From the University of Copenhagen – Niels Bohr Institute
(BTW, the phrase “Past temperature in Greenland adjusted” in the headline is their choice of words, not mine.)
One of the common perceptions about the climate is that the amount of carbon dioxide in the atmosphere, solar radiation and temperature follow each other – the more solar radiation and the more carbon dioxide, the hotter the temperature. This correlation is also seen in the Greenland ice cores that are drilled through the approximately three kilometer thick ice sheet. But during a period of several thousand years up until the last ice age ended approximately 12,000 years ago, this pattern did not fit and this was a mystery to researchers. Now researchers from the Niels Bohr Institute have solved this mystery using new analytical techniques. The results are published in the prestigious scientific journal Science.
The Greenland ice sheet is an archive of knowledge about the Earth’s climate more than 125,000 years back in time. The ice was formed by the precipitation that fell as snow from the clouds and remained year after year, gradually being compressed into ice. By drilling down through the approximately three kilometer thick ice sheet, the researchers draw up ice cores, which provide detailed knowledge of the climate of the past annual layer after annual layer. By measuring the content of the special oxygen isotope O18 in the ice cores, you can get information about the temperature in the past climate, year by year.
But something didn’t fit. In Greenland, the end of the Ice Age started 15,000 years ago and the temperature rose quickly. Then it became colder again until 12,000 years ago, when there was again a rapid rise in temperature. The first rise in temperature is called the Bølling-Allerød interstadial and the second is called the Holocene interglacial.
Temperatures contrary to expectations
“We could see that the concentration of carbon dioxide and solar radiation was higher during the cold period between the two warm periods compared with the cold period before the first warming 15,000 years ago. But the temperature measurements based on the oxygen isotope O18 showed that the period between the two warm periods was colder than the cold period before the first warming 15,000 years ago. This was the exact opposite of what you would expect,” explains postdoc Vasileios Gkinis, Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen.
The researchers investigated ice cores from three different Greenland ice cores: the NEEM project, the NGRIP project and the GISP 2 project. But amount of the oxygen isotope O18 was not enough to reconstruct period temperatures in detail or their geographic distribution.
To get more detailed temperature data, the researchers used two relatively new methods of investigation, both of which examine the layer of compressed granular snow that is formed between the top layer of soft and fluffy snow and the layer deeper down in the ice sheet, where the compressed snow has been turned into ice. This process of transforming the fluffy snow into hard ice is physical and both the thickness and the movement of the water molecules are dependent on the temperature.
“With the first method, we measured the nitrogen content and by measuring the relationship between the two isotopes of nitrogen, N15 and N14, we could reconstruct the thickness of the compressed snow 19,000 years back in time,” explains Vasileios Gkinis.
The second method involved measuring the spread of air with water molecules with different isotope composition in the layers with the compressed snow. This process of smoothing the original water isotope variations from precipitation is dependent on the temperature, as the water molecules in vapour form are more mobile at warmer temperatures.
Temperatures ‘fall into place’
Data for the spread of the water molecules in the individual annual layers in the Greenland ice cores has thus made it possible to calculate the temperature in the layers with compressed snow 19,000 years back in time.
“What we discovered was that the previous temperature curve, which was only based on the measurements of the oxygen isotope O18, was inaccurate. The oxygen temperature curve said that the climate in central Greenland was colder around 12,000 years ago than around 15,000 years ago, despite the fact that two key climate drivers – carbon dioxide in the atmosphere and solar radiation – would suggest the opposite. With our new, more direct reconstruction, we have been able to show that the climate in central Greenland was actually warmer around 12,000 years ago compared to 15,000 years ago. So the temperatures actually follow the solar radiation and the amount of carbon dioxide in the atmosphere. We estimate that the temperature difference was 2-6 degrees,” says Bo Vinther, Associate Professor at the Centre for Ice and Climate at the Niels Bohr Institute, University of Copenhagen.
See film about NEEM icecore project: http://www.nbi.ku.dk/english/sciencexplorer/earth_and_climate/secret_of_the_ice1/video/
FYI, this is what Alley et al. 2000 Grenland reconstruction from GISP2 cores looked like:
Well, now that they’ve found a proxy which gives them the answer they want, they can stop looking. Classic confirmation bias.
Exactly.
If they see data that differs from their desires, they change the data out until they find some that fit the need.
Data that fit the desires are not questioned.
No different than accepting tree ring temps that fit the political narrative, while replacing those that don’t with the instrumental record. Niels Bohr institute has discovered Mike’s Nature Trick.
This is not science.
Are you saying temperature follows CO2 rise? Theat would be “unprecedented “!
A fundamental requirement of scientific investigation is that you choose your methods before looking at the data. Otherwise you end up cherry picking your methods to confirm your own unconscious bias. Since bias is unconscious, you the researcher are not aware of the error you have made.
