There’s a new article at Nature News where they report on an amazing new paleoclimatology breakthrough with temperature reconstructions using clamshells. The Nature article reports on a new paper in PNAS from William Patterson at the University of Saskachewan. Here’s a short excerpt:
The study used 26 shells obtained from sediment cores taken from an Icelandic bay. Because clams typically live from two to nine years, isotope ratios in each of these shells provided a two-to-nine-year window onto the environmental conditions in which they lived.
Patterson’s team used a robotic sampling device to shave thin slices from each layer of the shells’ growth bands. These were then fed into a mass spectrometer, which measured the isotopes in each layer. From those, the scientists could calculate the conditions under which each layer formed.
Unlike counting tree rings which have varying widths due to all sorts of external influences such as rainfall, sunlight, temperatures, available nutrients, and available CO2, this method looks at the levels of different oxygen isotopes in their shells that vary with the temperature of the water in which they live. One simple linear relationship.
The data resolution from isotope counts is incredible.
“What we’re getting to here is palaeoweather,” Patterson says. “We can reconstruct temperatures on a sub-weekly resolution, using these techniques. For larger clams we could do daily.”
The reconstruction is shown below. We see familiar features the little ice age, the medieval warm period and the downturn which led to the extinction of Norse settlements on Greenland.
And the feature of this reconstruction to surely stick in the craw of many who think we are living in unprecedented times of warmth is the “Roman Warm Period”. Have a look:
From Nature: Shellfish could supplant tree-ring climate data
Temperature records gleaned from clamshells reveal accuracy of Norse sagas.
Richard A. Lovett
Oxygen isotopes in clamshells may provide the most detailed record yet of global climate change, according to a team of scientists who studied a haul of ancient Icelandic molluscs.
Most measures of palaeoclimate provide data on only average annual temperatures, says William Patterson, an isotope chemist at the University of Saskatchewan in Saskatoon, Canada, and lead author of the study1. But molluscs grow continually, and the levels of different oxygen isotopes in their shells vary with the temperature of the water in which they live. The colder the water, the higher the proportion of the heavy oxygen isotope, oxygen-18.
The study used 26 shells obtained from sediment cores taken from an Icelandic bay. Because clams typically live from two to nine years, isotope ratios in each of these shells provided a two-to-nine-year window onto the environmental conditions in which they lived.
Patterson’s team used a robotic sampling device to shave thin slices from each layer of the shells’ growth bands. These were then fed into a mass spectrometer, which measured the isotopes in each layer. From those, the scientists could calculate the conditions under which each layer formed.
“What we’re getting to here is palaeoweather,” Patterson says. “We can reconstruct temperatures on a sub-weekly resolution, using these techniques. For larger clams we could do daily.”
It’s an important step in palaeoclimatic studies, he says, because it allows scientists to determine not only changes in average annual temperatures, but also how these changes affected individual summers and winters.
“We often make the mistake of saying that mean annual temperature is higher or lower at some period of time,” Patterson says. “But that is relatively meaningless in terms of the changes in seasonality.”
For example, in early Norse Iceland — part of the 2,000-year era spanned by the study — farmers were dependent on dairy farming and agriculture. “For a dairy culture, summer is by far the most important,” he says. “A one-degree decrease in summer temperatures in Iceland results in a 15% decrease in agricultural yield. If that happens two years in a row, your family’s wiped out.”
Technically, the molluscs record water temperatures, not air temperatures. But the two are closely linked — specially close to the shore, where most people lived. “So, when the water temperatures are up, air temperatures are up. When water temperatures are down, air temperatures are down,” Patterson says.
Read the complete article at Nature News
The Roman Warm Period did not exist because Wikipedia felt fit to delete a well resourced article on it.
PNAS,
not Nature,
and here is the actual article
http://www.pnas.org/content/early/2010/03/02/0902522107.full.pdf+html
REPLY: Nature News covered the PNAS paper. That news article is what is referenced. – A
The full paper, much longer than the report in Nature is at http://www.pnas.org/content/early/2010/03/02/0902522107.full.pdf
I would recommend these folks not release any of their data or methods to any member of the “Hockey Team”. After all they’ll just want to find something wrong with it.
