New research in Antarctica shows CO2 follows temperature "by a few hundred years at most"

The question of “which comes first, the temperature or the CO2 rise?” has been much like the proverbial “which came first, the chicken or the egg?” question. This seems to settle it – temperature came first, followed by an increase in CO2 outgassing from the ocean surrounding Antarctica.

“Our analyses of ice cores from the ice sheet in Antarctica shows that the concentration of CO2 in the atmosphere follows the rise in Antarctic temperatures very closely and is staggered by a few hundred years at most,” – Sune Olander Rasmussen

Fig. 2. Lag histograms for the two methods of determining the lag of atmospheric CO2 after regional Antarctic temperature changes (direct correlation and correlation of derivatives), using each of the two CO2 data sets (Byrd and Siple Dome). The gray background histograms are based on the complete Tproxy composite, the same as in Fig. 1b. The superimposed curves show the corresponding lag histograms when excluding in turn each of the 5 records from the Tproxy composite (jack-knifing): excluding Siple (red), excluding Law Dome (green), excluding Byrd (blue), excluding EDML (cyan), and excluding Talos Dome (magenta).

From the University of Copenhagen – Rise in temperatures and CO2 follow each other closely in climate change

The greatest climate change the world has seen in the last 100,000 years was the transition from the ice age to the warm interglacial period. New research from the Niels Bohr Institute at the University of Copenhagen indicates that, contrary to previous opinion, the rise in temperature and the rise in the atmospheric CO2 follow each other closely in terms of time. The results have been published in the scientific journal, Climate of the Past. 

The Australian ice core drilling camp at Law Dome in Antarctica.

In the warmer climate the atmospheric content of CO2 is naturally higher. The gas CO2 (carbon dioxide) is a green-house gas that absorbs heat radiation from the Earth and thus keeps the Earth warm. In the shift between ice ages and interglacial periods the atmospheric content of CO2 helps to intensify the natural climate variations.

It had previously been thought that as the temperature began to rise at the end of the ice age approximately 19,000 years ago, an increase in the amount of CO2 in the atmosphere followed with a delay of up to 1,000 years.

“Our analyses of ice cores from the ice sheet in Antarctica shows that the concentration of CO2 in the atmosphere follows the rise in Antarctic temperatures very closely and is staggered by a few hundred years at most,” explains Sune Olander Rasmussen, Associate Professor and centre coordinator at the Centre for Ice and Climate at the Niels Bohr Institute at the University of Copenhagen.

An ice core from the deep drilling through the ice sheet at

Law Dome in Antarctica.

Deep-sea’s important role

The research, which was carried out in collaboration with researchers from the University of Tasmania in Australia, is based on measurements of ice cores from five boreholes through the ice sheet in Antarctica. The ice sheet is formed by snow that doesn’t melt, but remains year after year and is gradually compressed into kilometers thick ice. During the compression, air is trapped between the snowflakes and as a result the ice contains tiny samples of ancient atmospheres. The composition of the ice also shows what the temperature was when the snow fell, so the ice is an archive of past climate and atmospheric composition.

“The ice cores show a nearly synchronous relationship between the temperature in Antarctica and the atmospheric content of CO2, and this suggests that it is the processes in the deep-sea around Antarctica that play an important role in the CO2 increase,” explains Sune Olander Rasmussen.

Figure 1 – The research results show that the concentration of CO2 in the atmosphere followed the temperature in Antarctica closely throughout the shift from ice age to interglacial in the period 19-11,000 years before the present. The green curve shows the temperature from measurements from the 5 ice cores marked on the map. The red and blue curves show the atmospheric CO2 content in the air bubbles in the ice cores from the two bores at Siple Dome (red) and Byrd (blue). The analysis shows that the CO2 concentration follows the increase in temperature with a delay of no more than a few hundred years. That the CO2 concentration in the atmosphere follows the Antarctic temperature so closely suggests that processes in the ocean around Antarctica play an important role in the rise in CO2.

