How far into the past can ice-core records go? Scientists have now identified regions in Antarctica they say could store information about Earth’s climate and greenhouse gases extending as far back as 1.5 million years, almost twice as old as the oldest ice core drilled to date. The results are published in Climate of the Past, an open access journal of the European Geosciences Union (EGU).
Potential oldest ice study areas (Credit: Van Liefferinge and Pattyn)
By studying the past climate, scientists can understand better how temperature responds to changes in greenhouse-gas concentrations in the atmosphere. This, in turn, allows them to make better predictions about how climate will change in the future.
“Ice cores contain little air bubbles and, thus, represent the only direct archive of the composition of the past atmosphere,” says Hubertus Fischer, an experimental climate physics professor at the University of Bern in Switzerland and lead author of the study. A 3.2-km-long ice core drilled almost a decade ago at Dome Concordia (Dome C) in Antarctica revealed 800,000 years of climate history, showing that greenhouse gases and temperature have mostly moved in lockstep. Now, an international team of scientists wants to know what happened before that.
At the root of their quest is a climate transition that marine-sediment studies reveal happened some 1.2 million years to 900,000 years ago. “The Mid Pleistocene Transition is a most important and enigmatic time interval in the more recent climate history of our planet,” says Fischer. The Earth’s climate naturally varies between times of warming and periods of extreme cooling (ice ages) over thousands of years. Before the transition, the period of variation was about 41 thousand years while afterwards it became 100 thousand years. “The reason for this change is not known.”
Climate scientists suspect greenhouse gases played a role in forcing this transition, but they need to drill into the ice to confirm their suspicions. “The information on greenhouse-gas concentrations at that time can only be gained from an Antarctic ice core covering the last 1.5 million years. Such an ice core does not exist yet, but ice of that age should be in principle hidden in the Antarctic ice sheet.”
As snow falls and settles on the surface of an ice sheet, it is compacted by the weight of new snow falling on top of it and is transformed into solid glacier ice over thousands of years. The weight of the upper layers of the ice sheet causes the deep ice to spread, causing the annual ice layers to become thinner and thinner with depth. This produces very old ice at depths close to the bedrock.
However, drilling deeper to collect a longer ice core does not necessarily mean finding a core that extends further into the past. “If the ice thickness is too high the old ice at the bottom is getting so warm by geothermal heating that it is melted away,” Fischer explains. “This is what happens at Dome C and limits its age to 800,000 years.”
To complicate matters further, horizontal movements of the ice above the bedrock can disturb the bottommost ice, causing its annual layers to mix up.
“To constrain the possible locations where such 1.5 million-year old – and in terms of its layering undisturbed – ice could be found in Antarctica, we compiled the available data on climate and ice conditions in the Antarctic and used a simple ice and heat flow model to locate larger areas where such old ice may exist,” explains co-author Eric Wolff of the British Antarctic Survey, now at the University of Cambridge.
The team concluded that 1.5 million-year old ice should still exist at the bottom of East Antarctica in regions close to the major Domes, the highest points on the ice sheet, and near the South Pole, as described in the new Climate of the Past study. These results confirm those of another study, also recently published in Climate of the Past.
Crucially, they also found that an ice core extending that far into the past should be between 2.4 and 3-km long, shorter than the 800,000-year-old core drilled in the previous expedition.
The next step is to survey the identified drill sites to measure the ice thickness and temperature at the bottom of the ice sheet before selecting a final drill location.
“A deep drilling project in Antarctica could commence within the next 3–5 years,” Fischer states. “This time would also be needed to plan the drilling logistically and create the funding for such an exciting large-scale international research project, which would cost around 50 million euros.”
More information
This research is presented in the paper ‘Where to find 1.5 million yr old ice for the IPICS “Oldest Ice” ice core’ published in the EGU open access journal Climate of the Past on 05 November 2013. Please mention the publication if reporting on this story and, if reporting online, include a link to the paper or to the journal website.
Full citation: Fischer, H. et al.: Where to find 1.5 million yr old ice for the IPICS ‘Oldest-Ice’ ice core, Clim. Past, 9, 2489-2505, doi:10.5194/cp-9-2489-2013, 2013.
The other study mentioned in the release is by Van Liefferinge, B. and Pattyn, F.: Using ice-flow models to evaluate potential sites of million year-old ice in Antarctica, Clim. Past., 9, 2335–2345, 2013.
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I’m sure the scientists involved in this project know very well that greenhouse gases are incidental to their study but the only way to secure funding for the project is to trot out the usual trash that it is going to improve crystal ball gazing.
We all know it won’t but equally we would all like to see and study some million year old ice. I’d rather the money went to the drillers than to some other members of ‘the team’.
