Vostok and the 8000 year time lag

Guest essay by Euan Mearns

In their seminal paper on the Vostok Ice Core, Petit et al (1999) [1] note that CO2 lags temperature during the onset of glaciations by several thousand years but offer no explanation. They also observe that CH4 and CO2 are not perfectly aligned with each other but offer no explanation. The significance of these observations are therefore ignored. At the onset of glaciations temperature drops to glacial values before CO2 begins to fall suggesting that CO2 has little influence on temperature modulation at these times.

As discussed at the end of this post, consideration of the geochemical cycles of CO2 and CH4 in ice, permafrost, terrestrial and oceanic biospheres and in deep ocean water during freeze – thaw glacial cycles suggests that it is inevitable that CO2 and CH4 are going to correlate with temperature in a general way. This correlation shows that CO2 and CH4 are controlled by temperature and so provides no evidence for CO2 or CH4 amplifying temperature signals that are linked to orbital cycles.

Introduction

Figure 1 The location of Antarctica, Vostok and other ice core locations.

The Russian Vostok Antarctic base lies 1300 km from the S pole, close to the centre of the Antarctica continent at an elevation of 3488 m.  It currently receives 2.6 mm precipitation per year. Average temperature is -55˚C and the record low is -89.2˚C which is below the freezing point of CO2. Vostok is one of the most hostile places on Earth.

There is a history of drilling various ice cores at Vostok. The main ice core, the subject of this post, was drilled in 1995. The Vostok ice core is 3310 m long and represents 422,766 years of snow accumulation. One year is therefore represented by only 7.8 mm of ice. Vostok is a cold, cold desert and the very slow ice accumulation rate introduces significant uncertainties to the data.

In addition to ice cores, Vostok is famous for the sub-glacial lake that lies beneath that has been mapped as one of the largest lakes in the world covering 14,000 sq kms. It is clearly a lot warmer under the ice than on its surface.

Figure 2 Vostok scenery

Data: Temperature, CO2 and CH4

In comparing the temperature, CO2 and CH4 signals in the Vostok ice core, it is important to understand that the temperature signal is carried by hydrogen : deuterium isotope abundance in the water that makes the ice whilst the CO2 and CH4 signals are carried by air bubbles trapped in the ice. The air bubbles trapped by ice are always deemed to be younger than the ice owing to the time lag between snow falling and it being compacted to form ice. In Vostok, the time lag between snow falling and ice trapping air varies between 2000 and 6500 years. There is therefore a substantial correction applied to bring the gas ages in alignment with the ice ages and the accuracy of this needs to be born in mind in making interpretations. Vostok data can be downloaded here.

Note that in all my charts time is passing from right to left with the “present day” to the left. The present day (year zero) is deemed to be 1995, the year that the cores were drilled. The GT4 time scale of Petit et al is used [1].

The methane concentrations in gas bubbles and temperature variations in Vostok are incredibly well aligned, especially at the terminations and return to glaciation when temperature variations are at their greatest. (Figure 3).

Figure 3 Methane and temperature variations. Note how methane and temperature are particularly strongly aligned at the terminations and during subsequent decline back to glacial conditions.

This shows that the ice age to gas age calibration is good. But does it show that methane variations of ±200 ppbV (parts per billion) are amplifying the orbital control of glaciations?

The fit of CO2 to temperature is actually not nearly so tight as for CH4. There is a persistent tendency for CO2 to lag temperature throughout and this time lag is most pronounced at the onset of each glacial cycle “where CO2 lags temperature by several thousand years” [1] (Figure 4).

Figure 4 CO2 and temperature appear well-correlated in a gross sense but there are some significant deviations. At the terminations, the alignment is as good as observed for methane. But upon descent into the following glaciation there is a time lag between CO2 and temperature of several thousand years. Petit et al [1] make the observation but fail to offer an explanation and to take the significance into account preferring to make instead unsupportable claims about CO2 and CH4 amplifying orbital forcing.

It is therefore no surprise that CO2 and CH4 show significant differences (Figure 5) with CO2 lagging CH4 in a fashion similar to the lag between CO2 and temperature.

Figure 5 CO2 lags methane in a manner similar to the lag between CO2 and temperature. This time lag requires an explanation rooted in the geochemical environments that are both emitting and sequestering these gases. Petit et al [1] devote surprisingly little space to explaining the physical processes behind the CO2 and methane variations at all.

Petit et al [1] appear to have been more eager to emphasise the similarities than to report the important differences…

The overall correlation between our CO2 and CH4 records and the Antarctic isotopic temperature is remarkable (r2 1⁄4 0:71 and 0.73 for CO2 and CH4, respectively). This high correlation indicates that CO2 and CH4 may have contributed to the glacial–interglacial changes over this entire period by amplifying the orbital forcing along with albedo, and possibly other changes.

In fact the high correlation is best explained by CO2 and CH4 both responding to temperature change as opposed to “causing it” and there is zero evidence from this data that amplification of orbital forcing has taken place, which is not to say that it has not happened.

Figure 6 provides an expanded view of the last glaciation where it can be seen quite clearly that there is a time lag of about 8,000 years between temperature falling and CO2 being pumped down. The temperature fell to glacial conditions (-6˚C) with CO2 at interglacial values (265 ppmV). Methane fell immediately with temperature but CO2 did not. This suggets that CO2 has little control over the main structure of the glacial cycle that is controlled by orbital forcing. There are similar time lags at the beginning of each glacial cycle (Figure 4). This is clearly an important and reproducible geological process or sequential combination of processes.

Figure 6 Detail of the last 150,000 years showing how CO2 lags temperature by about 8,000 years following the Eemian inter-glacial. Full glacial conditions were established with inter-glacial CO2 concentrations.

Discussion

The cyclicity of the CO2 and methane needs to be interpreted in terms of flux, sources and sinks. When the concentration rises this shows that the rate of production exceeds the rate of removal and vice versa. Envisaging glacial cycles there are a multitude of processes that one can imagine influencing both CO2 and CH4 flux. For example, sea level rise and fall flooding or draining land, vegetation growth and decay, changes to soils, ice sheets and permafrost melting, changes in ocean bio-productivity, changes in ocean circulation,  in particular thermohaline circulation.

CH4 and CO2 rise together with temperature at the terminations and it is tempting to suggest that the source for these two gases is the same. This is likely to be only partly true. The most prominent source for the CH4 is likely to be melting permafrost around and beneath melting northern hemisphere ice sheets. This will also release some CO2. The ice itself also contains small amounts of both gases. The most likely source for most of the CO2 is considered to be the oceans where warming seawater can hold less CO2. It is straight forward to explain the concordant rise of CH4 and CO2 with temperature at a time of rapid warming and ice sheet melting. When the warming halts so does the rise of CO2 and CH4, but then, with greenhouse gases at a maximum things turn colder. This alone suggests that greenhouse gases play a minor role in modulating glacial temperature and climate.

So why do CH4 and CO2 not follow each other down during cooling? There is not actually a sink for CH4. It is destroyed rather in the atmosphere by reaction with sunlight and oxygen to form CO2. The residence time is rather short, about 10 years. And so once added to the atmosphere it is quickly destroyed by conversion to CO2. The rapid warming that marks the beginning of an interglacial is normally followed in short order by rapid cooling. One can imagine the permafrost gradually freezing again, resulting in a reduction of the methane flux, the rate of destruction overtakes the rate of release and the concentration falls.

The large time lag for CO2  is not so easy to explain. At the termination and during the warming phase one has to imagine poleward migration and growth of forests. I can only guess that the mass of the terrestrial biosphere increases. I don’t know what may happen to the mass of the ocean biosphere which is often more productive in cold water? I can also speculate that thermohaline circulation is established or amplified enabling the partial degassing of the deep, carbon rich ocean. It is difficult to fit these pieces together in a quantitative way but suffice to say that warming leads to an increase in atmospheric CO2. So why does cooling not draw CO2 down again immediately?

An obvious thought is that this is linked to thermal inertia of the oceans. That the land and atmosphere had cooled with the oceans lagging a few thousand years behind. A simple way to check this was to compare Vostok CO2 against the ocean temperature record as recorded by the d18O signatures of globally distributed benthic foraminifera [3] (Figure 7). There is a similar time lag in the oceans between temperature (d18O) and CO2 (Figure 7) so the thermal inertia idea does not work.

Figure 7 There is a similar time lag between CO2 from Vostok and the temperature record of benthic foraminifera in the N Atlantic [3] showing that the slow pump down of CO2 has nothing to do with the thermal inertia of the oceans.

So what may actually be going on? A few months ago Roger and I had a series of posts on Earth’s carbon cycle. We never really got to the bottom of it but in the process learned a lot and turned up much interesting data.  I made three interim conclusions 1) deep ocean water contains much more carbon than the surface, and because of this 2) the much publicised oceanic CO2 solubility pump cannot exist and 3) most CO2 is removed from the atmosphere by photosynthesis – trees on land and phytoplankton in the oceans [4]. This may help us to understand the CO2 time lag. The deep oceans contain vast amounts of carbon, the product of rotting plankton at depth, and when the oceans warm or overturn, this C can be released to the atmosphere, quickly. But the return trip is not so simple since this depends on photosynthetic rates. In short, it seems that the oceans can exhale CO2 much more easily than it can be inhaled again.

On land, the re-creation of northern hemisphere ice sheets will kill high latitude forests and cause global migration of climatic belt boundaries towards the equator. Killing forests reduces the size of the terrestrial CO2 pump whilst simultaneously adding a source of CO2 – rotting wood. This will tend to offset the oceanic biosphere’s ability to pump CO2 down during the cooling phase.

Conclusions

  • Over four glacial cycles CO2, CH4 and temperature display cyclical co-variation. This has been used by the climate science community as evidence for amplification of orbital forcing via greenhouse gas feedbacks.
  • I am not the first to observe that CO2 lags temperature in Vostok [2] and indeed Petit et al [1] make the observation that at the onset of glaciation CO2 lags temperature by several thousand years. But they fail to discuss this and the fairly profound implications it has.
  • Temperature and CH4 are extremely tightly correlated with no time lags. Thus, while CO2 and CH4 are correlated with temperature in a general sense, in detail their response to global geochemical cycles are different. Again Petit et al [1] make the observation but fail to discuss it.
  • At the onset of the last glaciation the time lag was 8,000 years and the world was cast into the depths of an ice age with CO2 variance evidently contributing little to the large fall in temperature.
  • The only conclusion possible from Vostok is that variations in CO2 and CH4 are both caused by global temperature change and freeze thaw cycles at high latitudes. These natural geochemical cycles makes it inevitable that CO2 and CH4 will correlate with temperature. It is therefore totally invalid to use this relationship as evidence for CO2 forcing of climate, especially since during the onset of glaciations, there is no correlation at all.

[1] J. R. Petit*, J. Jouzel†, D. Raynaud*, N. I. Barkov‡, J.-M. Barnola*, I. Basile*, M. Bender§, J. Chappellaz*, M. Davisk, G. Delaygue†, M. Delmotte*, V. M. Kotlyakov¶, M. Legrand*, V. Y. Lipenkov‡, C. Lorius*, L. Pe ́ pin*, C. Ritz*, E. Saltzmank & M. Stievenard† (1999) Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica. NATURE | VOL 399 | 3 JUNE 1999 |

[2] Jo Nova: The 800 year lag – graphed

[3] Lisiecki & Raymo (2005) A Pliocene-Pleistocene stack of 57 globally distributed benthic D18O records. PALEOCEANOGRAPHY, VOL. 20, PA1003, doi:10.1029/2004PA001071

[4] Energy Matters: The Carbon Cycle: a geologist’s view

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DocMartyn

Try a really simple model; aerosols cool the globe and aerosols increase the mineralization of carbon; thus when the ice-cores have high levels of dust the temperatures should be low due to global dimming, additionally CO2 and CH4 levels should be low as ocean sediments trap more organic matter.
Use the minus natural log of dust and compare the plots; note that dust levels change before temperature, but occur at the same time as CO2/CH4 changes.

Ian W

But the timescales are centuries for the reduction in CO2 after the temperature change. This does not match with aerosol cooling as they would normally be expected to settle out inside a year or at most 5 years. This is the nuclear winter scenario.
I think that the model is too simple to fit the timescales.

A nuclear winter scenario, with orbital regularity?
That sounds just like regular heavy bombardment! Methane bursts from a lot of rotting materials. Ending in a ice age.

Bill McCarter

This is where I would look. Except I would try to find the biological aeolian dust particles. Higher concentrations of methane and co2 means more fertilizer and more life and more clouds.

george e. smith

Here we go again:
“””””…..Average temperature is -55˚C and the record low is -89.2˚C which is below the freezing point of CO2. Vostok is one of the most hostile places on Earth……”””””
-89.2 de. C is the freezing point of CO2 AT ONE ATMOSPHERE PARTIAL PRESSURE OF CO2.
Atmospheric CO2 does not freeze, at any place in the earth’s atmosphere. (no they have ot claimed it does. But don’t mention it if it is irrelevant; we know what 89.2 deg. C means).

george e. smith

And I erred; -89.2 is not CO2 freeze, just lower than it.

george e. smith

Well I see a couple of 8,000 or so year edge shifts, but I don’t see anything like that for the bulk of the data.
I thought the CO2 to Temp delay was more like 800 years, not 8,000.

george e. smith

And I see from the commentaries that we have some very knowledgeable folks on these ice cores and their story.
So Euan, what is your role in these studies. This looks like one heck of a post to finish off the year 2014 with.
It certainly makes the tiny bubbles look even sillier.
You are going to put us all to work, digesting the information in your essay.
Thanks for the effort. The overall graphs look rather scary, in that we do seem to be getting close to falling off the edge again, in the not too distant future.
G

Clif Westin

if “-89.2 de. C is the freezing point of CO2 AT ONE ATMOSPHERE PARTIAL PRESSURE OF CO2.” And Vostok is at 3300m or so, what does it take to freeze co2?

george e. smith

“””””…..
Clif Westin
December 29, 2014 at 2:25 pm
if “-89.2 de. C is the freezing point of CO2 AT ONE ATMOSPHERE PARTIAL PRESSURE OF CO2.” And Vostok is at 3300m or so, what does it take to freeze co2?…..””””
Clif, I hope you noticed the correction there; I think the one atmosphere CO2 freezing point is around -78 deg C. But at the tiny partial pressure of CO2 in the atmosphere, even at sea level, it is something like -110 deg C. And of course the higher you go aka Vostok, the partial pressure is even less, so the freezing point is lower yet, which is why I said it NEVER freezes anywhere in the atmosphere.
The way you can see that it IS the PARTIAL pressure, and not the total ambient pressure, is think about the process (sublimation / evaporation).
With a piece of solid CO2, dry ice, in some atmosphere, you have the higher energy molecules escaping from the surface into the atmosphere, thereby establishing a partial pressure of CO2 above the solid, more importantly, in contact with the solid. Some CO2 molecules in the atmosphere will crash onto the dry ice and get attached. N2, O2, Ar, or anybody else, can land on the dry ice, but they do not turn into dry ice. Only CO2 molecules can turn into dry ice.
And with a low partial pressure of CO2, there aren’t many of them colliding with the surface, compared to the number escaping from the surface; so equilibrium is reached only when the number crashing back on to the solid, is equal to the number being emitted from the surface. And it is that partial pressure of the subliming species, that determines that equilibrium, and hence the sublimation / freezing point.
And other air molecules hitting the dry ice, can only transmit thermal kinetic energy to the surface e, and accelerate the sublimation by warming it. But they can’t ever become dry ice, so they don’t really matter in the scheme of things, other than heating up the ice.
G

Michael D

Very interesting and well-written summary. Thanks.

Very clear. I read it and understood it, despite having to look at wriggly lines. The discussion brought it all together very neatly. The rabbits and squirrels did not start playing “Turkey in the Straw” in my mind.

mpainter

Plaudits to Euan Mearns for a thoughtful study. Euan makes the observations and asks the questions that others have avoided.

tty

“There is a similar time lag in the oceans between temperature (d18O) and CO2 (Figure 7) so the thermal inertia idea does not work.”
Actually the ocean d18O values do not record temperature, but rather the amount of water in the continental ice-sheets. Closely related but not the same thing. The lighter oxygen isotopes evaporate faster from the ocean surface and during ice ages they become “caught” in the glacial ice instead of returning to the ocen, so the ocean water gets “heavier”.
The d18O in glacier ice on the other hand does record temperature, more specifically the temperature in the clouds where the snow crystals formed, since this determines the isotope ratio of the snow – > ice.

euanmearns

While the expansion and contraction of ice sheets does modify the d18O of ocean water, and this needs to be taken into account, the temperature linked fractionation of 18O/16O between water and calcite or aragonite is one of the best calibrated and widely used sedimentary geothermometers.
In ice cores it’s normally the dD that is used for temperature (deuterium / hydrogen ratio) employing some fairly complex modelling about what is going on in the clouds thousands of miles away.

Paul Dennis

Euan, tty is absolutely right here. The benthic ocean d18O record is primarily an ice volume and not a temperature record. Moreover, whilst you assert that the temperature linked fractionation of 18O/16O between water and calcite or aragonite is one of the best calibrated and widely used sedimentary geothermometers it can only work if one has a-priori knowledge, or independent knowledge of the water oxygen isotope composition. Also, you might be interested in just how robust that calibration is. More than 50 years after the pioneering work of Urey, Epstein, Buchsbaum, Lowenstein and McRea there is still ongoing debate in the community just what the calibration is and if any of the experimental studies are robust vis-a-vis equilibrium isotopic fractionation. One only needs to check the recent work of Coplen and Watkins et al. to see that there is as much as 2 per mille difference in empirical fractionation factors at any single temperature of measurement across the different studies. This equates to nearly 10 degrees C variation in estimaed temperature depending which calibration one chooses!
Whilst dD is often used as a temperature record in the ice core, d18O could equally be used. There isn’t anything particularly complex about the temperature-dD relationship in precipitation. It is well understood as a Rayleigh fractionation process and what the isotope composition is recording the temperature difference between source and precipitation regions. Of course one also has to make allowance for changing source region isotope composition and deuterium excess in this step.

Paul Dennis

Euan, a seconf point to that of the ocean isotope record that tty and I have made is that is is very difficult to compare the ice core gas record with the ocean isotope record on anything like an accurate temporal basis. The benthic d18O record is likely to be orbitally tuned or ‘wiggle matched’ to the Milankovich insolation record and doesn’t represent an independent age calibration based on,for example radiometric dating.

euanmearns

TTY and Paul – I am embarrassed to stand corrected since I am supposed to be an expert on such things 🙁 But this does answer something I never understood and that is why “global forams” should describe a single “temperature” curve. I understand it now.
http://www.euanmearns.com/wp-content/uploads/2013/12/benthic_vostok.png
The benthic d18O and dD from Vostok are two amazing data sets that are closely correlated with each other. But I accept that the correlation is achieved by tuning them to each other. But that is how much geochronology works.

Bill Illis

Even if d18O does not directly measure temperature but ice volume or something else instead, …
… It does a darn good job of telling us exactly what the temperature was at the exact date.
It is more than accurate enough to be the “go-to” proxy.

george e. smith

So tty, if the d18O records cloud temperatures, where the snow crystals form, how does that Temperature relate to surface Temperature ??

Paul Dennis

A good question George. The relationship between isotopic composition of precipitation and temperature holds true for annual average isotopic composition and mean annual temperature. It is not true for isolated rainfall events. Nor does it hold for regions where convective rainfall (e.g. monsoon) is dominant. Where the isotope-temperature relationship is strong (temperate to high latitudes) the surface and cloud temperatures are closely related by the lapse rate of the atmosphere.
The relationship between precipitation isotope composition and temperature first characterised by Dansgaard is remarkable. It is all the more remarkable that one can make a simple physical model of the atmosphere based on the clausius-clapeyron relationship and the latent heat of evaporation of water and the equilibrium liquid-vapour fractionation factors for oxygen and hydrogen isotopes that predicts to a high degree of coherence the temperature-isotope composition relationship.

mpainter

Docmartyn:
Do not the Greenland ice cores show that levels of dust correlate with precipitation? That is, higher precip.=lower dust & vice versa.
This would indicate dust level is a function of precipitation/dryness globally, it seems, and warming reduces dust via increase in precipitation.

euanmearns

I have a separate post on dust and Na that I haven’t published yet because of this exact problem. Their concentrations are dependent upon deposition rates.

Alan Watt, Climate Denialist Level 7

Euan:
What’s the correlation between CO2 levels from the ice cores and the Mauna Loa standard we commonly use today? Your Figure 4 shows CO2 concentration at year 0 (1995) of roughly 280-282 and the Mauna Loa average for that year was approximately 358, or a difference of roughly 75 ppmV.
Thanks.

euanmearns

The youngest gas age I have in Vostok is 2342 years and so way older than Mauna Loa data. But looking at other ice cores – Sipple and Law Dome – there tends to be excellent alignment with the Mauna Loa data. The deposition rates are much higher at these coastal sites and so the firn diffusion and ice age gas age corrections are much lower.

asybot

I may be way of base here. Seeing that the Vostok area is very much a “desert” with minimal precip. and I presume less dust as well, would the coastal area being more active (weather wise speaking being) not have higher precip. and dust rates and be so closer related to Mauna Loa data? , thanks.