The Arctic sea ice is at NORMAL levels in nearly all areas, except the sea area (South and West of Greenland) that has been readily affected by natural processes easily shown.
This is just begging for me to don furry underwear and insulated outwear to dig for clams around the entire edge of the Arctic basin. We just might find correlations between clams and ice. Bring beer and binoculars. We can laugh at yonder insurance company researchers trying to get their equipment to work.
Maurice Newman, Chairman of ABC Australia (BBC equivalent – tax-payer funded) has created a huge furore 0 especially with his own staff – with a speech he made to ABC journalists yesterday:
Maurice Newman’s address to ABC staff
Climate change is a further example of group-think where contrary views have not been tolerated, and where those who express them have been labelled and mocked. In his ABC Online blog last October Chris Uhlmann wrote a piece called In praise of the sceptics. ‘“Climate science we are endlessly told is “settled”’ he wrote. “But to make the, perfectly reasonable, point that science is never settled risks being branded a “sceptic” or worse a “denier”…one of those words, like “racist”, which is deliberately designed to gag debate…You can be branded a denier if you accept the problem and question the solutions.”
This collective censorious approach succeeded in suppressing contrary views in the mainstream media, despite the fact that a growing number of distinguished scientists were challenging the conventional wisdom with alternative theories and peer reviewed research.
Then came the sensational revelations of unprofessional conduct by some of the world’s most influential climatologists exposed by the hacked or leaked emails from the University of East Anglia’s Climatic Research Institute. This was followed by more evidence of dubious research and politicised advocacy contained in scientifically unsupported claims and errors in the IPCC 4th Assessment, including in the carefully vetted Synthesis Report. Questionable methods of analysis resulting in spurious temperature data have added further doubts on the underlying credibility of the science.
The lack of moral and scientific integrity shown by the IPCC serves only to reduce clarity and increase confusion, disappoint believers and give fuel to doubters. It has frustrated policy makers, and as polling now shows, it has clearly weakened public belief in climate change and devalued respect for science in general.
In defending the indefensible, Mr Gore, university vice-chancellors and those in the media, do a disservice to the scientific method and miss the point that no matter how noble your work, your first responsibility must always be to the truth.
As you would expect, as Chairman of a public broadcaster, I followed with interest the announcement by the BBC Trust that it would carry out a review of the accuracy and impartiality of the BBC’s coverage of science. It came after a year in which online science bloggers continued to raise concerns about mainstream media coverage.
A contributing factor for the review was the revelation that the CRU emails were known to Paul Hudson, the BBC climate correspondent one month before the story broke – but not reported at the time. While disturbing, it is heartening to know that the BBC takes quality control seriously.
The Guardian noted “The moment climatology is sheltered from dispute its force begins to wane.” Which raises an important question for a media organisation: who, if anyone, decides what to shelter from dispute? And when? Should there be a view that the ABC was sheltering particular beliefs from scrutiny, or failing to question a consensus, I would consider it to be a dangerous perception that could lead to the public’s trust in us being undermined…
http://www.theaustralian.com.au/business/media/maurice-newman-speech/story-e6frg996-1225839427099
this is hopefully the beginning of some changes at the ABC.
We’ll see how well this pans out. In the meantime, everybody keep clam.
The clams do not lie.
This is old hat. Even Wikipedia has an entry on 18Oxygen:
http://en.wikipedia.org/wiki/Delta-O-18
Emiliani figured all this out: Emiliani, C. 1955. Pleistocene temperatures. J. Geol. 63:538-578.
This data is obviously wrong! The peer review process has failed, clearly the data must undergo homogenisation and adjustment.
Looking at the chart and the caption beneath, which you did not post, I would conclude that parts of the little ice age were as warm as the medieval warm period.