Junior-high science class: as the temperature of water rises, CO2 that is dissolved in that water increasingly comes out of solution and escapes into the environment (i.e., temperature of the oceans rises, then rising CO2 concentration in the atmosphere follows).
(Where did these people go to school?)
BTW, do none of the gases in those trapped “air bubbles” not diffuse out over the millennia? Can it be said with certainty that the gases found in those bubbles today are in exactly the same concentrations as they were millennia ago? Surely this has been studied/established.
(Was this posting a test to see whether people are still paying attention?)
A Major Question for Climate Science:
In 2008 I demonstrated that in the modern data record, the only clear signal in the data is that dCO2/dt varies ~contemporaneously with temperature and atmospheric CO2 lags temperature by ~9 months. Also, others had demonstrated that CO2 lags temperature by ~800 years in the ice core record over much longer time cycles.
http://icecap.us/index.php/go/joes-blog/carbon_dioxide_in_not_the_primary_cause_of_global_warming_the_future_can_no/
I suggest that CO2 lags temperature at ALL measured time scales.
Therefore, the IPCC global warming argument requires that the future causes the past. This logical fallacy should be problematic for global warming alarmists. Their rationalization, that my above 2008 observation in the modern data record is a “feedback effect” is, I suggest, a “Cargo Cult” argument [that is, they KNOW that CO2 drives temperature and therefore it MUST BE a feedback effect = nonsense, imo].
I further suggest that within a decade, conventional climate science wisdom will shift to the view that temperature drives atmospheric CO2, and CO2 does not significantly drive temperature. This observation does not preclude the possibility that human activities, whether the combustion of fossil fuels and/or deforestation and other factors, are also driving the observed increase in atmospheric CO2 (but we cannot rule out the possibility that the increase in CO2 could also be primarily natural).
For example, please examine the 15fps AIRS data animation of global CO2 at
http://svs.gsfc.nasa.gov/vis/a000000/a003500/a003562/carbonDioxideSequence2002_2008_at15fps.mp4
It is difficult to see the impact of humanity in this impressive display of nature’s power.
So here is my Major Question, which I hope many of you will opine on:
Since CO2 lags temperature at all measured time sales, does “climate sensitivity to CO2” (defined herein as “macro” ECS, see below*) even exist on Earth?
Yes or No, based on the probabilities?
Thanks and regards, Allan
[ * “macro” ECS wherein temperature drives CO2 and overwhelms any “micro” ECS, the latter defined as any increases in atmospheric temperature that are caused by increased atmospheric CO2, but are not readily detectable due to other more dominant factors.]
RESnape says:
November 6, 2013 at 12:09 am
Exactly! That is precisely why Al Gory had those two plots of temperature & atmospheric CO2 separated in that bastion of science fiction, “An Inconvenient Truth”, or “Bollocks, Buggery, & Bullshit”, as it is known in English! That’s why he made that deliberate statement about how you think would fit together! The very last thing he & his useful idiots wanted was to fit the two together, because it would show precisely that!
“If the ice thickness is too high the old ice at the bottom is getting so warm by geothermal heating that it is melted away,” Fischer explains. “This is what happens at Dome C and limits its age to 800,000 years.”
The same situation exists in Greenland. The ice at the bottom is melted by geothermal heat and the age is limited to 115,000 years to 133,000 years.
Where the melt water goes I don’t know, but it does indicate there is a general limit to how high glaciers can build.
This has implications for how far back we can go with ice cores but also what occurred in the deep past when large ice-sheets built up. Geothermal heat will limit how high ice-sheets can build up.
Furthermore, when an ice age is ending, the temperature memory of the last remnants of the ice-sheet means they melt faster. They are only -2.0C to -8.0C to start with given the geothermal heating of the past.
“…an experimental climate physics professor at the University of Bern…”
experimental climate physics professor???
Okaaaaay.
“(T)hey need to drill into the ice to confirm their suspicions.”
This is not how scientists are supposed to work; this is how prosecuting attorneys work. They are not looking for whatever evidence they can find concerning what *really* happened. They are looking for evidence to support their presuppositions.
The results are published in Climate of the Past, an open access journal of the European Geosciences Union (EGU).
What results? WAGs about oldest/thickest ice are not results.
“By studying the past climate, scientists can understand better how temperature responds to changes in greenhouse-gas concentrations in the atmosphere. This, in turn, allows them to make better predictions about how climate will change in the future.”
If THAT is their objective, a dart board would more than suffice and be a LOT less expensive!
It’s a great idea to get accurate climate data going back that far, even if it turns out that the record is reliable for only half that time. In the end we’ll have additional cores to cross check with existing ones. But…
…I sure hope Steve Mc is still active when this study comes out. This PR lists some of the challenges, such as ice “slippin and slidin”, melting at the base, etc., not to mention gases migrating in the ice column for 1.5 million years. So, whatever results emerge will necessarily be subject to conflicting analyses; however, we should learn something about deep ice in the process, even if it turns out to be unrelated to prevailing expectations.
