Linking an ancient CO2 drop to the Antarctic Ice Sheet using algae as a proxy

From Purdue University , another “just in time for Durban” press release. When you see phrases like “the mother of all tipping points” and you know this is overhyped control knob science.

Drop in carbon dioxide levels led to polar ice sheet, study finds

WEST LAFAYETTE, Ind. – A drop in carbon dioxide appears to be the driving force that led to the Antarctic ice sheet’s formation, according to a recent study led by scientists at Yale and Purdue universities of molecules from ancient algae found in deep-sea core samples.

The key role of the greenhouse gas in one of the biggest climate events in Earth’s history supports carbon dioxide’s importance in past climate change and implicates it as a significant force in present and future climate.

The team pinpointed a threshold for low levels of carbon dioxide below which an ice sheet forms in the South Pole, but how much the greenhouse gas must increase before the ice sheet melts – which is the relevant question for the future – remains a mystery.

Matthew Huber, a professor of earth and atmospheric sciences at Purdue, said roughly a 40 percent decrease in carbon dioxide occurred prior to and during the rapid formation of a mile-thick ice sheet over the Antarctic approximately 34 million years ago.

A paper detailing the results was published Thursday (Dec. 1) in the journal Science.

“The evidence falls in line with what we would expect if carbon dioxide is the main dial that governs global climate; if we crank it up or down there are dramatic changes,” Huber said. “We went from a warm world without ice to a cooler world with an ice sheet overnight, in geologic terms, because of fluctuations in carbon dioxide levels.”

For 100 million years prior to the cooling, which occurred at the end of the Eocene epoch, Earth was warm and wet. Mammals and even reptiles and amphibians inhabited the North and South poles, which then had subtropical climates. Then, over a span of about 100,000 years, temperatures fell dramatically, many species of animals became extinct, ice covered Antarctica and sea levels fell as the Oligocene epoch began.

Mark Pagani, the Yale geochemist who led the study, said polar ice sheets and sea ice exert a strong control on modern climate, influencing the global circulation of warm and cold air masses, precipitation patterns and wind strengths, and regulating global and regional temperature variability.

“The onset of Antarctic ice is the mother of all climate ‘tipping points,'” he said. “Recognizing the primary role carbon dioxide change played in altering global climate is a fundamentally important observation.”

There has been much scientific discussion about this sudden cooling, but until now there has not been much evidence and solid data to tell what happened, Huber said.

The team found the tipping point in atmospheric carbon dioxide levels for cooling that initiates ice sheet formation is about 600 parts per million. Prior to the levels dropping this low, it was too warm for the ice sheet to form. At the Earth’s current level of around 390 parts per million, the environment is such that an ice sheet remains, but carbon dioxide levels and temperatures are increasing. The world will likely reach levels between 550 and 1,000 parts per million by 2100. Melting an ice sheet is a different process than its initiation, and it is not known what level would cause the ice sheet to melt away completely, Huber said.

“The system is not linear and there may be a different threshold for melting the ice sheet, but if we continue on our current path of warming we will eventually reach that tipping point,” he said. “Of course after we cross that threshold it will still take many thousands of years to melt an ice sheet.”

What drove the rise and fall in carbon dioxide levels during the Eocene and Oligocene is not known.

The team studied geochemical remnants of ancient algae from seabed cores collected by drilling in deep-ocean sediments and crusts as part of the National Science Foundation’s Integrated Ocean Drilling program. The biochemical molecules present in algae vary depending on the temperature, nutrients and amount of dissolved carbon dioxide present in the ocean water. These molecules are well preserved even after many millions of years and can be used to reconstruct the key environmental variables at the time, including carbon dioxide levels in the atmosphere, Pagani said.

Samples from two sites in the tropical Atlantic Ocean were the main focus of this study because this area was stable at that point in Earth’s history and had little upwelling, which brings carbon dioxide from the ocean floor to the surface and could skew measurements of atmospheric carbon dioxide, Huber said.

In re-evaluating previous estimates of atmospheric carbon dioxide levels using deep-sea core samples, the team found that continuous data from a stable area of the ocean is necessary for accurate results. Data generated from a mix of sites throughout the world’s oceans caused inaccuracies due to variations in the nutrients present in different locations. This explained conflicting results from earlier papers based on the deep-sea samples that suggested carbon dioxide increased during the formation of the ice sheet, he said.

