record, here is a way to put an end to the issue. Have Mann’s, Briffa’s and others tree ring samples submitted to isotope analysis. Given how much UEA and Penn State want to protect their research reputations, it seems to me that this would be an excellent way to settle the issue independently. Unless of course, they threw away the original samples. – Anthony
From a press release by the Arctic Institute of North America
Carbon and oxygen in tree rings can reveal past climate information
Isotope analysis provides accurate information
OTTAWA, DECEMBER 2009 – The analysis of carbon and oxygen isotopes embedded in tree rings may shed new light on past climate events in the Mackenzie Delta region of northern Canada.
Scientists have long looked at the width of tree rings to estimate temperature levels of past years. Larger rings indicate more tree growth in a season, which translates into warmer summer temperatures. But the analysis of carbon and oxygen isotopes in tree rings can also provide accurate data on past climate events, say researchers working in northern Canada.
In a paper published in the most recent issue of the journal of Arctic, Antarctic and Alpine Research, Trevor Porter, a PhD student in Geography and Environmental Science at Carleton University, and three other authors compared temperature data collected in Inuvik, Northwest Territories (NT) since 1957 with their own analysis of isotopes found in white spruce trees in the Mackenzie Delta region of the NT. They found a strong correlation between the two data sets and temperatures.
“Isotope analysis is a good way to measure past climate change,” says Porter about the results.
Isotope analysis is not a new way to measure past air temperatures. However, the method has not been widely used because lab costs have been prohibitive, especially when compared with the examination of tree ring width. Now, however, the cost of equipment has dropped substantially making it more affordable for researchers to use this method.
Porter’s work was carried out on the northern edge of the boreal forest in the NT where trees are small but surprisingly old. “A 15 to 20 cm. tree could be a 300 to 400 year old tree,” says Porter.
This slow rate of growth actually helps researchers because smaller trees stay standing longer. Trees that fall begin to decay making data analysis difficult or impossible.
“Once they get too large, it’s difficult for trees to persist. They are susceptible to wind and ice storms. One of the reasons trees (in the North) persist so long is because they don’t grow as much,” says Porter.
Isotope analysis allows researchers to conduct their work using a smaller sample size than needed when trying to re-construct temperature records using tree ring width. Porter explains that the width of rings can vary considerably between trees even when they are growing in the same stand. This variation can complicate reconstructions of past climate.
A number of factors influence ring size, including the age of the tree and the location of the tree within the forest. Older trees tend to have smaller rings than younger trees. And trees within the same area might not all receive the same amount of light, nutrients or even water.
“Growth is controlled by many things . . . they (trees) can all end up just a little bit different,” says Porter.
Isotope signals, on the other hand, are often very similar between trees. This means researchers can gather accurate data from three or four trees instead of the 20 they might need for tree ring width analysis.
“In ring widths there will be more variability between trees. There will be similar trends, but you have larger differences that you would find between the isotopes of different trees,” says Porter.
Porter is hoping his work will lay the foundation for a model that can be used to investigate the long-term climate history of the Mackenzie Delta region. Although the temperature record for Inuvik only dates back to 1957, the dead and live tree ring record stretches to nearly 1000 years before present. That prospect excites the young researcher.
“The tree ring record goes back almost a thousand years in this area, but it’s never been used for a temperature reconstruction. This is a really exciting time to work in climate research, especially for a young student,” he says adding, “This is a hot topic.”
More information can be found at www.arctic.ucalgary.ca
See this press release in PDF form here
Non-weapons science almost to 100% died with Climategate. RIP.
Weapons science (nuclear, and non-nuclear) is alive, and it is normally in conjunction with the scientific method, testing, hydrodynamics, computer simulation, quantum mechanics, special – and general relativity, the uncertainty principle, and in the future, if needed, with quantum fluctuations, as well.
Say No To Climategate!!!
I for one am very excited to read this paper. I am sure some of the longtime Climate Audit participants will be as well. There were some extended discussions on that site about Mackenzie River delta data years ago. The first extended discussion I remember delving into.
photon without a Higgs (19:31:36)
If anyone here knows Chris Horner I have some friendly advise for him that I’d ask you to pass along, if you would: please ask him to slow down. He has a good message but it gets garbled.
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I do not know Chris Horner and I did not recognize the garbled part of his message. Chris is being slowed by the good scientists at NASA by their ignoring his FOI requests for two years, which, in retrospect, is shorter than the delays in answering FOI requests made to the CRU.