The problem is that many of the “soft” sciences do not recognize this type of error as being an error. As a result their findings are more about pseudo science than science.
Peter,
Any paelo proxy is at the mercy of entropy. The climate is the state of the matter of the biosphere, some of the matter of the oceans, and most of the matter of the atmosphere. A very large amount of matter. After 15,000 years of entropy, almost almost all of the information of the state of that matter, the state of the climate matter 15,000 years ago, is lost. The quantity of matter in the world, matter that was climate and not rock, the quantity of climate matter in the world that is in the same state as it was 15,000 years ago, is vanishing-ly small. The inferential extraploation that is needed to ‘recreate’ the state of the all of the climate matter, 15,000 years ago, is an academic career. It is fun and it is entertaining, but it is not close to being “valuable” enough to to make international policy.
It is “valuable” to you who do it, and its development is “valuable” to your careers. But it is irrelevant to the present overcrowded, overarmed, hyperconflicted world.
So: No, it is not valuable to all of the rest of the world’s population. Sorry.
Tree rings, speliotherms, ice layers, silt deposits, pollin and bio indicators are a very very very small quantity of all of the measurable matter that is the climate. Yes, it’s a big amount of measurements, compared to speculating based on nothing. But as a measure of climate, it is nothing. Suggest that today, you will tell us the climate today, by presently measuring a few layers of snow, a few tree rings, a few stalagmites, and a few isotope ratios. What measure of the climate today could you get from those? No more measure than you can get from those of 15,000 years ago… Not much.
When all of the reconstructive work is done (hockey stick et al), all that comes out is global temperature, or hemispheric temperature. So the proxi climate is one number for everything, or one number for half of everything.
Well… at least they figured out the correlation part.
Now if only they could nail down that pesky correlation/causation conundrum, they might get somewhere…
‘Course they’d still only have a model for Greenland, not the whole world.
They saved Global Warming!
I smell another Nobel Prize winner here.
Are they saying that in Greenland temperature follows CO2 even though everywhere else it is the other way around?
yep
The logic seems Procrustean. Said another way, if you torture the data long enough it will eventually say what you want it to say
What now? Let me tell you what now. I’ma call a coupla hard, pipe-hittin’ climate scientists, who’ll go to work on the data here with a pair of pliers and a blow torch. You hear me talkin’, data? I ain’t through with you by a damn sight. I’ma get medieval warm period on your ass.
“Mark and two Cats has encapsulated the duty of every government-funded, policy-driven scientist.”
FYP
In other news, John Kerry today said that when it comes to Climate Change, we should all forgot about the silly “Separation of Church and State” stuff.
Secretary of State John Kerry said it was the United States’ biblical “duty” to confront climate change at home and abroad in “Muslim-majority” nations during a speech Wednesday..
“Confronting climate change is, in the long run, one of the greatest challenges that we face, and you can see this duty or responsibility laid out in Scriptures clearly, beginning in Genesis. And Muslim-majority countries are among the most vulnerable. Our response to this challenge ought to be rooted in a sense of stewardship of Earth, and for me and for many of us here today, that responsibility comes from God,” he continued.
http://freebeacon.com/issues/kerry-scripture-says-u-s-should-protect-muslim-countries-against-global-warming/
Anyone still think this issue has ANYTHING to do with “science”??? Anything at all?
The speechwriter for the Administration is probably an implementation of
http://en.wikipedia.org/wiki/Mark_V_Shaney
You feed in source text, it outputs gibberish that superficially looks like human sentences. Source material must have contained something about the Middle East carnage and something about Global Warming. And a sunday sermon.
So:
We can use Kerry as a proxy to determine the kind of source material the WH uses.
Anyone still think this issue has ANYTHING to do with “science”??? Anything at all?
No. In addition, John Kerry has ‘nothing to do with science’ either.
Hillary Clinton on one of her trips to China, (apologizing and imploring the Chinese not to repeat America’s mistakes), explained that the opposition to confronting ” Global Warming” was mainly from Christian fundamentalists but she thought that they could “get them” with the “stewardship of the earth” thing.
It’s a wonder they can tie their own shoes if that represents the level of sophistication of their thinking. How can someone possibly be that out of touch, both in the diagnosis of the problem and the ham-fisted strategy to “get them”.
Would this be the same John Kerry that predicted in October of 2009 that the Arctic would be “ice free by 2013”? http://www.huffingtonpost.com/john-kerry/we-cant-ignore-the-securi_b_272815.html
Would this be the same John Kerry that filmed his glorious retake on shooting a 13 year old “Vietnam Cong” when he was with the Swift Boats in Nam for later political use. The man was scum then ( ask any of us that knew him then) and has stayed consistent since then.