First of all:
THE WORST FALSE FIGURES of CO2-levels is the ones from Mauna Loa!!!!
All vulcanos send out CO2 -all lifetime and ever after.
The figures reading for CO2 on Mauna Loa is measured in order to know WHEN next outbreak might/will be close. Not to measure CO2 from air.
The CO2-readings on Mauna Loa as well as on every other important vulcano on land gives figures that goes from low to high depending on the pressure within the Vulcano. The CO2 readings that are in the “wind direction” is to help the other instruments!
What the so called experts CO2-believers forgotten to tell you all is that the above mentioned FACTS, is not the only problem in their so called models…… they have taken figures that never could tell anything at all re. CO2- value up in atmosphere or air, then they used three types of media value (!!!!) not only that – they also have “corrected them”…….
When the fox counts the chickens
Btw. How do I know which data the CO2-believers used for models? One of IPCC:s most refered “experts” was kind enough 🙂 to send me his raw data same year wattsup blogg started !!!! He thought I was on his side.
Well little did he know about CO2 and Natural forces. Even less about me. Sending such stuff to me of all people in the world!!!!

Brian H

vulcanoes volcanoes
It is characteristic of superstitions to try and anoint some effect as a forcing cause. See Feynman’s “Cargo Cult Science” for the mechanisms.

Thanks for correcting my spelling. I am dyslectic…
Yes Feynman. I had forgotten…

george e. smith

And dyslexic as well young Lady !
G

Young? 65 years old. First time I assisted my father taking chemical and biological samples in water and air, was back in 1957…..
it was then I was young.
btw. I grow up with these questions. Read all there was to be read from those day on.
And my father was one of the first four working fulltime with Environmental problems spec. Air and Water
He had started working with environmental questions back in second half 1930’s.
Forgotten to tell you that I do read many languages. Some like Swedish, Norwegian, Danish, Icelandic and so from age 5, others like English resp French and German from age 10 resp 11. Learnt Latin and Dutch later on 🙂

george e. smith

Well Norah, you confirm my “young” guesstimation.
The language listing is spectacular. English was my worst schooling subject; but I’d love to be able to speak Maori, just to put all our local ESL tower of Babel speakers in their place.
English IS the Official language of the State of California; decreed in the State Constitution no less.
And my music would be more enjoyable if I could speak German fluently.
g

Well my problem with German isn’t your’s.
When in Germany they usually believe me to be German or born by German parents. As long from the truth that can be. Worked for a German world known company three years here in Gothenburg Sweden in 70’s.
(I am dyslectic in every other language than German….. which is a bit strange to say the least)

DHR

Have you considered the diffusion of CO2 and CH4 in the ice core? If these species exist within trapped bubbles in the ice must there not be some diffusion or are we sure that all is in equilibrium? If there is diffusion, what would be the effect on your interpretation?

euanmearns

I had a section in this post on diffusion between firn and atmosphere and within firn but this grew to over 3000 words alone so I took it out. We see that CO2 and CH4 are well aligned at the terminations suggesting that differential gas species diffusion is not a major issue and so I don’t think that can be used to explain the 8000 year lag.

Mike McMillan

Diffusion exists through the ice, and I believe it’s greater for CO2 than for N2 or O2, but the rates are low and even though the time periods are very long, I don’t think it would affect the 8000 or 800 year lag.
The more significant aspect with diffusion is whether it blends out any CO2 spikes in the past. Were there any 400 ppmv CO2 spikes during the Eemian or previous interglacials? We don’t see them, but it’s possible they’ve been homogenized out.

euanmearns

Roger Andrews (who writes most of the climate posts on Energy Matters) convinced me that the rise in CO2 today is down to manmade emissions. In light of recent satellite data, this is a position that might change. Notwithstanding that, deposition rates at Vostok are so low that any sub-thousand year variations in CO2 would as you say be blended out. But the same does not apply to the coastal sites. There would be some blending but if there was natural transient spikes you would expect to see them. In Law Dome you do in fact see reduced CO2 during the LIA.
On the other hand, with gigantic natural fluxes, it is indeed difficult to imagine the system being so finely balanced for thousands of years.

Donb

Very nice post, the way scientific analysis ought to be done.
Most climate scientists think that Milkanovitch cycles, not CO2 changes, caused the ice-age cycles. But most do seem to think that outgassed CO2 enhanced those cycles.
There are limited data for some ice cores (don’t know about Vostok) on N2 and Ar fractionation during diffusion from gas bubbles. These presumably give temperature contemporaneous with the time of entrapment of CO2. The lag time between temperature to CO2 is much less, but interpretation uncertainties still are too large to say they are exactly contemporaneous.

Quinn the Eskimo

Could you please link to the series of posts with Roger on the carbon cyclewith that you referred to? Thanks in advance.

euanmearns

The residence time of CO2 in the atmosphere is …. 33 years?
What’s up with the Bern Model?
What’s up with the Bomb Model?
The Carbon Cycle: a geologist’s view
We never managed to close out this series. Topics to return to. The Bern Model with multiple Taus I think is a red herring that I know has been discussed extensively on WUWT (Willis had a post on this) and you get sucked in to trying to explain physical data using crazy ideas. The more important conclusions are that bomb 14C cannot be used to constrain sequestration rates and the deep oceans contain a lot more C and have lower pH than the surface. CO2 draw down can be explained using a single Tau – around about 33 years.

DocMartyn

That is what I get. You can take the present, about 0.13-0.44 GtCO2 by the total carbon in circulation, about 40,000 GtC and get a turnover rate of the whole system of 45,000 years. So the Vostok record shows 10 complete turnovers of biosphere carbon.

DocMartyn

450,000 years, sorry about the math

Excellent, thank you, and now that I’ve found your site I have a lot more good reading ahead.

Mike McMillan

Nevertheless, we have a cohort of CO2 molecules with eartags. We watch them, and we find they have a half-life of ~10 years. That’s hard data, not calculations. They’re gone, wherever. They can’t cause hurricanes and drowning polar bears if they aren’t in the atmosphere.

euanmearns

Mike, you want to have a read of my post called “What’s up with the bomb model”. The bomb 14C data cannot be used to determine the half life of CO2. That post went by a number of senior geochemists who gave it a clean bill of health, including some who had previously advocated the bomb 14C data.
Roger Andrews used a decline model to match emissions to atmosphere observations and got a residence time of 33 years. So its not as fast as the bomb data incorrectly implies but its much faster than Bern. We never got fully to the bottom of the C cycle, but from memory, CO2 can be modelled using a single Tau but it does not pump down to zero (pre-industrial) since we have added emissions the amount of C circulating in biosphere + atmosphere has gone up. The final equilibrium will reflect that.
I don’t believe there is a solubility pump, and I don’t believe that rock weathering is relevant either. The slow pump is sedimentary deposition of C in mudstones – both plant material and plankton – that is destined to become shale oil and gas one day. The C returns from whence it came.

Mike McMillan

I had read the Bomb Model post prior. Half-life and time of residence are two ways of looking at the same thing, but they come up with different numbers. A 10-year half-life gives 90% gone after 33 years, getting down toward the normal level that cosmic rays create, so it’s a matter of where you want to make the call.
Good post, by the way, lots of charts to sequester into my Global Warming folder.

george e. smith

At the north pole, when the sea ice melt starts, the atmospheric CO2 drops 18-20 ppm in 5 months.
How is that consistent with a 33 year decay time constant ??
At 19 ppm decay in 5 months, you would get over 1500 ppm drop in 33 years, and that would be just 63% of the total fall to the base level.
So just what is the equilibrium base level of atmospheric CO2 that would exist, sans any human contributions to CO2 ??

John another

euanmearns
December 28, 2014 at 4:03 am
“I don’t believe there is a solubility pump, and I don’t believe that rock weathering is relevant either”
I will save this post, but this is as far as I care to read at this time, seeing as none of the chemist present care to remark about this sentence, I am speechless.

If CO2 is drawn down to the ocean depths by the thermo-haline circulation – with the cold water at the downwelling sites sucking in the CO2, as many have supposed, then as my colleague Jackson Davis suggested to me some time ago, the expansion of sea-ice and slow-down of the THC would prevent the draw-down of CO2 at glacial inception. The oceans in equatorial regions take longer to cool (and some may get warmer!) and hence the drawdown eventually begins but is slow.
I agree that there is no evidence for CO2 amplification – but there never really was – this supposition rests entirely upon atmospheric physics and the theories of radiative forcing. The roughly 100ppmv drop/rise in CO2 associated with glacial/deglacial conditions is computed to produce about 2 watts/square metre, and then an old factor of 0.88 is used to convert this RF at the top of the atmosphere to degrees C at the surface. Hence, if we know the global average change (3-5 degrees) and the computed CO2 contribution is 1.6, then change is variously 32-53% driven by CO2. The problem is that this old factor should no longer be used – but IPCC still uses it, despite their advisory group recommending much lower factors (Keith Shine at Reading says values can vary from 0.3-1.2) – there are other authorities that think it can be lower still. This major uncertainty in the science underlies all of climate theory and accounts for the wide-spread of predictions of future temperatures. The computer codes (HIGHTRANS) are only accurate for clear-sky conditions and cannot handle aerosols and clouds at all well.
I think you are right to draw attention to the drop in global temperatures even though CO2 remains high. But I don’t think the orbital forcing arguments are very convincing as drivers – the rises especially of T are too rapid, as are some of the falls, and I am not impressed by arguments based on models of feedbacks like albedo change. The Greenland data point to rapid changes in atmospheric circulation (winds). The same may be true of the Antarctic. Doubtless orbital forcing primes the system, but the trigger remains a bit of a mystery!

mpainter

Nor am I convinced that it is the orbital cycles. Correlations of glacial expansion and retreat with the orbital cycles are too imperfect and every warming is too sudden to be explained by slowly evolving orbital cycles.

euanmearns

I’m with you there in part. The orbital cycles seem to be engrained in the data but fail to provide a convincing explanation. The terminations suggest something dramatic. CO2 minimum, albedo maximum and then lets all go off and melt. My current hunch is that it has to do with the Sun (I suspect Anthony doesn’t like some of this). I suspect the Sun we know is totally anomalous and that the “normal Sun” is different. And I suspect that spectral output changes are important for the vertical structure of the atmosphere and height of tropopause.

mpainter

I agree. The main force is the only thing that accounts for all observations. Big problem with supporting that. You have a number of proxies but what a clamor you would have to face.

gbaikie

I think orbital cycles only work because are creating pattern of oceanic circulation.
If Earth was uniformly covered with +3000 meter deep ocean, you would not get orbital cycles- or at least greatly diminish effects {though *maybe* a massive effect which require more time]
And/or without considering any solar input levels, a complete mixture of ocean will make this world very cold in terms of average temperature. Particularly cool for regions such as Europe- which we seem consider important- which quite far from the tropics.
It’s the mechanical motion of the ocean which fundamentally changes Earth’s climate, and of course, for most of this motion, it is primarily caused by our sun.

tty

There is really no doubt that the orbital cycles were in charge up to about 1 million years ago. The 41 000 year obliquity cycle is completely dominant and extremely clear in the climatic record, and has also been found in many older deposits back until the Paleozoic.
The big mystery is what caused the shift to approximately 100,000 year cycles about 800 000 – 1 000 000 years ago. These much longer, much deeper and somewhat irregular glacial cycles are not easily tied to Milankovich cyclicities.

euanmearns

I too am drawn to the notion of orbital cycles affecting ocean circulation – but have no hard evidence. The orbital cycles are a combination of Sun, Earth, Moon, Jupiter and Saturn. And so I also wonder if what affects Earth might also affect Solar activity.
The shift from 41,000 to 100,000 year cycles probably holds an important clue but you need big research dollars to answer that, and as we all know research dollars are doing everything but seeking out the truth.
Global thermohaline circulation is somewhat miraculous. One has to guess that the change from 41 to 100 has something to do with plate tectonics and the geometry of the ocean basins. Antractica moving over pole, closure of Panama and the other pinch point is the Bering straights that are above sea level during glaciations.

gbaikie

–I too am drawn to the notion of orbital cycles affecting ocean circulation – but have no hard evidence. The orbital cycles are a combination of Sun, Earth, Moon, Jupiter and Saturn. And so I also wonder if what affects Earth might also affect Solar activity.–
So we two things, the planets affecting the sun in terms the sun’s output/behavior [magnetic activity of sun] and planets affecting sun’s motion [and if sun moves this in turn affects the planets motion [orbit].
So for example, one way to find planets around distant stars is measure the wobble of the star caused by planets [it causes slight shift in light {redshift- ” A redshift occurs whenever a light source moves away from an observer.”- wiki}]. And the count so far: “Showing 1164 planetary systems / 1855 planets / 473 multiple planet systems”
http://exoplanet.eu/catalog/
And I believe most of them were found from redshift method.
And the major affect related cycles glaciation and interglacial periods is the change of Earth distance from the Sun- Earth’s Eccentricity. Meaning nearest Earth gets to the Sun and the furthest it gets from the sun over a period of 1 year. Or Earth’s Perihelion and Aphelion.
Currently, Earth’s Perihelion is 147.09 million km and furthest we get from the sun is 152.10 million km:
http://nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.html
So:
“The actual direct solar irradiance at the top of the atmosphere fluctuates by about 6.9% during a year (from 1.412 kW/m² in early January to 1.321 kW/m² in early July) due to the Earth’s varying distance from the Sun”- wiki [solar constant].
So in early January we at Perihelion- providing more solar energy to southern hemisphere [where there the highest percentage of ocean area].
Roughly it seems to me that the Aphelion distance increases and decreases or over about 100,000 years [though either or both could change in their distance.
Another change is the tilt of Earth orbit which occurs in shorter time period- which is called precession of axis:
“Observations indicate that the Earth’s spin axis is precessing with a period of about 26,000 years. The spin axis currently points close to Polaris, but in 13,000 years it will be pointed about 47 degrees away from Polaris since the tilt of the spin axis with respect to its orbital plane is about 23.5 degrees.”
http://hyperphysics.phy-astr.gsu.edu/hbase/solar/earthprecess.html
Also another general reference which say the eccentric shifts “0 to 5%”
and we currently at 3%. Meaning difference [of Perihelion and Aphelion] can be none or greater than we have now]
http://www.indiana.edu/~geol105/images/gaia_chapter_4/milankovitch.htm

emsnews

YES, it is the sun! The sudden plunges into Ice Ages is proof of this. It happens with virtually gentle glide, it is sudden.
Only one mechanism can create this. And none of these sudden plunges happen with astronomical clarity which would be the case if this was caused by planet tilt, etc. Of course, the tendency towards instability rises as the planet is wobbly on its own axis and has differentials with orbit, etc.
But this would mean a much clearer pattern. For example, the previous Interglacial was shorter than today’s but much warmer. And two Interglacials ago, it was colder but longer.
As our elderly star (aka: the Sun) becomes less reliable, we will have more Ice Ages, I suspect but cannot assume.

gbaikie

I would say the cause of Earth’s climate is vastly complicated. This is a different statement than Earth climate is vastly complicated.
What the Greenhouse Effect theory is [was], is an effort to simplify the cause of Earth climate to be caused by trace gases called greenhouse gases.
And that seems to me to be definitely wrong [proven wrong]. And instead, I would put the effect greenhouse of gases in a small bin with a question mark.
Or it was wrong to simplify Earth climate being caused by greenhouse gases [particularly wrong
when you exclude water in it’s liquid state [oceans and clouds] and the latent heat of water vapor- and instead making all about radiant effects of greenhouse gases.
Instead to simplify the vastly complicated causes of Earth climate, the sun is the obvious cause
rather than trace gases.
And mostly it seems the trace gases are the effect, rather than the cause.
Or using IPCC terminology, the Sun is main climate forcing element- which silly being that it’s redundant- it’s the elephant in the room.
Or one could say the term forcing was a trick to avoid the obvious and try to pretend the sun mostly doesn’t exist, as this chart indicates:
http://en.wikipedia.org/wiki/Radiative_forcing#mediaviewer/File:Radiative-forcings.svg
So in terms of Earth, it’s mostly about Sunlight effect upon the ocean. The warmed ocean has a large effect upon the atmosphere [it’s temperature]. And that’s the “greenhouse effect”.
Or why regions do not get as cold as one thinks they should be. The sun effect upon ocean also
why it’s warmer [why earth has 240 watt per square meter radiating in space yet is warm]
So actual greenhouse makes the air warmer and keeps the air warmer during the night.
Warmed ocean make the air warmer, and make the night and winter remain warmer [reduces freezing- an actual greenhouse can freeze at night but it’s usefulness is it can be freezing outside and not freezing in greenhouse. Of course one do more to stop the greenhouse from freezing- such as one add the large amount of water [ie, barrels of water] which retains the heat longer- and/or use a gas heater to maintain temperature above freezing].
So simple answer is earth is warmed by sun, but I would say it’s so complicated, that “support” for idea earth being warmed by trace gas was motivated in order to avoid the vast complexity involved with this simple and obvious answer.

Brian H

euan;
For future ref: the Bering straights → Bering = Danish explorer who explored the northern Pacific Ocean for the Russians and discovered the Bering Strait (1681-1741)

E.J. Mohr

You may be on to something there Euan.
One of the great surprises, at least to me, of the Ice Ages was that the tropical freeze level was a kilometre lower than today, even though tropical ocean temps were the same, or slightly warmer than today. To me this strongly hints at some kind of solar process, especially when you consider that the Milankovitch Cycles only introduce relatively small changes in insolation whose affects are should mainly be felt at high latitudes.

Michael Wassil

Further evidence that the sun is a variable star? A variable sun would help explain a lot.
http://science.nasa.gov/science-news/science-at-nasa/2010/05feb_sdo/
http://www.space.com/15396-variable-stars.html

Count to 10

Cosmic ray intensity?

euanmearns

Cosmic rays are another possibility. The trouble is that the deposition rates of 10Be are also dependent upon snow deposition rates.
Solar influence on glaciation in Greenland
There are also the facts that Earth’s magnetic field is currently falling and going walk about. Try Googling “Laschamp Event”.

emsnews

You know, our own star sends out this stuff, too. And perhaps the planet is being blasted by this by its own star, the sun!

Jim Francisco

Thanks Peter. I think I understood most of what you wrote. I try to read much of the technical stuff but it is mostly Greek to me. It really bugs me that most of it goes over my head. I was an instructor that tried to teach others about basic electronics and how aircraft instrument and automatic flight control systems worked so they could repair them. I took me a while to understand the things I later was required to teach others. I think most of my students and coworkers never did understand it. It seems to me that climate science may be like my experience with aircraft maintence.

asybot

Jim, I know how you feel but this site besides the “high falutin” science as you mentioned, your experience with electronics was much like mine trying to teach hands on horticultural practices to students but as luck would have,(and I am sure you had a few as well) some DID “get” it and went on to become very good in their field. All the people on WUWT are patient and do teach as they are here I have learned a lot from them and love every minute I spend here! And I know you and many do as well.

Walt D.

At least with the orbital data we have a reasonable confidence in the accuracy of the data. For many other things, we have no data at all – solar output, sunspots, cloud cover, ocean temperature, ocean acidity and any number of things that may or may not be important. We are using one single temperature and one single measurement of CO2 for the entire planet at any one point in time. The new CO2 data from the satellite cast doubt on the uniformity of CO2 concentrations over the globe. You can not have good models without good data to start with.

Robert of Texas

This is what I hate about proxies in ice cores – the results all depend on the “corrections” you apply.
(By the way, your article is well articulated and easy to follow, and I enjoyed it, but it hits a raw nerve in me. My following rant is not directed at you the Author, but on the never ending climate debate)
There seems to be an assumption that one should line up Methane to the proxy temperature, and then try to interpret the CO2 lag. Why would it not be as “correct” to try to line up the CO2 to proxy temperature, and then try to explain the early Methane build-up? Why could one not use any range in between to support their view? It actually seems reasonable to me that Methane might slightly precede temperature – but hey that’s just another frigging guess. Oh wait, let me go build a model to support my view…
Until there are good mechanics that explain either the CO2 lag or the Methane build-up, and that they are somehow testable (i.e. not another frigging model), I can see no reason to support how anyone “corrects” for the data – its a guess.
And BTW, I don’t trust the temperature proxy as much as most scientists seem to…I am just not sure how finely it really correlates with real temperature. I think there is a general agreement to decades, but getting to years just seems wishful thinking. It isn’t just how the snow falls, or packs, or melts…but also how it is drilled and contaminated and changed in the extraction process.
So in conclusion, I still wait for testable theories on WHY methane and CO2 behave as they do, as opposed to more interpretations about the available proxy data. That is the only way to put to bed this ridiculous argument about man-driven climate change.

euanmearns

The correlation between temperature and CH4 is so good, and when you consider the ice to gas age corrections and the flow models, I suspect that ice to gas age correction is hinged on CH4. CH4 has residence time of something like 10 years in atmosphere which explains why it may have been used for calibration purposes??

Lars P.