He explains that one of the theories is that when Antarctica warms up, there will be stronger winds over the Southern Ocean and the winds pump more water up from the deep bottom layers in the ocean where there is a high content of CO2 from all of the small organisms that die and fall down to the sea floor and rot. When strong winds blow over the Southern Ocean, the ocean circulation brings more of the CO2-rich bottom water up to the surface and a portion of this CO2 is released into the atmosphere. This process links temperature and CO2 together and the new results suggest that the linking is closer and happens faster than previously believed.

Climatic impact

The global temperature changed naturally because of the changing solar radiation caused by variations in the Earth’s orbit around the Sun, the Earth’s tilt and the orientation of the Earth’s axis. These are called the Milankowitch cycles and occur in periods of approximately 100,000, 42,000, and 22,000 years. These are the cycles that cause the Earth’s climate to shift between long ice ages of approximately 100,000 years and warm interglacial periods, typically 10,000 – 15,000 years. The natural warming of the climate was intensified by the increased amount of CO2 in the atmosphere.

“What we are observing in the present day is the mankind has caused the CO2 content in the atmosphere to rise as much in just 150 years as it rose over 8,000 years during the transition from the last ice age to the current interglacial period and that can bring the Earth’s climate out of balance,” explains Sune Olander Rasmussen adding “That is why it is even more important that we have a good grip on which processes caused the climate of the past to change, because the same processes may operate in addition to the anthropogenic changes we see today. In this way the climate of the past helps us to understand how the various parts of the climate systems interact and what we can expect in the future.”

Tightened constraints on the time-lag between Antarctic temperature and CO2 during the last deglaciation

J. B. Pedro1,2, S. O. Rasmussen3, and T. D. van Ommen2,4

1Antarctic Climate & Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, Tasmania, Australia

2Institute of Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia

3Centre for Ice and Climate, University of Copenhagen, Copenhagen, Denmark

4Australian Antarctic Division, Kingston, Tasmania, Australia

Abstract. Antarctic ice cores provide clear evidence of a close coupling between variations in Antarctic temperature and the atmospheric concentration of CO2 during the glacial/interglacial cycles of at least the past 800-thousand years. Precise information on the relative timing of the temperature and CO2 changes can assist in refining our understanding of the physical processes involved in this coupling. Here, we focus on the last deglaciation, 19 000 to 11 000 yr before present, during which CO2 concentrations increased by ~80 parts per million by volume and Antarctic temperature increased by ~10 °C. Utilising a recently developed proxy for regional Antarctic temperature, derived from five near-coastal ice cores and two ice core CO2 records with high dating precision, we show that the increase in CO2 likely lagged the increase in regional Antarctic temperature by less than 400 yr and that even a short lead of CO2 over temperature cannot be excluded. This result, consistent for both CO2 records, implies a faster coupling between temperature and CO2 than previous estimates, which had permitted up to millennial-scale lags.

Final Revised Paper (PDF, 463 KB)   Discussion Paper (CPD)

Citation: Pedro, J. B., Rasmussen, S. O., and van Ommen, T. D.: Tightened constraints on the time-lag between Antarctic temperature and CO2 during the last deglaciation, Clim. Past, 8, 1213-1221, doi:10.5194/cp-8-1213-2012, 2012.

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David Larsen

In other words, increased CO2 levels are a ‘lagging indicator’ and not a cause. There is no correlation with increased CO2 levels increasing any thermal levels on the earth’s surface. While the sun heats the earth, CO2 levels increase as a cause and effect relationship and that cause is the increased sun radiation and heating of the earth. NOT the other way around, PERIOD!

Given that only about 3.5 percent of annual atmospheric CO2 emissions are man-made (96.5 percent are from natural sources), I doubt it very much that “mankind has caused the CO2 content in the atmosphere to rise as much in just 150 years as it rose over 8,000 years during the transition from the last ice age to the current interglacial period and that can bring the Earth’s climate out of balance.
The tail does not wag the dog.

