The Intergovernmental Panel on Cllimate Change (IPCC) estimates pre-industrial levels of CO2 based largely on information derived from ice cores. These are kilometres long cylinders of ice drilled (in short sections) from the Greenland and Antarctic icecaps.
The theory is that air bubbles trapped in the ice are samples of the ancient atmosphere, and thus give an accurate reading of CO2 levels in those ancient times. The ice cores tell us that the pre-industrial level of
CO2 was about 290 parts per million (ppm).
Of course it’s not that simple. There are many factors to take into account, because ice from deep down in the ice cap is under enormous pressure, and that pressure is released when the cores are brought to the surface.
A brief summary of some of the processes going on in ancient, deep ice can be found here:
http://geoweb.princeton.edu/people/bender/lab/research_ice_cores.html
Zbigniew Jaworowski, a multidisciplinary scientist, has long been a critic of the ice core CO2 record:
http://www.21stcenturysciencetech.com/2006_articles/IceCoreSprg97.pdf
http://www.larouchepub.com/eiw/public/2007/2007_10-19/2007-11/pdf/38_711_science.pdf
He makes a number of claims:
1. Ice core results reported before about 1985 showed higher CO2 levels than those reported since 1985, which he details in his 1997 paper.
2. Low pre-industrial concentration of CO2 in ice cores is an artefact caused by more than 20 physical-chemical processes. For example, CO2 is more than seventy times as soluble in water as is nitrogen, and liquid water is present in deep ice, even at -73C.
3. Drilling and retrieval of ice cores, including their decompression as they are brought to the surface, drastically disturbs the sample.
4. Subsurface melting of snow due to absorption of solar radiation is common in very cold sites, and may occur several times a year. This implies that the practice of dating ice cores using isotopes of oxygen, which assumes the temperature peaks are yearly events, is wrong.
The net result of these effects is to lower the CO2 levels in ice compared to that found in the atmosphere, by 30 – 50%, and to minimise fluctuations in CO2 in ice compared to the atmosphere.
Jaworowski illustrates this by comparing ice core data to other CO2 proxy data, such as stomata indices, which gives higher atmospheric CO2, with more variation than the ice core data over the last 8,000 years.
There is no doubt that ice core analysis is a highly technical subject, and scientists must make many assumptions when interpreting the data. One assumption that I personally found very interesting was that air inclusions in the snow and firn, or compacted granular snow, are well mixed with the atmosphere. In other words, the air in the hard packed snow is basically the same as the atmospheric air, down to the level of the ice. This could be 50 – 120 metres below the surface. Imagine hard packed snow that far down having a connection (and circulation with) the surface air. To me this is very counter-intuitive, but apparently Argon dating confirms it.
Jaworowski claims this is wrong, and that impenetrable layers, caused by melting and refreezing, cut off air inclusions from the atmosphere much earlier. This is the basis of his criticism that ice core data from the Siple core showed similar CO2 levels as the atmosphere did 83 years later, and thus the air in the ice core was assumed to be 83 years younger than the ice it was in.
Jaworowski has been criticised here:
http://www.someareboojums.org/blog/?p=7
The late Hans Oeschger, a prominent ice core scientist, was also critical of Jaworowski, and wrote a letter in 1995 expressing his views :
http://www.someareboojums.org/blog/?p=12
Following are some other links.
Jaworowski interview in May this year:
http://www.canada.com/nationalpost/news/story.html?id=25526754-e53a-4
899-84af-5d9089a5dcb6&p=1
Diffusion of CO2 in atmospheric gas analysis (on pp10 – 11)
http://www.biomind.de/nogreenhouse/daten/AIGnewsNov06.pdf
———————————
From Paul Williams who lives in the Adelaide Hills, Australia
Other contributions to this blog from Paul Williams include:
Hockey sticks and ancient pine tree, at http://www.jennifermarohasy.com/blog/archives/001546.html
Measuring Atmosheric C02, at http://www.jennifermarohasy.com/blog/archives/001983.html
Build Dykes to Beat Global Warming, at http://www.jennifermarohasy.com/blog/archives/001983.html
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
Jennifer – “This is the basis of his criticism that ice core data from the Siple core showed similar CO2 levels as the atmosphere did 83 years later, and thus the air in the ice core was assumed to be 83 years younger than the ice it was in.”
I am not sure if this is shooting yourself in the foot however this is exactly the problem that saying that temperature preceeded CO2 rise from ice core data.
It is discussed here:
http://www.realclimate.org/index.php/archives/2007/04/the-lag-between-temp-and-co2/#more-430
Ender, just to clarify, this post is from Paul Williams… see the title. I should perhaps make it clearer with a note at the end?
