Does The Effect From The Cause Affect The Cause?

Guest Post by Willis Eschenbach

There’s been a recent paper claiming a long-term correlation between CO2 and sea level, discussed here at WUWT. The paper implies that CO2 controls temperature and thus indirectly sea level. I thought I might follow up the comments on that thread by looking at what the ice core records actually tell us about variations in CO2. There is plenty of dispute about the ice core records, but I don’t want to touch on that here, that’s a separate discussion. Instead, let me take the ice core records as given and see where that leads us. Figure 1 shows the Vostok ice core CO2 and temperature variations.

vostok co2 and temperatureFigure 1. Temperature and CO2 variations as per the cited data sources. Temperature variations have been divided by 2, as discussed in the text. Graph ends at 1950, most recent CO2 data is from about 2,300 years ago. Maximum temperature during the previous interglacial was about a degree and a half warmer than 1950. Photograph shows that  Photo Source http://dxing.at-communication.com/en/ri1anc_vostok-base_antarctica/

These two data traces, unfortunately, are from two different records. The temperature record contains almost ten times the number of data points as the CO2 record (~ 3,100 vs ~360). Accordingly, I have smoothed the temperature data (17-point Gaussian) and then interpolated it to match the dates of the CO2 data points.

In addition, the temperature record is (presumably) a proxy for the temperature of Southern Ocean and environs. This, like all areas near the Poles, tends to experience larger temperature swings than the world as a whole. As a result, I’ve followed the common practice of making a rough estimate of global average temperature changes by dividing the Vostok changes in half.

So what can we learn from these graphs? Well, first off, we can see that this is the coldest interglacial we’ve enjoyed in the last hundreds of thousands of years. I note that humans, and indeed the majority of all species, survived the previous warmer interglacials without thermal meltdown. Next, we can tell from this data whether CO2 is causing the temperature variations, or vice versa.

Let me introduce and discuss five pieces of evidence that all show that the likely direction of the causation is that the temperature is causing the CO2 change, and not the other way around. These are 1) the linearity of the relationship, 2) the agreement with known physics, 3) the lag in the CO2 with respect to temperature, 4) the Granger causality of the relationship, and 5) the disagreement with the IPCC values for climate sensitivity.

The weakest piece of evidence is the linearity of the relationship. The outgassing of the ocean is a linear function of temperature. Looked at the other way, the temperature of the world is said to relate, not linearly to CO2, but to the logarithm of CO2 to the base 2. In the data above, the R^2 (a measure of correlation) between the temperature and the CO2 is 0.68 … but the R^2 between the temperature and the logarithm of CO2, rather than being better as we’d expect if CO2 were actually driving temperature, is marginally worse for the logarithmic relationship (0.67) than the linear. Weak evidence, as noted, but you’d expect the correlation with log CO2 to be better than linear, if not a lot better, if the relationship were actually logarithmic.

Second, the agreement with known physics. Given the data above, I calculate that for every 1°C of temperature increase, CO2 goes up by about 15 ppmv. According to this source, for every 1°C of temperature increase, CO2 goes up by about 12.5 ppmv … so the number I calculate from the data is in rough agreement with known physics.

Third, the lag. Direct correlation of the two datasets is 0.83 (with 1.0 indicating total agreement). The correlation between the two datasets is better (0.86) with a one-point lag, with the change in CO2 lagging the change in temperature. That is to say, first the temperature changes, and then the CO2 changes at some later date. Additionally, correlation is worse (0.79) with the opposite lag (CO2 leading temperature). Again, this is in general agreement with other findings that the changes in CO2 lag the changes in temperature.

Fourth, the Granger causality. You can’t establish a cause statistically, but you can say whether something “Granger-causes” something else. A Granger test establishes whether you have a better chance of predicting variable A if you know variable B. If you do, if knowing B gives you a better handle on A (beyond random chance), we say that B “Granger-causes” A.

Now, there’s an oddity about Granger causation. There are four possibilities for Granger causation with two variables, viz:

1) Variable A doesn’t Granger-cause variable B, and B doesn’t Granger-cause A

2) Variable A Granger-causes variable B, and B doesn’t Granger-cause A

3) Variable A doesn’t Granger-cause variable B, and B Granger-causes A

4) Variable A Granger-causes variable B, and B also Granger-causes A

It is this last one that is an oddity … for example, this last one is true about the CO2 variation versus temperature on a monthly basis. This makes sense, because of the seasonally varying drawdown of CO2 by plant life and the seasonal temperature variations. CO2 levels affect plant life, and plant life also affects CO2 levels, and all of that is in a complex dance with the seasonal temperature changes. So the dual causality is not surprising.

In the current example, however, the results of the Granger test in the case of the Vostok data is that temperature variations Granger-cause changes in CO2, but not the other way around—CO2 doesn’t Granger-cause the temperature.

Finally, the disagreement with the IPCC values for “climate sensitivity”. If we use the data above, and we assume that the temperature actually is a function of the CO2 level, we can calculate the climate sensitivity. This is a notional value for the change in temperature due to a doubling of CO2. When we calculate this from the Vostok data given above, we find that to work, the climate sensitivity would have to be 23°C 7°C per doubling of CO2 (corrected, thanks to commenters) … and not even the most rabid alarmist would believe that.