Allan MacRae says:
A Major Question for Climate Science:
In 2008 I demonstrated that in the modern data record, the only clear signal in the data is that dCO2/dt varies ~contemporaneously with temperature and atmospheric CO2 lags temperature by ~9 months. Also, others had demonstrated that CO2 lags temperature by ~800 years in the ice core record over much longer time cycles.
http://icecap.us/index.php/go/joes-blog/carbon_dioxide_in_not_the_primary_cause_of_global_warming_the_future_can_no/
I suggest that CO2 lags temperature at ALL measured time scales.
===
Taking it one step further we can look at dT/dt vs d2/dt2(CO2)
http://climategrog.wordpress.com/?attachment_id=225
This allows us to estimate decadal as well as interannual sensitivity (of CO2 to temp, not the opposite).
It’s interesting that dCO2 seems to match Arctic Osc. index closer than temp since 1997:
http://climategrog.wordpress.com/?attachment_id=227
Also it would be worth doing your graph with a less distorting filter than the good ole runny mean. The correlation will probably be better.
http://climategrog.wordpress.com/2013/05/19/triple-running-mean-filters/
This all needs working out in a thorough engineering fashion. WbbHubTelescope had a go but got it wrong at the end.
http://theoilconundrum.blogspot.fr/2012/03/co2-outgassing-model.html
So this will give us past temperature with precision of 0.x Cº?!
Hahahah!
(article quotes)
By studying the past climate, scientists can understand better how temperature responds to changes in greenhouse-gas concentrations in the atmosphere.
[snip]
“Ice cores contain little air bubbles and, thus, represent the only direct archive of the composition of the past atmosphere,” says Hubertus Fischer, ………..
[snip]
As snow falls and settles on the surface of an ice sheet, it is compacted by the weight of new snow falling on top of it and is transformed into solid glacier ice over thousands of years.
——————
Given the above three (3) exerted statements from the article, I have a question, which is: “Just how reliable are the atmospheric CO2 measurements being calculated via those tiny air bubbles that are trapped in the glacial ice?”
And my reason for asking said question is, to wit:
Now I have to assume that if it is snowing then the local atmosphere contains a lot of water (H2O) vapor, even at the surface level, otherwise snow would not form and fall as precipitation.
And if there is a lot of water (H2O) vapor in the air at the surface where the snow is accumulating then I also have to assume that the CO2 ppm in the air at the surface is ….. “anyone’s guess”.
Now I said “anyone’s guess” because of the results of early studies done by both Charles Keeling and a Scandinavian group of scientists, to wit:
———————————-
The following was exerted from: http://www.aip.org/history/climate/co2.htm
A Scandinavian group accordingly set up a network of 15 measuring stations in their countries. Their only finding, however, was a high noise level. Their measurements apparently fluctuated from day to day as different air masses passed through, with differences between stations as high as a factor of two.
Charles David (Dave) Keeling held a different view. As he pursued local measurements of the gas in California, he saw that it might be possible to hunt down and remove the sources of noise. Taking advantage of that, however, would require many costly and exceedingly meticulous measurements, carried out someplace far from disturbances.
Keeling did much better than that with his new instruments. With painstaking series of measurements in the pristine air of Antarctica and high atop the Mauna Loa volcano in Hawaii, he nailed down precisely a stable baseline level of CO2 in the atmosphere.
=====================
And my 2nd reason for saying “anyone’s guess” is that no one knows whether said ice core layers were the result of actual snowfall accumulations during high humidity conditions or the result of wind-blown snow accumulations during extremely low humidity conditions …… or a combination of both.
Thus said, is my “CO2 ppm reliability” question legitimate or not?
Allan MacRae says at November 6, 2013 at 4:23 am…
Absolutely. And that is why there has been so much opposiiton to the MWP and so much support for Mann’s discredited Hockeystick.
It isn’t just that the warming can be questioned as being unexceptional.
It’s that a 800 year lag behind temperature leaves even the CO2 record as questionable as unexceptional.
But ice-cores show a flat line until now… and that can’t be due to diffusion through surface films in flaws within the ice crystal structures as ice is perfectly stable at the molecular level over hundreds of square miles and thousands of years.
That’s me quoting myself as no-one else would be so daft as to say it.
CO2 lags temperature, but not in lockstep. CO2 follows temperature more closely during the rise from glaciation to optimum than after the optimum. Although the processes that release-carbon-from or sequester-carbon-into the surface have received almost no attention, I find it easy to accept that the oxidizing processes of release respond faster to temperature change.