Jennifer – yes I see that now – sorry
“temperature preceeded CO2 rise from ice core data”
Errr.. that’s the truth isn’t it?
http://www.sciencebits.com/IceCoreTruth
Well unless you model the solar and CO2 forcing you aren’t going to learn much. There has been some formal challenges to the isotope dating and whether the lag is a lag.
Our finding suggests that the
phase relationship between CO2 and EDC temperature inferred at the start of the last
deglaciation (lag of CO2 by
800± 600 yr) is overestimated and that the CO2 increase
could well have been in phase or slightly leading the temperature increase at EDC.
http://www.copernicus.org/EGU/cp/cpd/3/435/cpd-3-435.pdf
RC said:
“[Response: During the ice age cycles, it was mostly likely a lag. The degree of that lag is actually quite uncertain and there is recent paper under review that suggests with good reason that it is less than the 800 years seen in the Caillon et al study. At other points in the past, such as the Paleocene-Eocene Thermal Maximum (55 million years ago), it looks like the CO2 (or possibly CH4) lead. Over very long timescales (millions of years) the overall level of CO2 (driven by weathering/geologic balances) probably lead – and is hypothesised to have contributed to the onset of the Quaternary ice age cycle in the first place. – gavin]”
Caillon paper here: icebubbles.ucsd.edu/Publications/CaillonTermIII.pdf
For longer views on CO2 relationships let’s look at 420 M yrs http://droyer.web.wesleyan.edu/climate_sensitivity.pdf
Ender, I’m not sure what you mean by “shooting yourself in the foot”. All I’ve tried to do is summarise/simplify Dr Jaworowski’s ice core argument for people who may not be familiar with his work.
It has become clear to me that ice core analysis is a very specialised field, and the problems are not easy for a lay person to understand. The scientists are forced to make assumptions about the what happens deep in the ice, but the validity of those assumptions is beyond my understanding. That is why it is interesting when someone with experience in the field, like Dr Jaworowski, challenges the accepted view.
Paul – “Ender, I’m not sure what you mean by “shooting yourself in the foot”. All I’ve tried to do is summarise/simplify Dr Jaworowski’s ice core argument for people who may not be familiar with his work.”
True enough and a good summary however the evidence from the ice cores that temperature rises preceeded CO2 rises has been used as evidence against AGW. Particularly in the case of AIT and what Gore said about it.
But why are the climate cadres only focussing on the parts of the ice core record that trace the temperature rise out of glaciation periods? These rises account for less than 5% of the record.
Of much more relevance are the numerous times when temperature and CO2 show no correlation at all. There are times when CO2 is high for more than 15 millenia but the temperature trends down by 6C.
Up to 6C of reversal over10 to 15 millenia is hardly something that can be ignored.
And no-one has adequately explained why this claimed feedback always seems to stop at 1 or 2 degrees C warmer than the present. We are expected to believe that this feedback only applies to the middle part of the rising trend and some sort of “invisible hand” stops the feedback at the top of the cycle.
For half of the geological record, temperature and CO2 go in opposite directions.
Well it all depends what the combination of solar (from Milankovitch or other) + greenhouse + volcanic and other aerosols adds up to at any time.
Why does the feedback stop – well it slows as the solar forcing again fades. CO2 is only a radiation recycler not a prime driver. No Sun – nothing !
You don’t have enough watts overall to have a runaway a la Venus. But if you want to burn absolutely everything and sequester nothing we could try I guess.
If you don’t model the forcings you won’t know. Just looking at the numbers won’t reveal anything.
Ian Mott – “And no-one has adequately explained why this claimed feedback always seems to stop at 1 or 2 degrees C warmer than the present. We are expected to believe that this feedback only applies to the middle part of the rising trend and some sort of “invisible hand” stops the feedback at the top of the cycle.”
The key is remembering that the ice cores, as useful as they are are not a global record. The Antarctic, in its present form, is isolated from the global weather by the circumpolar wind circulation.
“Falsification Of The Atmospheric CO2 Greenhouse Effects Within The Frame Of Physics.”
Gerhard Gerlich, Institute fuer Mathematische Physik, Federal Republic of Germany,
http://icecap.us/images/uploads/Falsification_of_CO2.pdf
The atmospheric greenhouse effect, an idea that authors trace back to the traditional works of Fourier 1824, Tyndall 1861 and Arrhenius 1896 and is still supported in global climatology essentially describes a fictitious mechanism in which a planetary atmosphere acts as a heat pump driven by an environment that is radiatively interacting with but radiatively equilibrated to the atmospheric system. According to the second law of thermodynamics such a planetary machine can never exist.