So those are my five reasons. The correspondence with log(CO2) is slightly worse than that with CO2. The CO2 change is about what we’d expect from oceanic degassing. CO2 lags temperature in the record. Temperature Granger-causes CO2, not the other way round. And (proof by contradiction) IF the CO2 were controlling temperature the climate sensitivity would be seven degrees per doubling, for which there is no evidence.

Now, the standard response from AGW supporters is that the CO2, when it comes along, is some kind of positive feedback that makes the temperature rise more than it would be otherwise. Is this possible? I would say sure, it’s possible … but that we have no evidence that that is the case. In fact, the changes in CO2 at the end of the last ice age argue that there is no such feedback. You can see in Figure 1 that the temperatures rise and then stabilize, while the CO2 keeps on rising. The same is shown in more detail in the Greenland ice core data, where it is clear that the temperature fell slightly while the CO2 continued to rise.

As I said, this does not negate the possibility that CO2 played a small part. Further inquiry into that angle is not encouraging, however. If we assume that the CO2 is giving 3° per doubling of warming per the IPCC hypothesis, then the problem is that raises the rate of thermal outgassing up to 17 ppmv per degree of warming instead of 15 ppmv. This is in the wrong direction, given that the cited value in the literature is lower at 12.5 ppmv

Finally, this is all somewhat sensitive to the assumption that I made early on, which is that the global temperature variation is about half of the variation shown in the Vostok data. However, this is only a question of degree. It does not negate any of the five points listed above.

w.

PS—One final thought. IF we assume that the change in CO2 is due to the temperature change, as my five arguments support, this would indicate that the degassing from temperature changes is far from sufficient to cause the recent rise in CO2. I hold that the recent rise in CO2 is anthropogenic, but others have claimed that it is not from the burning of fossil fuels, that it is (at least in significant part) due to the temperature change.

But my calculations, as well as those in the reference I cited, show that CO2 only goes up by ten or fifteen ppmv for a one-degree temperature rise. As such, this is way too small to explain the rise in atmospheric CO2, which has been on the order of 75 ppmv since 1959.

SOURCES

Vostok CO2

Vostok Temperature

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Gene Selkov

Willis, the outgassing of water is not a linear function of temperature, although you can treat it as approximately linear in a small range of temperatures. Is such approximation good enough for your argument or do you know something about the oceans that makes CO2 solubility in them more linear than in pure water?
I’m looking at the solubility graph on this page: http://www.sott.net/article/177136-Basic-Geology-Series-CO2-in-the-Atmosphere-and-Ocean

Chris4692

Very interesting, but it all depends on how well the data series can be pinned together. How well can two ice core series be related to each other in time?

GlynnMhor

Another oft reproduced graph is this one:
http://s691.photobucket.com/albums/vv271/runawaymachine/?action=view&current=720px-Co2-temperature-plot_svg.png&sort=ascending
While the current CO2 level is highlighted, the current temperature anomaly is not, doubtless because it loiters down around 0.5 (not 5.0, but 0.5) , making it look as if CO2 can vary enormously wuthout having any discernable effect on temperatures.

Policy Guy

Thank you Willis,
for showing graphs back to 450,000 years ago to establish a cyclical trend in ice cold and warm. There are many papers that I have read in the Paleo Climatology section of American Geophysical Union (AGU) that support that trend extending back approximately more than 2 million years. The cycles are amazingly consistent: 100,000 years of ice, 15-20,000 years of warmth. Our time is virtually up in this warming period. The question is how to respond to the next change.
Unfortunately, we have Johnny-Come-Lately’s that call themselves scientists of this new realm of “science” called “climate science”. Please excuse the humor, but it appears to me that these individuals have no concept of climate beyond maybe the past fifty years. Recorded history as data means little if anything. . These individuals have no appreciation of this older data set and papers based upon evidentiary observation. Apparently, these well known research papers have escaped their review.
Thank you for sharing some light on this research, so that others may have a glimps of where to start, in trying to understand our climate.

dan houck

Very nice article (as are most of your posts – I always learn something). Your last point strikes home; regardless of the causality issue, the chart certainly makes one question the forcing argument.
I am new to this, and I was wondering why the recent (100 year) increase in CO2 ppm has been so linear. Can you point me to any references? Thanks.

But my calculations, as well as those in the reference I cited, show that CO2 only goes up by ten or fifteen ppmv for a one-degree temperature rise. As such, this is way too small to explain the rise in atmospheric CO2, which has been on the order of 75 ppmv since 1959.