Robbie

Well it looks like everywhere you read in the scientific literature it is constantly the same story. CO2 causing warming and the climate to change. The amount of warming and what impact it will have is still a mystery, but a change will come.
Nice piece by the way.

Merovign

Pro hoc, ergo propter hoc…?

wikeroy

I thought this was shown by Petit et al…….

cui bono

I don’t quite see why getting more precision on the temperature -> CO2 timeframe casts more light on the debate of chicken and egg. That temperature rise precedes CO2 rise in Antartica is accepted. It was Shakun et al (2012) who came up with the most egregiously Heath Robinson (sorry, Rube Goldberg) ‘get out clause’ for this, which was well-covered here. Am I missing something?
http://wattsupwiththat.com/2012/04/06/a-reply-shakun-et-al-dr-munchausen-explains-science-by-proxy/
http://wattsupwiththat.com/2012/04/07/shakun-redux-master-tricksed-us-i-told-you-he-was-tricksy/
http://wattsupwiththat.com/2012/04/11/shakun-the-last-i-hope/

AleaJactaEst

“……..“What we are observing…..is the mankind has caused the CO2 content in the atmosphere to rise as much in just 150 years as it rose over 8,000 years …. and that can bring the Earth’s climate out of balance,…..” – the “we won’t get published unless we h/t to CAGW” moneyshot.
“……that can bring the Earths’ climate out of balance….” – what balance?, scientific credence please. Correlation is not causation. Basic, simples.

chris y

The graph leaves little room for the hypothetical positive feedback of additional temperature rise from increased CO2.

Don

Hmmm… interesting headline on that press release. Makes as much sense as, “Tractors and trailers follow each other closely on highways.”

From the beginning of the article: “This seems to settle it” Careful when you say that, is this settled science?

He explains that one of the theories is that when Antarctica warms up, there will be stronger winds over the Southern Ocean
I’d expect the opposite for 2 reasons.
The winds over Antarctica are katabatic. That is they are driven by the density of the air and colder is denser. These katabatic winds drive air circulations over the adjacent ocean and in particular the upwelling near the coast.
Secondly, it’s generally accepted that the temperature differential between the tropics and the poles influences the strength of the mid to high latitude circulation systems. A warmer Antarctica would reduce this temperature difference, reducing wind strength in the mid-latitude circulations.

R. Shearer

The accuracy of CO2 measurements in ice cores has never been established. In any case, cause preceeds effect not the other way round, Robbie.

RoyFOMR

@Robbie
‘CO2 causing warming and the climate to change’
You just scored an F on reading comprehension mate. Try again (Hint – get a responsible adult to help)
🙂

Entropic man

If I remember the sequence correctly, an interstadial starts as the alignment of the Milankovich cycles increases solar insolation in high Northern latitudes.
This increases the temperature in that region, triggering changes such as thawing of tundra and subsequent decay of previously frozen organic matter.
Decay releases CO2 and this amplifies the temperature change.
At the end of the interstadial slow cooling due to orbital realignment reduces temperatures and respiration, reducing CO2 and, once again accelerating the cooling trend.
CO2 is not the driver of the temperature changes , but an amplifier of the Milankovich changes in both directions.
You would expect the CO2 concentration to follow the temperature, which is what Rasmussen has found.

David G

When people I really like like Paul McCartney use the carbon devil to rustle up converts to save the Arctic, I get depressed. I was fantasizing about the arctic and antarctic when I was 5 or 6 in the late 50’s when he didn’t know what it was. But now that he’s spouting some absolute nonsense about saving the north pole.I find it just dead depressing.
I find it extremely depressing to see people I really like and admire so thoroughly brain-washed. I learned so much from him about music and other things, that it feels churlish to beef about his need to save people, After all didn’t that ex-wife with the stump cost him about $250M?:] I felt badly about that. After all, when I was 12 I tried to move heaven and earth to get to the airport to see the Beatles land their first visit to the US. Murray the K and Cousin Brucie were exhorting us all to go. Alas, I didn’t get there. So I guess Paul McCartney gets a pass because I just can’t make myself be angry at him, no matter what he says.
But I wish that skeptics had a cause so we could look cute and fuzzy, on google+ or Facebook or wherever instead of looking like the heartless bastards we are standing by and watching while the planet fries in its own grease!:]