Nevertheless, in almost all texts of global climatology and in a widespread secondary literature it is taken for granted that such mechanism is real and stands on a firm scientific foundation. In this paper the popular conjecture is analyzed and the underlying physical principles are clarified. By showing that
(a) there are no common physical laws between the warming phenomenon in glass houses and the fictitious atmospheric greenhouse effects,
(b) there are no calculations to determine an average surface temperature of a planet,
(c) the frequently mentioned difference of 33 C is a meaningless number calculated wrongly,
(d) the formulas of cavity radiation are used inappropriately,
(e) the assumption of a radiative balance is unphysical,
(f) thermal conductivity and friction must not be set to zero,
the atmospheric greenhouse conjecture is falsified.
—
That is to say, “the atmospheric greenhouse conjecture is falsified.”
(a) gives it away – yes strangely I think scientists know that.
(b) OK let’s do spatial then or satellites.
Just an unpublished bit of contrarian twaddle. If they were any good they’d get published – but they won’t. Horseshit in fact. Might as well read a Mickey Mouse comic.
With regard to the original post, hasnt CO2 been directly measured over the past 30 or 40 yrs? And doesnt this period show a steady increase, broadly commensurate with preindustrial CO2 being 280ppb?
I thought just sbout everyone (bar Jawoworoski), accepted that 280-380 was what CO2 has done recently.
It maybe that past CO2 was a little more volatile than the data suggests because of multi-decadal mixing in the snow pack.
A neat summary from a contributor at Anthony Watts blog
Of course the problem with the whole global warming issue is that the data and science are hyped, misreported or poorly reported. Scientific staff, especially working for the government, do not stand up and question the data.
Almost all of the hype from the politicos is based on seven climate models that none of these folks could ever possibly explain. All the models have significant difficulty since they do not adequately model two significant and closely related components of our climate, water vapor and three fourths of the earth’s surface, the oceans.
Without adequately modeling those two components and without having accurate terrestrial data going forward to verify these models no one can guess what the climate will do a hundred years from now.
Bill – refer you to here http://cdiac.esd.ornl.gov/trends/co2/contents.htm
Very good measurements made from the late 1950s.
The blog has discussed the 280ppm issue here http://www.jennifermarohasy.com/blog/archives/001971.html
At 12.21pm Schiller T. presents a web reference involving nearly 100 pages of complex mathematics and analyis.
At 1.32pm on the same day, and undoubtedly after much careful reading and thought, Luke responds,with:
“Just an unpublished bit of contrarian twaddle. If they were any good they’d get published – but they won’t. Horseshit in fact. Might as well read a Mickey Mouse comic.”
Just because it hasn’t been published does not mean it is without merit.
But I would like to know which bit of the mathematics and analysis was/is “Horseshit in Fact”, and was readily discernible inside less than an hour.
All of it actually ! Gee Motty can knock over 17 pages of GRL paper by intuition only – and you never hear about that. Do you hating Mal.
Malcolm,
he makes the basic mistake of saying that CO2 is just a trace gas in the atmosphere. Just because some is present in small elements, doesn’t mean it has no influence on it’s environment. If a person was to take a trace amount of strchnine, that fact would become apparent very quickly.
He then waffles on about the conductivity of CO2, which is not the issue, for some reason. Apparently just to pad out a piece of paper.
I’m seriously wondering if this is just a joke at the expense of deniers. It is page after page of utter waffle and nonsense.
SJT,
I appreciate your depth of concern about trace gases in the atmosphere. Since you consider trace gases to be as deadly as “strchnine” [sic] you will of course educate us on the deadliness of neon, argon, and, of course–nitrogen, which kills divers in droves.
Ground-based records of global temperature are totally busted, while satellite recordings show the warming trend has ended.
Work on the sheep-fart angle, dude, you might get an angle there.
Well dickhead if you look here it seems the satellites are not cooling. http://www.remss.com/msu/msu_data_description.html
And note that “solar not the cause” cooling stratosphere too.
Speaking of hot news aren’t those European heatwaves cool
http://www.voanews.com/english/2007-07-26-voa37.cfm
Perhaps we need to put it up “Neon” lights for you as you brain case is so thick it would need an “Argon” welder to open.
P.S. It’s not sheep farting – it’s ruminant belching of methane. Get around to the right end dumb bum.
I can’t open the link to the interview….
However , the first paper
http://www.21stcenturysciencetech.com/2006_articles/IceCoreSprg97.pdf
is headed ” ANOTHER GLOBAL WARMING FRAUD EXPOSED ”
which seems to be a disappointing appeal to emotion rather than science.