Constraints on temperature and nutrient concentrations were achieved through modeling of past circulation, temperature and nutrient distributions performed by Huber and Willem Sijp at the University of New South Wales in Australia. The collaboration built on Huber’s previous work using the National Center for Atmospheric Research Community Climate System Model 3, one of the same models used to predict future climates, and used the UVic Earth System Climate Model developed at the University of Victoria, British Columbia.

“The models got it just about right and provided results that matched the information obtained from the core samples,” he said. “This was an important validation of the models. If they are able to produce results that match the past, then we can have more confidence in their ability to predict future scenarios.”

In addition to Huber, Pagani and Sijp, paper co-authors include Zhonghui Liu of the University of Hong Kong, Steven Bohaty of the University of Southampton in England, Jorijntje Henderiks of Uppsala University in Sweden, Srinath Krishnan of Yale, and Robert DeConto of the University of Massachusetts-Amherst.

The National Science Foundation, Natural Environment Research Council, Royal Swedish Academy and Yale Department of Geology funded this work.

In 2004 the team used evidence from deep-sea core samples to challenge the longstanding theory that the ice sheet developed because of a shift from warm to cool ocean currents millions of years ago. The team found that a cold current, not the warm one that had been theorized, was flowing past the Antarctic coast for millions of years before the ice sheet developed.

Huber next plans to investigate the impact of an ice sheet on climate.

“It seems that the polar ice sheet shaped our modern climate, but we don’t have much hard data on the specifics of how,” he said. “It is important to know by how much it cools the planet and how much warmer the planet would get without an ice sheet.”

###

Writer: Elizabeth K. Gardner, 765-494-2081, ekgardner@purdue.edu

Sources: Matthew Huber, 765-494-9531, huberm@purdue.edu

Mark Pagani, 203-432-6275, mark.pagani@yale.edu

Related website:

Matthew Huber Climate Dynamics Prediction Laboratory: http://web.ics.purdue.edu/~huberm/Matthew_Hubers_Climate_Dynamics_Prediction_Laboratory/CDPL.html

Related news releases:

Antarctic iced over when greenhouse gases – not ocean currents – shifted, study suggests: http://www.purdue.edu/uns/html4ever/2004/041227.Huber.Antarctica.html

Prehistoric global cooling caused by CO2, research finds: http://www.purdue.edu/uns/x/2009a/090226HuberPete.html

Abstract on the research in this release is available at: http://www.purdue.edu/newsroom/research/2011/111201HuberGlaciation.html

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FrankSW

For a mother of all tipping points it’s certainly got a long fuse, not quite as dramaitc as “ice free by 2020” is it
eventually reach that tipping point,” he said. “Of course after we cross that threshold it will still take many thousands of years to melt an ice sheet.”

Ceri Phipps

There is a major problem with this study, it assumes that CO2 is the cause and not the effect even though there is no empirical data to support such a claim. The only data showing good correlation between CO2 and temperature comes from Antarctic ice cores and shows that CO2 lags temperature.

Cart before the horse, anyone? It is becoming boring.

John Marshall

A report based on some rubbish model.
As far as we know the atmospheric CO2 levels have varied over large values for billions of years. We do not know the exact levels 100 years ago let alone thousands/millions of years ago. Claims that recent levels have been 280ppmv can be shown to be wrong by looking at the measured levels in the 1800’s in Europe which go up to 490ppmv near Gore’s tipping point. And it was colder then.
Fossil evidence shows that corals, molluscs etc all thrived with high atmospheric CO2 levels. And not a drop of acid sea water in sight!!!!

ian middleton

Sorry guys I have to do this. I have just read this report and my BS filter just went into overdrive. Words and phrases such as “appears”, “mystery”, “tipping point”, “likely”, ” is not known”, ” modelling”, and the mother of them all ” but we don’t have much hard data”. Jeez. I’m done, have a great day .

Gunter S.

Even if the correlation does exist, correlation does not explain cause.
Take the financial markets as an example. People trade within their own mindset, for their own motivations, according to their thruth about the markets, …
Within those trades you can find correlations for sure which are higher than can be explained with the random theory, but this doesn’t mean that those correlating measures are the driving force behind the market moves.
And yes, even the moon seems to give a higher correlation to the financial markets, but would it be rational to mark the moon as a ‘direct’ driving force?