Not sure we have enough information to say that, really. What I mean is that ocean cools a lot faster than it warms. We were in a pretty cold period during the LIA. If we assume that the ocean contains a lot of CO2 and that cooler water holds more CO2 than warmer water and that one can cool the ocean a lot faster with a change in surface conditions than one can warm it, if we maintained the current surface temperature, it would take about 600-800 years for the ocean to completely give up all the CO2 it absorbed during the LIA. And that assumes that temperatures at the surface stay flat for 600 to 800 years (which they won’t).
It takes about 800 years to ventilate the ocean which means it takes about 800 years for most of the water to touch the surface and exchange gas with the atmosphere. Cooling the ocean works fast for a couple of reasons but mostly because that works with convection. We also have more brine rejection from sea ice that sends a lot of very cold, very salty water to the bottom of the ocean in a hurry. If you warm the surface, the water wants to stay on the surface. It is hard to warm the abyssal deep from applying heat to the surface. You have to wait until the water circulates to the surface for the heat to be applied. It is really easy to cool the abyssal deep by cooling the surface. So the ocean takes up CO2 faster than it gives it back.
Looking at old plant stoma, it has been suggested that CO2 content during the MWP was possibly at or a little higher than today’s levels. (remember this? http://wattsupwiththat.com/2010/12/26/co2-ice-cores-vs-plant-stomata/ )
So there is another reason to believe that while humans certainly ARE adding CO2 to the atmosphere, it isn’t the primary component (we already know it isn’t the primary component because the atmosphere is accumulating CO2 at a much faster rate than humans add each year) because while human emissions have been rising nearly exponentially, atmospheric CO2 has been rising linearly and that rate of rise did not change when global human CO2 emissions fell in absolute terms (tons of CO2 emitted to atmosphere fell in 2009, rate of increase of atmospheric CO2 unchanged).
It is going to take some 600+ more years for the ocean to give back all the CO2 it took up during the LIA.

Steve Keohane

Good analysis Willis. I also look to the last interglacial where temperature peaked and dropped 2°C with CO2 barely changing over 15-20K years.

Mike Smith

Nice paper.
Looks like the links to the Vostok temp and CO2 data were flipped.
[Thanks, fixed. -w.]

William McClenney

Nice Willis. Some good food for thought……
Crossposting from http://wattsupwiththat.com/2013/01/03/paleo-sea-level-and-co2/#comments
I have not read the paper yet, but before I do it may be useful to point out some constraints. The first one being resolution. Some of the better proxies include Greenland ice, which gets us back something in the range of ~130kya (~130,000 years ago), and speleothem (stalactite/stalagmite) and flowstone deposits, which arguably can get us back a few million years or so. Beyond that are various isotopes isolated from ostracods etc. in deep sea sediment cores. Some studies for Greenland ice core studies lay fairly credible claim to be able to attain as good as decadal resolution, but more towards the upper cores, not so much the lower sections, where slip planes and other things can complicate matters considerably. There are others, I just decided not to go into them.
From the Greenland cores there are two really important considerations; (1) ~130k DOES NOT get us back to the start of the last interglacial, from which one can infer that the Greenland sheet may have completely melted away during the inception and early millenia of the Eemian, and (2) the better resolution of Greenland ice (as opposed to Antarctic ice) has repeatedly shown that temperature changes precede CO2 changes.
According to Mudelsee (2001) (http://manfredmudelsee.com/publ/pdf/The_phase_relations_among_atmospheric_CO2_content_temperature_and_global_ice_volume_over_the_past_420_ka.pdf) from the abstract:
“Over the full 420 ka of the Vostok record, CO2 variations lag behind atmospheric temperature changes in the Southern Hemisphere by 1.3 +/- 1.0 ka, and lead over global ice-volume variations by 2.7 +/- 1.3 ka.”
For reference, this was one of the definitive papers establishing which came first, and it was published some 4 years before Gore’s “Inconvenient Truth” inversion. Cause and effect unraveled 12 years ago, why this is even an issue now is really quite beyond me.
Beyond the onset of northern hemisphere glaciations, some ~2.8Mya, which is some 2 or so million years older than we can really guess which came first, it becomes sort of a ‘silly-buggers’ game.
Others here have already pointed out that coincidence is not causation. Still others have expanded on the degree to which CO2 is better absorbed by cold water than warm. It is somewhat difficult to imagine a world in which sea levels were much higher than today if it was not indeed warmer. What may not have been considered is the increased areal extent of littorals resultant from a sea level increase of +65m (~213 feet). Plot the areas covered up to +65m on coastlines worldwide and see what percent sea surface is increased over present. I know I have seen several papers which have considered this, but I am just not going to take the time this evening to look that up. But it’s big.
So more surface area to degas, if that means anything here.
As so often is the case, seemingly especially in this lopsided debate, is a phenomena best illustrated by Ziggy. One of my all time favorite cartoons is of Ziggy standing before three vending machines, scratching his head. The first vending machine says “The Truth – 25c”. The middle vending machine says “The Whole Truth – 50c”. and the last machine is entitled “The Truth, The Whole Truth, and Nothing But The Truth – $1.00”. The numbers might be memory faded, but you get the point (I hope).
In terms of “The Truth” this “debate” is about AGW. But “The Whole Truth” might skew closer to that it is about GW, AGW and GC (global cooling), in other words what is our attribution “signal” relative to normal climate “noise”, or signal to noise ratio.
But what would a buck get us from the climate vending machine? What is “The Truth, The Whole Truth, and nothing but the Truth?” That would include the univers of what we do know and what remains to be known about climate. At a minimum it would necessarily include the miserable state the 4 global data sets are in, the various methods and means of which this record consists, loss of ~70% of reporting stations (predominately high latitude, high altitude and rural) post 1990, and what resides in my mind at least as pure horror at the state of the surface stations Anthony et al have and are documenting. To this we must necessarily add when we live, about half a precession cycle since the more or less agreed beginning of the Holocene (termination of the YD event). Five of the past six such interglacials have each lasted about half a precession cycle……
And the ends of the “extreme” interglacials (those that have achieved at least our sea level, the highstands of which continue to be documented), provide a chilling and robust record of the climate extremes which appear to occasion their ends. An analysis of some of this may be found here http://wattsupwiththat.com/2012/03/16/the-end-holocene-or-how-to-make-out-like-a-madoff-climate-change-insurer/
My initial impression is that this paper, only having read what is here, may fall at the “blue light special” (heavily discounted) end of the 25c The Truth. Meaning to me that I may learn a thing or two by reading it and vetting the cited papers critically. With so much end extreme interglacial normal climate “noise” it is seems like such a LEAP to matheMANNically manufacture CO2 numerical/Nutticelli attribution anywhere near close enough to allow calculation of the ideal gas law concentration.
I am just not so sure that any correlation drawn prior to the closing of the Panama Seaway (some ~5Mya) is oceanic circulation comparable to the present except in the grossest terms.
“The onset of the LEAP occurred within less than two decade, demonstrating the existence of a sharp threshold, which must be near 416Wm-2, which is the 65N July insolation for 118 kyr BP (ref. 9). This value is only slightly below today’s value of 428Wm-2. Insolation will remain at this level slightly above the inception for the next 4,000 years before it then increases again.”
http://einstein.iec.cat/jellebot/documents/articles/Phis.Lett.A_2007.pdf
Repeating myself:
So be ever thoughtful of both facts and predictions before leaping to a conclusion. It was in fact a LEAP that terminated the last interglacial, the cold Late Eemian Aridity Pulse which lasted 468 years and ended with a precipitous drop into the Wisconsin ice age. And yes, we were indeed there. We had been on the stage as our stone-age selves about the same length of time during that interglacial that our civilizations have been during this one.