No argument here.
Trying to inflate the paper by using Bohr’s name? Niels Bohr practiced real science and did not need to be a name dropper.
If you’re so set on the value of the paper why aren’t you quoting relevant data and the ‘new’ flashy analysis.
Or, perhaps you can explain why these characters can ‘prove’ CO2’s impact on temperatures using paleo ice cores but are unable to demonstrate any modern CO2 impacts?
Past temperature in Greenland adjusted to fit new theory
Translation:
We didn’t get quite the curve we wanted on the AGW Etch-A-Sketch…. sooooo we just shook it up and drew another one! Simples..
So, they are adjusting again…. What else is new? In any event, the last 1000 years, according to their new adjusted figures, looks nothing like the Mannian hockey stick, so at least we can agree on that.
So they destroyed O18 as a temperature proxy.
That is the unstated implication. At least it is “inaccurate”. So what does that do to certainty? Nothing. The certainty is in the general, not the detail: 1C or 4C. All the same, react the same.
Yes, but only situationally. O18 is still fine to use, when doing so produces the desired results.
Kind of like how treemometers need to be replaced with other datasets when they break the blade of the hockey stick, but are AOK for the haft …
“We have always been at war with Eastasia”
I think that at tomorrow’s Two Minutes Hate, I’m going to focus on Anthony’s parents and their failure to mold him into a goodthinking Party member…
REPLY: my first thought here was to tell you to go ” ” yourself, and put you in the permanent troll bin. Both of my parents died prematurely from smoking related effects, and I have a hearing loss because of complications of 2ndhand smoke effects. So, it is a touchy subject with me. I assume now that you are being sarcastic, but please don’t raise the subject again – Anthony
My apologies – I only meant to compare you to Emmanuel Goldstein, as you are the embodiment of the anti-Party (anti-alarmist) movement for some. I was picturing your face on the telescreen when the warmists have their daily Two Minutes Hate. I made a ham-fisted joke in expressing the metaphor, and I am truly sorry to have broached a touch subject.
I am very disappointed. Never could I imagin that Niels Bohr institute of all, doesn’t understand that they are presenting themselves as fools. Have they forgotten the basic natural laws for water cycle? Is it really possible that they don’t know WHY the ice core examples doesn’t give them correct information re. CO2 in the past? I think it would have been good had they studied the analyse methods of last 30 years in archaeologic field analyse methodology and technology.
* Water in all form tries to reach the lowest point possible.
* In ice core there are differences in structure as well as in density not to mention the simple fact that erosion, wind-/water-/temperature change each period’s surface.
* the “heavier” structure, such as soot, vulcano ashes and other particles from nano up, due to gravity and so on “falls” quicker.
* Ice core aren’t reliable in anyway on same level as sediment layer which btw not always are as well. (Depending on many different factors)
I never thought Niels Bohr Insitute to present such bad level of Theory of Science usage. Sorry. But I had to say this. Mathematic models, computers or not, doesn’t hold water if one don’t take ALL needed factors for a premise to be true into consideration.
Bohr is spinning in his grave.
This is what happens when scientific institutes transforms into political ones …
Result is what we seen in the “paper”…… 🙂
I agree at 97.5%
That’s ok. I wouldn’t like a copy of myself walking around somewhere…. 🙂
And the Science Mag editorial staff, led by Marcia McNutt, bought into it. Thus implicitly the AAAS is as guilty of political corruption of science as the Bohr Institute. But we already knew that.
I thought it was established that rises in atmospheric CO2 FOLLOWS rises in atmospheric temperature? or am I wrong? LOL
When all else fails manipulate the data.
Have a real real good look at Alley 2000
Notice how snow accumulation and isotope temperature show a corrolation tht seems too good to be true.
http://wattsupwiththat.files.wordpress.com/2013/02/alley2000.gif
Isn’t there anybody frowning and thinking, if they are so incredibly alike, aren’t they just the same?
Consequently, could the isotopes be a proxy for moisture/aridness/precipitation rate, rather than for temperature?
If the temperatures at various points in time were high around the world, then there would be more water in the atmosphere, and so more precipitation including snow.
But how about the sahara? Also it can be relatively warm and still dry on an ice sheet.
Wouldn’t this strong corrolatlion be a reason to revisit the research after the exact process of how isotope ratios are formed in the complete hydrological cycle?
“But how about the sahara? Also it can be relatively warm and still dry on an ice sheet. ” When exactly ? e.g. during a time when the earth is colder, the ice sheet and the world generally will be ‘dryer’.
There is a large difference in the amount of 18O in snow and rain. The rain fall in Greenland is about 0.2m in the North and 0.9m in the south of Greenland.
The trends in the curve might be fine but the actual temperatures might need to be taken with a pinch of salt.