FergalR

. . . continuous data from a stable area of the ocean is necessary for accurate results . . . Constraints on temperature and nutrient concentrations were achieved through modeling of past circulation . . .
“The models got it just about right and provided results that matched the information obtained from the core samples,”

Redundant tautology is redundant.

burnside

It’s fascinating that the mechanism producing the sudden drop in atmospheric CO2 is said to be unknown. I personally suspect it was a significant drop in global temperatures and that, mirabile dictu, we have researchers unwilling to consider they’ve got cause and effect wrong way ’round.

Lloyd

correlation or causation? Can they really see the date so specifically in this proxy to know?

Ian W

Question 1 – what is the main source of CO2 in the atmosphere it produces ~ 96%?
That’s right nature, plants and animals.
Question 2. What happens to that natural source of CO2 when it is buried under a ‘mile high ice sheet’?
That’s right it plants and animals die and stop producing CO2 and what CO2 is produced is ‘buried under a mile high ice sheet’.
So one would expect a drop in CO2 – claiming that it is the cause displays confirmation bias not logic.

Edmond Walsh

“Mammals and even reptiles and amphibians inhabited the North and South poles, which then had subtropical climates.”
Is that correct? Doesn’t the North Pole have a long night when the sun is barely seen. Was the earth’s axial tilt different then?

Jeff Wiita

What drove the rise and fall in carbon dioxide levels during the Eocene and Oligocene is not known.
I think we need to know the answer to this question before we establish policy that may have a detrimental effect on the human race. Besides that I do not think we will be here in 100,000 years to worry about something that may actually be good to the ecosystem.

Bill Illis

They tried a new technique for estimating CO2.
At 5 of the 7 drill core sites, the CO2 numbers came in near previous estimates of 1,500 to 3,000 ppm with no discernable drop at the Antarctic glaciation time period until millions of years later.
2 of the 7 sites, however, showed a reduction around the right timeline from 1,000 to 600 ppm. So just using the two contradictory sites, they make a conclusion. Interesting.

H.R.

Huber next plans to investigate the impact of an ice sheet on climate.
“It seems that the polar ice sheet shaped our modern climate, but we don’t have much hard data on the specifics of how,” he said. “It is important to know by how much it cools the planet and how much warmer the planet would get without an ice sheet.”

And here I thought the change in climate created/melted ice sheets. The Arctic alarmists say the Arctic will be ice free due to climate change. Will somebody make up their mind?

Surprise! Surprise! I thought that it was reasonably accepted that 65 million years ago CO2 in the atmosphere was about 3000 ppm. Antarctica was a warm wet greenhouse. Despite this CO2 the earth cooled for 20million years when South America had drifted far enough from Antarctica to open Drakes Passage and allow the circumpolar current to freeze the Antarctic and change earth climate to a succession of Ice Ages. In the Vostok cores the CO2 changes lag 6-800 years behind the temperature changes -one of the many reasons to query their role in greenhouse effect. Is all this known only to geologists? There is no “Gulf Stream” equivalent in the southern oceans. Mystified, Geoff Broadbent

Leon Brozyna

Let’s look at just one little quote from Matthew Huber:

“We went from a warm world without ice to a cooler world with an ice sheet overnight, in geologic terms, because of fluctuations in carbon dioxide levels.”

What is it with this intense fixation on carbon dioxide being such a powerful climate driver? What if it’s not in the driver’s seat but just a passenger? What if it were the oceans that cooled, which cooled the atmosphere while at the same time becoming a huge sink for atmospheric carbon dioxide? Seen in this light, perhaps one day a climate scientist might just say something like this:

We went from a warm world without ice to a cooler world with an ice sheet overnight, in geologic terms, resulting in massive fluctuations in carbon dioxide levels.

Of course, if you drop carbon dioxide as a major climate driver, you’re left with a messy situation … what’s changing the climate with the resultant changes in carbon dioxide levels?
And one day, the scientists will find that the answer to the climate question is: “All of the above.”

Carl Chapman

“40 percent decrease in carbon dioxide occurred prior to and during the rapid formation of a mile-thick ice sheet over the Antarctic”
As the oceans cooled, they aborbed more CO2, and the atmospheric CO2 decreased. This is just a rehash of Al Gore’s graph showing CO2 and temperatures go up and down together. Scientists checked and found that the warming occurred 800 years before the CO2 went up.