2012-400=1612
Well, what do you know – 1612 is in the Little Ice age!
Thanks
JK

gator69

Yawn…. zzzzzzzzzzzzzzzzzz

Jimbo

“”What we are observing in the present day is the mankind has caused the CO2 content in the atmosphere to rise as much in just 150 years as it rose over 8,000 years during the transition from the last ice age to the current interglacial period and that can bring the Earth’s climate out of balance,” explains Sune Olander Rasmussen adding….””

That’s right folks, a greening biosphere is a bad thing. A very tiny rise in temperature coming out of the Little Ice Age has lead to more (less) famines. Prepare for calamity and Thermarmageddon.

Robbie says:
July 23, 2012 at 3:17 pm
Well it looks like everywhere you read in the scientific literature it is constantly the same story. CO2 causing warming and the climate to change. The amount of warming and what impact it will have is still a mystery, but a change will come…..

Yaaaawn! Can you let me know right now when the climate never changed???? This is your opportunity. Or do you mean the lack of warming caused by co2 over the past 15 years??? Take your pick but give me an answer. By the way far higher levels of co2 failed to stop ice ages. So much for runaway global warming and tipping points.

Gail Combs

David G says: @ July 23, 2012 at 4:18 pm
… But I wish that skeptics had a cause so we could look cute and fuzzy, on google+ or Facebook or wherever instead of looking like the heartless bastards we are standing by and watching while the planet fries in its own grease!
_____________________________________
But we do have a “Cause” that cause is trying to prevent little old ladies from freezing to death and babies from starving while the Banksters make money hand over fist and so does the Ag Cartel and the World Bank funds the theft of land from peasant farmers. All moves disguised as “helping fight CAGW”
Heck we are even fighting the Meglomaniacs trying to take over the world!
See all you have to do is frame your message correctly and WUWT are bloody HEROES!
(I wish I could add the /sarc tag but I can’t because the above and the links are the truth.)

If CO2 follows temperature and it certainly appears so and given that CO2 is a green house gas then it is also has a positive (undesirable) feedback effect. I do not see this issue mentioned in the literature. With both CO2 and water vapour being positive feedback, where is the negative feedback that leads to moderate short term stability?

joel

Imagine if we lived in a time of free scientific inquiry. This scientist would be saying that this data throws doubt on the central role of CO2 in raising temperature.
I have only previously seen scientific dissembling on a massive scale like this during the IQ and race debates of the 1960’s. After failing in their goal , the people who had confidently predicted the “gap” would be closed had the IQ tests banned. But, they never admitted they were wrong, and never apologized to the people they vilified for speaking the truth. And, no “respectable” social scientist ever spoke up to criticize this effort. Because, like global warming, if you criticized the effort you were expelled from respectable social science circles. The intolerance then was no different from the intolerance now. And, the outcome will be the same. Failure, and many, many lives blighted, all in the name of vanity.

Pamela Gray

I hear ya. Sean Connery, who is still hot, hot, hot, is a green watermelon. I cried for days. And I DO mean loud wailing and gnashing of teeth! I was even ready to cut my long red locks in mourning but was afraid my fellow Irish elves and leprechauns would have a fit.
Long live Charlton Heston. One of the few hollywood stars with cojones.

Mason P Wilson, Jr, Ph.D retired professor of Thermodynamics and a weatherman in service

A few years after the first core was analyzed and found CO2 preceding the temperature rise , a second core was analyzed showing that many times CO2 lagged the temperature. I don’t know why this second core never appears to be cited, even by the skeptics.

epolvi

Do we know how much the atmospheric pressure and consequently the partial pressure of CO2 has changed over that period of time?