geologyjim

From the geological perspective, I’ve always argued that there is another qualitative signal that CO2 cannot be a strong factor. That is, if T is assumed to be driven by CO2, then why does T always change direction (sign of trend) when CO2 should be resisting change the most?
T always begins to decline just when CO2 is at its highest level
T always begins to rise just when CO2 is at its lowest level.
I think that the same signature over the last 4 glacial-interglacial cycles is ample evidence that a “strong CO2 model” cannot be true.
The lag also indicates that CO2 responds to T (not vice versa), but I think the change-of-direction is stronger evidence of cause-effect.
It’s hard to sustain the notion of “tipping points” when the evidence shows the exact opposite. Climate mostly reflects negative feedbacks (conservative conditions).

Henry Clark

Some good points.
But a graph so zoomed out as figure 1 should be posted with a more zoomed-in version too. For instance, the following, while somewhat like the GISP 2 plot I often post, is for Vostok data specifically to match the Vostok subject of this article:
http://c3headlines.typepad.com/.a/6a010536b58035970c01348128c941970c-pi
Without a graph so zoomed out as to make a millenium be close to a pixel, without century-scale info in the data being hidden, CO2 being the prime driver of temperature becomes blatantly absurd, as opposed to the oceans slowly warming or cooler (slower than the surface), with the temperature affecting CO2 release or absorption as this article notes.
As often so, a trick is asking what the CAGW movement is very careful to never, ever, ever publicly show, as that is the best of all.

Willis Eschenbach

Gene Selkov says:
January 3, 2013 at 7:52 pm

Willis, the outgassing of water is not a linear function of temperature, although you can treat it as approximately linear in a small range of temperatures. Is such approximation good enough for your argument or do you know something about the oceans that makes CO2 solubility in them more linear than in pure water?
I’m looking at the solubility graph on this page: http://www.sott.net/article/177136-Basic-Geology-Series-CO2-in-the-Atmosphere-and-Ocean

Thanks, Gene. We’re only talking ± 6°C temperature swing, so the linear approximation will be quite close.
All the best,
w.

Quinn the Eskimo

A full mathematical work-up of the relationship between CO2 solubility in water and temperature in the Vostok record is here, http://www.rocketscientistsjournal.com/2006/10/co2_acquittal.html, with the conclusion that “Throughout the past 420 millennia, comprising four interglacial periods, the Vostok record of atmospheric carbon dioxide concentration is imprinted with, and fully characterized by, the physics of the solubility of CO2 in water, along with the lag in the deep ocean circulation.”

since hansen predicted the lag of versus temperature in 1990, folks might want to watch this

D Böehm

Steven Mosher,
Dwell on this chart for a few minutes. The cause and effect is clear. ∆T causes ∆CO2; not vice-versa.

u.k.(us)

Steven Mosher says:
January 3, 2013 at 9:26 pm
—————————
At about 7:10 in the instructive video, the narrator said “denier” twice in two sentences.
Propaganda is only that, nothing more.
So, here we are.

Well, with every passing year we build up more and more empirical evidence. We will find out soon enough. We have been watching CO2 vs Temperature for a while. What gets me is that from 1910 to about 1940 we saw nearly identical temperature increase over nearly an identical span of time at a point when human CO2 emissions could not possibly have been a factor.
All we need now is a cooling trend and it blows the entire thing right out of the water.