Sounds to me like they use the same methods as young-earth creationists. They start with many assumptions from authority, limit their data to the two sites they like, and then run models, known to not work, to prove their assumptions are correct, and then assert that the results validate the model.
Okay, perhaps it is a bit more involved than that. I hope it is. But there are many unsupported assertions in the write-up, and perhaps the assertions are supportable, but they all sound like they are based on assumptions about how the world was so long ago. I suspect the confidence in each of the assumptions and findings is rather low, yielding very low overall confidence that CO2 played a significant role in the ice sheet formation. The old hypothesis had to do mostly with the location of the land masses. That hypothesis seems reasonable still. This is a water world. It is reasonable to suppose land masses affect the water circulation. It is not obvious that CO2, as such a small trace gas in the low-heat value atmosphere is actually ever significant. I also note that most geoscientists discount global warming alarmism entirely.
Overall, the conclusions are based on a lot of extraordinary claims, and the rule is, extraordinary claims require extraordinary evidences.

Latitude

A drop in carbon dioxide appears to be the driving force that led to the Antarctic ice sheet’s formation
roughly a 40 percent decrease in carbon dioxide occurred prior to and during the rapid formation of a mile-thick ice sheet over the Antarctic approximately 34 million years ago.
What drove the rise and fall in carbon dioxide levels during the Eocene and Oligocene is not known.
================================================
A drop in temperature caused it…..the drop in temps caused CO2 levels to drop….ice doesn’t form until after that
Of course weathermen wouldn’t know…….grasses evolved and drove CO2 levels down to where they are limiting today…and have remained limiting ever since

bertief

So, am I to take it that all the previous research to the effect that changes in CO2 levels have always lagged changes in global climate by almost 1000 years are all wrong?
This is, therefore, a seminal paper.

Jay Davis

Sounds like an argument for increasing CO2, not decreasing it. Better warm than cold.

This is supposed to be funny, right?

Espen

“Tipping” takes many thousand years? Even if they were right about the role of CO2 here, that doesn’t sound scary. We’d have time to adapt to the much nicer and warmer climate, then.

jim hogg

I see possible correlation, but certainly not proof of causation or anything remotely close, and, most obviously, well timed speculation possibly intended to induce fear driven political agreement . . . . . When they’ve produced evidence that the rise and decline of ice follows the rise and decline of CO2 and nothing else throughout most of Earth’s history then we’ll have evidence that might be worth looking at, though even then both the ice and CO2 levels may be the product of some other as yet unknown changing factor . . .. . . All of which is surely very obvious, even to climate scientists . . .

tty

Now it only remans to explain why the Oligocene Ice Age 1 (Oi-1) in Antarctica mostly melted in he Late Oligocene with no noticeable increase in the CO2 level. The definitive freeze-up only happened about 14 million years ago, when the CO2 level was much the same as now.

Steve from Rockwood

These “climate knobs” are out of control.

MAK

I was in impression that Antarctic plate reached south pole around 30 million years ago and THAT was the reason of rapid formation of ice sheets.

jeanparisot

Bill, What’s new about that technique, seems to be the norm in climate studies.

Blade

‘Extra, extra, read all about it. Climatologists dismiss plate tectonics and continental drift.’ Alfred Wegener please call your office.

“The evidence falls in line with what we would expect if carbon dioxide is the main dial that governs global climate; if we crank it up or down there are dramatic changes,” Huber said. “We went from a warm world without ice to a cooler world with an ice sheet overnight, in geologic terms, because of fluctuations in carbon dioxide levels.””

This statement falls in line with what we would expect if carbon dioxide is the main obsession of your meaningless life. This is classic jumping the shark. The only explanation for this insanity is that they were in a rush to get this out before AGW Climatology completely collapses and found sympathetic pal review. The alternative explanation is that Science was completely destroyed by the AGW cult and is beyond repair.

“For 100 million years prior to the cooling, which occurred at the end of the Eocene epoch, Earth was warm and wet. Mammals and even reptiles and amphibians inhabited the North and South poles, which then had subtropical climates. Then, over a span of about 100,000 years, temperatures fell dramatically, many species of animals became extinct, ice covered Antarctica and sea levels fell as the Oligocene epoch began.”