Rob Dawg

Anthroprogenic CO2 today has caused global warming several hundred years in the past. Proven. This is sooooo cool. Cool? Sorry. Think of the lives we can save in 1816 by pumping out a few gigatons at the right moment sometime in the next few hundred years.

Pamela Gray

When it warms up and starts to rain on parched ground after a cold spell, everything blooms and everything has babies. I would totally expect resultant CO2 increase to be rapid.
That aside, this article seems to be saying that the error bars tell us there is no way we can say that CO2 was a driver of increased temperature in the past.

JA

”What we are observing in the present day is the mankind has caused the CO2 content in the atmosphere to rise as much in just 150 years as it rose over 8,000 years during the transition from the last ice age to the current interglacial period and that can bring the Earth’s climate out of balance,” explains Sune Olander Rasmussen adding…
What bullshit.
Was not the Medieval Warming Period as warm or warmer than present?? Did not the MEWP PRECEDE the Industrial Revolution??
If CO2 increase follows temperature well then, so much for the AGW (total BS) thesis.

Bill H

the conclusion is astounding..natural CO2 intensified warming.. and then she goes off the reservation where there is no evidence to support her hypothesis.. got to love the CWAG crowd.. take promising science and bind it with political crap.

TimTheToolMan

That result seems to fit perfectly with the notion that the poles feel the effects of any global warming more strongly than equatorial regions. It is the downward slide that AGW proponents need to adequately cover and IMO and they completely ignore it.
So “something” causes the earth to warm and the poles warm quickly. The rest of the earth is lagged behind and increasing ocean temperatures eventually alter their balance to have more CO2 in the atmosphere as well as increased life causing larger CO2 cycles.
And then on the downward slide that “something” reverses and now causes cooling which the poles feel first and there is a lag before the rest of the planet feels it and the oceans readjust their CO2 balance to be less in the atmosphere as well as decreased life causing smaller CO2 cycles.
By comparison AGW explanations of CO2 being the driver “after a point” are contrived and feel very wrong IMO.

Chuck Kraisinger

Rob Dawg says:
July 23, 2012 at 5:46 pm
Anthroprogenic CO2 today has caused global warming several hundred years in the past.
Tele-connections.

RockyRoad

But Al Gore is so backwards in his science he’ll still use this as evidence that CO2 drives temperature. I wonder–does Al drive his car backwards; does Al walk backwards?
Good questions all.

Steve O

Could alarmists say that a small increase in CO2, such as what mankind is capable of emitting, can drive a small temperature increase, which then results in a series of effects that dramatically increases CO2 content? If you believe in multiplicative forcings, it seems possible that it wouldn’t matter which came first, the warming or the CO2. Either one could lead to much more of both.
No, I’m not an alarmist. I just don’t want to use arguments that can be easily rebutted.

DocMartyn

The fairest way to see the lag of CO2 and temperature in the ice core is to use the Ar/N2 ratio as your, gaseous, temperature sensor.
There is only one good Ar record in the Antarctic, Caillon et al. (2003).
This gives 800 years, +/- 200 years.
http://icebubbles.ucsd.edu/Publications/CaillonTermIII.pdf
It is a real pity they didn’t look at Ar/N2 in the high resolution Law Dome core.

cms

I wish I knew how to cut and paste this graph from WoodsforTrees, but I can only post the link. It show that the variations in temperature preceed those of CO2 in the atmosphere since 1958. It is very dramatic and obvious.
http://www.woodfortrees.org/plot/esrl-co2/isolate:60/mean:12/scale:0.2/plot/hadcrut3vgl/isolate:60/mean:12/from:1958

Brian H

The AGW CO2-acceleration meme attempt to rationalize the cause → effect inconvenient sequencing has always been a desperate attempt to cover the hypothesis’ sucking chest wound. The article is a fine example.