Others mileage may vary, but more clam shells need to be processed in order to give a complete and robust temperature reconstruction, don’t you think.
REPLY: try a refresh. I did indeed post it, but Nature News doesn’t like to share. – Fixed now -A
The history of this method can be found here: http://www.leif.org/EOS/12-740Spring2002.pdf
Come on Leif. I’ve had a really rough day at “group-think” central today and I need to let off a little steam…steam…mmmmmm.
So does Mann NOT read Wiki? Why on Earth would he go around goring poor defenseless trees that he does not intend to eat, when he can measure clams and then eat the contents? This seems a no brainer to me. Trees – Clams. Trees – Clams.
But then I didn’t know about temperature and clams either. In fact, don’t know squat other than my first bite of oysters on the half shell at the Oyster Bar in Portland, OR, which caused me to ring my waiter and complain that my food wasn’t cooked. He graciously (without a word) took my plate away and brought steamed oysters. I then caught his eye again and said I wanted the other oysters back, that I had changed my mind.
You know what? He brought out another plate of raw oysters, telling me he hadn’t had a chance to dump the plate. Now that I am older, I will have to admit that I was a dumb-ass then and that good waiters are hard to find. I have found only one worthy of his clams. Who probably still thinks I’m a dumb-ass.
Leif Svalgaard (18:48:03) :
What’s not old hat is the confirmation of the Medieval Climate Optimum and the falsification of the treering data.
So will the “mainstream” clam-media finally open up and cover this story?
No. Don’t ya know that you have to cook clams to get them to open up without using a pry bar?
So now we can get our clams read after dinner?
If this catches on, M Manns job is chowder.
Pamela Gray (19:00:06) :
But then I didn’t know about temperature and clams either.
The 18Oxygen stuff has been know for more than half a century. See the historical notes I provided. But every so often people has to be reminded of the known knowns.
I’m not certain I’m buying this. According to the study some of those clams would have been dead for hundreds of years. Those were HOLLOW clams. Robust claims can only come from robust clams, and these ones were hollow. There’s no way to cut them open and count the rings which is the only way to get a robust clam claim. And this business of shaving them? CLAMS DONT SHAVE THEY DONT EVEN HAVE HAIR! And this clown claims the clams aren’t clamming up about climate?
Wasn’t there an old BC comic about clams talking?
The automated, fine-tuned shell-shaver seems to be a new advance. It promises much more detailed and reliable results. This alone ought to promote increased use of this technique.
LOL! Great job with the Mann/clam photoshop.
I should think you would have to nail down with great resolution when the clams being tested were alive in order to use the data on a timeline showing sub-weekly temperatures. How accurate are the sediment dating methods? Or, are they determining the age of the mollusks individually using an isotope, carbon or other dating method?
Is my thinking off-kilter here?
Thousand Foot Krutch — Clam It Up lyrics
Chorus:
I’ve got a bad case of clammin it up
It’s getting cold in here so clam it up
I’ve got a bad case of clammin it up
It’s getting cold in here so somebody clam it up
Come on and clam it up
Verse 1:
I’m in love with the feeling
Of temps to the ceiling
We come with intention
To face my opposition
Get raw when it’s time
To lay it on the line
To the walls where we’re taking it
Let your tree shine, like
Let your tree shine, like
Let your tree shine
[Chorus]
Take it higher, take it higher
Til the roof is on fire
Take it higher, take it higher
Let’s burn it up
We throw down
When it’s time for the action
Make it happen, and the sound
That you’re feeling like lead
Might just happen
When you’re warm
You might not
Get a warning or a sign
To the walls where we’re taking it
Let your tree shine, like
Let your tree shine, like
Let your tree shine
Mann’s least liked movie? The Silence of the Clams.
I am reminded of the early papers on tree ring data and see some of the same localized problems. However I hope to see development of more data from all over the world.
On viewing the graph I see that it is worse then I thought, we are already heading into the next Iceage. The AGCC people better get ahead of this because we are all doomed, and I left Alaska because I was tired of the cold and snow. ;-[