All of the tectonic animations I have seen show Antarctica almost completely outside of the Antarctic circle at 175 MYA (and obviously teeming with life), at which point it begins a 100 million year trek heading straight to the South Pole, and at 70 MYA it appears to be centered there. Needless to say, it is at this geographic point where it receives a scheduled 6-months of dark and below freezing temperatures. This is a fact.
This geographic shift is the momentous change that occurred, not CO2. This is what allowed 2 mile thick ice to accumulate, solid frozen land within a polar circle with its endless night. All of the life that flourished prior to this event and had the plants at the bottom of their food chain collapse, likewise died. Saying that: “Mammals and even reptiles and amphibians inhabited the North and South poles” is exceedingly ridiculous (perhaps cold blooded reptiles hibernated in the ice for six moths?). Oh yeah, and then their was that other little event at 65 MYA. This one was also kind of important. The event that most likely wiped out all the dinosaurs and many other species, not to mention crushing the food chain itself.

“The team found the tipping point in atmospheric carbon dioxide levels for cooling that initiates ice sheet formation is about 600 parts per million. Prior to the levels dropping this low, it was too warm for the ice sheet to form. At the Earth’s current level of around 390 parts per million, the environment is such that an ice sheet remains, but carbon dioxide levels and temperatures are increasing. The world will likely reach levels between 550 and 1,000 parts per million by 2100. Melting an ice sheet is a different process than its initiation, and it is not known what level would cause the ice sheet to melt away completely, Huber said.”

550 and 1,000 ppm by 2100. Is that with or without error bars? LOL!
A crackpot paper that takes a dump on the big three in Earth Science advancements in recent years: (1) Continental Drift from plate tectonics, (2) Orbital Parameters (Milanković, etc), and the (3) K–T boundary Chicxulub Impact. Way to go! Now who are the flat-Earthers again? Who are the Science deniers again? ROTFLMAO!

FergalR

“Bill Illis says:
December 2, 2011 at 4:15 am
. . . So just using the two contradictory sites, they make a conclusion.
Interesting.”
——————————-
But Bill, the model told them that those 2 sites had low ocean circulation in the distant past, which proves that any idiosyncratic changes there must be real, which in turn validates the model. Which is good news apparently.
The paper was peer-reviewed by a trio of lobotomised chimps. Understand now?

son of mulder

Was the formation of the Antarctic ice sheet a good thing or a bad thing?

Vince Causey

Correlation, correlation, correlation.
Look you guys who wrote this paper, just because CO2 decreased at the approximate time of cooling, it doesn’t mean that it was the CO2 fall that caused the cooling. Any event that caused cooling would result in a fall in CO2 as more is retained in the oceans. This is probably what happened.
One cause of rapid cooling could be attributed to cosmic ray increases. It is believed by proponents of this theory, that as the solar system journeys around the galaxy, it passes through areas associated with high rates of star deaths and violent cosmic ray bursts.
Another reason that makes the CO2 explanation dubious, is the levels involved. CO2 levels are supposed to have fallen from about 1000ppm to 600ppm. But most of the radiative forcing of CO2 is done in the first 100ppm. Going from 1000ppm to 600ppm would not likely have a significant effect on temps.
All this research shows is that during the period of rapid cooling 37mya, CO2 levels dropped to 600ppm. But as the effect of cooling would be to absorb more CO2 in the oceans anyway, there is no way that you can conclude that it is the CO2 that caused the cooling rather than the other way round.
It is clearly a fallacy to try and the claim they are making. If they can show CO2 leading temps however, they may have a case. But so far, all the evidence we have from ice core data is the other way round. Why should it be any different during that episode/

Bill Illis

For a little perspective, here is a chart of the last 45 million years of temperatures versus all CO2 estimates at 3.0C per doubling (not including these new estimates – I think if I put ALL of them in, rather than just cherrypicking 2 of 7 sites, it would look very much the same).
Antarctic glaciation timeline, 33.5 million years ago.
http://img199.imageshack.us/img199/4927/tempco245mlefttoright.png
Some other details regarding the timeline.
http://img844.imageshack.us/img844/6939/tempgeog45mlr.png

Steve Keohane

Apparently the little blip down to the right of 100mya froze Antarctica=crap. At c. 375mya to c. 340mya, CO2 changed -95∆%, to even lower CO2 levels, but Antarctica didn’t freeze then. They obviously have the cause wrong.
http://i46.tinypic.com/2582sg6.jpg

Bertram Felden says:
December 2, 2011 at 4:57 am
———————————————-
The CO2 lag is evident in highly resolved measurements in the last 800,000 years of ice cores. While I’d like to see the paper in question, I would be surprised if the authors are able to show a contradictory CO2 lead in 34-million-year-old deep-sea sediments far removed from the ice sheets.