AndyG55

“The outgassing of the ocean is a linear function of temperature.”
Its a solibility product issue. The relative concentrations in the air and water also affect the rate.

John F. Hultquist

. . . but to the logarithm of CO2 to the base 2.
Is it not the natural logarithm (ln; base e) and not the binary logarithm (log2 n)?

JPeden

Steven Mosher says:
January 3, 2013 at 9:26 pm
since hansen predicted the lag of versus temperature in 1990, folks might want to watch this
Nice Cartoon, Steven:
~”The climate denial industry”…”contradicts the overwhelming mainstream consensus”…and “the very study that climate deniers hope you won’t read”…”Yabba-dabba-dooo!”

William McClenney

Steven Mosher says:
January 3, 2013 at 9:26 pm
The problem here is, Steve, that if CO2 concentrations precede temperature changes, and that if these changes occur naturally up to at the very least +6m above present sea levels, then the 2007 AR4 “worst case” rise in MSL by 2100 clocks in at just 10% of what happened at the end of the last extreme interglacial, MIS-5e.
There were no SUVs for, at least, well before the industrial revolution. So the problem becomes a best anthropogenic (currently), +0.59m estimate of sea level by 2100 vs. a low estimate of +6.0m at the end of the second thermal pulse at the very end of the last interglacial.
OK, I’ll give you +.01m to make the math easy.
So, what you are telling me is that I am supposed to be concerned of a possible anthropologically derived sea level rise (signal) 1/10th the range of the lowest estimate of the last interglacial’s lowest estimate of sea level rise at the second thermal pulse at yet another half-precessional old extreme interglacial.
Your anthropogenic signal, is at best, 10% of the most recent end-extreme-interglacial noise.
Right. I am righteously scared.
But wait, if you call now, we will throw in the last time gaia was at an eccentricity minimum, that would be that 6th interglacial back, which lasted from just 1.5 to 2 whole precession cycles.
Not to worry, that little booger might have achieved a single thermal pulse, right at its very end, scoring a mere +21.3m rise over present MSL,
http://si-pddr.si.edu/jspui/bitstream/10088/7516/1/vz_Olson_and_hearty_a_sustained_21m_sea-level_highstand_during_mis_1.pdf
You’re kidding, right?
Please enlighten me as to why I should be reasonably concerned with an anthropogenic signal, sea-level wise, which is at best 10% of the most recent end extreme interglacial climate “noise”, and which, at worst, is 2.8% of the possible +21.3m MSL which may have been achieved the last time we were at an eccentricity minimum…….
OK, I am duly scared. But not so much

William McClenney

“that would be that 6th interglacial back”
Oops! That would be that oddball “five out of the last six Interglacials” that did not strictly conform to the half-precessional clock, post Mid-Pleistocene Transition.
That would be MIS-11…….

geologyjim says:
January 3, 2013 at 8:52 pm
T always begins to decline just when CO2 is at its highest level
T always begins to rise just when CO2 is at its lowest level.
=========
There is only one conclusion possible. Adding CO2 to the atmosphere causes cooling and reducing CO2 causes warming.
The mechanism is the partial pressure of gas law. Adding CO2 displaces H2O. Since H2O is a stronger GHG than CO2, the net effect of adding CO2 is cooling. The ice cores make this clear.

crosspatch says:
January 3, 2013 at 8:16 pm
What I mean is that ocean cools a lot faster than it warms.
========
Agrees, good analysis. Warm water doesn’t sink, while cold water does. Therefore the mixing rate rises as temperature drops. Thus, you can’t heat the deep oceans from above, but you can cool them.

r murphy

Mosh you are better than this, c’mon.

Hoser

Caveat emptor. You might want to be careful relying too much on the timing and amplitude of ice signals. Siegenthaler and others covered this ground pretty well already, but I like the 5 points.

Mosher: Do you think that video is more than propaganda? Again letting someone else influence you rather than you explain why you think CO2 was anything more than a short lived correlation? Hansen et all say that the recent warming was 90% certainly caused by CO2. Yes – CO2 went up and temperatures went up. But what does Hansen say now that CO2 continues to go up and correlation stoppedis this period not important, but the last 30 year period was important?

RockyRoad

Jeeze, Steve–Did you study the graph D. Boehm posted for your benefit? Do you know how to tell which came first–temperature increase or CO2 increase? Or the converse–temperature decline or CO2 decline?
Is your “belief system” so inculcated in your soul that logical thought and rational deduction are impossible? If so, you are no scientist, but simply a cult follower.
Perhaps Ayn Rand said it best in Atlas Shurgged when she had John Galt say (p. 1059):
“Learn to distinguish the difference between errors of knowledge and breaches of morality. An error of knowledge is not a moral flaw, provided you are willing to correct it; only a mystic would judge human beings by the standard of an impossible, automatic omniscience. But a breach of morality is the conscious choice of an action you know to be evil, or a willful evasion of knowledge, a suspension of sight and of thought. That which you do not know, is not a moral charge against you; but that which you refuse to know, is an account of infamy growing in your soul. Make every allowance for errors of knowledge; do not forgive or accept any breach of morality. Give the benefit of the doubt to those who seek to know but treat as potential killers those specimens of insolent depravity who make demands upon you, announcing that they have and seek no reasons, proclaiming, as a license, that they ‘just feel it’–or those who reject an irrefutable argument by saying ‘It’s only logic’ which means: ‘It’s only reality.’ The only realm opposed to reality is the realm and premise of death.