George E. Smith;

“””””…..From the University of Copenhagen – Rise in temperatures and CO2 follow each other closely in climate change….. “””””
How in the hell can Temperature rise and CO2 rise “follow each other closely.” ? That’s got to be just about the stupidest thing I have ever read in what purports to be a “scientific study report.”
Make up your minds; which one is leading and which one is following ??

J.Hansford

Rasmussen said….”“What we are observing in the present day is the mankind has caused the CO2 content in the atmosphere to rise as much in just 150 years as it rose over 8,000 years…”
Yet despite that increase in CO2…. There is no solid observations that show that dramatic rise in CO2 causing any significant rise in global temperatures, either in itself or as feedback on watervapour…. Indeed the last 15 years have shown a pause in warming despite that much increased rise in CO2.
It would seem that when it comes to GHG’s and their effects on temperature…. Water vapour is the essential gas and it is entirely driven by the energy of the sun… not CO2’s small insignificant and trailing effect.

What a nice confirmation of Shakun, et al
Shakun et al. find that at the end of the last ice age temperature increased immediately in the Arctic but only slightly, probably as a result of increased radiation during the northern hemisphere summer. As a result a small portion of the Arctic ice melted. The melt water had a lower salt concentration and thus was less dense than the surface water and sank although mostly not to great depths. The result was that the AMOC and thus the associated redistribution of heat between the Arctic and the tropics was interrupted. This meant that the temperature in the high northern latitudes no longer rose, but may, in fact, have even decreased slightly. This is exactly what was found in the data. As a result, the temperature rose in the southern tropics and then the southern temperate latitudes and finally in Antarctica. Only then did the data show an increase in CO2. So somehow warming of the southern latitudes leads to increased emissions of CO2. Simultaneous determination of the isotopic ratio (for example, according to RF Anderson, S. Ali, LI Bradtmiller, SHH Nielsen, MQ Fleisher, BE Anderson, and LH Burckle, Wind-Driven Upwelling in the Southern Ocean and the Deglacial Rise in Atmospheric CO2, Science, 323 , 1443-1448 (2009).) suggests that the CO2 source is a consequence of biological fixation of carbon residues, for example in plankton deposited on the ocean floor. This increase in CO2 concentration is more than twice as strong as expected from outgassing of CO2 from warmer sea water alone. It indicates that the exchange with the Southern Ocean deep water became more intense and carbon deposits were transferred from the depths to the surface. Only after a significant temperature increase in the south and an increase in CO2 concentration, did the temperature rise again in the northern hemisphere. This is interpreted as providing a feedback mechanism for for greenhouse gases to drive global warming. The temperature data shows that after temperatures initially rise in the north they drop again. Apparently, the collapse of the AMOC, cuts off the flow of heat to the north from warm tropical sea water.

Just goes to show that when given the opportunity to demonstrate superior reasoning skills global warming alarmism proved us humans laid an egg.

Allan MacRae

http://wattsupwiththat.com/2012/05/29/an-observational-estimate-of-climate-sensitivity/#comment-996002
[Excerpt]
Some Thoughts Regarding the Evidence of Longer Cycles and Lags:
We know there is a ~9 month lag of atmospheric CO2 concentration after temperature on a ~~4 year cycle of natural global temperature variation.
http://icecap.us/index.php/go/joes-blog/carbon_dioxide_in_not_the_primary_cause_of_global_warming_the_future_can_no/
We also know that CO2 lags temperature by ~800 years on a much longer time cycle (ice core data).
… there is probably at least one intermediate lag, and quite possibly several, between these two – perhaps associated with the Wolf-Gleissberg Cycle, Hale Polarity Cycle, etc., AND-OR with the PDO, etc.
The lag of CO2 after temperature observed in these longer cycles is probably mostly physical in origin, related to ocean solution and exsolution of CO2, but also includes a long term biological component.
Willis’s analysis deals with the seasonal (annual) cycle, in which the biological component of the CO2 lag is comparatively much greater.
I have the opinion that we are looking at several natural cycles of varying duration in which there are external natural drivers (Sun, Earth orbits, stars), then some randomization associated with large ocean phenomena (PDO, etc.); these drive Earth’s natural temperature cycles at all time scales, and result in a series of related CO2 lags after temperature.
Finally:
Atmospheric CO2 variation is primarily a result, not a driver of temperature, and human fossil fuel combustion is probably NOT causing the recent increases in atmospheric CO2 – it is more likely the result of the cumulative impact of all these aforementioned natural cycles – for example, the Medieval Warm Period was ~~800 years ago.