I was just wondering:
“One year is therefore represented by only 7.8 mm of ice. ”
If currently it “receives 2.6 mm precipitation per year.” does that make 0.5 mm ice or less?
Was it receiving a lot more in the past?
How uniform are those strata?

euanmearns

Good observation. The 2.6 mm comes from Wikipedia. If anyone wants to check my sums…..

tty

It is very difficult to measure precipitation in Antarctica since it is almost impossible to separate falling snow and drifting snow. 7.8 mm ice per year equals about 8.5 mm precipitation (glacier ice having a density of about 0.91).

tgasloli

I don’t think you area actually answering Lars concern. If there is 2.6 mm snowfall now, how can you assume 7.8 mm of ice pre year? Doesn’t this indicate problems with the entire time series from the core?

tty

No. The surficial part of the ice-core can be directly dated by counting annual varves. The thickness of the varves can be measured directly. Actually these figures would be a lot more reliable than “ordinary” precipitation measurements, though they might of course not apply at the present time.
In the deeper and older parts of the ice-core varve count is not possible because of compression and diffusion, and dating is therefore indirect through modelling of the ice-flow, verified by the known ages of glaciations and interglacials. I presume that the 7.8 mm figure refers to the last few thousand years. Precipitation at greater depth could certainly be estimated, but would have larger uncertainties.

At the onset of the last glaciation the time lag was 8,000 years and the world was cast into the depths of an ice age with CO2 variance evidently contributing little to the large fall in temperature.
============
It is surprising that this has not been studied further, as the time lag is rather strong evidence that CO2 does not influence temperature significantly. A much stronger case exists that methane influences temperature.
Perhaps this explains why the issue has not been studied. There is too much at stake riding on CO2. A whole lot of scientists would end up with egg on their faces if it was shown to be false, so they are never going to approve any study or paper that might bring down their careers.
Something that is interesting in the data is the sharp uptick in temperature that marks the end of the ice age and start of the interglacial. What causes the rise to be rapid but the decline to be slow?

Looking at the data, one could conclude that the earth did not transition from ice age to interglacial until CO2 become low enough. That CO2 actually causes the earth to cool.
Looking at the graphs: When CO2 levels become low enough, the earth rockets out of the ice age into the interglacial. This warming causes a lagged release of CO2, and as CO2 levels rise the earth starts cooling. As the earth cools CO2 levels drop with a lag, until we enter another ice age. Eventually CO2 levels become low enough to end the cooling effect of CO2, and we again rocket out of the ice age into an interglacial and the cycle repeats.
So, looking at the data one could build a fairly strong argument that CO2 leads to cooling and ice ages, and it is only when CO2 levels are low that we transition to an interglacial.

Count to 10

Correlation and causation: I’m not sure there is any mechanism by which CO2 could cause cooling, but there could be something that is correlated with CO2 levels that does.

Ian W

CO2 is a radiative gas. N2 and O2 are not radiative gases. If you add CO2 to a warm atmosphere of N2?/O2 then the CO2 will be warmed by sensible heat tranfer (molecular collisions), the infra red radiation from the N2/O2/CO2 atmosphere will be much greater and the atmosphere will cool

Ian W has it right. CO2 cools the atmosphere via increased radiation to space. A colder atmosphere will conduct more heat away from the surface, all things being equal.

Brian H

Google papers by Cao on the effects of CO2. Another voice crying in the CAGW widerness.

gbaikie

–CO2 is a radiative gas. N2 and O2 are not radiative gases. If you add CO2 to a warm atmosphere of N2?/O2 then the CO2 will be warmed by sensible heat tranfer (molecular collisions), the infra red radiation from the N2/O2/CO2 atmosphere will be much greater and the atmosphere will cool–
As I understand it, CO2 molecules have only elastic collisions with Earth’s atmospheric gases.
Whereas gases which can condense, such H20 gases can have inelastic collisions
with other H20 gas molecules. And because H20 gases do condense in the atmosphere it’s why
the amount water vapor affects the atmospheric lapse rate. Dry vs Wet lapse rate.
elastic collision
noun, Mechanics
1.a collision in which the total kinetic energy of the colliding bodies or particles is the same after the collision as it was before (opposed to inelastic collision ).
inelastic collision in Science
inelastic collision
(ĭn’ĭ-lās’tĭk)
Physics
A collision between bodies in which the total kinetic energy of the bodies is not conserved. In an inelastic collision, the total momentum of the two bodies remains the same, but some of the initial kinetic energy is transformed into heat energy internal to the bodies, used up in deforming the bodies, or radiated away in some other fashion. Inelastic collisions, such as the collision of two balls of clay, tend to result in the slowing and sometimes the joining together of the colliding bodies. Comapre elastic collision.
http://dictionary.reference.com/browse/inelastic%20collision

george e. smith

Does somebody have a reference to a good peer reviewed paper that shows how CO2 molecules in a cooled atmosphere, maybe even as low as 240K or less at airliner altitudes, can collect enough KE from collision with an N2 or even O2 molecule , to excite an 87mV excited state in the CO2 molecule , equivalent to a 15 micron wavelength photon capture event.
Because unless the thermal KE collisions, can couple that much energy to the internal energy of the CO2 molecule, it is not going to emit its characteristic 15 micron LWIR molecular resonance radiation.
I understand how the CO2 molecule captures such a photon from the hotter surface emission, which at a global average of 288 K has a 10.1 micron spectral peak; and how that degenerate bending mode can then be terminated by a collision, resulting in re-emission of a 15 micron photon, subject to Temperature and pressure broadening shifts.
But I don’t see how a 26, 27, 30, 32, 34, 36 molecular weight molecule colliding with a 42 to 48 molecular weight CO2 molecule, can impart that much internal energy to the CO2 molecule, so as to cause it to oscillate in the bending mode, and later emit a 15 micron photon.
I don’t have a problem with understanding that a thermally heated atmospheric molecule (N2 or O2 or Ar) warmed by conduction, can increase the mean global KE of the CO2 molecules, but that energy is only perceived in the macro co-ordinate frame of the gas, and only manifests itself when the heated (higher KE) CO2 then collides with some other molecule. The CO2 molecule is totally unaware of its global frame KE, until it hits something else. The 15 micron resonance energy is internal to the CO2 molecule, and will result in a near 15 micron photon, when that excited state oscillation ceases.
The other significant CO2 resonance; the asymmetrical stretch mode is at around 4 4.5 microns (can’t remember), and needs something more like 960 K Temperatures to excite.
So I don’t get how CO2 cools anything, unless it can convert global atmospheric thermal KE into purely internal molecular resonance oscillation energy.
But then I am not a quantum mechanic. Now I understand high energy tails on Maxwell-Boltzmann distributions, but that is fringe butterfly wing stuff.

euanmearns

Thinking totally irresponsibly out loud…. The CO2 greenhouse effect is based on the principle of radiative transfer up through the atmopshere and an emission height of the 15 µm band equivalent to -57˚C that is roughly the tropopause. The warming theory is dependent on it getting colder as you go up. If it gets warmer as you go up then CO2 will act to cool the atmosphere. Think of it as a conducter, conducting heat away from the surface. That’s why I believe the thermal structure of the atmosphere is important.

Donb

As I understand it, the tropopause is located much higher in the tropics than near the poles. Thus, the emission height is well within the troposphere nearer the equator, but may be in the lower stratosphere nearer the poles. But, temperatures are much higher at lower latitudes, and much greater IR emission occurs there. So the dominant IR emission by far occurs where temperature decreases with height.

Jim Francisco

So you are saying that the blanket is more like a sheet of copper than a batt of fiberglass?

euanmearns

Jim, more to do with the potential difference.

tty

“So the dominant IR emission by far occurs where temperature decreases with height.”
The temperature decreases with height practically everywhere (exception: occasional shallow inversions at high latitudes in winter).

Interestingly, a deep sea welder on a green FB page, was using the argument that CO2 is used as a conductor in his work as proof that AGW is real. Apparently CO2 is a really good conductor. He has since become silent as I pointed out to him that a good conductor would transfer heat away from the surface faster, not slower than an insulator.

euanmearns

TTY

The temperature decreases with height practically everywhere (exception: occasional shallow inversions at high latitudes in winter).

I’m skating on thin ice 🙂 This is something I’m still looking in to. But I think the 15 µm radiation band may set height of tropopause. Above that most models I’ve seen show temperature uniform as you go up through stratosphere before they begin to rise upwards. So raising CO2 ppm may raise the emission height without changing the emission temperature of the central 15 µm band – no greenhouse effect. It is only the side bands that are emitting at higher temperature lower in the stratosphere that are shifted upwards to colder emission temperatures.

beng1

euanmearns sez:
That’s why I believe the thermal structure of the atmosphere is important.
Certainly. That’s why the Nimbus IR satellite looking down over Antarctica showed upward bumps of CO2 and O3 instead of the usual downward bumps. Temp inversion where the surface was colder than the high radiating altitudes — actually an anti-greenhouse effect. But those conditions are rare & localized.

george e. smith

Well my Infrared Handbook, shows in Chapter 3 “The Earth as Seen from Space” an emission spectrum, that always has the envelope of a 288 K BB spectrum characteristic of the 10.1 micron peak surface spectrum (plotted versus wavelength, NOT wave numbers).
So I don’t buy this notion of the atmosphere acting as a cooler, and effectively radiating from some high altitude.
Earth radiatively cools from the surface, which is the highest temperature level, and therefore the most efficient radiating level.
The cooling rate in the hottest deserts, is more than factor of ten higher than at Vostok, (and at the same time too).
And those space spectra show the CO2 and O3 dips at 13.5-16.5 microns, and 9.6 microns respectively.
The space spectrum never peaks at 15 microns, corresponding to a super low temperature source. The source is the surface; not the atmosphere.
I’m not going to cite the peered papers behind the IR Handbook. Anyone can bingle that for themselves; I’ve posted it many times here. It’s getting tiresome.

Jim Francisco

We must stop the CO2 rise or we will all freeze err burn up ..well something bad will probably happen.

ironicman

Yeah, CO2 might lead to cooling. At the Thermal Max ‘there was a pronounced cooling trend of 0.05C’ and the modelers appear to have a climate conundrum on their hands.
http://www.co2science.org/articles/V17/dec/a22.php

Yeah, CO2 might lead to cooling.
============
From the article:
“How can the global annual temperature exhibit a cooling trend in response to global warming forcing … mainly in response to rising CO2 and the retreat of ice sheets?”
Looking at the data, this is also what struck me. If CO2 causes warming, then the graph of ice age and interglacial temperatures is impossible. Which leads to the inescapable conclusion that CO2 cooling, not warming.

Brian H

My Venus hypothesis explains its uniformity of temperature pole-equator and day-night as “short circuiting” by CO2-CO2 radiative transfer. Even more efficient than a copper blanket!

milodonharlani

There is no past interval which the GCMs model well. They are worse than worthless except to demonstrate the opposite of which they were designed to show.

Mario Lento

ferdberple December 27, 2014 at 11:33 am:
I love how you can use logic to completely turn the tables on the alarmist. We done sir!!!

The logic is in the numbers. All that is required is to look past the dogma, and try and explain the graphs if CO2 causes warming. You cannot. Not logically at least. The only explanation that will connect the numbers in the graphs is that CO2 causes cooling. It is inescapable.

Mario Lento, iPhone

Yes Ferdberple. What I usually say is that they have it precisely backwards.

gbaikie

–The logic is in the numbers. All that is required is to look past the dogma, and try and explain the graphs if CO2 causes warming. You cannot. Not logically at least. The only explanation that will connect the numbers in the graphs is that CO2 causes cooling. It is inescapable.–
Except logically, if out gassing of CO2 is a result of warming, then graphs do not show that CO2 causes warming or cooling.
It seems the rising CO2 levels are related to rising ocean temperatures- though there could be other factors- but we can pretty certain that these rises and falls had nothing to do with human activity.

Phlogiston

Fredberple
Interesting. Vegetation especially trees cool the planet by moistening to air by transpiration. They bring the hydrological cycle to inland regions that would otherwise be arid.
Low CO2 below a certain level will harm and reduce vegetation and trees. This dries the atmosphere and warms the climate. So according to your proposal, the low-CO2 trigger could be damage to the photosphere from CO2 starvation.

@ ferdberple: December 27, 2014 at 11:33 am
When CO2 levels become low enough, the earth rockets out of the ice age into the interglacial.
—————–
But, … but, …. but I can say the same about “temperature levels”.
When Winter temperature levels become low enough, the earth rockets out of the winter season into the warmth of Springtime.
“Low enough” is a highly subjective measure of temperature.

Pat

This premise coincides with the belief of many biologists that methane needs constant replenishment in the atmosphere because it so well utilized. Hence it is a lagging indicator or general warmth.
OT: I see Anthony has picked up a rather vitriolic search engine misdirection shadow. Is that a complement? Early reviews say it is crude, juvenile, and extremely unlearned.

Vostok and the 8000 year time lag
=========
thus, what the lag tells us is that while CO2 cannot be the cause of the warming, it can be the cause of the cooling.

this would also explain “the pause”. the clear air act caused temperatures to rise due to reductions in aerosols, but the increased CO2 from China and India caused this warming to plateau due to the cooling effects of increased CO2.

Brandon Gates

By your logic, at 400 ppmv CO2, things should be freezing.

By your logic, at 400 ppmv CO2, things should be freezing.
=================
You must allow for the lag. Marcott et al. (among others) showed that temperatures have been dropping for thousands of years, in line with the increase in CO2 that occurred after the start of the interglacial.
Current CO2 levels went up substantially with China and India industrializing, but temperatures Plateaued (The Pause). This completely contradicts the climate model predictions that temperature increases would accelerate with increased CO2 emissions from China and India. A failed prediction is strong evidence that the climate models and climate science are wrong about CO2.

Brandon Gates

ferdberple,

You must allow for the lag.

I’m going to print that out and frame it for reference the next time someone says, “bbbut temperatures have been flat for 20 years while CO2 has skyrocketed!”
Question you need to be asking yourself is why warming continues even after insolation begins to decline. And look at the relative slopes of things as they change — some trends are consistently steeper than others in ice core records, not just from Petit & pals.

Marcott et al. (among others) showed that temperatures have been dropping for thousands of years, in line with the increase in CO2 that occurred after the start of the interglacial.

There is one GHG, the most important one in terms of total instantaneous GHG effect, which cools the surface: water. It does so by evaporating at the surface and carrying away latent heat due to the phase change. CO2’s phase diagram doesn’t lend itself to such a mechanism, and being gaseous across the range of “normal” terrestrial temperatures is limited to acting as an warming insulator at lower altitudes and a cooling radiator at higher altitudes. Nothing but simple, straightforward first principles of radiative physics (with a smattering of QM) here.

Current CO2 levels went up substantially with China and India industrializing, but temperatures Plateaued (The Pause).

And just like that, the aforementioned “allowing for the lag” sublimes in a puff of ad hockery.

This completely contradicts the climate model predictions that temperature increases would accelerate with increased CO2 emissions from China and India.

Are we forgetting about aerosols? What happened when the Clean Air Acts were passed? Particulate and SO2 emissions were curtailed, not so much CO2. Temperatures (ironically) did what?
BTW, have you seen picutres of Beijing lately? Neither have I.
See also: AMO, PDO, ENSO, etc. and think about the thermal “inertia” of water. Lots and lots and whole heck of lots of water.

A failed prediction is strong evidence that the climate models and climate science are wrong about CO2.

Leaving out crucial, known observations is strong evidence of building strawmen and forming motivated conclusions.

don penman

The oceans are shrinking when the glaciation gets going but the land surface is increasing so that both volume and surface area of the ocean is decreasing perhaps this could explain the slow uptake of co2 by the oceans while temperatures are falling.

euanmearns

Just to repeat an evolving point of view that may be wrong. Warming and overturning oceans “exhale” CO2 readily. But the main uptake mechanism is driven by photosynthesis. Solution of CO2 at surface then removed by phytoplankton setting up a surface diffusion gradient maintained by photosynthesis and gravity (dead plankton sinking). The rate of turnover of phytoplankton is amazingly fast – 3 weeks from memory.
So ocean surface area may be subordinate to ocean productivity that is driven by upwelling deep water that is full of rotting plankton.

@ euanmearns: December 27, 2014 at 1:19 pm
Just to repeat an evolving point of view that may be wrong. Warming and overturning oceans “exhale” CO2 readily.
———————
The only ones that think it “may be wrong” …. or think it is “definitely wrong” ….. are those persons that have been convinced that the Northern Hemisphere’s growing biomass is responsible for the Spring and Summer “uptake” of atmospheric CO2 that is reflected in the bi-yearly decrease in CO2 as defined by the Keeling Curve Graph.
Or those persons that have been convinced that the microbial rotting and decaying of dead biomass in the Northern Hemisphere’s Fall and Winter season is responsible for the atmosphere’s “uptake” of CO2 that is reflected in the bi-yearly increase in CO2 as defined by the Keeling Curve Graph. (Of course the aforesaid convincing is in violation of the Refrigerator-Freezer Law of Microbial Decomposition of Dead Biomass).
But the actual fact is, as you stated above, …. the October thru March “warming” of the Southern Hemisphere oceans “exhale” CO2 readily (avg 6 ppm), …. whereas the April thru September “cooling” of the Southern Hemisphere oceans “inhale” CO2 readily (avg 6 ppm).
Reference – this KC Graph with added equinox and ppm notations, to wit:
http://i1019.photobucket.com/albums/af315/SamC_40/keelingcurve.gif

Samuel, we have been there before, but indeed the NH extra-tropical forests are the dominant cause of the large variability in the NH as the opposite variation of CO2 and δ13C over the months show:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/seasonal_CO2_d13C_MLO_BRW.jpg
If it was from the oceans, the CO2 and δ13C levels would go up and down in parallel.

@ Ferdinand Engelbeen: December 30, 2014 at 7:50 am
The plotted monthly CO2 data on your above graph shows no correlation whatsoever to the monthly Mauna Loa CO2 data.

Samuel, the graph is the average of the seasonal variation where the January value of each year was subtracted from the following months in the same year. The average for Mauna Loa is a rise of about +3.5 ppmv in the first months dropping to -2 ppmv in summer and back to +2 ppmv in January of the next year… You can see that if you detrend the CO2 data or look at each year apart.

Lars P.

Fascinating, very interesting article, good to have a fresh view at the correlations!
Indeed CH4 close correlation to the temperature can be explained by CH4 production depending on temperature with short live time of about 10 years.
The CO2 not correlating so well is due to the more complex cycle – interesting to see that the removal seems to be mostly delayed, the “production” seems closer in sync with the temperature

Latitude

you know……the theory was a small increase in CO2 would cause run away global humidity
Every ice core blew that crap away….
..why are people still talking about this?

JohnWho

Just a guess, Latitude, but the answer to you question may be:
“Because the inmates are running the asylum.”

The bigger question is why climate science down plays the importance of these graphs.

Weekly paychecks.

Brian H

Whose quote was that, paraphrasing, that it is difficult to get someone to understand something when his paycheck depends on his not understanding it? Check with employees of GISS, EPA, NOAA, UofAdelaide, etc. on how that works.

Bill Treuren

The study of historical CO2 and temperature is important but we, people, have changed things differently and we need to understand this impact.
We all talk about burning carbon and consequent CO2 but in my mind the biggest impact of our period is the loss of Fe in the oceans.
The greening of the plant reduces dust storms and thus reduces ocean fertility and the oceans photosynthesis is 75% of the conversion of CO2 but much more of the semi-permanent lock up of CO2. Add to that industrial scale fish and thus Fe removal from the oceans and you have a problem.
The greens could never argue against replacement of Fe so long as it was certified “organic” and we must be able to find an organic Fe mine.

Back when Hurricane Katrina blew in, more and stronger hurricanes were predicted. That year or the year after dust was blowing off the coast of Africa. That dust had the effect of cooling the waters in the Atlantic basin. The storms that started, started out further and could not reach the strength of previous storms. That dust also contains Fe. It can get blown all the way across and kill coral in the Caribbean. I’m not so sure that adding Fe to the environment is a good idea. You can have an unintended consequence without knowing what is going on first. So far nobody has convinced me that they do know.

euanmearns

This is an interesting point. More storms, more dust, greater ocean productivity? I think the glaciations were much stormier, though as discussed else where, the dust and Na records in ice cores are not straight forward to interpret. But adding nutrients to oceans would enhance the phytoplankton pump.
Is there any record of ocean productivity with time?

gbaikie

–This is an interesting point. More storms, more dust, greater ocean productivity? I think the glaciations were much stormier, though as discussed else where, the dust and Na records in ice cores are not straight forward to interpret. But adding nutrients to oceans would enhance the phytoplankton pump.
Is there any record of ocean productivity with time?–
Don’t know.
But one should keep in mind the oceans are vast and mostly sterile in terms of life. And the depths
are largely unexplored with average depth of 4 km.
I don’t think blowing dust from the land get very far out into the ocean. And tend think volcanic activity would be way to get some nutrients to vast reaches of the ocean. Also there fair amount of dust from Space.
“In the current issue of Science, the scientists from New York and Bremerhaven for the first time present chronologically resolved measurements of the 3He and 4He flux of interplanetary and terrestrial dust particles preserved in the snow of the Antarctic. According to current estimates, about 40,000 tons of extraterrestrial matter hit the Earth every year. ”
http://www.universetoday.com/443/constant-rain-of-space-dust-adds-up/
But volcano can eject 1 km cubic km [or more] of rock into the sky. So cubic km of rock is couple billion tons.
Of course if ocean got more nutrients, then the phytoplankton will eaten and it will move up the food chain. And fish swim.