Now the colder it is, the less rain there is and the less compressed ice due to rain. If you take the proxy for ice fluffiness seriously, then they have shown that there is less rain when its colder and not a different temperature profile.
Regardless of the actual temperature profile, the implication that atmospheric CO2 drove temperature rather than the other way around has never been established to my satisfaction. Does this revision do anything to clarify that issue?
Cant see much difference myself. Temperatures rose, fell and rose again at about the same time in both but the new chart suggest the lowest ‘tween-the-rises value was about 2 degrees less cold. How that is news escapes me.
Picture all there is to know about science as the Pacific Ocean. Now picture all that man THINKS he knows as the Atlantic Ocean. Now take that bucket your kid uses in his sand box and fill it with water. That bucket will actually, in scale, represent what man REALLY knows about science. I’ve said it before, proxies are guesses, not data. Useful in trying to understand the truth, but they do not represent truth any more than does all those global climate models represent the probably climate. Like proxies, they are guesses, not facts.
The method seems dubious. If things are freezing, they are already cold. I find it difficult to see how they can use such an indirect proxy and claim such levels of accuracy. It also seems that the paper shows CO2 is *not* the big driver.
My interpretation of the Alley picture is, that snow accumulation increases with temperature, so what is the problem. Correlates with the fact that the Summit station needs to be raised now and then.
The 2 proxies they are suggesting, even if we assume they are accurate, are very local. The O18 proxy is more global in reach than their methods. Low O18 shows that the evaporation happened very far away from Greenland, ie the ocean that surrounds the island was way too cold to support evaporation. Greenland is a frigid place no matter the climate at 45 degrees latitude. Also colder global climate means fewer precipitations in Greenland, we ca easily see that from the last plot in the article (that itself could be a better proxy for the global temperatures than the O18 itself). During glacial periods, the ice sheet should be less thick than during warm period (the thawing of the ice at the bottom is independent of the global climate as thick ice is a good insulator). This means that the surface of the ice sheet is at a lower elevation allowing for higher local temperatures.
[SNIP !!! Pat, when will you learn to stop posting OFF TOPIC ARTICLES??? You’ve been warned several times. This article is about Colorado, not Greenland. Do we have to ban you to get this point across? – Anthony]
Maybe you meant “This article is about Greenland, not Colorado”? Otherwise, I’m confused.
I think Anthony meant the article pat posted, which got snipped. Since it’s not about Greenland, it’s off topic. By the way, Anthony, thanks for blocking pat’s indiscriminate thread bombing.
“We could see that the concentration of carbon dioxide and solar radiation was higher during the cold period between the two warm periods compared with the cold period before the first warming 15,000 years ago. But the temperature measurements based on the oxygen isotope O18 showed that the period between the two warm periods was colder than the cold period before the first warming 15,000 years ago”
====
So we will just charge ahead assuming we have the correct CO2 and solar proxies…and we know what they do.
bad science is self replicating
No, it’s not speculation
If the data tells you something other than what you “expect” you change you expectations, not the data.
If dO18 is not longer a reliable proxy a lot of work goes out of the window. That requires solid justifications, not just averaging with a second proxy.
There is clearly a very significant variation that caused this reversal that can not be accounted for by banal relationships to CO2 or solar. Unit that is explained and understood there is not reason that 12k BP being marginally cooler than 15k BP should be a problem.
The problem is refuting the evidence because it does not fit some trivial hypothesis that expects simple linear correlations with _supposed_ drivers of climate.
LOL. Grants are essentially never given to duplicate an experiment. Publishers and reviewers tend to reject papers about duplicated experiments because “it’s already been done”. Peer reviewed publications have nothing to do with being part of the scientific method. Also, the review of a proposed publication is not duplicating an experiment, it’s a simple check to make sure that the article content is somewhat relevent to the field and is not full of obvious problem (and that does not seem to even be working in numerous cases).
The “cold period between the two warm periods” is the Younger Dryas, the cause of which is being debated constantly. In fact, a tiny bit of searching will reveal that there are serious operators out there who believe that they have proved that the YD is due to an impact event. If so, then it’s occurrence would be causally unrelated to the Wisconsinan glacial epoch and its ending. It simply happened as the epoch was ending. So what we really see is a regime change between the “real” glacial and the Holocene. That change effects basic relative concentrations of isotopes. The YD did not effect these, it simply made things colder for a (geologically) short time span.
So, seems to be a very strong correlation between snow accumulation rates and warming/temperature. Thus, are snow accumulation rates rapidly increasing?
“With our new, more direct reconstruction, we have been able to show that the climate in central Greenland was actually warmer around 12,000 years ago compared to 15,000 years ago”
That would imply the Younger-Dryas did not occur. What is next???? …. a dry Doggerland until man started using fossil fuels?