This is the first time I have ever come across a single-word oxymoron: “Science”.

Rob Wilson

“For 100 million years prior to the cooling, which occurred at the end of the Eocene epoch, Earth was warm and wet. Mammals and even reptiles and amphibians inhabited the North and South poles, which then had subtropical climates”
Can anyone tell me how amphibians inhabited the North pole in the Eocene epoch? As far as I am aware, much like now, there was no land there, and presumably no sea ice if the climate was “subtropical”.

Hu McCulloch

Temperature and CO2 are correlated, but it’s hard to disentangle which causes which — a classic econometric system of equations with endogenous variables problem.
But for what it’s worth, it might be worth trying to get CO2 up to 400-500 ppm, without going much above 600, in order to ward off the next Ice Age, without melting the big ice sheets. I say “try”, because it’s likely that a) we will soon start to run out of easily accessible fossil fuels, and b) the biosphere may start to gobble up whatever we can put out.

jaypan

So it needs a lack of CO2 to form ice at the south pole … surprising

Barry R

This is the sort of thing that I’m pretty sure is giving the AGW crowd a bad name among scientists outside their little world. The events that lead to Antarctica become the ice continent seem fairly clear. (1) As of 65 million year ago, Antarctica was still connected to Australia and South America and there was a gap between North and South America. Ocean circulation was pushed to the poles. Result: warmer ocean. (at times very warm, and yes for a few hundred thousand years at the start of the Eocene subtropical animals did reach nearly to the arctic circle) (2) When first Australia and then South America broke away from Antarctica that allowed the ocean circulation to be around Antarctica, isolating it from the tropics and allowing it to get colder and colder. Much of Antarctica without the ice is high mountains anyway, and susceptible to glaciation. (3) The process of glaciation was prolonged, with western Antarctica, which is actually a separate rather large island without the ice cover, experiencing temporary reduced ice or ice-free conditions up to 20-25 million years after the glaciation started.
The picture I piece together for the AGW crowd is that a couple of young politically oriented scientists painted an apocalyptic scenario for global warming. The political powers that be asked the senior scientists in the field if they could prove the scenario. Understanding the complexities of the science, they said no, not for a good twenty to thirty years at least. However a bunch of second-rate younger types rushed in where wiser people knew enough not to tread. The second-raters got money. They got political power. Scientists who know they’re full of cr@p on one piece or another of the AGW picture will say so privately, but mostly hold their tongues in public because they don’t want the cr@pstorm the likes of Romm will unleash on them if they go public, and they don’t want the likes of Jones/Mann trying to get them fired.
The Jones/Mann crowd are stepping on a lot of toes though, rewriting history (no Medieval Warming Period), rewriting Paleontology (a carbon dioxide-based explanation for Antarctic glaciers) and ‘reinventing’ statistics in ways that leave people with real expertise in statistics biting their tongues.
None of this is to say that there isn’t or won’t be man-caused global warming. Even a broken clock is right a couple of times a day. Certainly we should be monitoring, getting good quality statistics and measurements and trying to understand how climate actually works. Unfortunately, trying to stuff everything into the current AGW framework is wasting a lot of research money that should be going to understanding the fundamentals.

1DandyTroll

So, essentially, it is rather lucky we live in an carbon dioxide rich time so as we not go extinct. And by 2100 we may see a normalization of the poles back to their warmer climate.
That’s good to know.