Tony

Is there any shred of evidence that CO2 has ever led temperature on ANY timescale?

euanmearns

Rud Istvan references Shakun (Harvard I think) that purported to show CO2 leading temperature that I seem to recall Willis blew totally out of the water by simply looking at the raw data used.

Correctly remembered, Euan.
There are two ways ‘to blow Shakun out of the the water’. Willis posed one here back in 2012?, and it is noted, referenced, and hyperlinked in my essay Cause and Effect. I used another, histograms of proxy deglaciation onset/end. Both methods require going back to the original proxy data as published in Shakun’s SI. Both methods reveal a statistical hash that should never have gotten past peer review. My essay explains how Shakun cooked up his hash. Forewarned: if you like the scientific method and know a little bit about statistics, you will find Shakun’s sausage making stomach turning. The paper came from his OSU Ph.D thesis, and was rewarded by a Harvard post doc.

euanmearns

Rud, this comment from Dave Rutledge links to 4 WUWT posts, but not one of yours ;-(
http://euanmearns.com/the-vostok-ice-core-temperature-co2-and-ch4/#comment-5433
Do you have a link?

Euan, I am a great admirer of Prof. Rutledge of Caltech. He (plus Patzek at U.T Austin and Arulepp at Upsalla) have done the most rigorous work on ‘peak coal’. And Dave was invited to guest lecture at Georgia Tech by JC. Another sign IMO of academic credibility.
That said, I did not post the essay Cause and Effect deconstructing Shakun CO2 lack of lag either here or on Climate Etc. So Dave could not have linked to it. Is only published in the new ebook. Hope you will like it. Of the 52 essays on energy and climate, all or parts of just 11 were previously guested at Judiths. She was asked to review others (like When Data Isn’t on temperature record modifications), but not for blog posting. TonyB reviewed Northwest Passage (he is an expert with several related guest posts here) and Somerset Levels ( he lives in that area of southwest England, served on a local Water Board for several years, and opined my portrayal was milder than the actual scandalous situation wrongly blamed by Slingo on climate change). Neither essay was blog posted, only appear in the book.
Highest regards on your careful scholarship and near encyclopedic knowledge.

Tony

Thank you Euan. I’d missed Willis’ excellent article.
http://wattsupwiththat.com/2012/04/07/shakun-redux-master-tricksed-us-i-told-you-he-was-tricksy/
It is most interesting that Willis’ fig 2 shows rising CO2 for the past 7000 years or so, while temperatures have been falling!

It is most interesting that Willis’ fig 2 shows rising CO2 for the past 7000 years or so, while temperatures have been falling!
===================
which supports my previous argument that the only explanation that fits the data is that if CO2 has any effect on temperature, it is a cooling effect.

euanmearns

Ferdberple – pushing the CO2 acts to cool the planet is an interesting line. I have a good astrophysics friend who has been promoting this view for years and I simply dismissed it. I’ve spent months trying to get to grips with CO2 greenhouse. One of the best references sources I have is Clive Best who has a collection of papers here:
http://clivebest.com/blog/?page_id=6048
If the thermal structure of the atmosphere was such that it got warmer higher from the tropopause then I believe that more CO2 would indeed act as conductor removing heat from surface.

CO2 is a radiant gas (IR energy) ….. therefore it is a “cooling” gas.
If you are using a fan on a “hot” day to “cool” your body, or whatever, the CO2 in the air will absorb the thermal energy via conduction when the CO2 comes in contact with your body ….and/or will directly absorb the IR energy that your body is radiating …….. and then said CO2 will radiate a major portion of that thermal (IR) energy directly away from the vicinity of your body ….. thus effecting the “cooling” of your body temperature.
But don’t get too excited about that because there is an insufficient quantity (400 ppm) of CO2 in the air for anyone or anything to measure that “cooling” effect.
And H20 vapor (humidity) will do the same exact thing, ….. except for the fact the H2O vapor is extremely more efficient at doing said simply because under normal conditions (except in desert climates) there is a minimum of 15,000 to 20,000 ppm of H2O vapor verses 400 ppm of CO2.
Thus iffen you double, … or triple, …. the amount of CO2 in the atmosphere, … it still won’t even come close to having the same effect that the H2O vapor does.
Just because a satellite can detect atmospheric CO2 radiating IR energy doesn’t prove that said CO2 is causing any “warming” of the atmosphere ….. simply because the IR energy it is detecting is actually headed for outer space.

MikeB

How about this?comment image
I’m not saying I approve of this graph, but this is what you have to contend with.

MikeB,
That graph is a simple overlay, of T and CO2. It does not show which is the cause, and which is the effect — although to the unthinking, it looks like CO2 is the cause. But it’s not. Temperature change comes first, then CO2 follows. On all time scales, out to a million years or more.
I have plenty of graphs like this that prove cause-and-effect: temperature is the cause, and CO2 is the effect. If you would like to see more, just ask.

MikeB

DBStealey
Your graph is not a simple overlay and CO2. It is not a simple anything. It purports to be showing rates of change of these variables, which is something else. The processing description is very confusing but, whatever it is, it is very hard to say what is leading what.
There is no scale for the rate of CO2 change.
The graph I provided, which as I said, I don’t approve of, is produced by NOAA; the provenance of your graph is unknown.
Do you have any graphs which are peer-reviewed or from scientifically acceptable sources? This is what you need.

David Socrates

Mike B
..
Dbstealey doesn’t understand that the slope of the line is the “rate of change” you know, first year calculus.
His chart is bogus because it uses GHCN data which is not absolute in value, but anomaly data.
Secondly, comparing dT/dt to dCO2/dt obscures causal relationships. Everyone knows the first derivative of a curve detrends the absolute levels.
For example if you look at 1960-1965 the relationship he tries to sell you is backwards. Similarly the entire period between 2000 and 2010 is out of phase. The graph is just a mishmosh of “noise” in the data that shows nothing obvious.
.
..
Lastly, Mr dbstealey says that CO2 follows temperature, however that hasn’t happened in the past 15 years or so. Global T is flat, but CO2 continues to rise at 2 ppm/yr. He can’t explain that.

Yes, Mike, that is a simple overlay.
Then Socks says:
Mr dbstealey says that CO2 follows temperature, however that hasn’t happened in the past 15 years or so.
That, right after I had posted a chart showing exactly that cause and effect relationship over the past ±15 years.
Next question …?

Brandon Gates

dbstealey,
Next question: Explain how CO2 is 50% higher than the Eemian interglacial, but two degrees cooler in Antarctica.

TimTheToolMan

David So crates writes “Lastly, Mr dbstealey says that CO2 follows temperature, however that hasn’t happened in the past 15 years or so. Global T is flat, but CO2 continues to rise at 2 ppm/yr. He can’t explain that.”
That’s easy. If CO2 follows a temperature increase (as it has historically) but is lagged then right now we are experiencing that temperature increase but putting the CO2 into the atmosphere ourselves and removing that lag. In fact we’ve put more there than would have naturally happened if we’d simply waited for the CO2 to catch up.

rooter

[Snip. Sockpuppetry not allowed. ~mod.]

richardscourtney

MikeB, Brandon Gates and rooter:
dbstealey is correct and you are wrong because he is talking about coherence while you ignore that and talk about correlation.
Correlation and coherence can each and both provide information pertaining to causality.
Correlation is a mathematical relationship between two parameters. If the correlation is known over the length of the data sets, then their correlation indicates the magnitude of a change in one parameter that is expected when the other parameter changes by a known magnitude.
Correlation does NOT indicate a causal relation between two parameters.
But
Absence of correlation indicates absence of a direct causal relation between two parameters.
Coherence of two parameters indicates that when one parameter changes then the other parameter changes later.
Coherence can disprove that change of one parameter causes change in the other; i.e. if change in parameter A follows change in parameter B then the change of A cannot be the cause of the change of B (because a cause cannot occur after its effect).
So,
1.
absence of correlation indicates absence of a direct causal relationship
and
2.
when there is a direct causal relationship then coherence indicates which of the two parameters is causal.
Furthermore, coherence in the absence of correlation is strongly suggestive that both parameters are affected by another parameter (or other parameters).
For example, leaves fall off trees soon after children return to school following their summer break.
The coherence is great; i.e. both effects occur each year.
But the effects do not correlate; i.e. the number of returning children is not indicative of the number of falling leaves.
In this example, the time of year is the additional parameter which causes children to return to school and the leaves to fall off trees.
So, if it is known that there is a causal relationship between two parameters then he coherence between the parameters indicates which is causal.
In this case, as dbstealey says, at all time scales the coherence indicates that if there is a correlation between atmospheric CO2 concentration and temperature then the CO2 causes the temperature. And, as ferdberple argues upthread, the effect of this coherence at millenial time scales is such that it suggests a negative correlation of CO2 with temperature (i.e. higher CO2 concentration is associated with cooling).
But Euan Mearns, dbstealey and ferdberple are discussing what the data indicates whereas you guys are promoting what you want to be true,
Richard

David Socrates

Richard Courtney
..
You say: “Coherence of two parameters indicates that when one parameter changes then the other parameter changes later.”

A fine example of this is what has happened in the past 15 years with CO2 rising and global T not rising.
CO2 has risen (changed) about 300 ppm then the other parameter (temperature) changes later.
Thank you
..

David Socrates

Typo …30 ppm not 300

DEEBEE

Dbstealy, whatever other criticism other folks can come up with, just following yiur graph, CO2 does not follow what you assert, in 1970 or so and again at the end if the graph. Either temp follows CO2 or it does not. If it does it always should unless there are other confounding factors. If there are such factors then we have a different theory. Saying Co2 mostly follows temp is meaningless as a mechanistic explanation.

DEEBEE, then just post a comparable graph showing that ∆T is caused by ∆CO2. I have been asking anyone to find and post such a graph for the past couple of years. But no one seems to be able to find one. What does that tell you?
=============================
B. Gates says:
Next question: Explain how CO2 is 50% higher than the Eemian interglacial, but two degrees cooler in Antarctica.
Gates, you’re not making sense.
+++++++++++++++++++++++++++++
Next, rooter, socrates and MikeB all ignore the fact that the charts I post clearly show that ∆T is the cause of ∆CO2. Making baseless assertions does not refute any of the charts I post. Only contrary data can do that, and the alarmist crowd is very short on contrary data. They are very short on data, period.
The cause and effect relationship between T and subsequent CO2 changes is apparent on time scales from years to hundreds of millennia. We see it everywhere.
MikeB says:
There is no scale for the rate of CO2 change.
You can clearly see which came first. A change in T is followed by a subsequent change in CO2. Scale does not matter. I am trying to teach you about cause and effect.
Now, what we don’t see is the reverse cause and effect: there are no comparable charts showing that changes in CO2 cause changes in temperature. Thus, reasonable people will conclude that if CO2 causes any change in T, that change is simply too small to measure, and therefore CO2 levels can be disregarded as inconsequential.
Carbon dioxide is, after all, only a tiny trace gas comprising only 4 parts in 10,000. Yet it is essential to all life on earth, therefore demonizing CO2 is self-destructive.
Finally: rooter, why don’t you try to re-phrase your comment above. I’ve read it a couple of times, and it still makes no sense.

David Socrates

dbstealey …..“that the chart I posted shows clearly that ∆T is the cause of ∆CO2”
..
Your chart shows that between 1960 and 1965, CO2 was falling while T followed it
Your chart shows that in 1975 CO2 fell and T rose
Your chart shows that in 1985 T rose and CO2 fell
Your chart shows that in 1989 T rose and CO2 stayed constant
Your chart shows that from 1990 to 1991 there was no lag at all, they dropped synchronously.
Your chart shows that in 1999 CO2 rose and T dropped
Your chart shows that from 2001 thru 2004 CO2 led the rise in T

In other words, your chart does not show causation.

D. Socrates says:
In other words, your chart does not show causation.
Any fool can simply look and see the causation. But you’re not even up to that level. Further, you have nothing to refute it with. Where are your charts showing that changes in CO2 are the cause of changes in temperature? You know, the charts I’ve been asking for over the past 2 – 3 years.
Answer, as usual: you’ve got nothin’.

David Socrates

Dbstealey
..
I pointed out to you seven individual places in your chart where your “causation” argument falls apart. I suggest you address each one of them , or find a chart that actually shows something besides weak correlation.

David Socrates

Dbstealey

Again you post the WFT chart
http://www.woodfortrees.org/plot/esrl-co2/isolate:60/mean:12/scale:0.26/plot/hadcrut3vgl/isolate:60/mean:12/from:1958
..
That chart uses the “isolate” function

From the WFT help page…
http://www.woodfortrees.org/help
“Isolate Does the same running mean as ‘mean’, but then subtracts this from the raw data to leave the ‘noise'”

So, what your graph is showing, is a comparison of “noise” to “noise”

Socks,
Wrong again — I’ve posted many charts from numerous different sources, with different functions. What you are doing is your usual cherry-picking of anything you think you’ve found, in order to continue your climate alarmism. Not only are you wrong, but let me point out once more: you’ve got nothin’.
You have no real evidence showing that CO2 is the ‘control knob’ of the climate. You have no real measurements of AGW. Really, you’ve got nothing at all.

David Socrates

Dbstealey
” I’ve posted many charts from numerous different sources, with different functions.”

Just because you post a chart, that does not make the chart correct. The WFT chart is bogus, and continually posting it does not make it valid. The “isolate” function is clearly explained on the WFT help page. That chart is comparing noise to noise. I suggest you stop posting that chart because it shows only that you don’t know what you are posting.

You still have yet to address the seven problems with the other chart I mentioned. I’m not “cherry picking” anything, I’m just showing you that the charts you post are of questionable value. Instead of addressing the issues I bring up, you dig your heels in and deflect. A real scientific type would stop posting bogus charts and find one that passes scrutiny

Socks says:
find a chart that actually shows something besides weak correlation.
Ah, so you admit that it shows corellation. Adding “weak” is nothing but your editorializing; backing and filling. A climbdown. That chart shows corellation as you admit, and corellation is evidence.
Next, you assert:
The WFT chart is bogus, and continually posting it does not make it valid.
The WoodForTrees databases are accepted by both sides of the debate. You seem to be the only one who has a problem with WFT. When a WFT chart based on empirical evidence is used, the choices are to either accept it, or to produce one of your own that contradicts it. Nitpicking using your own perceived flaws is a non-starter. The chart clearly shows that the temperature changes came first, lagged by CO2. That is the essence of the debate.
The article is about time lags, and I have posted lots of charts showing various time lags. Every one of them shows that CO2 lags temperature. But you have not posted even one chart showing the opposite cause and effect; that changes in CO2 are the cause of changing temperature.
Therefore, you lose the debate. As you admitted, I showed corellation. But you have shown nothing. All you do is try to find something to nitpick. That’s the way it always is in these skeptic vs alarmist debates: skeptics produce empirical evidence — while the alarmist crowd produces verbiage. Conjectures. Opinions. Speculation. What-ifs. Scary stories. Anything except solid scientific evidence.
No wonder you’ve lost the debate. You lack any convincing evidence.

David Socrates

Dbstealey
“Adding “weak” is nothing ” …….correlation weak or strong does not show causation as you claim your charts show.
..
“The WoodForTrees databases are accepted by both sides of the debate.” …yes….but when you use the “isolate” function, you are comparing noise to noise. Ever hear of a thing called “signal to noise” ratios? Your chart is comparing noise to noise per the description of the isolate function on the WFT help page. If you continue to use that deceptive chart, you are guilty of posting misleading data.
..
” Every one of them shows that CO2 lags temperature.” except the WFT does not show that, and the other cart has seven issues you’ve failed to address Posting garbage over and over doesn’t change the fact that it’s garbage.
..
“Therefore, you lose the debate” …….that is your opinion.

You still need to address the seven flaws in your chart, and you need to explain why the “isolate” function is used to compare noise to noise. That’s not nitpicking, it’s just pointing out to you the weakness of your argument.
..

David Socrates

Dbstealey
..
Here is the same chart from WFT without the “isolate” function.
http://www.woodfortrees.org/plot/esrl-co2/mean:12/scale:0.26/plot/hadcrut3vgl/mean:12/from:1958
Note it shows that CO2 is rising while T is flat.
See how deceptive the “isolate” function is? It hides the fact that CO2 has not followed T in the past 50 years.

David Socrates

Dbstealey

Speaking of WFT charts, don’t show this to Monckton, he might get upset with the 0.1 degree C rise in the past 3 and a half years.
..
http://www.woodfortrees.org/plot/rss/from:2011/plot/rss/from:2011/trend
See what you can do with WFT charts?

rooter

[Snip. Sockpuppetry not allowed. ~mod.]

@ David Socrates: December 27, 2014 at 2:24 pm
Lastly, Mr dbstealey says that CO2 follows temperature, however that hasn’t happened in the past 15 years or so. Global T is flat, but CO2 continues to rise at 2 ppm/yr. He can’t explain that.
————————
DUH, …. says you it hasn’t happened.
But dbstealey is correct, ….. right as rain he is.
You are wrong ….. because you are assuming that it was the calculated average near-surface air temperature that dbstealey claimed the CO2 was following.
The increase or decrease in atmospheric CO2 could care a twit less what the calculated average near-surface air temperature is, was or going to be.
The outgassing/ingassing of atmospheric CO2 is highly dependent upon the daily, weekly, monthly, seasonal and/or yearly average temperatures of the biomass containing land forms and the oceans, lakes and rivers of the world ….. with the ocean waters being by far the dominate factor.
Thus it matters little that the calculated average near-surface air temperatures have been decreasing for the past 15 or 18 years …… simply because of the enormous volume of ocean water it will surely require anywhere from 100 to 1,000 years before anyone can detect or determine a reversal in/of the current average yearly increase in the temperature of the ocean waters.
And it is the aforesaid …… average yearly increase in the temperature of the ocean waters ….. that is responsible for your aforesaid …. “average 2 ppm/yr increase in CO2”.

Brandon Gates

dbstealey,

Gates, you’re not making sense.

Given the amount of nonsense you churn out on a daily basis, it’s hardly surprising that you don’t understand such a simple question. Your contention is that CO2 always, on all time scales, lags temperature. I don’t dispute that you are correct on most time scales. But you are clearly wrong about ALL. Here again are CO2 concentrations from various proxy records spanning the past three complete glacial/interglacial cycles:
https://drive.google.com/file/d/0B1C2T0pQeiaST3RiNEczdEVGdmc
If my argument was that CO2 always follows temperature, I’d find it qute difficult to explain how in the latest interglacial, CO2 suddenly spiked from 280 to 400 ppmv smack dab in the middle of an overall global decline in temperature. I’d really have a difficult time explaining why “recovery” from the LIA turned into an ever-accelerating period of warming. In the midst of such difficulty, it goes without saying that I’d be completely flummoxed by this scatterplot of CO2 vs. temperatures from the ice core record compared to modern instrumentation:
https://drive.google.com/file/d/0B1C2T0pQeiaSQzlvYUk3d19zb0E
One of these things is not like the other … da dum da dum de dum … hmm hm hm hm hmmmmm hm …

David Socrates

Brandon take a look at this time scale.
..
This is how CO2 varies by time of year
http://www.woodfortrees.org/plot/esrl-co2/from:2010.7/to:2012.4

I picked one year at random, but the wiggle in the CO2 data follows an seasonal cycle.
..
Now…..we’re so accustomed to looking at temperature anomaly data, we forget this…
..
http://wattsupwiththat.files.wordpress.com/2013/03/clip_image0041.jpg
By combining these two data graphs you come up with the following
..
From autumn (2010.7) until spring (2011.4) CO2 levels are rising…..but if you look at the monthly average temp chart, you note that absolute global temps drop (commonly known as “winter” )
From spring (2011.4) until autumn (2011.8) CO2 levels are dropping……again, absolute global temps per the chart rise (commonly known as “summer”)

So Mr dbstealey has some explaining to do….seems when global temps drop in winter, CO2 rises, and when global temps rise in summer, CO2 drops ( 😉 )
This happens year after year after year.