Mind you the first rebuttal
http://www.someareboojums.org/blog/?p=7
titled
The Golden Horseshoe Award: Jaworowski and the Vast CO2 Conspiracy
makes the same mistake – though it isn’t a published scientific paper.
The fact that LaRouche publishes it isn’t significant – as Shakepeare said , even the Devil can quote scripture for his own purposes.
The rebuttal appears ( to an amateur ) to raise some genuine questions about the paper – though mixed in with some irrelevant assumptions as to personal credit.
Hans Oeschger’s comments are much more credible IMO.
I am impressed and gratified at the level of discourse regarding “catastrophic global warming.”
“dickhead”
“brain case is so thick”
“dumb bum”
SJT seems to be representative of “the consensus.”
Not only because of his tendency to hurl verbal offal, but also because of his brash, vociferous and voluble ignorance.
Sheep don’t belch.
Courtesy of a youth spent with livestock Schiller – sheep most certainly DO belch. If they don’t they bloat and die.
Schiller we can’t help it given he’s mainly familiar with sheep rear ends – have you been to New Zealand.
Wiki says:
Enteric fermentation is fermentation that takes place in the digestive systems of ruminant animals.
It is one of the factors in increased methane emissions.
Ruminant animals are those that have a rumen. A rumen is a special stomach found in cows, sheep, and water buffalo that enables them to eat tough plants and grains that monogastric animals, such as humans, dogs, and cats, cannot digest.
Enteric fermentation occurs when methane (CH4) is produced in the rumen as microbial fermentation takes place. Over 200 species of microorganisms are present in the rumen, although only about 10% of these play an important role in digestion. Most of the CH4 biproduct is belched by the animal, however, a small percentage of CH4 is also produced in the large intestine and passed out as gas.
http://www.epa.gov/methane/rlep/faq.html
Schiller
I didn’t say everything in trace amounts is potent, I just said that because something is present in trace amounts doesn’t mean it’s not potent.
Jim, here is the link to the Jaworowski interview.
http://www.canada.com/nationalpost/news/story.html?id=25526754-e53a-4899-84af-5d9089a5dcb6&p=1
Hans Oeschger was certainly a very influential figure, judging by the papers he published. He seems to have been very concerned about man-made global warming, but betrays a certain circularity of argument when he says;
“But JAWOROWSKI maintains that the age of the ice and that of the occluded gases are the same and shifts the CO2 increase revealed from studies of the SIPLE core (Fig. 5 a) – which in the uppermost part overlaps convincingly with the atmospheric measurements by ca. 100 years back in time (assuming identical ages for the ice and the gases in the ice). Fig. 5 b speaks for itself; why should there be such a drastic increase of CO2 and of CH4 (Fig. 5 a) in the middle of the 19th century?”
Elsewhere he wrote that he was very concerned that scientists should not be judged to have know of the problem of AGW, and done nothing about it. In other words, he apparently saw himself as an activist, which may have clouded his impartiality. In such a specialised field, it is not easy for a non-scientist to judge.
Thanks Paul!
I shall read with interest.
“Sorry, this url contains an invalid document id. Please check your url or click Back and try again.”
Is the answer I get.
Have to wait till Monday for the IT boys to tell me what I’m doing wrong.
Sheep and cows cannot belch. That is why bloat kills them. All they can do is fart.
Jim and SJT are ignorant urbanites. When ignorant urbanites run policy, trouble is on the way.
Schiller – are you that big a goose ?
Eructation or belching is how ruminants continually get rid of fermentation gases. As mentioned above, an eructation is associated with almost every secondary ruminal contraction. Eructated gas travels up the esophagus at 160 to 225 cm per second (Stevens and Sellers, Am J Physiol 199:598, 1960) and, interestingly, a majority is actually first inspired into the lungs, then expired.
http://www.vivo.colostate.edu/hbooks/pathphys/digestion/herbivores/rumination.html
Luke,
I don’t give a rat’s what you want to cite. I’m a farmer and I’ve raised sheep and cattle. I know, and urbanites like you, don’t.
Well Schiller I’ve worked with sheep & cattle too so you’re a total nutcase/fuckwit which explains your total stupidity on an ongoing basis.
Luke,
Now I know you’re a liar. Unless, when you say, “worked with sheep & cattle” you mean your urbanite green zealots in their office cubicles.
If you believe sheep and cattle belch (aside from the ones in your office), you owe the world, and veterinarians everywhere, an explanation of bloat.