Politically-driven “scientists” keep trying to blur the shorter glaciation-to-optimum lag, by “revisiting” the dating of air bubbles or specious proxy-selection, but the Dome C results show the lag to be reasonably consistent in every cycle for the last 800,000 years. A pitiful mission, considering the post-optimum lag is also there, consistent, and too large to obscure.
http://www.woodfortrees.org/plot/uah/from:1979/trend/plot/rss/from:1979/trend/plot/gistemp/from:1979/trend/plot/hadcrut4gl/from:1979/trend
So, what does the actual data tells us:
1. CO2/GHG cannot be the cause of the observed warming. CO2/GHG warms the planet by warming the atmosphere. This warming of the atmosphere then warms the surface as a result of the lapse rate. As a result the surface cannot warm faster than the atmosphere due to CO2/GHG, which is contradicted by observation. When observations contradict theory, the theory is wrong.
2. The accuracy of the satellites is better than the surface records due to the smaller absolute error between the signals, and the accuracy of the satellites is increasing (convergence) while the accuracy of the surface records is decreasing (divergence).
Perhaps it’s me not keeping up, but presumably ice at the bottom of the borehole is under considerable pressure.
Is the structure of the ice at such pressures the same as ice at lower pressure?
Is anything known concerning the relative diffusion rate (if any) of various gases through ice at such pressures, and the behaviour of the gas when the pressure is released?
There’s a reason for the disclaimer “past performance is no guarantee of future results.” I don’t wonder if estimated past performance from a singe source is more reliable than actual.
techgm says:
November 6, 2013 at 4:16 am
I seem to recall reading somewhere, & it may have bee on Doug L Hoffman’s Resilient Earth site, that not only do the bubbles diffuse over time reducing the level of CO2 measured, but that losses occur (as they do with everything) during the drilling process reducing the gas readings further!
I know it is off topic but it has been allowed here so I will comment as an engineer, & a picky one to boot. The article about Suzuki is partially right but misleading, as is typical of him. Neither the earthquake nor the tsunami took out the plant at Fukushima. The earthquake was several hundred miles away. What the resulting tsunami did, was to take out the back-up power generators that ran the cooling systems for the reactors! It was a cooling system failure that caused the disaster, not an earthquake or tsunami! I presume however that when calmer heads are restored to appropriate levels of authority in the Western world, that in future such back-up systems will be elevated to a sufficiently high level to prevent a similar failure in the future! I also point out that so far, thousands have not been killed by the disaster at Chernobyl, & wild life seems to be flourishing! Hmmmm!
Apologies, I meant to add that as an accolade to the designers of Fukushima, an aging plant at that, that all the back safety systems came on line as designed!
Alan, I agree about Fukushima, however, there have been thousands of deaths attributed to increases in cancer rates attributed to Chernobyl. Wildlife is not useful as a good measure because those animals most affected will die leaving the field to others (those younger or having migrated in from the sides). This leaves an external view that looks relatively pristine.
Comment classification
Comments asserting or agreeing with sceptical talking point
Comments attacking scientists
Off topic
commenters who actually read the paper.
I think I will program a WUWT comment bot. No matter what the post you can count on certain classes of response. Let’s see if anyone can spot the comment bot in future threads
[Reply: “I think I will program a WUWT comment bot.” You had better check with Anthony first. ~ mod.]
RESnape: This is about as far as I am going to read because it has been discussed over many threads and proven that increases in greenhouse-gas follow increases in temperature
Don’t close your mind on purpose. You never know when something new will be discovered.
I really do not have anything good to say about this. Quite the contrary I am sick of the pursuit of
pursuing for the sake of pursuing that is devouring massive sums while producing imaginary benefits to perpetuate more of same.
My impression is that the totality of ALL ice research up against the expenditures and policy outcomes has produced perhaps less than nothing for mankind. That it has contributed to what has been and will continue to be worse than useless.
Perhaps I am confused and someone can give me an encapsulated summary of exactly what authentic NET benefit is being produced from ALL of the ice coring, ice measuring, ice monitoring and speculation about what it all means.
I am a skeptic who’s cynicism reigns supreme.
My take on this idea of deeper drilling into older ice is that it is an act of expanding futility.
What for?
Because of the multiplying of complexities the further back they go in time it is implausible that researchers will ever be able to draw any truly reliable conclusions about how any of it relates to current observations or may be useful in predicting the future.
Suppose researchers arrive at a juncture when they know precisely every CO2 level every year going back a billion years. So what? They spent billions and piled up a heap of ice stuff that tells them what exactly? That things have varied throughout the history of the planet?
Sorry but I am having trouble seeing the lure or any real payoff?
Ice is not outer space, ocean depths or molecular structure in need of exploration. Is it?