Owen

WOW, just WOW. If I turned in a thesis paper that included throwing out 5 of 7 samples because they disagreed with the foregone conclusion, I would be looking for another degree program after being dismissed for academic dishonesty. When will people learn that negative results are still good results! Not every hypothesis is correct no matter how beloved.
Doesn’t the ocean absorb more CO2 as temps decline? (I seem to remember something about that in beer going flat faster when warm due to decreased carrying capacity – boil the beer and there are no bubbles at all). So if ocean temperature declines the ocean takes in more CO2 from the atmosphere, as temperatures increase they out gas CO2 to the atmosphere. It kind of makes sense that the two would track with the phase on the CO2 time-series lagging by some (not necessarily linear) amount. This study appears to be measuring two effects of a common unknown/unmeasured cause and attempting to lay one as the cause of the other. My professor belabored this point on causation in Physics 201 back in the 1980’s, though some of my classmates still asserted false causation in a few labs reports. The prof had a good time publicly ridiculing them in class. Maybe that is what these climate scientists needed when they were undergrads!

beng

*****
“The system is not linear and there may be a different threshold for melting the ice sheet, but if we continue on our current path of warming we will eventually reach that tipping point,” he said. “Of course after we cross that threshold it will still take many thousands of years to melt an ice sheet.”
*****
Well at least that statement is true.
Funny thing, tho, carbon fuels, if not outdated in a thousand yrs, will mostly be used up by then. CO2 will be declining. So what’s the “worry”, other than, by their own Pretzel Logic, the globe would then begin to slide into a new glaciation?

Owen

Ok, there are bubbles while the beer is boiling – but who would boil a beer anyway? Of course the CO2 content would be miniscule however.
Wouldn’t want to be too imprecise. This is beer we’re talking about after all! Nothing at all like some pseudoscience that threatens to destroy the economies of the west.

Gee, another long-winded tome about nothing. Astounding how much thought goes into sidestepping the need for data and causation, to produce an uncertainty-saturated speculation. It just doesn’t make any sense. Time to go back to (cold) Kurdish Iraq.

What drove the rise and fall in carbon dioxide levels during the Eocene and Oligocene is not known.
Say What?
http://web.me.com/uriarte/Earths_Climate/4._Tertiary_Era.html
One of the most significant characteristics of this downwards cooling trend is the evolution of the temperature of deep ocean waters, which dropped from around 12º C 50 million years ago to just 6º C at the end of the Eocene, 35 million years ago. Today, deep ocean waters have a temperature of just over 2º C.
Now, where did the co2 go again? – Oh, that’s right: you don’t know, do you?
From source above:
Another, more complex, signal, namely the sudden drop in the lysocline (the depth in the ocean below which the rate of dissolution of calcite increases dramatically), also indicates an abrupt variation in the carbon cycle 34 million years ago, a variation linked to the accumulation of ice on the continents.
Drop in lysocline – you say?
http://en.wikipedia.org/wiki/Lysocline
Oh, so that means the oceans acidified? – Well, I wouldn’t have expected that, now, would I?
And then again:
http://en.wikipedia.org/wiki/Oligocene#Oceans
The opening of the Drake Passage enabled the formation of the Antarctic Circumpolar Current (ACC), which would have kept cold, Antarctic waters circulating about the continent and strengthened the formation of Antarctic Bottom Water (ABW).[9][8]
Isotopic evidence suggests that during the early Oligocene, the main source of deep water was the North Pacific and the Southern Ocean. As the Greenland-Iceland-Faroe (GIR) sill deepened, connecting the Norwegian-Greenland sea with the Atlantic Ocean, North Atlantic Deep Water began to come into play as well.
I think I know where the carbon went, now:
Specifically, it is the deep waters that are undersaturated with calcium carbonate primarily because its solubility increases strongly with increasing pressure and salinity and decreasing temperature.
And as we know from the propaganda and the nice formula on Wiki:
CaCO3(s) + H2O + CO2 → Ca2+(aq) + 2HCO3-(aq)
Is also dependant on co2, which increases with the fall in the bottom water temperature.
http://askville.amazon.com/temperature-water-hold-carbon-dioxide/AnswerViewer.do?requestId=1674443
So, the carbon went into the oceans as they cooled. Primarily because the equatorial throughflows were narrowing or closing during this period. Driving warm surface waters into polar regions, where they release heat and moisture to the polar atmosphere.
Now you don’t create a miles thick ice sheet with cold alone. Actually, that is impossible: what you need is plenty of precipitation, which would move heat out of the oceans into the atmosphere and out into space, while depositing tons and tons of albedo increasing ice in the process. The transfer of warm tropical surface waters into polar regions accomplishes (over time) this task. The Ferrel cell will have a field day converting this energy into labour, depositing the resulting presipitation in the mountains, in the form of ice slowly creeping into the lowlands as temperatures drop..
Which is why we are currently in an ice age, and have very low co2 levels. 🙂
Per