John West

@ Steven Mosher
Projection much? That was propaganda.
Note the one blurb about the Sun with no supporting evidence?
Note the “denier” label in like every other sentence?
Note the “Professional Climate Deniers” idiocy?
Note the Hansen hero worship?
Note the “amplification” meme that you and Lief are critical of wrt solar?
Come on man, snap out of it! Is there no cure for SkS Syndrome?
You’re listening to activists like they’re scientists:
http://climatecrocks.com/about/
“Peter Sinclair is a long time advocate of environmental awareness and energy alternatives. An award winning graphic artist, illustrator, and animator”
I wonder if asked to sign a petition to ban dihydrogen monoxide what he’d do.
More to the point if he promoted signing it would you?

S. Meyer

Professor Hayden at the ICCC7 reported a very striking 99% correlation between sea surface temperature anomalies and atmospheric log(CO2 ratio). He stressed that this was a correlation, not a time series, and came to the conclusion that temperature is likely to be the main driver of CO2 and not the other way around. I have a hard time reconciling this 99% correlation with the fact that human emissions must have added some amount of CO2 to the atmosphere. The only way the correlation could remain 99% (that I can think of) is, if human contribution were a constant, which is plainly not the case. Can anybody shed some light on this for me?
http://climateconferences.heartland.org/howard-hayden-iccc7/
And similarly this one:
http://icecap.us/images/uploads/Globalclimatechangehasnaturalcauses.pdf

Peak Warming Man

So are you saying that you don’t believe that an increase in co2 in the atmosphere will increase the earths temperature?

The video that Steven Mosher links to, mentions the movie The Great Global Warming Swindle, which was debunking the alarmist claim that CO2 was a climate DRIVER. The video explains that the argument is that CO2 is, rather, an “amplifier”. That’s not the argument. Sceptics appreciate the amplifier claim and the issue is whether the amplifier is a significant player in climate or not. So why link to an argument that assumes sceptics are (a) stupid and (b) knocks down a strawman?

phlogiston

CAGW is Granger-dead.

Willis Eschenbach

Henry Clark says:
January 3, 2013 at 8:53 pm

Some good points.
But a graph so zoomed out as figure 1 should be posted with a more zoomed-in version too. For instance, the following, while somewhat like the GISP 2 plot I often post, is for Vostok data specifically to match the Vostok subject of this article: …

You’re busting me because my graph doesn’t look like your graph? It doesn’t show the details you say that you are interested in?
Well, since in this topic I could care less about the details, and I’m just interested in the overall view, I use an overview graph. So sue me.
Certainly, when you write a post, you are free to use the specific graphs that you judge will best elucidate the points you wish to make.
As am I …
Best regards,
w.

ColdinOz

Possibly the strongest indication of whether A drives B or B drives A; is that the lag is much greater during the cooling periods than it is during the warming periods. During warming periods CO2 will be outgassed from whatever part of the ocean profile that exceeds the temperature at which the existing CO2 concentration can stay in solution. However during the cooling periods, CO2 can only go into solution at the atmosphere, ocean surface interface, irrespective of the ocean temperature.profile. This would lead to a much greater lag during cooling should temperature be the driver; and this is the observed evidence. If Co2 drives temperature than this would not be the case.

In Wills article he says:-
“because of the seasonally varying drawdown of CO2 by plant life and the seasonal temperature variations. CO2 levels affect plant life, and plant life also affects CO2 levels, ”
Temperature certainly changes the rate of respiration – photosynthesis – not so much – otherwise the Yamal trees and the hockey stick would not be controversial.

LazyTeenager

Weak evidence, as noted, but you’d expect the correlation with log CO2 to be better than linear, if not a lot better, if the relationship were actually logarithmic.
——–
Ignoring that the equilibrium relationship between CO2 partitioned between atmosphere and ocean is not linear, but logarithmic.
Most physical and chemical processes that depend on temperature are logarithmic with temperature. Not good if temps are going up.

P. Solar

John F. Hultquist says:
. . . but to the logarithm of CO2 to the base 2.
Is it not the natural logarithm (ln; base e) and not the binary logarithm (log2 n)?
It’s the same thing. I was going to point out that Willis was making an unnecessary detail in specifying log2. A log relationship is a log relationship , whatever the base. The only difference is a scaling factor: the logA(B) eg log(2.0) or log2(10.0) or ln(10.0) etc .
It would have been sufficient (and perhaps clearer) if Willis had just said ‘logrithmic’.
Thanks to Willis for yet another informative article. Especially in covering the question of outgassing.