It is quite possible that this could be developed into a useful technique although I can also see a lot of problems over calibration etc. But it might be possible to sort all that.
We did with radiocarbon dating after all which went from an initial plus or minus the odd thousand years, good enough for Piltdown Man of course, to, if suitable calibration samples are available, tens of years. Certainly as a student I was able to date an old wooden settle which had been in the family for centuries, it had probably been a highly ornate choir stall from a monastery which had been abolished during the dissolution, to around 900 AD plus or minus fifty years or so.
And we could do better than that today.
I can say with some confidence that it would certainly be far more precise than Mann style concepts which are and always were, IMHO, pure balderdash. You might as well use a set of tarot cards.
Dendrochronology I have no problem with: but tree rings as thermometers? Really. And they sold this snake oil for vast amounts of money? Well stranger things happen at sea I suppose.
Kindest Regards
There is some discussion on the matter and in any case, the ratio of 18O:16O is dependent on where the ice/raindrop formed and fell, not what the temperature was on the ground. In other words, it can be more of a proxy for temperatures aloft but it does take more energy to vaporize water containing 18O than it does for water containing 16O to begin with.
But it isn’t limited to only tree ring studies. The same can be done with limestone to attempt to learn the temperature when it formed.
Ed Scott (20:04:45) :
I am saying he talks to fast.
I am not against him.
“sorry folks, the pine beetle ate my tree rings….”
Ed Scott (20:04:45) :
He is not always understandable. That is all I am saying. He seems to be in a hurry.
photon without a Higgs (19:31:36) :
I disagree with your assessment. Chris Horner did indeed speak fast, but he did not ramble or garble.
He covered ALOT of material, and I think knew he had to speak fast because time was limited.
That is hard to do that in a small sound-byte interview.
What a bulldog.
Give NASA Goddard Institute hell, CEI!
Smoke those rodents out of their hiding.
GRRRRRR.
Chris
Norfolk, VA, USA
I hate to be a nudge but I’d like to remind folks of this post from June 08
http://wattsupwiththat.com/2008/06/13/surprise-leaves-maintain-temperature-new-findings-may-put-dendroclimatology-as-metric-of-past-temperature-into-question/#comments
I think this is 6 times now. I used to have a link to the original paper but it was lost a while back. I do recall that one of the points made was that the theory of isotope ratios of O in tree rings relating a record of temperature was based on the notion that tree foliage was at ambient temperature, which this paper disproved. The last time I looked for the paper I wasn’t able to locate it thru Google. I’m sure the fact that it was done by people from the University of Pennsylvania, which shares a neighborhood with another prominent educational institution, has absolutely nothing to do with that.
And by all means, [back to topic….sorry about that], subject Mann/Briffa raw data to this testing.
Sorry, Michael, but you must yield to the standards of the scientist’s own “Hippocratic Oath”, the Scientific Method….i.e. can it be falsified??
Let’s see it!
Chris
Norfolk, VA, USA
Correction: From my last post: Should say “Michael Mann”, so as to clarify which Michael to whom I am referring.
Thanks.
Chris
Norfolk, VA, USA
Jason Johnson (19:57:47) :
I recall a Climate Audit discussion on a tree ring study in the MacKenzie Mountain. Do you have a link to CA on the MacKenzie Delta study?
I found the paper at Nature. It’s still behind the paywall, but here is the abstract
The oxygen isotope ratio (18O) of cellulose is thought to provide a record of ambient temperature and relative humidity during periods of carbon assimilation1, 2. Here we introduce a method to resolve tree-canopy leaf temperature with the use of 18O of cellulose in 39 tree species. We show a remarkably constant leaf temperature of 21.4 2.2 °C across 50° of latitude, from subtropical to boreal biomes. This means that when carbon assimilation is maximal, the physiological and morphological properties of tree branches serve to raise leaf temperature above air temperature to a much greater extent in more northern latitudes. A main assumption underlying the use of 18O to reconstruct climate history is that the temperature and relative humidity of an actively photosynthesizing leaf are the same as those of the surrounding air3, 4. Our data are contrary to that assumption and show that plant physiological ecology must be considered when reconstructing climate through isotope analysis. Furthermore, our results may explain why climate has only a modest effect on leaf economic traits5 in general
For those who may be interested, here is the link
http://www.nature.com/nature/journal/v454/n7203/full/nature07031.html
We discussed several paleoclimate records way back in October, including some ice core oxygen isotopes.