A distinguished scientific prize awaits your revelation.
Sometimes I wonder about feeding trolls like Luke, but I figure, he’s so foul-mouthed and easily refuted that it scares off other trolls.
‘Fermentation in the rumen generates enormous, even frightening, quantities of gas. We’re talking about 30-50 liters per hour in adult cattle and about 5 liters per hour in a sheep or goat.
Eructation or belching is how ruminants continually get rid of fermentation gases. As mentioned above, an eructation is associated with almost every secondary ruminal contraction. Eructated gas travels up the esophagus at 160 to 225 cm per second (Stevens and Sellers, Am J Physiol 199:598, 1960) and, interestingly, a majority is actually first inspired into the lungs, then expired.Bloat can be a sudden and lethal occurrence for sheep. Often, unless the livestock is being monitored closely, the first symptom one notices is dead or distressed animals.’
‘Pasture bloat (or green legume bloat) is caused by increased pressure by the ruminal contents. Pasture bloat is usually a build-up of trapped gas caused by the failure of the animal to undergo normal eructation. Gas production in the rumen normally consists of primarily CO2 and CH4 produced through feedstuff fermentation. Under normal conditions, ruminants have a predictable sequence of eructation cycles, whereby, gas that is produced is released to the environment. When an animal is experiencing pasture bloat, ruminal conditions are such that a stable froth is produced in the rumen. This froth then “layers” on top of the ruminal contents (mostly liquid) and prevents the gas bubbles from rising to the top and dispersing their contents. This could be analogous to taking a drinking straw and blowing air into a glass of liquids and seeing the air bubbles rise to the top and bursting. Under pasture bloat conditions, the bubbles cannot burst, thus, a build-up of gas and pressure. Furthermore, the froth produced in a bloat situation can block the cardia and prevent normal eructation and release of gas through the esophagus.
Pasture bloat is often brought on by a rapid intake of immature, highly nutritious green legumes (alfalfa or clovers). These plants, when in a vegetative state, contribute high levels of ruminally degradable protein, high levels of carbohydrates and are digested quite rapidly. This causes a drop in the pH of the rumen, an increase in gas production and a binding of protein molecules into a surface film over the ruminal contents. These events contribute to the production of froth, and subsequently, trapped gas.’
Schiller are you sure you have raised sheep and cattle, I mean live sheep and cattle? At least now I know why you are so ignorant on issues of other life forms – you spend too much time belching and farting here instead of observing your livestock. The only troll here is you Schiller, and you’ve been kept fat and happy for too long.
Thanks Travis .. ..
Silly Schiller – searching for eructation and cattle in Google Scholar finds 365 scholarly journal references – and 433 for sheep. Strange how well researched with so many measurements something is that supposedly does not exist. So I can only conclude Schillsy that you are a denialist fuckwit on all science matters. Explains heaps including recent earth tremors.
Much as it pains me to agree with those abusive warmers, Luke and travis, they are right in this instance. All ruminant animals belch gas. As Travis says, pasture bloat is caused by foam that prevents normal stimulation of the eructation reflex. Bloat also occurs if the oesophagus is blocked mechanically, eg by a potato.
I was a veterinarian in large animal practice many years ago.
Schiller, hello Schiller, are you there?
Cripes Paul – you should have told us. We would have given you much more respect.
Why, Luke?
A joke? OK then – before that we just thought you were some dill. (OK didn’t mean it – honest 🙂 )
Here goes Luke again;
*Speaking of hot news aren’t those European heatwaves cool*
Now havent your minders told you the difference between climate and weather?
Oh I see, you forgot.
I’m the same old dill I’ve always been Luke. No more shoulder length plastic gloves for me though, I’m much more refined now.
Rog – you mean I can’t do what you guys do all the time. And it was only Schiller, the ruminant denier, not someone of intelligence. Drat. Good to see you’re keeping tabs on me too. But as usual you left out the context of the wider discussion.
Rog I’m very sensitive – do I sense some hostility? Was it something I said.
But yea – one exceptional event doesn’t make a trend. Luke sulks off stage (stage left of course). As my son would say “Owned!”.
>Luke sulks off stage (stage left of course).
Did you find Schiller there too Luke?
Oh no – he left stage right. The very very far right door. It’s on an extreme angle and very hard for most people to get through.
This recent paper from Drake would seem to add to the criticism of how CO2 levels before 1900 were determined: http://homepage.ntlworld.com/jdrake/Questioning_Climate/userfiles/Ice-core_corrections_report_1.pdf .
This seems to me to add further credibility to the theory that temperatures drive CO2 levels rather than the opposite.