Willis Eschenbach

Steven Mosher says:
January 3, 2013 at 9:26 pm

since hansen predicted the lag of versus temperature in 1990, folks might want to watch this …

Or they might not want to watch it. Let me give people the digested version of the video you link to. First, it is viscerally unpleasant, with lots of “deniers” and well funded skeptics and the like. Next, it contains lots of cutesie tricks, cartoons and bits from movies, that mark it for the meretricious trash that it is, and aren’t funny in the bargain.
More to the point, his argument is that CO2 is necessary to explain the ice ages. He doesn’t establish that, he asserts it. In support of his assertion, he cites only one paper, called “Timing of Atmospheric CO2 and Antarctic Temperature Changes Across Termination III“.
He refers triumphantly to the following section in the paper, which says:

This confirms that CO2 is not the forcing that initially drives the climatic system during a deglaciation. Rather, deglaciation is probably initiated by some insolation forcing (1, 31, 32), which influences first the temperature change in Antarctica (and possibly in part of the Southern Hemisphere) and then the CO2. This sequence of events is still in full agreement with the idea that CO2 plays, through its greenhouse effect, a key role in amplifying the initial orbital forcing. First, the 800-year time lag is short in comparison with the total duration of the temperature and CO2 increases (_5000 years). Second, the CO2 increase clearly precedes the Northern Hemisphere deglaciation (Fig. 3).

Note that this statement does nothing to support the assertion that CO2 is necessary to explain the ice ages. It does nothing to support the idea that CO2 plays a “key role”.
All it says is that the new finding, that changes in temperature lead changes in CO2 by 800 ± 200 years, is not inconsistent with the assertions. It provides no supportive evidence for the assertions. It just says, we can’t rule them out.
But the guy in the video thinks he’s found the Holy Grail. He thinks he has the scientific proof that CO2 is required to explain the ice ages. Unfortunately, you can read it for yourself—the paper said nothing of the sort. All he has is a statement that the new findings don’t rule out the hypothesis. It does nothing to support it.
Man, what a waste of time. One saving grace, though. The inclusion of the cartoons wasn’t as inappropriate as I thought at first, given the childish nature of the scientific claims. After hearing the claims, the cartoons fit right in. That whole extravapalooza was a waste of electrons.
w.
PS—In the paragraph above, there is a cryptic reference to how the “CO2 increase clearly precedes the Northern Hemisphere deglaciation (Fig. 3)”. However, I see no such thing in Fig. 3, which shows the rise in CO2 and CH4 (as a proxy for NH deglaciation) occurring pretty much simultaneously. Next, remember that the temperature rise would of necessity precede and be the cause of the deglaciation, since the ice sheets would respond only slowly to increased summer insolation. They would not melt instantaneously, so deglaciation would necessarily lag temperature rise by some years. Since the deglaciation and CO2 rise are contemporaneous, we can conclude that the NH temperature rise must have preceded the CO2 rise, and not the other way around as they claim.

Dr Burns

“CO2 only goes up by ten or fifteen ppmv for a one-degree temperature rise” that might apply if ocean and air temperature was constant around the globe. Various areas of the ocean at different times of the year absorb, as other areas desorb, to a total of almost 20 times man’s CO2 output. A slight imbalance might be sufficient to account for recent increases.
I also find the claims that ice cores trap an exact representation of the air at the time the core is dated, extremely dubious. Beck and Jaworowski have been dismissed too easily.

P. Solar

Steven Mosher says:
“since hansen predicted the lag of versus temperature in 1990, folks might want to watch this”
I clicked because I was interested in what Hansen may have “predicited”. I got about 10s into it and binned it when it became clear it was smart-arsed propaganda not information.
If you have a link that tells us something about Hansen’s lag (I presume this is his “pipeline” hypothesis) in a factual way that may be of interest.

Willis
Nice article.
I think that co2 outgasses at the rate of 6ppm per 1 degree C temperature rise of the ocean. So is it the oceanic temperature we need to be most concerned about? That will vary according to the ocean temperature gradient in as much water is not at all well mixed and so some strata will be warm whilst other parts will be cool. Equally temperatures vary according to the geographic area.
I was most struck by the scientific reports from the arctic in the 1940’s that SST’s in many parts of the Arctic were up to 10C warmer than measured by Nansen fifty years earlier. There were also some very high readings taken of co2 in the greenland area by various scientists at that time that showed that CO2 concentration was very similar to today.
I make no conclusions about any of this as co2 readings made in the relatively recent-pre mauna loa era-are regularly discounted.
tonyb

LazyTeenager

I am inclined to think that this is another article somewhat poverty stricken in understanding feedback, when the climate system can be subject to different driving forces at different times.
Consider for example a feedback stabilized dc power supply. When the input supply changes negative feedback keeps the output constant. When the output load changes the negative feedback keeps the output constant. So the power supply can be subject to multiple forcings either singly or together with varying amounts.
The same applies to the climate with multiple positive and negative feedbacks operating on different timescales.
Both external changes to CO2 and solar insolation can affect temperature and these both can affect the amount of CO2. To varying degrees at different times and simultaneously.

P. Solar

Willis: “PS—In the paragraph above, there is a cryptic reference to how the “CO2 increase clearly precedes the Northern Hemisphere deglaciation (Fig. 3)”. However, I see no such thing in Fig. 3, which shows the rise in CO2 and CH4 (as a proxy for NH deglaciation) occurring pretty much simultaneously. Next, remember that the temperature rise would of necessity precede and be the cause of the deglaciation, since the ice sheets would respond only slowly to increased summer insolation. They would not melt instantaneously, so deglaciation would necessarily lag temperature rise by some years. Since the deglaciation and CO2 rise are contemporaneous, we can conclude that the NH temperature rise must have preceded the CO2 rise, and not the other way around as they claim.”
Thanks for parsing that for me Willis, Probably saved me half an hour pouring over details to find out what dubious Fig3 claim was all about.