Brandon Gates

Socrates, you wily cherry-picker you. For shame. 😀

Sockrates says:
…correlation weak or strong does not show causation as you claim your charts show.
Compare that with what you’ve got, which is nothing but opinions.
“The WoodForTrees databases are accepted by both sides of the debate.” …yes….but…
No ‘yes, but…’. Either accept the database, or don’t. Everyone else accepts it, but that doesn’t mean you have to.
I posted:
“Every one of them [the charts I linked to] shows that CO2 lags temperature.”
Socks doesn’t like that, he calls it “garbage”. But in fact, every chart I posted does show that CO2 lags T. That is not even a point of contention in the literature any more. It is accepted that ∆T causes ∆CO2. I simply posted links which chart that cause and effect. I suspect that Socks is the only one who would call that evidence “garbage”. When someone lacks good facts, they generally tend to resort to name-calling like that.
The alarmist crowd cannot simply admit what the evidence shows: that changes in temperature are the cause of changes in CO2. That would upend their entire narrative.
Next, socks says:
…in the short term at least, seasonal temperature changes are causing changes in CO2 concentrations.
And in the mid-term, and also in the long-term. On all time scales: CO2 follows T. Therefore, all the “seasonal” arguments can be disregarded. We cannot discern seasonality in a chart covering thousands of years, or hundreds of thousands…
Next, all that evidence that CO2 follows T is not a mere ‘coincidental correlation’, as Socks contends; it is *very* strong evidence of causation, and it occurs at every time scale we observe, out to a million years and more. Socks just can’t admit it is evidence, that’s all. Because if he admitted that the ‘carbon’ scare was baseless, the alarmist narrative would take a fatal hit. Because it is all based on demonizing ‘carbon’.
Finally, Socks asks why CO2 doesn’t follow T. But it does, as I have shown repeatedly in dozens of charts like this. Socks just doesn’t understand the difference between an anomaly chart and a trend chart, or any other type of chart. The only thing that is important in this context is what was the cause, and which was the effect? Clearly T is the cause, because CO2 lags T on time scales from years, out to hundreds of thousands of years.
Next, @rooter, who says:
Did temperature lead CO2 1945 – 1975?
Yes. I have posted several charts from diferent sources, all showing that ∆T causes ∆CO2. But you have no comparable charts showing that CO2 causes any change in T. All you have are overlay charts — but they tell us nothing about cause-and-effect.
The following question is directed at my BFF ‘rooter’:
What, exactly, am I “avoiding”? You seem to think that if I don’t respond within a short time, that you have a credible argument. You don’t. You cannot find a chart showing that changes in CO2 control temperature, but I have posted a lot of charts, all showing that temperature controls subsequent changes in CO2. But you have no comparable charts showing that CO2 is the control knob for temperature.
Thus, despite all your assertions/opinions/conjectures, you really have no supporting facts for what you believe. Most importantly: you have no measurements of AGW. Do you? If you think you do, then post them here. Quantify the percentage of AGW, out of total global warming. Exactly what fraction is it? [That question is also directed at Gates, or anyone else who thinks they have the answer.]
Now, AGW may well exist. I think it does. But since there are no measurements of AGW, that means that AGW is too small to quantify. AGW is just too minuscule to matter. So, where does that leave your climate alarmism? As Chicken Little was told: the sky isn’t falling. It was only a tiny acorn.

richardscourtney

David Socrates
In response to my post which concluded saying

But Euan Mearns, dbstealey and ferdberple are discussing what the data indicates whereas you guys are promoting what you want to be true,

You have responded saying in total

You say: “Coherence of two parameters indicates that when one parameter changes then the other parameter changes later.”

A fine example of this is what has happened in the past 15 years with CO2 rising and global T not rising.
CO2 has risen (changed) about 300 ppm then the other parameter (temperature) changes later.
Thank you

But, as you admit, temperature has not risen over the last 15 years. The rise in CO2 over that 15 years cannot be said to be indicating coherence unless and until temperature does rise. Simply, you are claiming that your belief in ‘CO2 causes warming’ provides you with deific knowledge of the future.
Your response is a very clear example of you promoting what you want to be true.
Richard

David Socrates

Logic 101
“Seasonal” is a time scale.
On all time scales: CO2 follows T.

Therefore, all the “seasonal” arguments can be disregarded.

The winner is Mr dbstealey !!!!

David Socrates

Dbstealey posted…. ” ∆T causes ∆CO2. ”
..
Please provide the explanation requested in this post…
http://wattsupwiththat.com/2014/12/27/vostok-and-the-8000-year-time-lag/#comment-1824604
RE: “when global temps drop in winter, CO2 rises, and when global temps rise in summer, CO2 drops”

Socks says:
Please provide the explanation…
I’ve provided endless explanations, as have others here. This article is full of explanations. But socks is like a little kid who keeps asking, “But why… ?”
Socks is unteachable. He cannot learn, no matter how many facts are presented. That’s what happens when someone’s belief trumps the scientific method.
Throughout this article and thread endless examples have been presented showing that CO2 lags temperature. But no examples have been posted showing the opposite cause and effect. One side of the debate refuses to accept reality, because if they accept the fact that ∆T is the cause of ∆CO2, their entire Narrative comes crashing down.
So folks like Socks keep asking their endless questions. They know what’s really happening. They just cannot admit it.

David Socrates

Mr Dbstealey

I provided you a clear example of when global temperature drops, CO2 rises.. It happens every winter.
I provided you a clear example of when global temperature rises , CO2 drops….It happens ever summer.

I guess you have a hard time when someone points out concrete facts that debunk your theory. You either must modify your “theory” to account for the facts, or abandon it all together. That’s how science works.

D. Socrates continues with his never-ending commentary: “But why…?”
He is typically avoiding my central poiunt that seasonal changes cannot be discerned in thousand year charts.
I post facts, while socks makes nonsense assertions claiming that he is ‘debunking’ the facts I post. The obvious answer is to go argue with the source of my links, but socks won’t do that — he would be laughed at.
Tell me, Mr. S, how do I get a job like yours? It must be great working where you can post non-stop throughout the work day. Assuming you work…
This entire article and thread makes a solid case that CO2 lags temperature. No one has posted any credible evidence showing that changes in temperature are caused by CO2. And that is the central point: the premise that CO2 is the ‘control knob’ of the planet’s temperature has no evidence to support it, while the premise that changes in T are the cause of changes in CO2 has a mountain of supporting evidence.
But that fact is always ignored or deflected by the alarmists, who cannot admit that the planet is proving them wrong.

David Socrates

Dbstealey says: “On all time scales: CO2 follows T.”

Seasonal is a time scale.
CO2 goes up in winter when global T goes down
CO2 goes down in summer when global t goes up.

That’s the facts.
Bob, weave and dodge all you want, you can’t dismiss the facts.

David Socrates

“On all time scales: CO2 follows T.”

Seasonal is a time scale.
CO2 goes up in winter when global T goes down
CO2 goes down in summer when global t goes up.

Those are the facts.

@ David Socrates: December 30, 2014 at 6:46 am
Please provide the explanation requested in this post…
RE: “when global temps drop in winter, CO2 rises, and when global temps rise in summer, CO2 drops”

————-
First of all, there is no such thing as global temps, …. a global temp, …. or a global temperature.
There is only a calculated global average temperature which is an abstract numerical value whose only purpose is reference information.
And secondly, the seasonal (summer to winter) rise and drop in atmospheric CO2 is determined by the seasonal temperatures in the Southern Hemisphere, ….. not the Northern Hemisphere.
Atmospheric CO2 is now increasing …. because it is now Summertime in the SH. They just experienced their Summer solstice there on December 21st.
Those hot summertime temperatures in the SH are warming up the ocean waters down there and they are outgassing CO2 into the atmosphere. And that outgassing will continue until mid May 2015, which is after the Vernal equinox.in March.

David Socrates

Mr Cogar.

If you are correct and say there is no such thing as as global temps, …. a global temp, …. or a global temperature, then for the same reasons there is no such thing as “seasonal temperatures in the Southern Hemisphere” It is really cold in Antarctica around Dec 21st…..not much “outgassing” happening in the waters surrounding that continent.
You can’t acknowledge one, and reject the other.
Besides, you seem to forget that the cold waters in the NH oceans are sucking up the CO2.
Can you tell me what is wrong with this graph?
http://wattsupwiththat.files.wordpress.com/2013/03/clip_image0041.jpg?w=700

george e. smith

Well the CO2 and temperature track one way from 1880 to 1920, then they switch directions from 1920 to 1945, where they switch again until 1980, and only from 1980 to 2000 do they match with this totally phony overlay.
If you rescale the graphs, to track from 1880 to 1920, or 1920 to 1945 or 1945 to 1980, you get three totally different pictures.
Michael Ernst should be pilloried in the stocks for generating this piece of camel dung graphics.

george e. smith

I was of course referring to Mike B’s graph from Woods Hole.
BUT “””””….. In Vostok, the time lag between snow falling and ice trapping air varies between 2000 and 6500 years. …..”””” from Euan’s article.
So plotting temperatures from 1880 to 2000, versus ice cores, which aren’t even ice cores in 1880, would seem to be totally worthless.
But anyhow, this 1880 to 2000 temperature graph has 4 separate and different slope regimes, and you can scale the CO2 plots to each of those four gradients, and get four different pictures of what is total crap. There is no functional match between these graphs whatsoever.
g

@ David Socrates: December 30, 2014 at 3:53 pm
If you are correct and say there is no such thing as as global temps, …. a global temp, …. or a global temperature, then for the same reasons there is no such thing as “seasonal temperatures in the Southern Hemisphere”
———————-
David, look at your “outdoor” thermometer and then tell me what the “global temp, temps, temperature” is there where you live.
Then look at your “outdoor” thermometer again and tell me what the “seasonal temperature” is there where you live.
Ps: Do you know anyone that has a thermometer for measuring global temp, temps or temperature?
===================
It is really cold in Antarctica around Dec 21st…..not much “outgassing” happening in the waters surrounding that continent.
—————–
There is a lot more “outgassing” of CO2 happening there than there is from the Arctic Ocean around Dec 21st. And that doesn’t include all the “outgassing” of CO2 from the Penguins and the zillions of Krill that are swimming in those Antarctica waters.
================
Besides, you seem to forget that the cold waters in the NH oceans are sucking up the CO2.
——————
Not those portions of the NH oceans that are covered with ice ….. ain’t sucking up any CO2.
And besides, comparing the NH oceans to the SH oceans a sucking up CO2 …. was akin to comparing a horse to a camel a sucking up water.
You really should educate yourself on the “difference” in square miles of ocean surface waters between the two hemispheres …… and the fact that iffen it’s the winter solstice in one hemisphere then it is the summer solstice in the other hemisphere.
Just like a cold can of beer, … when those cold ocean waters start warming up …. they start outgassing CO2, ….. simply because “CO2 lags the temperature”.
David, pour yourself a glass of champagne … and next week I’ll explain the “bubbles” to you.
==============
Can you tell me what is wrong with this graph?
———————-
David, there is nothing wrong with that graph ….. iffen you comprehend and/or understand what you are looking at. If you are ignorant of why that data was plotted on that graph, …… then you could potentially find 100 things wrong with it …… or you could potentially think up 100 things that you “think you see” in/on that graph and be totally wrong about all 100 of them.
And me thinks your problem is best described by the latter of the above two.

Nice post. A surprising amount of ‘junk science’ has gone into trying to disappear the CO2 lag Euan discusses. See essay Cause and Effect in Blowing Smoke for several rather ripe examples. Worst was Shakun’s paper. He was also second author on the Marcott abomination. Two fine examples of recent OSU ‘climate science’ bordering (for sure in Marcotts case, essay A High Stick Foul) on academic misconduct.

the lag was predicted, nobody is trying to disappear a successful prediction
http://www.atmos.washington.edu/2009Q1/111/Readings/Lorius1990_ice-core.pdf

mpainter

Lots of people have tried to attribute climate change to atmospheric CO2,
Mosher, ice ages, whatnot, and still do. Perhaps you should help deliver the truth.

Stephen, the several peer reviewed papers cited in my essay Cause and Effect, most notably Shakun’s, provide rather clear evidence that your comment ‘nobody is trying to disappear a successful prediction’ is not correct. Several such nobodies are specifically called out, including but not limited to Shakun. It would seem even you might learn something by reading it and checking the references.

DEEBEE

Rud ut is typical Moshian (and Stokian) style to take a fuzzy general statement, pretend it is absolute and give a single contrary example and then effectively proclaim SEE?!

whiten

“Over four glacial cycles CO2, CH4 and temperature display cyclical co-variation. This has been used by the climate science community as evidence for amplification of orbital forcing via greenhouse gas feedbacks.”
—————–
Let me share a thought here.
Have taken the first conclusion as an example to clarify my point here.
As far as I can tell the bigger problem in climatology is the assumption that the orbital forcing has an impact in global climate and global temperatures, because it can be shown that it does have a significant impact in the polar climate and polar temperature variations in long term.
It can not be proven as far as I can tell that the same holds true in the case of the global term.
It is very expectable that the extremity of the polar reagons will be in tune with the orbital forcing.
So if this true what considered as climate cycles or glacial cycles is only the periodic extremity variation in the polar regions, not necesarely the climate and climate change in the meaning of global.
With that in mind, it is impossible that the CO2 effect can be analyzed in regard to the polar variation, and will be most probably confusing. Also as in the case of the CH4 which depends more than CO2 in the actual polar temperature especially in the local terms (while CO2 doesn’t), the corrolation will be expected and is not an explanation for anything in the terms of global but more in the terms of regional.
Now I can be in plenty of error here, but if this the truth than we are trying to understandand and explain the global climate in terms of polar extremity variation and failing to recognize that the climatic global pattern may not be in synchronity at all with that of the extreme periodic variation of the polar reagions.
For example in the extremes of orbital forcing periods, during an Interglacial optimum the temps in Antarctica will be similar and considered as same as during a glacial period during a minimum orbital forcing period, therefore relying in it, will give the wrong impression of the glacial cycles and the global climate pattern.
The climate actually could be in an Interglacial and we will end up considering it in as it been in the mids of a glaciation.
A glaciation period does not necessarily depend in the regional polar regions, it depends primarely in the global temps in accordance to climatic trends. The temp measurements do not represent the global ice extent actually, and could lead to huge errors if the polar temps used to estimate that without the global climate signal considered.
Orbital forcing is not a climate changer, as the last 18K years clearly show, but the heavy relying on the polar reagions behaviour and data to estimate the global climate makes that so by default.
Actually is more feasible to consider under all circumstances that the orbital forcing does make not an observable impact in climate unless the polar regions considered.
cheers

euanmearns

http://www.euanmearns.com/wp-content/uploads/2013/12/CB_all.png
This one of the more important and stunning data sets on d18O in benthic foraminifera from the global oceans suggesting that what was happening at the poles was happening in the oceans as well. An earlier comment pointed out that ice sheets caused d18O to change in the oceans. I’m unsure of my facts here, but I think that this chart is driven by temperature and not ocean water d18O.

Mike McMillan

Source for the chart data, please. Thank you in advance.

euanmearns

The chart I grabbed from Clive Best, not sure where he grabbed it. The data is here:
http://www.lorraine-lisiecki.com/LR04stack.txt
A Pliocene-Pleistocene stack of 57 globally distributed benthic D18O records
Lorraine E. Lisiecki Department of Geological Sciences, Brown University, Providence, Rhode Island, USA
Maureen E. Raymo Department of Earth Sciences, Boston University, Boston, Massachusetts, USA
PALEOCEANOGRAPHY, VOL. 20, PA1003, doi:10.1029/2004PA001071, 2005

Kitefreak

Sorry I blew up on you in the previous thread; I hastily mistook you for a troll. My apologies.

Louis

I was thoroughly confused by the charts until I realized that they read from right to left. I’m used to reading left to right, which is also the way Mann’s hockey-stick chart reads. It would be nice if it was standard practice for time to be charted left to right to avoid confusing amateurs like me. But then why make things easier?

euanmearns

Sorry about that but I just can’t get XL to plot charts with 2 Y axes with x axis travelling the way you want.

Rainer Bensch

Have you tried x from -1400000 to 0 ?

johann wundersamer

but its simple:
starting NOW retracting to ever deeper PASTS –
left 2 right!
2 converse:
converse the sorting of time / dates.
Regards – Hans

Don K

You’re right that most time charts read left to right. For some reason it is the convention in ice core work and a few other things to plot time right to left. Perhaps it has to do with plotting depth normally (left to right) which puts the oldest age (greatest depth) on the right. And yes, it confuses almost everyone.

Richard

“Average temperature is -55˚C and the record low is -89.2˚C which is below the freezing point of CO2.”
Not so. The freezing point of CO2 at the concentrations they are on Earth would be more like -140 C.

euanmearns

🙂 OK
Is there any possibility of CO2 combining in water ice clathrates?

Richard

Does it form this presently in the arctic or antarctic?

michael hart

“Is there any possibility of CO2 combining in water ice clathrates?”
I wouldn’t be surprised. It is generally sensible for chemists to not be surprised. Climate scientists appear to find themselves surprised more often. Except when they say the science is settled.
CO2 certainly forms aqueous hydrates as well as chemical reaction to form carbonic acid. e.g:
http://web.mit.edu/wbdurham/www1/papers/76-Circone-et-al-2003.pdf
What happens at heterogenous interfaces is often a completely different ball game to what happens in the bulk phase.

Mike McMillan

Yes.
eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/32477/1/P393-421.pdf

Mike McMillan
euanmearns

The air-bubbles are gradually compressed with depth and begin to transform into clathrate hydrates below the level at which the hydrostatic pressure becomes greater than the dissociation pressure o f the phase o f air clathrate hydrate.

I’ve now reached information overload 🙁 I guess the CO2 recovery process does not distinguish between bubbles and clathrates?

Euan,
Clathrates of CO2 and at higher pressure (deeper) even of O2 and N2 are partly decomposed during relaxation: decompressing the ice core after drilling for at least a year at the surface around – 20°C.
For the ice core parts above the clathrate forming depth and below (all clathrates), there is no problem at measuring time (mostly grating of the ice under vacuum, which liberates air from the bubbles), but the depth where clathrates start to form until fully formed show some redistribution of CO2 over clathrates and still open bubbles (only the latter is measured in the grating technique). That can be avoided by using complete sublimation, cryogenically separate all components and measuring over a mass spectrometer (thus also measuring the different isotopes).

Richard,
Correctomundo. We had this conversation a while back, and it was a doozy. You could look it up in the search box.
Conclusion: CO2 never solidifies.

Dbstealey
Oh no! I have this sense of deja vu all over again. Some people here obviously weren’t around five years ago
Tonyb

SandyInLimousin

Probably confirmed by Martian winter at the poles, temperature reaches -150’C or lower and as I understand there is “solid” CO2 at the Martian poles in winter. The summer temperature of Mars is about -50’C but Mars isn’t covered in solid CO2. The Martian atmosphere contains about 10x as much CO2 as Earth’s atmosphere.

Richard

@SandyInLimousin What is important is the temperature and the pressure not the quantity of CO2. It just so happens that because Mars atmosphere is 96% CO2 and its surface pressure in 6% that of the Earth’s that the temperatures that CO2 would solidify on Mars and the Earth are comparable.
But the polar ice caps are mostly water ice I believe. The CO2 subliming back to the atmosphere during the summer.

Beautiful clarity in your work, Euan. Thanks very much.
Just one question – as I’m not familiar with the methodology of the Petit et al work :
The correlation produced for CH4/CO2 and temperature determines the calculation of the lag – is that so?
If so, then the assumption is made that the trapped air bubbles have a complement of CH4 and CO2 that is not modified during the long compaction process, or we could end up with different lag errors for the different gases. What is your take on this? Am I just being difficult? It would throw a different light on the conclusions if the lag(s) were questioned.

Looks like Robert of Texas (above) was on about the same thing and I didn’t really notice. Sorry. But maybe others have some useful comments on this?

euanmearns

Figure 5 (above) is probably the most important here. This is also dealt with in another comment. The time to make ice at Vostok is several thousand years. So there is plenty time for exchange between firn and atmosphere and for diffusion within firn before bubble closure. All I have to go on is the observation that CO2 and CH4 are quite closely aligned at terminations but not so on return to glaciation. The diffusion characteristics of CO2 and CH4 may well vary, but I don’t think this explains the 8000 year time lag.

Brian H

The intermediate 800-yr lag puts the MWP as the precursor of the current CO2 rise. Note that the Mona Loa records show no fluctuations corresponding to known variations in human emissions.

Brian, the lag of CO2 after a temperature change between the MWP and LIA is only 50 years at the onset of the LIA and the change in CO2 is only ~6 ppmv for a temperature change of ~0.8°C. As the MWP is about as warm (if not warmer) as today, the change of CO2 caused by the temperature increase since the LIA is not more than 6 ppmv. The rest of the 110 ppmv increase is from human emissions. See the Law Dome ice core:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/law_dome_1000yr.jpg
from Etheridge e.a. 1996.
The overall change over the 8 glacial – interglacial transitions and back is about 8 ppmv/°C, mainly caused by the deep oceans (as the change in δ13C is small). The current increase needs at least 12°C temperature increase of the ocean surface to have the same effect…

Brian H

Wrong way round. It’s the onset of the MWP that drives current CO2 rises.

Neville

The recent Royal Society and NAS report also states at point 20 that if we stopped all human co2 emissions today it would take thousands of years before co2 levels or temp changed. Rather a different story than some of the scientists and MSM are telling the public.
https://royalsociety.org/policy/projects/climate-evidence-causes/question-20/

euanmearns

If you accept as a starting point that rise in CO2 is down to burning FF then you quickly conclude that about 50% of CO2 emissions are removed from the atmosphere each year. It’s actually quite miraculous. Our tentative conclusions are CO2 fertilisation and biosphere expansion are the processes. How long this can go on? One thing for sure, burning forests in power stations instead of coal is probably the worst thing you can do.
Switch off emissions today and the photosynthetic terrestrial and ocean pumps continue to pump and we should return to substantially reduced levels of CO2 within a couple of centuries. Apollo astronaut Phil Chapman blogs on Energy Matters and described an equilibrium distribution theory that I think may be correct. Burning FF has changed the amount of C circulating in the atmosphere and biosphere, so we don’t pump down to pre-industrial, but a shifted baseline. But with climate sensitivity likely less than 1.5 that doesn’t really matter.