However, it seems that Mann hasn’t been handling many tree samples. He must just be tinkering with the numbers which others create, or he wouldn’t be repeatedly using upside down data.
However, it has become apparent that Mann’s funding would surely have better results if directed to others who have a better understanding of the trees. Start by giving the money to someone who has tree samples, so they can get more testing done.
Great article
CLIMATEGATE SCANDAL AND THE DEFEAT OF AUSTRALIA’S EMISSION’S TRADING SYSTEM
http://www.thecypresstimes.com/article/News/National_News/CLIMATEGATE_SCANDAL_AND_THE_DEFEAT_OF_AUSTRALIAS_EMISSIONS_TRADING_SYSTEM/26212
Another potential correlation. Not the same as cause. Like the length of women’s dresses and the state of the economy. Correlation but meaningless.
What we need is documented tree ring data that shows temperature is a greater driver of growth than moisture.
Trees grow more when it is wet. More moisture does not, of necessity, require warmer temperatures.
Without hard benchmarked data, sampled from multiple species, and from multiple biomes; — that documents tree-ring-to-moisture-to-temperature parametrics — using known and validated site specific temperature and rainfall data,
I argue that larger tree rings only mean a wetter yaer, not necessarily a warmer one.
An honest study would first determine the growth rate of species of trees in different environments. Reading through the documents, they haven’t done that. There is skeptisicm among the scientists because of the small sample area and the probable growth due to fertilizers (CO2), water and warmth. To document temps with tree rings, they would have to eliminate all those factors. They haven’t. It’s a fraud.
BTW, anyone notice a Google search on ‘climategate’ doesn’t produce suggested links (again). [snip] is going on at Google?
If there are no “magic trees” in these samples –i.e. if there is indeed a very close regional consistency to each and every tree by this method. . . .then they may have something.
I’d still like to know the theoretical underpinnings for why this is felt to work. . .
No theory whatsoever can ever be “proved”. Proof is for mathematics, or other logical systems.
A “real” theory has to be falsifiable. Often, the proponents of a theory put forth examples of how their theory could be falsified.
From Wikipedia: “Scientific method refers to a body of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge. To be termed scientific, a method of inquiry must be based on gathering observable, empirical and measurable evidence subject to specific principles of reasoning.[1] A scientific method consists of the collection of data through observation and experimentation, and the formulation and testing of hypotheses.[2]
“Although procedures vary from one field of inquiry to another, identifiable features distinguish scientific inquiry from other methodologies of knowledge. Scientific researchers propose hypotheses as explanations of phenomena, and design experimental studies to test these hypotheses. These steps must be repeatable in order to dependably predict any future results. Theories that encompass wider domains of inquiry may bind many independently-derived hypotheses together in a coherent, supportive structure. This in turn may help form new hypotheses or place groups of hypotheses into context.
“Among other facets shared by the various fields of inquiry is the conviction that the process be objective to reduce biased interpretations of the results. Another basic expectation is to document, archive and share all data and methodology so they are available for careful scrutiny by other scientists, thereby allowing other researchers the opportunity to verify results by attempting to reproduce them. This practice, called full disclosure, also allows statistical measures of the reliability of these data to be established.”
Pretty much as I was taught scientific method, lo those many years ago.
I managed to locate a full version of the leaf temp paper I referenced above
http://www.sas.upenn.edu/earth/pdf/nature07031.pdf
I hate to subsidize Nature, given their nasty editorial of the other day
REPLY: Thanks – I’ll have a look, Anthony
Carbon-14 date estimation is regularly used in archaeology and in soil science to date cultural features and soils respectively. C-14 dates are commonly calibrated against dendrochronologically dated assays. One of the most important is the bristlecone pine curve from the White Mountains on the California-Nevada border. The calibration curve extends some 9,000 years. Oxgen and carbon isotope ratios are normally applied as a check against anomalous conditions. Some sources such as marine shell, C-4 and CAM cycle plants. The C-4 plants have a tendency to sequester carbon isotopes differentially leading to skewed isotopic ratios. Oxygen isotope ratios are also used as checks on the nature of the formation environment. I imagine that a little cross-discipline collaboration could acquire much of the necessary data easily.
Gregg E. (21:59:38) :
The study demonstrated that contrary to the necessary assumption that foliage be at ambient temperature for the O isotope ratio to work, the foliage actually acted to maintain itself in a much narrower range, thereby contradicting the possibility of using isotope studies of tree rings for temperature proxies.