Matt Ridley

Having debated this issue with British Antarctic Survey scientists and found astonishingly that they had no evidence for the hypothesis that CO2 amplifies the orbital-induced warming once it has begun — they were left lamely saying that the data “is entirely consistent with” that hypothesis — I have to agree with Willis’s characterisation of the very weak video above: it amplified rather than damped my doubts about that hypothesis. Ever Since Gore’s film, the attempt to link ice ages to CO2 has been one of the most egregious examples of confusing cause with effect. It is time that polar scientists were brave enough to admit it.
Thanks, Willis, for a superb essay.

If the CO2 is driving the temperature, what is then increasing and decreasing the level of CO2?
Assuming (knowing) that more CO2 improves the plant grows and the plants would use more CO2, then I think we have a Predator-Prey Relationships.
Assuming that the CO2 drives the temperature, then the plants would grow even better and this would then remove even more CO2 from the air.
The argument for me is that I haven’t seen any credible explanation for CO2 to go up for a time frame of estimated 10% and then go down to a low level for a time frame of estimated 90%.
What’s about the Daisyworld simulation, which is a self regulating system? The white Daisies have a negative feedback and the black Daisies have a positive feedback. This means they will balance the temperature in the end.
As long as we can’t explain both direction, increase and decrease, of CO2 on its own we have no explanation at all for the past. How could we than predict the future?
My conclusion is that there must be an external source. Someone is playing with something like a dimmer. Who could that be. Don’t tell me it is the sun. 😉
Professor. Dr. Mojib Latif, German meteorologist and oceanographer, had said on German TV “This is obviously a lie, if it is claimed that we do not consider the sun. There is no climate model that the sun is not taken into account. I mean we’re not idiots. This will somehow give the impression as if we are the biggest idiot ever.”. I would never say that they are the BIGGEST idiots ever. You can top anything that was before.
/joke on/ Some comedian said that we have not investigated the moon energy. How much energy is used by the moon to make it dark? ;-))

Willis says: “Certainly, when you write a post, you are free to use the specific graphs that you judge will best elucidate the points you wish to make.
“As am I …”
Well said. In fact, many times, if not presented as the author wishes, a graph will lead to off-topic discussions, which always detract from a thread.

Willis, nice summary. Indeed the change of CO2 after temperature changes is near-linear, where CO2 lags some 800 years. That ratio doesn’t change over the past 800 kyears (including Epica Dome C, which shows the same CO2 and temperature changes), which shows that there is little CO2 migration in the ice cores over that time span, or the ratio should fade away each interglacial back in time.
A few additions:
– While coastal ice cores reflect the temperatures of the nearby Southern Ocean (via dD and d18O proxies), the deep inland, high altitude, ice cores of Vostok and Epica Dome C reflect the ocean temperatures for near the whole SH. These are less variable than Southern Ocean alone or the whole NH, where ice sheets did cover large parts of land during most of the time. But the Greenland ice sheet temperature record shows a similar trend over the glacial-interglacial transition, be it with much larger swings, as that mainly reflects the North Atlantic seawater temperature:
http://www.climatedata.info/Proxy/Proxy/icecores.html
That means that the CO2-temperature ratio is probably less than 15 ppmv/°C. Vostok shows 8 ppmv/°C and is taken as rather globally representative.
– 12.5 ppmv/°C is the solubility curve of CO2 in seawater (other sources give 16 ppmv/°C), but at higher temperatures, land plants in general sequester more CO2 in more permanent way and more land area is occupied by plants, reducing the CO2 levels with increased temperatures. That too reduces the ratio of CO2 to temperature.
– An interesting part of the Vostok record is the end of the previous interglacial, the Eemian: while CO2 and temperature go up in parallel, temperatures go down while CO2 levels remain high. At the moment that the temperature is again at a new minimum (and ice sheet growth at a maximum). CO2 starts to go down. The 40 ppmv drop in CO2 level has no observable effect on the temperature record… See:
http://www.ferdinand-engelbeen.be/klimaat/eemian.html

P. Solar

Dr Burns says:
“CO2 only goes up by ten or fifteen ppmv for a one-degree temperature rise” that might apply if ocean and air temperature was constant around the globe. Various areas of the ocean at different times of the year absorb, as other areas desorb, to a total of almost 20 times man’s CO2 output. A slight imbalance might be sufficient to account for recent increases.
Very good point. Too much global averaging going on. This is particularly important when dealing with what is apparently a T^5 relationship. Average global temp may be a fair indication in the presence of a linear relationship. If it’s T^5 it mostly likely needs to be broken down to at least regional average temp.
While Willis’ linear approx may be good enough for rough estimate with small variations, with ampified warming/cooling at the poles where cold waters will be providing a CO2 sink the effect could be much greater.
I have not thought through how this would affect his arguments or conclusions, maybe Willis can comment on that.