Latitude

Switch off emissions today…and all processes dependent on CO2 will reduce it to limiting again….back to where we were

Brian H

Biodeposition of carbonates as minerals has a much longer timescale than we’re used to, but ends with starved plants and their consumers. Gaia wants us to recharge the air with some of that lost plant food.
>:)

The recent Royal Society and NAS report also states at point 20 that if we stopped all human co2 emissions today it would take thousands of years before co2 levels or temp changed.
That is not what the Royal Soc report says, it says: “if emissions of greenhouse gases were to suddenly stop, Earth’s surface temperature would not cool and return to the level in the pre-industrial era for thousands of years.” Not the same thing at all.

mpainter

Same thing Phil.
Assumed CO2. How else do temps stay .5° higher when natural variation does that in half a century.
All alarmist BS, Phil. Do not let them frighten you.

Neville, the slow reduction of the extra CO2 in the atmosphere is based on the Bern model, which assumes a saturation of the deep oceans, for which is not the slightest sign. The current sink rate is directly in ratio to the CO2 pressure difference (pCO2) between atmosphere and the ocean surface, the latter slightly depends of the surface temperature. That gives an e-decay rate of about 50 years or a half life time of ~40 years, not much different from a similar calculation made by Peter Dietze some 17 years ago:
http://www.john-daly.com/carbon.htm
That shows that the deep oceans still don’t show any sign of saturation…

Donb

Concerning orbital (Milankovitch) cycles inducing the glacial cycles. It is well known that changing orbits vary the solar irradiance at Earth. But the main effect alternates between northern and southern hemispheres. So when the NH is in glaciation, the SH is receiving extra irradiance on the 22 kyr cycle. Yet the NH gets heavily glaciated, the SH not. This must indicate a strong dependence on the greater ocean surface in the SH moving heat around, and possibly on changing cloud cover. The colder NH possibly turns off the AMO, chilling the Arctic even more, and this is further amplified by higher albedo.

euanmearns

I wish I new the answer 😉 I think thermohaline circulation / Gulf Stream is critical to the presence or absence of ice in NW Europe. My thinking goes: Sun – spectral output – thermal structure of atmosphere – sub polar jet stream – atmospheric circulation – ocean currents – large scale heat transfer to high latitudes.
I have been a fan of Bond et al 2001 (science) for many years but I’m finding hard to validate their data. They advocate competition between Labrador Current and Gulf Stream.
Linking any of this to Milankovitch is a bitch.

Donb

To Euan: One factor that we KNOW changes Earth’s energy input is the orbital cycles. So we are obligated to work them into the mix. I agree they are not the whole story, but likely are what begins the cycles.
To tty below: I agree that the NH has much available land to collect ice, whereas the SH does not. Even if Antarctica rew more ice, that would chamge albedo very little. Another likely factor is that the NH has restricted ocean current circulation, whereas circulation in the SH is wide open, and includes the circum-Antarctic current.

tty

Donb:
The circum-antarctic current (and associated weather, which is cold, wet and stormy) will, if anything, promote glaciation if there were only some land for it to occur on. Nearly all the Subantarctic islands have been, or still are heavily or completely glaciated and the same is true for the only two major landmasses that really stick down into the stormy belt (Patagonia, South Island).

tty

The reason there is not much glaciation in the South is mostly due to there being no place for much more ice than is already there. It is impossible for an ice cap to expand beyond the 500 meter isobath, because a glacier front can’t become higher than c. 50 meters because of mechanical strength constrainta. This means that the Antarctic ice cap cannot grow very much during glaciations, no matter how cold it becomes. It does grow a bit because NH glaciation lowers the sea-level, but it never becomes more than about 30% larger in volume than it is today.
Outside Antarctica there were substantial icecaps over southern South America and the South Island of New Zealand,, but there are no other land areas of any size at reasonably high latitudes (and with reasonable precipitation). Australia is too low, too far north and too dry for major glaciers (except for Tasmania), and the same applies even more to South Africa (though there are traces of small-scale glaciation in Lesotho, so if future glaciation gets just a little colder….).

William McClenney

Euan,
This may be of interest as well:
“In this work ice-core CO2 time evolution in the period going from 20 to 60 kyr BP [15] has been qualitatively compared to our temperature cycles, according to the class they belong to. It can be observed in Fig. 6 that class A cycles are completely unrelated to changes in CO2 concentration. We have observed some correlation between B and C cycles and CO2 concentration, but of the opposite sign to the one expected: maxima in atmospheric CO2 concentration tend to correspond to the middle part or the end the cooling period. The role of CO2 in the oscillation phenomena seems to be more related to extend the duration of the cooling phase than to trigger warming. This could explain why cycles no coincident in time with maxima of CO2 (A cycles) rapidly decay back to the cold state.”
http://einstein.iec.cat/jellebot/documents/articles/Phis.Lett.A_2007.pdf

We have observed some correlation between B and C cycles and CO2 concentration, but of the opposite sign to the one expected:
==========
which is consistent with the graphs. if CO2 has an effect on temperature the sign is opposite to what climate science believes. More CO2 causes cooling.

rah

Last sentence of first paragraph brought my first question:
“At the onset of glaciations temperature drops to glacial values before CO2 begins to fall suggesting that CO2 has little influence on temperature modulation at these times.”
When does CO2 have real influence on temperature modulation? When has it had such influence?

with greenhouse gases at a maximum things turn colder” says it all.

Steve Keohane

That’s always been my take on the ice core graphs, why, if the GH gases are a strong ‘forcing’, do we re-glaciate when they are at their highest levels.

We re-glaciate when oceans are warm and the polar sea ice is thawed. This polar ice cycle does not really care what the GH gases are doing. Look at actual data.

Randy

I have trouble believing we can use air bubbles to give us any meaningful level of accuracy for any of these variables.

Randy, having read up a fair bit on ice core interpretation, let me qualify your doubt (butnonly as a self educated layman on the subject). It is not as bad as you might think.
There are two problems. First, when did the bubble form as firn converts to ice. That depends on a lot of things. So lends an estimable amount of temporal uncertainty to the bubble. Second, sunsequent diffusion from the bubble into the ice. The further back in time, the more this can distort results. So uncertainty increases with age. But careful ice core analyses bound these issues. Euan’s post carefully stays in territory outside those uncertainty bounds, that is on pretty solid ground.

Donb

Rud,
I agree with your comments, but add some extra.
Diffusion of CO2 is driven by both pressure and concentration gradients between the bubble and outside. As the bubble is squeezed and pressure grows, air inside diffuses outward. But CO2 concentrations are measured relative to N2 which also diffuses outward. So in principle this process should not change the relative CO2 concentration. CO2 diffusion driven by concentration moves both ways, into the bubble and out. This is presumably why the relative CO2 concentration reflects changes in the atmosphere, or at least CO2 in firn above. So long as the bubble remains in diffusion communication wit the atmosphere, it tends to represent changes in air CO2.
BUT there are minor factors which are harder to predict. CO2 and N2 likely differ in the degree they are “sticky” inside the bubble due to physical or chemical absorption. Such may fractionate CO2 from N2. Also, at very low temperature the diffusion rate is slow, and will cause some lag time in response to concentration gradients. These effects are hard to evaluate.

Rud, there was some theoretical estimate of CO2 migration in relative “warm” coastal ice cores, based on migration near remelt layers in the Siple Dom ice core. That translates to a broadening of the resolution from 20 to 22 years at middle depth and to 40 years at near bedrock. Not a problem. See:
http://catalogue.nla.gov.au/Record/3773250
In the much colder inland cores (Vostok, Dome C) there is no measurable migration, as if there was any migration, the CO2/T ratio over the interglacials/glacials would fade for CO2 for each interglacial 100 kyear back in time…

It’s the-nothing-is-what-it-seems magic show.
If you zoom in on the last glacial transition (<20ka), you'd see that the CH4 corrolates strongly (instantaneous) with the Greenland ice core isotope thermometer, while the CO2 corrolates (lagging) with the Antarctic ice core isotope thermometers, while there is a clear significant difference between the two groups, http://img38.imageshack.us/img38/9509/transitioniceagegrlndan.png
Yet, both gasses are global in nature. So what was the global temperature doing?
But then again CO2 from ice cores seem to underestimate CO2 compared to quickly increasing and -apparantly robust stomata record ie Steinthorsdottir et al 2014 QSR 99 -pp 84-96, while the isotope paleothermometer may be considered suspect at best (. https://dl.dropboxusercontent.com/u/22026080/non-calor-sed-umor.pdf ).
Maybe we should start from scratch again interpretating the geological records.

tty

The isotope paleothermometer may be suspect but anyone who thinks the Younger Dryas wasn’t cold in Northern Europe is simply ignorant. Says one who grew up literally on the end-moraines left by the Younger Dryas. Don’t tell me that those moraines, and sandur fields, and nivation niches, and niche glaciers, and frost wedges, and patterned ground, and fossil pingos were caused by warm climate.

Sure, but you checked the time scale. If anything was cold, why not the Allerod, shortly before the Younger Dryas?
http://www.sciencedirect.com/science/article/pii/S0277379107001035

tty

Because Alleröd, in contrast to Younger Dryas was a time when the inland ice retreated, sea-level rose and animals and plants (including humans) dispersed northwards and colonized the newly deglaciated areas.

André, ice cores don’t underestimate CO2, CO2 levels at closing depth are the same in the newly formed ice bubbles as in the still open pores. There mat be some migration, but that only broadens the resolution and can’t change the average over the time of resolution. Stomata data are far from robust and while they have a better resolution (of local CO2 changes over land, not necessary in the bulk of the atmosphere), if they show higher CO2 levels over the resolution period of the ice cores, they are certainly wrong…

David Socrates

One thing notable in the entire ice core record is that there never was a time where the concentration of CO2 came anywhere near 400 ppm. In other words, irrespective of any lead-lag relationships, we currently are in uncharted territory.

Latitude
David Socrates

That study does not say how the C4 pathway affects climate.

Latitude

David, you have it backwards…..

tty

It should be: “there never was a long time where the concentration of CO2 came anywhere near 400 ppm.”
Ice core records are notoriously unable to resolve brief event. Actually stomata studies suggest that CO2 levels did touch 400 ppm briefly during the last deglaciation. Rather worryingly it happened just before temperatures plunged at the beginning of the YD.

David Socrates

Per the article “One year is therefore represented by only 7.8 mm ”

Therefore 50 years would be over 15 inches.

You would surely see a “blip” in CO2 concentrations in a 15 inch long core. There aren’t a whole heck of a lot of stomata in the Antarctic. You won’t find 400 ppm of CO2 in any of the Greenland ice cores either.

Actually stomata studies suggest that CO2 levels did touch 400 ppm briefly during the last deglaciation. Rather worryingly it happened just before temperatures plunged at the beginning of the YD.
=============
consistent with the graphs. if increased CO2 has any effect on temperature, it is increased cooling not warming.

tty

David Socrates:
Remember that the gasses aren’t isolated until the pressure is high enough to compress the snow into solid ice. That happens at a depth of about 300 feet. To accumulate that much snow takes millenia in inland Antarctica and centuries in coastal Antarctica and Greenland.
The gasses in a single bubble is a mixture of atmospheric gasses from this whole interval, though of course in lesser proportions from the later part.
The recent WAIS Divide ice-core (from a high precipitation site) has better resolution than earlier cores and can apparently just barely resolve century-scale events in the Late Pleistocene. Not unexpectedly it is much “bumpier” than earlier ice-core records, but still very smeared-out compared to stomata measurements.

Donb

tty:
I don’t know how much to trust stomata data. Plant stomata serve mainly to intake CO2 into the leaf for photosynthesis. But H2O also escapes through stomata, and this may be deleterious for the plant. If the plant has ample water, then CO2 alone may control stomata size and number. But if water is limited, the plant may lessen the size and number of stomata to prevent H2O loss (and limit its growth rate), even when CO2 is plentiful.

tty, the resolution of ice cores depends of the local snow accumulation rate at the place of the core. That is very high at coastal cores (Law Dome, Siple Dome) and very low for inland cores (Vostok, Dome C). The resolution is less than 10 years for Law Dome, but the 1.2 meter ice equivalent makes that rock bottom was reached for 150 years of ice only. For Vostok, the resolution is 600 years and for Dome C 560 years but go back in time for 420 resp. 800 kyears.
As for any ice core the reproducibility of CO2 measurements is about 1.2 ppmv (1 sigma), that gives that the current increase of 110 ppmv over 160 years would be visible in all ice cores, even Vostok and Dome C, as a peak of at least 15 ppmv and more for the better resolution ice cores.
Forget stomata data, they show local CO2 levels over land which may go all over the scale, depending of what happens in the main wind direction (land use changes, type of crops,…). Taylor Dome has a resolution of ~40 years and spans the LGM-current deglaciation. There is no peak of 400 ppmv visible…

David Socrates

Latitude, you point about the C4 pathway evolution is irrelevant to the discussion of CO2 in ice cores.

Latitude

David Socrates
December 27, 2014 at 2:30 pm
One thing notable in the entire ice core record is that there never was a time where the concentration of CO2 came anywhere near 400 ppm. In other words, irrespective of any lead-lag relationships, we currently are in uncharted territory.
==========
David, if you don’t have an ice core that goes back prior to C4’s……then you only have ice cores when CO2 was limiting

Dariusz

No this is not correct. From geology point of view we currently live on the CO2 starved planet. Most of the time co2 level was much higher. Stromatolites that existed since the Archean are intertidal bacteria endured co2 of more 10% in the atmosphere.

David Socrates

Dariusz

From an evolutionary point of view plants have adapted to the levels of CO2.

Yes, plants have adapted to the present starvation levels of. They prefer much higher levels of CO2. That’s why greenhouse growers jack up the CO2: it is harmless, and it is very beneficial.
Of course, that deconstructs the entire alarmist narrative. So as Richard Courtney writes above:
dbstealey is correct and you are wrong…
There is no one who is less inclined to face facts than D. Socrates. Because if he did, he would be forced to admit that skeptics have been right all along: CO2 is harmless and it is beneficial to the biosphere. More is better.
But some folks just cannot admit that anyone else is right. They would rather die first. Remember: Martyrs will die to be right. But that doesn’t mean they are. All it means is they are too unreasonable and too stubborn to accept reality.

David Socrates

“““Yes, those of us up to speed on the subject know that global temperature (T) rises or falls the most at night”
….
Boy, I’m glad I’m not up to speed like you are.
….
http://wattsupwiththat.com/2014/12/31/2014-in-review/#comment-1825830

mpainter

Sock rats:
What’s the matter? Did you run out of junk science? Nothing left but sneers?
Something tells me this is the real sock rats.

David Socrates

Mpainter…….payback for all the name calling dbstealey does.

Besides, I’m just pointing out how “up to speed” he is.

joel

I did hear a speaker address this. He said that the gases do migrate in these ice cores. They are not in a crystalline lattice. So, you would expect CO2 in areas of higher concentration to migrate to areas in the ice of lower concentration. He concluded that the concentration of CO2 was certainly higher than the values found in the ice cores today.
I don’t know if any of this is true or accepted by other climatologists. But, it makes sense.

Mike McMillan

If you google “diffusion of CO2 in ice” you’ll get several pdf’s that address the topic. The short answer is yes, but not a lot.

http://popesclimatetheory.com/page16.html
This tiny bit of CO2 in uncharted territory is still a tiny bit and cannot regulate the temperature of Earth.
Go find something abundant, such as water in all of its states.
http://popesclimatetheory.com/page76.html

DEEBEE

That first link is p, at best, irrelevant, if not juvenile. If one of ten thousand is insignificant according to you, then at what point is it significant and why. Is this a molecular democracy?

Gary Pearse

“re-creation of northern hemisphere ice sheets will kill high latitude forests and cause global migration of climatic belt boundaries towards the equator. Killing forests reduces the size of the terrestrial CO2 pump whilst simultaneously adding a source of CO2 – rotting wood.”
I don’t think you can be correct that such a freezing is going to cause wood to rot. There is driftwood on the north shore of Greenland that had to have been beached during a warmer period, maybe even the Holocene Optimum. Rotting suggests abundant bacteria and moisture and I believe it was a pretty dry cold desert we are talking about here.

tty

Dead forests burn well, even when it’s cold. Ever try to find any remaining wood from the previous interglacial?

trafamadore

“These natural geochemical cycles makes it inevitable that CO2 and CH4 will correlate with temperature. It is therefore totally invalid to use this relationship as evidence for CO2 forcing of climate, especially since during the onset of glaciations, there is no correlation at all.”
It may be “invalid to use this relationship as evidence for CO2 forcing of climate” but I assume you don’t mean to suggest the opposite, that CO2 forcing isn’t happening now. Just checking.
Exactly why CO2 lags temp in the distant past is still an unanswered question, which is why Petit et al don’t speculate as to the cause. That strengthens the paper in my opinion.

DEEBEE

And it is also unwarranted to suggest that CO2 forcing is happening at a level that is appreciable to hyper ventilate. Requires a much more precise estimate I’d sensitivity. Which we do not have.

It’s the expansion and contraction of the solar system and it’s effect on the sun, two major players in actual climate fluctuations, I’m just letting you know. and yes there are observations on this spanning hundreds of years!

Phlogiston

About the CO2 lag to temperature at glacial inception. Ryan mentions die-off of taiga forests. I can think of one more process that would have similar effect in decreasing CO2 uptake and increasing supply. Sea levels would fall rapidly so that the shallow seas with high primary plankton productivity would be drained and become exposed mud. They would rot and stink for a while before eventually becoming covered in terrestrial vegetation.

Phlogiston

iPhone spellcheck changed Euan to “Ryan “.
I meant Euan.

Bill Illis

CO2 lags behind the temperature changes. Simple as that. And they are sometimes going in opposite directions as well.
The ice ages start when the snow and sea ice does not melt-out in the summer at 75N. Summer solar insolation needs to drop below 420 W/m2 at 75N for this to happen. Today it is about 450 W/m2 and the sea ice and snow melts out with a few months to spare. The solar insolation at 75N will not decline to the 420 W/m2 level until either 52,000 years from now or, more likely, 125,000 years from now. No ice age for a long, long time.
Once the glaciers start building up at 75N, they gradually start to reflect more and more sunlight and they start pushing south, reflecting ever more sunlight. It is only until the summer solar insolation stays high enough, for a long enough period of time, say 5,000 years that enough 2 km thick glacier can be melted back starting at Chicago and ending at Eureka at 80N, before an ice age comes to end. It takes time to melt all that ice out. If the Milankovitch Cycle spikes up for 3,000 or 4,000 years, that is not enough time to melt out the ice and the ice age goes on and on. It is more-or-less just a fluke that in the last 800,000 years, the upspike ending the ice ages come at 100,000 years apart. They are not regular.
It is snow melting at 75N or not and then at least 5,000 years of upswing to melt out the glaciers.
Notice there is no role for CO2 in that physical explanation.

tty

I strongly doubt those 50 000 / 125 000 year interglacial theoiries. It seems extremely unlikely that we just happen to be living in the longest warm period for at least 15 million years (yes, it was as warm or warmer during parts of the early Pliocene, but there were no uninterrupted warm periods nearly that long). The whole thing reeks of “the anthropic principle”. It seems much more likely that there is some unknown factor we haven’t figured out yet that prevents the occurrence of very long warm intervals. After all it isn’t as if we really understand why glacials are about 100 000 years long, so I don’t really have much confidence that we can predict the length of an interglacial.

Donb

The important orbital cycles for glaciation are about 22 kyr and about 100 kyr in length (see Euan’s graph). We are entering a time when these two cycles tend to cancel out, and so any cooling in the next 50-100 kyr will be less than prior.
Back before the ~100 kyr glacial cycles began about a million years ago, glacial cycles were less intense and on ~44 kyr cycles (another orbital cycle). It is unknown why the change-over. Global temperature began dropping about 5 million yrs ago. That was likely due (at least in part) to changes in ocean circulation and land mass distribution, especially the closing of the ocean connection between South America and Central America.

whiten

@tty
December 27, 2014 at 3:49 pm
tty, you see the peaks of warming in the graphs above do show at least the last three Interglacials, acoording to the data and the interpretaition of the glacial and interglacial cycles. There the interglacials seem to be as 15k years long and the glacial periods at about 100K years long.
But that is according to the polar regions temps.
What shown by the data is that actually the chance of the interglacials to be 15K years long is a good enough one, BUT NOT THE SAME CHANCE FOR THE LENGTH OF THE GLACIAL PERIODS.
So the accuracy of the polar regions temps showing an interglacial and it’s correct length could be explained by the coincidence that the orbital forcing minima (once every 100K years) coinciding with an interglacial period, meaning that there inbetween could be other interglacials inbetween but the signal will be weaker in the polar regions temp data and in accordance the whole period between such clearly defined interglacials will be considered a glacial period.
The Ice core data in their own can not be showing an accurate picture of the global climate, but more so for the regional polar climate.
The most and the only accurate thing that Ice cores data can show about the climate is the length of what called interglacials, and that so only because of a coincidence of the interglacials periodicity and the orbital forcing minima, meaning a stronger signal for only these “lucky” interglacials in the Ice cores, while the “unlucky” ones missed and considered as glacial periods..
cheers

Bill Illis
The ice ages start when the snow and sea ice does not melt-out in the summer at 75N. Summer solar insolation needs to drop below 420 W/m2 at 75N for this to happen. …. Once the glaciers start building up at 75N, they gradually start to reflect more and more sunlight and they start pushing south, reflecting ever more sunlight.