P Wilson

the consensus says – well, infers, that co2 is the source of radiation thus, since they argue that it causes the temperature to change. (evidence: Ice sheet formation caused by c02 decreasing)
That means that co2 has greater thermal properties than electrically powered radiators, that will heat homes, will melt ice, will theoretically run cars, will effectively run all industry with energy – since even other forces don’t have the energy required to cause ice ages and cause warm periods, according to this *opinion*.
One can therefore summarize that we don’t use c02 for the above mentioned activities because there just isn’t enough of it, if, indeed decreases in c02 is of such great magnitude that it *causes* ice sheets to form.

Pamela Gray

The paper, once again, has been mortally wounded by 2 epic failures: First they fail to discuss real data on current oceanic oscillation patterns and these affects on algae growth; all of which is well known and fairly well understood. This isn’t like studying extinct dinos. We can study live algae now. Second, the jump to CO2 as the cause was done completely without plausible mechanism. How, pray tell, does CO2 and the miniscule amount of energy it adds, overcome the far stronger natural drivers of weather and oceanic pattern variations and oscillations?????

Gail Combs

A bit of background for the dummies like me who forgot most of our geology: (Courses taken at Purdue, my old Prof would be ashamed of this guy.)
The key point that is missing from this is continental drift. A picture of the world 65,000,000 years (link below) ago shows South America, Antarctica and another large land mass all connected. North America is connected to Europe and is NOT connected to South America.
This means the whole ocean circulation would be completely different that it is today.
I vaguely remember that the change in continent configuration and the resulting change in ocean currents is what was supposed to cause the beginning of the Ice Ages.
http://anthro.palomar.edu/earlyprimates/early_2.htm
Interesting facts about increasing oxygen in the atmosphere and the Eocene.

….the Eocene Epoch (55.8-33.9 million years ago) coincides with the emergence of early forms of most of the placental mammal orders that are present today. In addition, placental mammals with larger bodies and bigger brains began to appear in the fossil record at this time. Paul Falkowski has suggested that this is due to the fact that the amount of oxygen in the earth’s atmosphere more or less doubled around 50 million years ago. Larger mammals have relatively fewer capillaries for the distribution of oxygen to the cells of their bodies. Subsequently, they must breathe air that is more oxygenated. Brains have especially high oxygen requirements. In addition, pregnant placental mammals must transmit a substantial portion of the oxygen in their blood to their fetuses. Coinciding with the increase in atmospheric oxygen at the beginning of the Eocene Epoch was a relatively abrupt global warming of 9-16° F. (5-9° C.) lasting at least 200,000 years. This also would have been a major factor in the rapid evolution of animals and plants at the time…. http://anthro.palomar.edu/earlyprimates/early_2.htm

Grasses are C4 and are a response to a much lower atmospheric CO2 level BTW so the lowering of CO2 happened before the Ice Ages.

Eocene epoch
Eocene – The first grasses appeared in the Eocene Epoch (from about 54 to 37 million years ago) with growth near the root as opposed to the tip, providing a vastly expanded and renewable food resource for the herbovores; this allowed adaptation to life on the savanna and prairie and the evolution of running animals …. The grazing mammals evolved the teeth enabling a diet of harsh grass. The Eocene Epoch was a period when flowering plants continued a massive radiation that began in the Paleocene Epoch…. Many new species of shrubs, trees and small plants appeared. A variety of trees thrived in a warm Eocene climate, including beech, elm, chestnut, magnolia, redwood, birch, and cedar, and more. The evolution of plants was providing a powerful selective pressure across the entire animal Kingdom, and many new symbiotic systems appeared.
http://www.fossilmuseum.net/Paleobiology/Cenozoic_Paleobiology.htm

These guys are really getting pathetic in their attempts to link everything to CO2.

G. Karst

If lack of CO2 caused the ice ages, would someone explain why we are doing, our best, to lower it’s atmospheric concentration. Does anyone really believe that increased glaciation is good? Besides how can we have increasing CO2 concentrations while temperatures have been flat for half a climatic period? Is logic dead? GK