Crispin in Waterloo

@Merovign says:
>Pro hoc, ergo propter hoc…?
Or, “First the temperature rose, so it caused the rise in CO2”
That at least is only bad logic (correlation, not causation).
They really mean: Pre hoc, ergo propter hoc…
“First the temperature rose, so it was caused by the CO2 that followed.”
That is plain ridiculous.
Re the comment above that CO2 drove the temperature rise once it ‘got going’. When the tundra thaws, it allows the same tundra to absorb much more CO2 in the form of plants and underground stored carbon. Methane is quickly broken down to CO2 and taken up by plants. The “CO2 made it continue'” is not supported by science, even though it is a socially attractive tale. It remains unproven and even might, one day, be shown, however there is nothing physical yet to support such a CO2-accelerated rise in temperature. The reason is simple: CO2 does not appear to have a strong warming effect and quickly tapers off when it has any at all. There is no proven feedback effect that is definitely positive, and some evidence that if there is one, it is negative.
I agree that the wording ‘they follow each other’ is weasel-wording hoping to support the confused view that CO2 leads or drives the recorded increase in temperature.
One day, there may be empirical evidence that CO2 drives global temperatures but that day is not this one. So far the evidence points to CO2 being a consequence of temperature.

P. Solar

More science by press release.
It’s a shame that whoever got to write spin version for the press release does not even know the difference between a glacial period and an ice age. Perhaps they should have read the paper.
The paper is in fact a strong confirmation that temperature drives CO2 and reduces the rather large uncertainty of the previous estimates of the lag ( 800 +/- 600 from memory).
It also rejects the recents sloppy attempt to reverse the dependancy by shifting time scales and comparing temperature and CO2 from difference sources.
“He explains that one of the theories is that when Antarctica warms up…”
They also don’t seem to know the difference between the terms theory and hypothesis.
It would appear that whoever wrote the press release has a degree in media communications rather than a science based subject.

Jockdownsouth

To my inexpert eye this does look exciting but I’m a bit concerned that so many commenters on here are allowing their exuberance to get carried away. This is something we rightly accuse many warmists of. Remember what happened to Gerghis.

tty

It is worth noting that this “lag effect” is asymmetric. If one studies ice cores from the beginning of the last ice age about 100 000 years ago it is obvious that the CO2 decline lags temperature by as much as several thousand years. At times temperatures and CO2 even go completely out of phase, e. g. at the end of the MIS 5d stadial and beginning of the mild MIS 5c interstadial, when temperatures go up while CO2 goes down. Strangely I’ve never seen this phenomenon mentioned in the peer-reviewed litchurchur.

The ipcc claimed a causal correlation between CO2 & temperatures, This claim served as the bedrock foundation of AGW theory. But the ipcc claim was debunked, and yet the theory still stands as if nothing has changed.
See the three minute excerpt from The Great Global Warming Swindle where algor repeats the ipcc deception on CO2 (neglecting to mention the temp / CO2 lag, and what that means). I say it’s a must see (and promote) video as perhaps 98% of the public doesn’t know this about CO2, and sharing or linking to the video is a good way to get the word out about this: http://www.youtube.com/watch?v=WK_WyvfcJyg&descrip=GreatGlobalWarmingSwindle_CO2_Excerpt

rogerknights

Alan Smith says:
July 23, 2012 at 5:17 pm
If CO2 follows temperature and it certainly appears so and given that CO2 is a green house gas then it is also has a positive (undesirable) feedback effect. I do not see this issue mentioned in the literature. With both CO2 and water vapour being positive feedback, where is the negative feedback that leads to moderate short term stability?