In today’s world, there is almost no land at all north of 75 N latitude. Are you sure of this latitude? Even the north coast of the Siberian and Canadian arctic is between 70 – 72 north. Sea ice? Yes. But glaciers? No.

Bill Illis

Ellesmere Island, northern Greenland, generally non-glaciated right now, the Arctic sea ice which melt out in the summer is at 75N.
Even in the deepest downturns of the Milankovitch, the summer sun is more than strong enough to melt out the snow at 65N in the summer The sea ice always melts out at 65N in the summer.
75N is the make-or-break latitude where the ice ages start.

tty

It’s not just a matter of latitude. Altitude and precipitation are extremely important too. The mountains of Scandinavia was a core area for previous glaciations and they are between c. 60 and 70 degrees north (we know that the ice reached the coast near Bergen even during the very first cold snap of the latest glaciation, MIS 5d) .
On the other hand Eastern Siberia and Alaska and Yukon north of the coastal mountains have never been glaciated – too dry.

the Iceage correlation is with insolation at 65ºN.

Bill Illis

Just a chart showing the Milankovitch Cycles versus the last Four Ice Ages. To say it is complicated is an huge understatement.
It takes a really good down-turn to kick us out of an interglacial into an ice age and then it takes a long time to melt out all that ice and overcome its thermal inertia. One should also keep in mind that at the southern edges of the ice-sheets (as in Chicago), the summer sun is almost the same as today and the ice-fronts are melting rapidly in the summer at least. They should never actually get down to Chicago. The Mississippi River is a massive torrent all year long in the ice ages.
Its the ice volume building up and the volume drawing down and then how much time it takes for a full build-up or a full draw-down. As an example, the southern third of Greenland is going to melt out if this interglacial lasts another 5,000 years and it is going to melt out completely if the interglacial lasts a further 25,000 years after that.
http://s16.postimg.org/63v3fs8xx/Last4_Ice_Ages_Milankovitch.png

Tom in Florida

Bill, you say ” the summer sun is almost the same as today” however at the time an interglacial starts perihelion is advancing towards NH summer solstice while obliquity is increasing. Currently perihelion is in NH winter just after the winter solstice and obliquity is decreasing. Those differences are what determines whether we are heading into or out of an interglacial. The third piece of course is eccentricity, which is now low and that show allow this interglacial to linger a while longer; similar to the one 400,000 years ago.
Also your chart show summer insolation at 75N. Isn’t the standard 65N?

Bill Illis

Tom in Florida, the difference in the solar insolation in the Milankovitch Cycles is extremely small. For Chicago, it is a difference of something like 160 kms north or south. The summer sun in Chicago in the deepest downturns of the Milankovitch is like the summer sun in Milawaukee today (a little farther north than that actually but anyway) And then the winter solar insolation in Chicago is actually higher, something like Lafayette Indiana. It is almost no change at all.
That is why I use 75N, because that is the latitude where 160 kms of difference makes a difference between the snow and ice melting or not. It doesn’t make a difference at 65N. 65N snow stops melting in the summer when there is 500 metre high glaciers and permanent sea ice at 70N, thousands of years after there is 500 metre high glaciers at 75N.
http://s18.postimg.org/9zec2vst5/Milwaukee_Lafayette.png

euanmearns

Bill, do you have a source for the nice chart and the Milankovitch data plotted on it? While there seems little doubt that Milankovitch is exerting some control, there are in fact a number of significant departures as well suggesting that the orbital influence is rather loose. The 100,000 year cycles in fact vary in length by quite an amount – I’m away to dig out the numbers that didn’t make my final cut.
Eyeballing this chart it seems there should have been an interglacial around 225,000 that for some reason got delayed.

Phlogiston

Bill
Complicated is the wrong word. Nonlinear-chaotic is the term you are looking for.
As Tsedakis concluded, the glacial inception at MIS 11, an analog of our own at a node of low amplitude eccentricity oscillation (as well as MIS 19) that interglacial 400 kya was “not prolonged by subdued insulation forcing” (his words). What this means is that the magic number of 420 w/m2 may not have been reached but the interglacial ended anyhow.
With nonlinear oscillatory systems the absolute numbers are less important.
So I agree with try that the super long interglacial that you are calling which essentially means the end of the current Pleistocene glaciation, is very unlikely. What makes this even more so is the fact emphasised by Maslin and Ridgewell 2005 that this glacial period far from having ended is in fact deepening. The MPR (change from 40 to 100 kyr interglacial spacing) is part of this.

Phlogiston

I meant “I agree with tty ” not “try”.
I hate smartphone spellcheckers.

euanmearns

Here is where I have the T peaks
8135
128357
237975
322638
410483
I have numbered cycles on my charts 1 to 4, here are the cycle lengths:
1) 120222
2) 109618
3) 84663
4) 87845
The beginning of cycle 4 could be wrong since it is at the bottom of the core (maybe not beginning of cycle). But its that cycle 2/3 boundary that looks like it might be “in the wrong place”.

Bill Illis

euanmearns, I’m using the numbers from Huybers 2006. A simple index of the summer solar insolation above 400 W/m2 at 75N. Below 400 W/m2 is not enough to melt the snow from the winter. It is more-or-less the same as the 65N measure one will have seen but this is a more physically realistic measurement in my opinion. We can be reasonably certain about these numbers for +/- 5 million years. Beyond that, there is too much uncertainty.
ftp://ftp.ncdc.noaa.gov/pub/data/paleo/climate_forcing/orbital_variations/huybers2006insolation/j_75north.txt
Other latitudes at:
ftp://ftp.ncdc.noaa.gov/pub/data/paleo/climate_forcing/orbital_variations/huybers2006insolation/

Donb

Bill:
You underestimate the insolation change over orbital cycles. The 65N TOA insolation change reached over 80 watts/m^2 at 65N.
Here is my favored explanation. Likely Orbital cycles began the NH cooling. This then stopped the AMO, which brings much of the heat into the Arctic. As the Arctic began to ice over, albedo increased, causing further cooling. During max glaciation, the Arctic (e.g. Greenland ice cores) chilled by a few 10s of deg-C, but the globe chilled by only several deg-C. When the NH receives low TOA insolation from the 21-kyr apsidal precession of the eccentricity cycle, the SH receives more TOA insolation. (see my earlier comment). NH glaciation was largely the consequence of decreasing all forms of energy input — insolation from orbital and possible changes, ocean currents, especially the AMO, and increased albedo. These factors complicate the effects of the orbital changes alone, and may produce irregularities in precision of the effects of orbital alone.
Further, the orbital cycles are complex. Likely cycles are predicted at ~21, ~41, ~100, ~125, and 400 kyr, which may interact with one another.
During warming from glaciation, all these effects are reversed. T
hus ice melting is driven by more than just TOA insolation from orbital cycles.

Phlogiston

Euanmearns
About interglacial timings, this paper by Maslin and Ridgewell 2005 has an interesting take on the MPR:
http://sp.lyellcollection.org/content/247/1/19.short
In short the post-MPR ~100,000 yr spacing is not simple eccentricity forcing but a complex interaction of precession forcing with “pacing” by eccentricity. This is typical of weak nonlinear forcing by multiple impulses.
Note also that the MPR change from 41 kyr to 100 kyr periodicity is also indicative of progressively deepening glaciation. At some future time we may transition to permanent glaciation.

tty

Euanmearns:
“The beginning of cycle 4 could be wrong since it is at the bottom of the core (maybe not beginning of cycle). But its that cycle 2/3 boundary that looks like it might be “in the wrong place”.”
Not to worry. MIS 7 was a rather atypical interglacial, appreciably colder than MIS 1, 5, 9 and 11, and consisting of three separate peaks MIS 7a, 7c and 7e (7.1, 7.3 and 7.5). In the Vostok curve 7e at c. 235 KA BP looks very dominant, but other records are much more ambiguous and the “true MIS 7” might well have been 7c at c. 215 KA BP or 7a at c. 195 KA BP instead.
It was the weakness of MIS 7 (= low sea level) that was the reason that this interglacial long remained unknown and outside the “classical” Penck-Brückner four-glacial scheme.

Phlogiston

A very different interpretation suggests itself from Bill’s glaciation versus insolation graph. Most interglacial a peak with maximal insolation but as insolation sharply falls there is a “jagged forward projection” as temperatures unstably persist at interglacial levels despite falling insolation, rather like cartoon figures running of a cliff but staying “air-running” at the same level till they look down, notice the drop beneath them and duly fall.
This means the interglacial will likely end imminently. This will happen when the climate “looks down” and notices that insolation no longer supports interglacial conditions.

euanmearns

A number of commenters here are clearly better informed than I am about many of the details. But here’s a few of my hunches. Whilst accepting that insolation matters, I remain unconvinced it is the over riding driver. Heat is transported to high latitude in the Atlantic by The Gulf Stream. The rotation of the Earth then takes that warmed moist air over Europe and beyond. Where I am sitting right now, Aberdeen Scotland, was under 3 kms of ice about 12,000 years ago. At about 1000 m altitude today we enter Arctic conditions. The survival of winter snow in the mountains is determined by how much snow falls in winter and by how mach rain falls in summer. Sunshine and insolation appear to play a minor role. It seems to me that atmospheric circulation pattern and the Gulf Stream are all important.

Donb

Euan,
On your Dec-29th comment, I agree that ocean circulation and amount of snowfall are important. But something is required to BEGIN NH glaciation. A warm and possibly open Arctic Ocean and North Atlantic will furnish moisture for snow. Ocean current will furnish heat. But when that ocean heat is turned off, the northern oceans grow cold and evaporation for new snow is curtailed.
Further, for land glaciation to begin in earnest, summer temperature must fall significantly below that of today, or snow melts away. Other than Greenland (which is already glaciated) most NH land lies at low elevation (e.g. much of northern Canada and northern Euro-Asia). So, how does one get BOTH ample snowfall and lower temperatures in summer to preserve that snow and turn it to ice?
My suggestion is an orbital cycle drops summer temperature over land. But ocean currents (from the still warm tropical and southern oceans) continue for awhile into the northern oceans to keep the sea unfrozen and evaporation available. So ice accumulates on land; the sea level falls. At some point falling sea level (most sea entry into the Arctic occurs over shallow continental shelf, which becomes land with falling seas) and falling NH temperature turns off the northern flow of the warm Atlantic current and snowfall begins to be reduced.
My point is that a factor is required to lower NH land temperature to initiate NH glaciation. Once begun, other factors become partially controlling. These other factors also disrupt a simple relation between glaciation times and orbital cycles.
Comments?

tty

“Further, for land glaciation to begin in earnest, summer temperature must fall significantly below that of today, or snow melts away”
Not really, there are at least two highland areas where a very slight lowering of summer temperatures would be sufficient to initiate large ice-caps:
1. Baffins Land (known to have been snow-covered for long periods during the LIA, fortunately not long enough to initiate glaciation)
2. Putorana Plateau in northern Siberia

euanmearns

Hope I have this reply in the right place.
A starting point is a popular theme of mine and that is that ordinary folks perception of climate change can be heavily influenced by where they live. Where I live in NE Scotland I really can’t see much change in the 50+ years I’ve lived here. If you live in southern California it’s different.
My main point is this. Where I live the Gulf Stream, N Atlantic Current, thermohaline circulation, whatever you want to call it is paramount in keeping us warm. The Shetland Islands, the most northerly bit of Scotland, is at the same latitude as Oslo in Norway (where I lived for 8 years enjoying the baking hot summers) and S Greenland, where I’ve never been. But Norwegians went there on vacation 1000 years ago.
I think if you live in N America you view and think about the problem from a different angle. From where i’m sitting, ocean circulation is paramount, and that is likely influenced by atmosphere circulation. And from what I’ve said else where on this thread, that may be controlled by the thermal structure of the atmosphere.
Solar forcing of winter climate variability in the Northern Hemisphere
Sarah Ineson1*, Adam A. Scaife1, Jeff R. Knight1, James C. Manners1, Nick J. Dunstone1, Lesley J. Gray2 and Joanna D. Haigh3
NATURE GEOSCIENCE | ADVANCE ONLINE PUBLICATION | http://www.nature.com/naturegeoscience

Bill Illis

For those still reading this, I wanted to point out just how strong the Sun is in the summer at my favourite latitude of 75N (or 80N in this case). Let’s put some real numbers on it.
Eureka Nunuvut Canada radiation tower data throughout the year 2009. Eureka has a world-class climate research station.
Around the peak solar radiation date of June 21, the Sun is coming in about 500 W/m2 (give or take cloudiness). If you live in Chicago, the summer solar radiation will be something like 950 W/m2 so this is much much lower strength.
The snow still on the ground in Eureka until mid-June is reflecting back something on the order of 70% of this sunlight. So the net solar radiation that is actually influencing the surface temperature (or melting the snow) is only about 100 W/m2 rising slowly to 200 W/m2 but by mid-June the snow melts and the full 450 W/m2 (after Albedo) or so is coming in. It slowly declines to about 200 W/m2 in August and then the snow comes back by the end of August and all the solar radiation is reflected away again.
These numbers need to fall by about 25 W/m2 or so before the snow stops melting out in the summer. Then glaciers will start building up and the increased reflection of the Sunlight means a self-fullfilling ice age will start (unless the Milankovitch Cycles switches back rapidly). This is not going to happen for probably 125,000 years. There will be a small decline in this solar radiation (of less than 1.0 W/m2 really) in the next 3,000 years and then it will go back up again before falling to slightly less than today 52,000 years from now. It will then promptly go back up until the big decline happens in 125,000 years.
http://www.esrl.noaa.gov/psd/arctic/observatories/eureka/img/eureka.tower.2009.png

pochas

I suspect sea ice may have something to do with this. As Salby has shown, the major fluxes of CO2 come from absorption / desorption from the oceans, and if anything interferes with absorption of CO2 by the northern oceans, it will cause CO2 to persist in the environment. Sea ice could have just that effect.
http://www.environment.harvard.edu/docs/faculty_pubs/tziperman_sea.pdf

Steve from Rockwood

I have a few problems with this (excellent) post:
1. In Figure 4 CO2 lags temperature but the lag appears to increase toward the base of the core. There is no real discussion of errors / calibration issues. Is there a calibration problem with the older ice (compression, contamination etc)?
2. In Figure 6 around 110,000 years ago there is a discontinuity in the temperature curve that, if you eliminate it, makes the two curves match much more closely. So is the discontinuity real or is the departure of the two curves real?
3. The lag between T and CO2 is not as convincing in Figure 6 as it is for the whole time series in Figure 4. Again can there be a calibration problem with CO2 and time (as you go back in time CO2 time error increases)?
4. The T curve has many more data points than the CO2 curve. What happens when you display the two curves with data points representing only the same years (i.e. a sub-sampling of the T curve)?

tty

1. The larger lag at the end of MIS 11 (fourth interglacial back) is more likely due to the unusual length of this interglacial.
2. No discontinuity. Just a very quick temperature rise at the beginning of the MIS 5c interstadial.
4. Not possible. Temperature and CO2 analysis was not usually done at the same points in the ice-core. It would be possible to use only the closest temperature points (leading or lagging). I’ve done it, and it doesn’t really make much difference.

Brandon Gates

tty,
4. It’s possible if you’re not afraid of interpolating. The “safer” way to do it is as Steve from Rockwood suggests: use the CO2 timescale as is and interpolate T. It doesn’t make much difference, but if you’re really finicky about accuracy you’ll get better results this way than by choosing only the leading or lagging T value.

Brandon Gates

Steve from Rockwood,

3. The lag between T and CO2 is not as convincing in Figure 6 as it is for the whole time series in Figure 4. Again can there be a calibration problem with CO2 and time (as you go back in time CO2 time error increases)?

In general, the further back in time, the greater the time uncertainty. The Petit 1999 Vostok CO2 data show an interesting pattern; the time resolution is lower (more years btw data points) at lower CO2 levels, which sort of makes sense — need more ice to accurately detect a smaller concentration of gas. The average resolution of the entire CO2 record is 1,460 years, but the worst time resolution is within the most recent 100kyrs of the record — four of the 6 data points with > 5,000 years between them are in this interval, and the average is 2,200 years. Very oddly, the best time resolution is between 200-330ka, nothing above 3,000 years, average 960.
More recent lead/lag studies use cores from Siple Dome and/or Taylor Dome which don’t go back as far (~22ka for Siple, ~62ka for Taylor) but which have better time resolution. Shakun et al. (2012) — I think mentioned in this thread somewhere — is a multi-proxy study which gets more representative global temperatures and higher resolution CO2 from EPICA Dome C in Antarctica. They find that temperature leads CO2 in the SH, but lags in the NH. Sort of a push-me-pull-me sloshing thing going on.

tty

Shakun’s paper is a joke, as anyone with practical experience of radiocarbon dating (and other applicable geological dating methods) can tell you. They are not nearly exact enough to correlate distant proxies with the kind of precision needed. This is particularly true during the Late Glacial when changes in the carbon cycle caused a millenium-long “radiocarbon plateu”, making all dates from the Younger Dryas interval extremely ambiguous.
The dating methods for ice cores (beyond varve-count range) are also rather inexact, but this doesn’t really matter as long as you only use CO2 and temperature measurements from the same core since the errors affect both equally.

Phlogiston

Shakun’s goal was very simple – destroy and eliminate palaeo climate data from the climate discussion. His method was to smear together dozens of proxy datasets, some so weak that they hardly show a difference between the Holocene and preceding glacial maximum, in order to create a homogenised blended meaningless curve from which any information about prior climates was ironed flat, crushed and destroyed.
Shaking should be in prison.

Phlogiston

Shakun. not shaking.
How do you turn off the f***ing spellchecker from iPhone?

Brandon Gates

tty, as a prestigious journal with a reputation to protect, Nature does not publish “jokes”.
Phlogiston, results which don’t fit your chosen narrative are not a priori fraud.

tty

Brandon Gates:
For your information I originally started doubting the CAGW narrative when I found that Nature does publish “jokes”. This happened when Nature published a number of CAGW-related papers that partially involved my own field of study (Quaternary Geology) and which were so factually and methodologically bad that they should under normal circumstances have been instantly turned down by the reviewers.
By the way if you know of any evidence that radiocarbon dates from the Late Pleistocene actually have the kind of precision Shakun et al. thinks seem to think they have I would be most interested in references.

Brandon Gates

tty,

This happened when Nature published a number of CAGW-related papers that partially involved my own field of study (Quaternary Geology) and which were so factually and methodologically bad that they should under normal circumstances have been instantly turned down by the reviewers.

I don’t typically trust the alleged qualifications of nameless folk on the Innerwebz, but in this case I allow a small exception: as a credentialed geologist you should know that the way to more robust results is to use multiple dating methods.

By the way if you know of any evidence that radiocarbon dates from the Late Pleistocene actually have the kind of precision Shakun et al. thinks seem to think they have I would be most interested in references.

Well, I’d start with reference 13 from Shakun 2012, which is: Lemieux-Dudon, B. et al. Consistent dating for Antarctic and Greenland ice cores. Quat. Sci. Rev. 29, 8–20 (2010).
I can’t find an open access .pdf of the entire paper, but the data and abstract are available from NOAA’s paleo archive: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/lemieux-dudon2010timescales.txt
ORIGINAL REFERENCE:
Lemieux-Dudon, B., E. Blayo, J.-R. Petit, C. Waelbroeck, A. Svensson,
C. Ritz, J.-M. Barnola, B.M. Narcisi, and F. Parrenin. 2010.
Consistent dating for Antarctic and Greenland ice cores.
Quaternary Science Reviews, Vol. 29, Issues 1-2, pp. 8-20, Jan. 2010.
doi:10.1016/j.quascirev.2009.11.010.
ABSTRACT:
We are hereby presenting a new dating method based on inverse techniques, which aims at calculating consistent gas and ice chronologies for several ice cores. The proposed method yields new dating scenarios simultaneously for several cores by making a compromise between the chronological information brought by glaciological modeling (i.e., ice flow model, firn densification model, accumulation rate model), and by gas and ice stratigraphic constraints. This method enables us to gather widespread chronological information and to use regional or global markers (i.e., methane, volcanic sulfate, Beryllium-10, tephra layers, etc.) to link the core chronologies stratigraphically. Confidence intervals of the new dating scenarios can be calculated thanks to the probabilistic formulation of the new method, which takes into account both modeling and data uncertainties. We apply this method simultaneously to one Greenland (NGRIP) and three Antarctic (EPICA Dome C, EPICA Dronning Maud Land, and Vostok) ice cores, and refine existent chronologies. Our results show that consistent ice and gas chronologies can be derived for depth intervals that are well-constrained by relevant glaciological data. In particular, we propose new and consistent dating of the last deglaciation for Greenland and Antarctic ice and gas records.

