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
Spenc Canada,
Obama may do what he wishes, but his power is limited. Ratification of a Copenhagen agreement would require agreement by 2/3 of the members of the Senate. The likelyhood of that is close to zero, at least for any treaty that the green left would be happy with. Remember, Bill Clinton signed the Kyoto agreement, but fell approximately 67 votes short of Senate ratification.
What does Obama have to do with what Canada does at Copenhagen, anyway? The failure of the US to sign on to Kyoto did not prevent Canada from doing so.
Forgive me, but it looks as though they are merely constructing another house of cards. Lucy Skywalker hits home the most salient point here: Replication and transparency.
Bill Illis raises an intriguing point as well! What a tangled mess…
Oh Lord, here we go again.
BTW, have Mann and Briffa moved lately? 😉
Now some one is saying they can spook about a one degree difference in temperature out of a tree again.
Because WUWT is becoming so popular these days, please don’t mind if I contribute some OT points for the lurkers for teaching purposes.
CO2 Contributed by Human Activity: 12 to 15ppmv / version 1
Lulo (16:27:17) : Thank you . I didn’t mean to imply that the research would not be worthwhile – it could be very enlightening . But given the problems enumerated above , how reliable would the results be ? Also , I have to assume that tree samples taken before a certain time would degrade to some extent . In other words , how long ago were the earlier samples taken and how well were they preserved ?
I am stunned that this sort of research has not been done before. Paleotemperature estimates are anchored on stable isotope measurements – this sounds like a terrific idea and based in sound science.
Any advancement to the science of finding usefull and reliable proxies for paleoclimates is welcome. Isotope analysis is fairly robust but previously was too expensive. This recent improvement is a good thing for those interested in the science as opposed to ideology. Let the real climate chips fall where they may. Good data analyzed properly should trump polemics. We need more science entries in this science blog.
rbateman (15:47:51) :
We have a picture of Mann holding one of those slices.
“If I could draw attention to Exhibit ‘A’ m’lord.”
The isotope data is not the same as tree-rings.
In tree-ring width analysis, someone cores a tree 1 to 10 times and gets out a ruler and measures the ring widths. Have you ever looked at a tree cross-section? They are not symmetrical, especially all these slow growing trees like the Yamal pines and the Bristlecone Pine trees. Have you ever seen a cross-section of a Bristlecone Pine tree – only one-quarter of the tree is alive at any one time and you can not possibly obtain a temperature signal from them.
Here is one Bristlecone Pine cross-section.
http://www.rmtrr.org/images/Firescar.jpg
Then someone like Mann or Briffa puts together a new processing algorithm that artificially inflates the recent widths and discounts the Medieval Warm Period numbers and “hides the decline” in the recent ring-width figures by appending the temperature record to it. ie. one big subjective analysis that is more than a little prone to observer bias.
The d018 and carbon isotopes, however, have been scientifically calibrated to international standards on how they vary with temperature, latitude, altitude, and local conditions in most cases.
http://en.wikipedia.org/wiki/Vienna_Standard_Mean_Ocean_Water
They are not subjective tree-rings.
Zachos database contains over 14,000 individual measurements which can then be averaged out reasonably well so one can be reasonably certain about any time period.
In this case, the researchers have to prove their measurements reflect local temperatures accurately. It does not matter how wide a ring is, they just need a sample from ring 56 which is from the year 1945. Then someone has to show the same isotope-temperature correlation exists throughout the world at different latitudes, altitudes and local condition changes.
Viola, we move from the world of Mann to the world of real science.
I’m with those who are not really thrilled by this. It still involves using sampled near-surface temperatures to attempt to measure global temperature. But the atmosphere is the smallest and most variable carrier of global heat. Microclimate and micrometeorological processes make such measurements inherently very noisy and susceptible to systematic biases.
I’d be a lot more interested in an announcement of a reliable ocean energy storage proxy, but I suppose that’s not too likely. We’ll just have to wait a few decades and see what Argosy turns up.
Pamela Gray (16:05:44) :
I am assuming they mean CO2 isotopes?
No. They mean the carbon and oxygen isotopes of the cellulose material in the wood. The assumption is that the plant takes up the isotopes in equilibrium with the surrounding environment.
Rex Murphy on Climategate
CBS NEWS
Tempers Flare In Climate Change Flap
http://www.cbsnews.com/blogs/2009/12/05/blogs/coopscorner/entry5905404.shtml
OT but,; here we go again! Almost the exactly same time as last year.
Environmental Canada:
“There’s no indication that this cold air mass is going to move off – it’s such a large-scale system and it covers such a big portion of Western Canada . . . there’s nothing in the foreseeable future that’s going to push it off.
“There’s no good news, whatsoever.”
It’s been -3 to -5 here for three days already. Just going to get colder. Same large persistent mass of cold air forming up. Jet stream has gone totally kinky.
Climategate expert Chris Horner discusses dishonest climate scientists on Hannity
They refer to the trick used to hide the decline as something trivial that covers only the tail end of the 1000+ years of climate history.
In actuality what they are hiding is the fact that for 30% (50 years out of 160) of the period in which they have actual temperature data to compare to their proxies, including what they claim is the warmest part of that period, there is no correlation between the two.
Why should we assume the record for the periods where there is no temperature data are any more accurate, how are we supposed to trust their claims that there are no previous warm periods that were missed like the latest one has been?
Is this another attempt at doing science by press release?
Some immediate questions not answered by the press release:
– What is the actual physical process that maps temperature to isotope absorption?
-What’s the method by which water-born Oxygen is distinguished from atmospheric Oxygen ( is that even possible) ?
-What the actual frequency of the uniformity of the isotope signal within species ? What about other species within the same vicinity ?
-Is the data available for independent review ?
The science is not evident from the release. One assumes the paper would elaborate on those questions.
Does anyone have access to that paper or know of a link ?
Christopher Brooker in the Telegraph – The Emperors’ New Clothes
http://www.telegraph.co.uk/comment/columnists/christopherbooker/6738111/Climategate-reveals-the-most-influential-tree-in-the-world.html
Please; I get the impression you don’t have the slightest idea how things work in a large, vertically stacked enterprise.
It’s as if you think things should work out as they are depicted in Super-Hero Comic books.
.
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Well, obviously, this is how isotope dating is done. The question I’m asking is whether or not the relative abundance of one isotope or another is strongly correlated with temperature. When I say strongly, I don’t mean in a Mannian sense, I mean strongly!
The Washington Times
Media complicity in Climategate
http://www.washingtontimes.com/news/2009/dec/07/media-complicity-in-climategate/
Anthony,
Do you know if Steve McIntyre would submit his bristlecone pine samples from Almagre for isotope analysis? It would be an interesting check on the stripbark issue.
_Jim (18:45:22) :
“It’s as if you think things should work out as they are depicted in Super-Hero Comic books”
One can dream, can’t he?
Ed Scott (18:19:07) :
Rex Murphy on Climategate
Excellent. I have only 2 small corrections to what he said. But they won’t change the essence of his talk.
Ed Scott (18:35:41) :
Climategate expert Chris Horner discusses dishonest climate scientists on Hannity
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.