Climate contrarians like Willis Eschenbach have argued that the earth has a natural thermostat in the form of tropical thunderstorms. Here are Willis’s WUWT threads on thermostatic effects that I referred to above. The first and last are the most important.
http://wattsupwiththat.com/2009/06/14/the-thermostat-hypothesis/
http://wattsupwiththat.com/2011/08/14/the-tao-that-can-be-spoken/
http://wattsupwiththat.com/2011/08/25/taotriton-take-two/
Willis: “This [below] is the third in a series of occasional posts regarding my somewhat peripatetic analysis of the data from the TAO moored buoys in the Western Pacific.”
http://wattsupwiththat.com/2011/09/15/cloud-radiation-forcing-in-the-tao-dataset/
Willis: “I hold these results out as strong support for my hypothesis that the temperature of the tropics is regulated by the combined action of clouds and thunderstorms. The difference in the temperature response of the warm and cool days shows the homeostatic mechanism in action, with warm mornings having cooler afternoons, and vice versa. All of this shows the clouds and thunderstorms at work.”

michel

If the fall in temperatures preceded the fall in CO2 levels, the argument would be watertight. Does it? The argument that the rise follows the rise in temperature is not decisivie because the counter is that the rise in CO2 then leads to further temperature rises. This also affects your view of the merits of lowering CO2. Has there ever been a fall in CO2 in the past that has produced a fall in temperature?

P. Solar

Despite the spin in the press release , the paper is well worth the read. It looks very thorough and is realistic and clear about its own limitations. They use both time series and rate of change and look at the effects of removing various segements of data, varying the lengths of the filters (real ones not just running-mean “smoothing”) and varying the period analysed.
It compares their results to other studies of which it does a good resume.
If all climate science was conducted like this we’d be much better off.
It’s a shame the press release is totally misleading. The paper does not “contract” previous studies it confirms them.

Eli,
Yes they had a nice section at the end of the paper, devoted to that.
Its nice to have papers free to read..
Folks: C02 causes warming. It doesnt cause all the warming we find in the record. For example, if c02 is at 240 ppm and you get a change in orbital forcing ( like + 6 watts in some configurations) that 6 extra watts of solar will increase the temperature. and then… more c02 is released from the ocean. we know C02 lags a temperature rise. That fact has nothing whatsoever to do with whether c02 causes warming. it does. so do other things

Caillon et al in 2003 showed an 800-year lag. This fits nicely with the Medieval Warm Period and the thermohaline cycle. However, oceans are complex. I personally think the recent large CO2 increase (which has to be from the oceans, by Henry’s Law) is a combination of MWP from deep water rising, and surface water warming with the recent warm period. I therefore expect the CO2 “ladder to heaven” to reverse some time.

Gail Combs says: July 23, 2012 at 4:50 pm

“And there was war in heaven, Michael and his angels fighting against the dragon…” One reason I use my handle is it helps me remember, helps me see the real nature of our issues.

Mason P Wilson, Jr, Ph.D

Do you have a reference for this “unmentioned” second ice core?

What we are observing in the present day is the mankind has caused the CO2 content in the atmosphere to rise as much in just 150 years as it rose over 8,000 years

The notion of a recent “unprecedented” CO2 rise is rubbish, and the mother of the whole CAGW scare IMHO.

Steve O says: July 23, 2012 at 7:11 pm [re. CO2 having a delayed warming effect]

When I investigated, I found zero evidence.

George E Smith: How in the hell can Temperature rise and CO2 rise “follow each other closely”?

That way of talking is in Al Gore, Earth In the Balance 1992