Soooo, good old-fashioned convergence hard at work again. What happens when one overly-focuses on their own expertise is it often becomes easy to miss miss what else has been done to address the weaknesses of the particular method in question.

tty

Indeed, we now have several alternative dating methods (OSL, U/Th, K/Ar and AAR to mention the most common ones). Unfortunately they are all less exact than 14C, and so not much use for “tightening up” chronologies (beyond establishing that 14C accumulation has indeed been non-linear beyond the currentl range of calibration curves).
The only methods that are more precise that 14C are varve counts and treering counts. Even these have some uncertainty, but less than 14C which is why they are used for calibration of the 14C record.
Personally I prefer uncalibrated 14C dates, except for comparisons with historical records and other dating methods. This is mainly because calibration curves keep changing and “calibration” is a mathematically irreversible process, i. e. one can always recalibrate a “raw” 14C date, but there is no way to convert a calibrated date back into a “raw” date, or re-calibrate it according to a newer (and better) calibration curve. A lot of people (particularly archaeologists) are unaware of this.
I am familiar with Lemieux-Dodon et al. and the follow-up AICC 2012 time scale. The methodological descriptions sound very fancy (it is of course a Bayesian technique), but basically it is a matter of interpolation between dated tie-points. What is new is that the interpolations are (slightly) non-linear based on glaciological modelling which is certainly an improvement, and that they “wiggle” tie-points to obtain best fit between records which is rather doubtful methodologically. Furthermore AICC 2012 depends strongly on orbital tiepoints so it is not really independent of the Milankovitch curve.
Also in constructing the time-scale glaciological parameters for Greenland were “tailored” to force the resulting timescale to fit to the GICC05 timescale based on varve-counting in the NGRIP core. GICC05 is admittedly not absolutely precise, but maximum error is very well constrained. This apparently required rather unlikely glaciological assumptions for some time intervals. Without this “tailoring” the two timescales would have differed by up to 400 years. So, as so often with Bayesian statistics, it is basically a question of selecting the “correct” prior.

Brandon Gates

tty,

Indeed, we now have several alternative dating methods (OSL, U/Th, K/Ar and AAR to mention the most common ones). Unfortunately they are all less exact than 14C, and so not much use for “tightening up” chronologies (beyond establishing that 14C accumulation has indeed been non-linear beyond the currentl range of calibration curves).

L-D mention in their abstract: … glaciological modeling (i.e., ice flow model, firn densification model, accumulation rate model), and by gas and ice stratigraphic constraints. This method enables us to gather widespread chronological information and to use regional or global markers (i.e., methane, volcanic sulfate, Beryllium-10, tephra layers, etc.) to link the core chronologies stratigraphically.
Stratigraphy I’m already familiar with from my lay childhood hobby of rockhounding. How that translates into glaciology may not be the same beast, and I understand chemostratigraphy, which relies on isotope ratios, is a relative newcomer. That would seem to cover U/Th and K/Ar from my naive point of view. Totally clueless about OSL and AAR. Dunno if Shakun or any references cited in his 2012 study rely on any of those.
Now that I’ve told you what I think I understand and lots more about what I don’t, it doesn’t ring true to me that a suite of dating methods is only as strong as its strongest link as you imply above. Perhaps you could expound.

The only methods that are more precise that 14C are varve counts and treering counts. Even these have some uncertainty, but less than 14C which is why they are used for calibration of the 14C record.

I’m guessing that varve counting in ice cores is problematic because the layers get smeared. Even if not, the constraint would be that a single annual layer of ice wouldn’t yield up enough trapped gasses to get a reliable count. Am I in the ballpark?

Personally I prefer uncalibrated 14C dates, except for comparisons with historical records and other dating methods. This is mainly because calibration curves keep changing and “calibration” is a mathematically irreversible process, i. e. one can always recalibrate a “raw” 14C date, but there is no way to convert a calibrated date back into a “raw” date, or re-calibrate it according to a newer (and better) calibration curve. A lot of people (particularly archaeologists) are unaware of this.

That’s what raw data are for, yes? I do see a plethora of competing time scales in NOAA’s paleo ftp archives and I gather that the bulk of them are not ginned up from freshly gathered samples but from reworking raw data from previously done field work.

I am familiar with Lemieux-Dodon et al. and the follow-up AICC 2012 time scale. The methodological descriptions sound very fancy (it is of course a Bayesian technique), but basically it is a matter of interpolation between dated tie-points. What is new is that the interpolations are (slightly) non-linear based on glaciological modelling which is certainly an improvement, and that they “wiggle” tie-points to obtain best fit between records which is rather doubtful methodologically.

You should know that fancy stats techniques don’t much impress me in and of themselves. Much of that is due to ignorance of anything beyond basic frequentist descriptive stats and simple significance tests, so what I don’t understand implicitly translates into default skepticism. Interpolation generally is not something which falls into that default bucket for me, particularly when applied to physical systems. If I can’t believe that the first principles of physics at work here are sound enough to use as modeling constraints, I may as well give up on most scientific findings since Newton. To say nothing of Planck who did as much as say he could find no reason to conclude that physical laws won’t change tomorrow just for the heck of it.

Furthermore AICC 2012 depends strongly on orbital tiepoints so it is not really independent of the Milankovitch curve.

You say that like it’s a bad thing. I see Milankovic’s work as one of the more elegant explanations set forth to explain the past million years or so of ice-age cycles. The result is a quite short list of mathematical formulae with great predictive power; a rarity in climatology. To throw out such a solidly regular timer which also embeds rate and magnitude of change over time in a field where seemingly intractable uncertainty abounds strikes me as exactly the worst possible thing for a paleochronologist to do.

Also in constructing the time-scale glaciological parameters for Greenland were “tailored” to force the resulting timescale to fit to the GICC05 timescale based on varve-counting in the NGRIP core.

Here is the point where a specific citation would be lovely so I can read and decide for myself.

GICC05 is admittedly not absolutely precise, but maximum error is very well constrained.

I’m confused, that sounds like one of those good problems to have.

This apparently required rather unlikely glaciological assumptions for some time intervals.

Such as? Again, citation?

Without this “tailoring” the two timescales would have differed by up to 400 years. So, as so often with Bayesian statistics, it is basically a question of selecting the “correct” prior.

Ah yes, there’s always that. One hopes that the “correct” prior is the one which best explains the bulk of observations. Probably not a good idea to arbitrarily cast aside too many observations as you and some of your compatriots would apparently have Shakun do.

B. Gates says:
Nature does not publish “jokes”.
It published MBH97/98, didn’t it?

euanmearns

Steve, I’m running short on time now. My quick answer to your points is to look at Figure 5 where CH4 and CO2 are determined on same samples and CH4 is a proxy for the temperature curve.
I don’t understand your point 3.

Steve from Rockwood

Over a shorter time period the lag between CO2 and T does not appear to be so large. Could there be an issue with CO2 in the older (deeper core) where the bubbles have somehow migrated up the ice. If you were to stretch the CO2 curve you could better match CO2 and T versus time with less lag. I guess my point is that these data sets seem to be taken as error free measurements.

In looking at all these temperature graphs, they look like sawtooth oscillator output to me from my years of looking at scopes. Is it possible they are indicators of power pulses traveling through plasma? That would provide a mechanism for periodic heating and cooling over almost any time scale. The shape of the pulse is very closely tied to the mechanics of how the pulse was made.
Brant
“The spiral structure of the Milky Way, cosmic rays, and ice age epochs on Earth
Nir J. Shaviv
Nir J. Shaviv
Racah Institute of Physics, Hebrew University, Jerusalem, 91904, Israel; Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Str., Toronto, ON M5S 3H8, Canada
New Astronomy (Impact Factor: 1.85). 01/2003; DOI: 10.1016/S1384-1076(02)00193-8
Source: arXiv
ABSTRACT The short term variability of the galactic cosmic ray flux (CRF) reaching Earth has been previously associated with variations in the global low altitude cloud cover. This CRF variability arises from changes in the solar wind strength. However, cosmic ray variability also arises intrinsically from variable activity of and motion through the Milky Way. Thus, if indeed the CRF climate connection is real, the increased CRF witnessed while crossing the spiral arms could be responsible for a larger global cloud cover and a reduced temperature, thereby facilitating the occurrences of ice ages. This picture has been recently shown to be supported by various data [PhRvL 89 (2002) 051102]. In particular, the variable CRF recorded in Iron meteorites appears to vary synchronously with the appearance ice ages.Here, we expand upon the original treatment with a more thorough analysis and more supporting evidence. In particular, we discuss the cosmic ray diffusion model which considers the motion of the galactic spiral arms. We also elaborate on the structure and dynamics of the Milky Way’s spiral arms. In particular, we bring forth new argumentation using HI observations which imply that the galactic spiral arm pattern speed appears to be that which fits the glaciation period and the cosmic-ray flux record extracted from Iron meteorites. In addition, we show that apparent peaks in the star formation rate history, as deduced by several authors, coincides with particularly icy epochs, while the long period of 1 to 2 Gyr before present, during which no glaciations are known to have occurred, coincides with a significant paucity in the past star formation rate.”
http://www.researchgate.net/publication/222828472_The_spiral_structure_of_the_Milky_Way_cosmic_rays_and_ice_age_epochs_on_Earth

Dawtgtomis

More compelling evidence that the wrong tree was chosen by the barking hound.

Doug Proctor

The entire discussion here comes down to the time lag between gas sealing and ice formation. I have read before that barometric changes on the snow-ice surface cause the near surface to “breathe” for only 70 years; here the number is 2000 or more. The variation would seem to be in the speed that snow first become ice and then the ice loses all its permeability; this would probably reflect net snow retention and aspects of humidity (the interstital spaces need to be filled to seal the entire column).
I can see from the thoughts above that different ice cores would, at different times, have different lag times. Ice layers should be, like tree-rings, correlatable, but the lag times would still be individual. Adjustments would still be needed. I get the idea this has not been done.
The lag time between deposition of ice – the hydrogen isotope data – and the sealing of the ice column – methane and CO2 content in bubbles – is the critical parameter. The apparent 800-year lag that is not top-and-center of our discussions suggests to me that the lag time is THE “unsettled” scientific parameter being avoided by at least the warmist camp. I say “at least the warmist camp” because the lack of focus on this subject makes me worried that the skeptic camp of note are concerned that the lag might disappear with focused research.
I believe we are being lied to in all the CAGW discussion. The question we have to ask ourselves as skeptics, is not how much the warmists are lying (which they are) but how much we are being lied to by the people “on our side” also (not being informed is the same as being lied to when our support is on the line). There are things that don’t make sense, and not just things that come from a Gore, Hansen or Suzuki.

Donb

Doug
Here is part of a comment I may far above.
There are limited data for some ice cores (don’t know about Vostok) on N2 and Ar isotopic fractionation during diffusion from gas bubbles. These presumably give temperature contemporaneous with the time of entrapment of CO2. The lag time between temperature to CO2 is much less, but interpretation uncertainties still are too large to say they are exactly contemporaneous.
This implies that a significant part of the time difference between snow deposition and CO2 closure against diffusion in bubble is caused by the time required to actually seal CO2 in bubbles.

Brandon Gates

Euan,

In their seminal paper on the Vostok Ice Core, Petit et al (1999) [1] note that CO2 lags temperature during the onset of glaciations by several thousand years but offer no explanation.

Except they do discuss it:
There is a close correlation between Antarctic temperature and atmospheric concentrations of CO2 and CH4 (refs 5, 9). This discovery suggests that greenhouse gases are important as amplifiers of the initial orbital forcing and may have significantly contributed to the glacial–interglacial changes 14–16
The overall correlation between our CO2 and CH4 records and the Antarctic isotopic temperature 5,9,16 is remarkable (r^2 = 0.71 and 0.73 for CO2 and CH4 , respectively). This high correlation indicates that CO2 and CH4 may have contributed to the glacial–interglacial changes over this entire period by amplifying the orbital forcing along with albedo, and possibly other changes 15,16 .
Vostok temperature, CO2 and CH4 increase in phase during terminations. Uncertainty in the phasing comes mainly from the sampling frequency and the ubiquitous uncertainty in gas-age/ice-age differences (which are well over +/-1 kyr during glaciations and terminations). In a recent paper, Fischer et al. 44 present a CO2 record, from Vostok core, spanning the past three glacial terminations. They conclude that CO2 concentration increases lagged Antarctic warmings by 600 +/- 400 years. However, considering the large gas-age/iceage uncertainty (1,000 years, or even more if we consider the accumulation-rate uncertainty), we feel that it is premature to infer the sign of the phase relationship between CO2 and temperature at the start of terminations.
Our results suggest that the same sequence of climate forcings occurred during each termination: orbital forcing (possibly through local insolation changes, but this is speculative as we have poor absolute dating) followed by two strong amplifiers, with greenhouse gases acting first, and then deglaciation enhancement via ice-albedo feedback. The end of the deglaciation is then characterized by a clear CO2 maximum for terminations II, III and IV, while this feature is less marked for the Holocene.

The significance of these observations are therefore ignored.

No, they just don’t reach the conclusions you’re looking for.

At the onset of glaciations temperature drops to glacial values before CO2 begins to fall suggesting that CO2 has little influence on temperature modulation at these times.

Review the charts again and note that temperature generally rises much faster than it falls, what the authors call a “saw-tooth” pattern. There is proper understanding to be found by pondering the implications of the differences in slope.

euanmearns

Brandon, The gradient of warming at terminations is usually not to different to the gradient of cooling post-interglacial. Petit et al do discuss the general lag (600±400 years) and correctly say that this cannot be resolved within the errors of dating. The elephant in the room I’m talking about here is exclusively the 8000 year lag that occurs each time the earth is plunged back into glacial episode. This is clearly not subject to dating errors since the CH4 and CO2 are measured on same samples. Petit et al do identify this big lag but then as far as I can tell ignore it, chosing instead to focus on the general lag that Jo Nova and others discuss that is more easy to dismiss.
I got the feeling that the conclusions of the Petit paper would have been the same regardless of the data. And it is trying to prove something that drove Shakun to their data manipulation.

Brandon Gates

Euan,

The elephant in the room I’m talking about here is exclusively the 8000 year lag that occurs each time the earth is plunged back into glacial episode.

Between 110 and 140 Ka, summertime insolation at 65°N rose to a peak, and then declined at a slope steeper relative to the rise. Temperature, which I find lags insolation by about 3,500 years, followed the exact opposite pattern — relatively steep rise, relatively shallow decline:
https://drive.google.com/file/d/0B1C2T0pQeiaSb3VMMWJnZGpMUVE
A similar series of events occurred between 65-90 Ka. Note throughout these data that GHG concentrations tend to persist in the atmosphere once they’ve been introduced even as temperatures are dropping sharply due to steep falloffs in insolation. The general rule is that temperature and GHG rises are steeper than the increase in insolation, and declines are shallower than the declines in insolation.
Insolation drives the timing of trend reversals and directionality, GHGs (and albedo feedbacks, etc., not shown in this plot) affect the slope and amplitude. It’s a quite clear and easy to understand relationship when one looks at the appropriate data all in one place at the same time.

Petit et al do identify this big lag but then as far as I can tell ignore it, chosing instead to focus on the general lag that Jo Nova and others discuss that is more easy to dismiss.

Petit and friends do discuss it here:
An intriguing aspect of the deglacial CH₄ curves is that the atmospheric concentration of CH₄ rises slowly, then jumps to a maximum value during the last half of the deglacial temperature rise. For termination I, the CH₄ jump corresponds to a rapid Northern Hemisphere warming (Bölling/Allerød) and an increase in the rate of Northern Hemisphere deglaciation (meltwater pulse IA)43. We speculate that the same is true for terminations II, III and IV. Supportive evidence comes from the δ¹⁸Oₐₜₘ curves. During each termination, δ¹⁸Oₐₜₘ begins falling rapidly, signalling intense deglaciation, within 1 kyr of the CH₄ jump. The lag of deglaciation and Northern Hemisphere warming with respect to Vostok temperature warming is apparently greater during terminations II and IV (~9 kyr) than during terminations I and III (~4–6 kyr). The changes in northern summer insolation maxima are higher during terminations II and IV, whereas the preceding southern summer insolation maxima are higher during terminations I and III. We speculate that variability in phasing from one termination to the next reflects differences in insolation curves 41 or patterns of abyssal circulation during glacial maximum.
Properties change in the following sequence during each of the last four glacial terminations, as recorded in Vostok. First, the temperature and atmospheric concentrations of CO₂ and CH₄ rise steadily, whereas the dust input decreases. During the last half of the temperature rise, there is a rapid increase in CH₄. This event coincides with the start of the δ¹⁸Oₐₜₘ decrease. We believe that the rapid CH₄ rise also signifies warming in Greenland, and that the deglacial δ¹⁸Oₐₜₘ decrease records rapid melting of the Northern Hemisphere ice sheets. These results suggest that the same sequence of climate forcing operated during each termination: orbital forcing (with a possible contribution of local insolation changes) followed by two strong amplifiers, greenhouse gases acting first, then deglaciation and ice-albedo feedback. Our data suggest a significant role of the Southern Ocean in regulating the long-term changes of atmospheric CO₂.

GHGs are not sources of heat. At the surface they act as insulators which reduce the rate at which absorbed solar energy can be emitted back out to space as long-wave radiation. When incoming long-wave radiation from the Sun, the expectation is that temperatures will rise more rapidly and to higher levels than if GHGs were not present. Conversely when incoming LWR decreases, the expectation is that temperatures will not fall as quickly or to as low a level when higher levels of GHGs are present in the atmosphere.
This is not motivated thinking, it’s first principles of quite standard, long-standing, tried and tested thermodynamic physics.
It’s also entirely consistent with the data I’ve plotted.

Mods, etal,,,
Sorry to go off the subjet: But…
Just watched the TV show America Unearthed, with Scott Wolter. Show about possible Ming explorer getting to N. America prior to Columbus. Nice show some evidence this and that about rock walls, maps and stuff.
So after it went off I checked in internet on this Scott Wolter. Found this site:
scottwolteranswers.blogspot.com
http://www.scottwolteranswes.com
hope one othose is correct
Any how there is a back and forth between Scott Wolter and a guy from “In Search of Giants” TV show.
James Colavito , today around noon shows Dec. 27, 2014 at 11:12 and it started on 26th.
Scott is saying the ones of China got here first.
The back and forth there is very much like here. Sort of of intrest seems.
Sorry to go off the subject.

fobdangerclose
Any how there is a back and forth between Scott Wolter and a guy from “In Search of Giants” TV show.
James Colavito , today around noon shows Dec. 27, 2014 at 11:12 and it started on 26th.
Scott is saying the ones of China got here first.
The back and forth there is very much like here. Sort of of [interest] seems

.
The “academic trivia” is in “Who got to the Americas first”?
Rather, the real question is “Who made a difference discovering the Americas?”
Did it matter if the Vikings landed first? No – They did nothing with their landing.
Did the “native Siberians” get here first? Absolutely! They had several wide-ranging (and very destructive!) civilizations and cultures all over from the Arctic to the Strait of Magellan. But did nothing else.
Did the Chinese get here? Maybe. Maybe. So what? They did nothing with their possible landing.
Did Columbus’ discovery in 1492 matter? Yes! Everything worldwide changed. Immediately.

wayne Job

A cursory glance at your first chart shows that a drop of 2to3k puts us in an ice age. The fools in the alarmist camp are worried about a bit of warming, makes one wonder if they have all their marbles. Thanks for your good work.

Donb

Wayne, Proxy data indicate that global temperature was only several degrees lower than today’s, but Arctic zone temperature was lower by a few tens of degrees, according to Greenland ice cores. And orbital data predict that the southern hemisphere during NH max glaciation was receiving higher solar energy. An ice age is not the same globally.

tty

“An ice age is not the same globally.”
Prehaps not the same, but it is global. Glaciations and interglacials in the Southern Hemisphere occurr at the same times as in the Northern. Yes, there are leads and lags, but that is true on a smaller geographic scale as well. The latest ice-age started about 5,000 years earlier in Northern Europe, sompared to Southern Europe.
Actually there is strong reasons to believe that the scale of glaciation in Antarctica is directly tied to NH glaciation, since it seems to be regulated more by sea-level change than temperature,

Donb

To tty comment below:
I agree. When TOA insolation is low in the NH the world glaciates. When TOA is low in the SH little occurs. That is why I think ocean currents play a significant role in moving heat. See my reply above to Bill posted several minutes ago.

instead of thinking in terms of arctic perafrost, think in terms of a swamp.
When heated, it rapidly rots giving off methane and CO2.
When cooled, rot slows and so does photosynthesis.
It’s that photosynthesis that’s the issue on the downside.
A fast growing tree can suck down all the CO2 above it in just a few years. Cold and dead trees don’t do that. Warm ones do. So in cold and cooling world, less plant life absorbs the CO2.

Phlogiston

EM
As I suggested upstream, at glacial inception I can think of one more process that would have similar effect in decreasing CO2 uptake and increasing supply. Sea levels would fall rapidly so that the shallow seas with high primary plankton productivity would be drained and become exposed mud. They would rot and stink for a while before eventually becoming covered in terrestrial vegetation.