The CO2 – Temperature link

Dear Frank,
The Poona data are on line available at Ernst Beck’s web site:
http://www.biokurs.de/treibhaus/literatur/misra/misra1941.doc
Have a look at page 277, where the test data are published of five days measurements over bare ground:
Minima just after noon (14:00 h): 300-340 ppmv,
maxima (06:00 h): 510-870 (!) ppmv.
No wonder that one finds high averages, as the build-up of CO2 at night with low wind speeds gives an enormous bias. Despite the positive bias, some days even show an average of 300 ppmv if the wind speed is high enough.
As the minima are measured in the afternoon, when turbulence is at maximum, the CO2 measurements are approaching the “background” CO2 values. That can be seen in the old data (high wind speed gives values near the ice core levels) as good as in modern data. Thus of more interest are the historical minima where huge diurnal variations are measured than the historical averages, which are clearly influenced by local sources and don’t give any indication of something which can be called “background”.
The researchers in Poona were aware of the diurnal variations, but the tests were done specifically for research purposes in crop fields (jowar, sugar cane, betel vine), there was no interest in that period for “background” CO2 levels.
Thus about your questions:
1. No, they took CO2 samples at different hours of the day.
2. The researchers were aware of the diurnal variations, but were interested in the difference in CO2 levels under crops compared to bare ground. There was no interest that time in “background” CO2 levels.
3. The peak hours did give 200 ppmv more at night than during the day.
4. I am not saying that, the measurements show that…
General conclusion: never measure at locations with huge diurnal variation, if the intention is to calculate a “global” or “background” CO2 level, as that has always a positive bias of variable magnitude, depending of local release/uptake and wind speed/diurnal turbulence changes. Only the minima at high wind speed may be of interest, as these approach background CO2 levels.
The problem with the historical data is exactly that all measurement series which add to the “peak” value around 1942 are of the Poona type. Series with less diurnal variation show no peak at all. Or if one looks at all minima of all series in the period 1935-1950, the ice core data are included in the ranges:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/beck_1930_1950.jpg
Thus in my opinion, choosing the averages of historical data without looking at the diurnal variation gives a huge positive bias against the real “background” CO2 levels of that period in time.
Regards,
Ferdinand

Dear Ferdinand!
And as Beck said: “A lot of CO2 data series are on the oceans and at stations without such extreme influence and they also show higher CO2”
Please see overview:
http://www.biokurs.de/treibhaus/180CO2/bayreuth/bayreuth2e.htm
Becks rather important comments:
The Giessen data
He conducted 64 000 measurements in 4 differnet altitudes using a high precision gas analyser invented by P Schuftan, Accuracy: 1,5%. The yearly average for 1939/40 was 385 ppm. Country air with lowest CO2 was in average 372 ppm. The seasonal amplitude was 54 ppm which was roughly 20 ppm more than the data measured at the coast of the Baltic sea at that times. Most interesting is that the about monthly variations correlate with the lunar phases (peak on full moon)
The Helsinki Background measurements 1935
The first background measurements in history; sampling data in vertical profile every 50-100m up to 1,5 km; 364 ppm underthe clouds and above
Haldane measurements at the Scottish coast
370 ppmCO2 in winds from the sea; 355 ppm in air from the land
Wattenberg measurements in the southern Atlantic ocean 1925-1927
310 sampling stations along the latitudes of the southern Atlantic oceans and parts of the northern; measuring all oceanographic data and CO2 in air over the sea; high ocean outgassing crossing the warm water currents north (>~360 ppm)
Buchs measurements in the northern Atlantic ocean 1932-1936
sampling CO2 over sea surface in northern Atlantic Ocean up to the polar circle (Greenland, Iceland, Spitsbergen, Barents Sea); measuring also high CO2 near Spitsbergen (Spitsbergen current, North Cape current) 364 ppm and CO2 over sea crossing the Atlantic from Kopenhagen to Newyork and back (Brements on a swedish island
Lundegards CO2 sampling on swedish island (Kattegatt) in summer from 1920- 1926;
rising CO2 concentration (+7 ppm) in the 20s; ~328 ppm yearly average
Why do you dismiss such data?

Another thing, Engelbeen, why does your graph not match this:
http://www.icsu-scope.org/downloadpubs/scope29/images/fig3.4.gif
?
Its clear that “something” happends around 1930-40.
Your graph:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/sponges.gif
Its a problem when you want to use this to dismis my findings.

Onr more thing, Engelbeen – if you are still there: Its true that stronger winds gives better CO2-measurements. But is it not true, that the only data point you accept from Poona, is the situation where there was not only windy, but also strong monsoon rain? Rain will have the effect that it washes out CO2 from the air, ecpecially rain as strong as happends in India. There are data points from Poona with winds without the severe rain. These show no less than around 380 ppm CO2 in the 1940´ies.

Part 2…
The coralline sponges d13C measurements are not a direct indication of CO2 levels, but they are a very good indication of the source of any change in CO2 levels. There are two main fast sources of CO2, besides human emissions: the oceans (which have a zero to positive d13C level 0-4 per mil) and vegetation decay (which has app. the same negative d13C level, -24 per mil, as fossil fuels in average). Vegetation growth uses 12CO2 preferentially, thus increases d13C in the atmosphere, while vegetation decay reduces d13C levels in the atmosphere.
The resolution of the sponges is 2-4 years and the accuracy of the measurements is good enough to detect an addition of 4 GtC from the oceans or 1 GtC from vegetation decay.
Thus let us look at what should have happened with the d13C levels, if we assume that the historical data are right and some natural release and disappearance of 80 ppmv (160 GtC) in 15 years time (1935-1950) took place.
If all came from the oceans (which is likely with increased temperatures), this would give an increase of the d13C level by 1.6 per mil in the atmosphere.
If all came from vegetation decay (very unlikely, except from war, but that means about 1/5th of all land vegetation!), that would give a decrease of 4 per mil d13C in the atmosphere. In both cases the increase/decrease should go the other way out, back to the previous trend, around 1950.
Neither such a large increase or decrease, nor a recovery in less than a decade is seen in the d13C record: less than 0.1 per mil decrease in atmosphere (ice cores) and upper oceans (sponges) 1935-1950. The decrease is simply in line with human emissions over the whole period.
Simple conclusion: most of the historical data taken over land are too much influenced by local/regional sources/sinks and don’t reflect the CO2 levels over the globe at all. With the knowledge of today, we know that data from Giessen, Poona, Vienna,… are unreliable indicators for background CO2 levels and all show a (variable!) positive bias. That are exactly the data which cause the peak value around 1942 in Beck’s historical overview. Thus that is simply an artifact of the sampling locations.
For the response of CO2 in ice cores vs. temperature: we do agree that temperature has a huge, fast (and slow) influence on CO2 levels. But we disagree the time constraint:
You (and others, like Dr. Spencer) attribute near all of the recent increase of CO2 to a temperature increase by an unlimited in time increase caused by temperature: 3.5 ppmv/yr/K.
I attribute a huge, but limited in time, influence of temperature on CO2:
3.5 ppmv/K
In your case, the ice cores must be wrong, in my case, there is no problem with ice core CO2 (neither with historical CO2 levels over the oceans), as the 0.3 K temperature increase in the period 1900-1950 causes an increase of about 0.9 ppmv CO2, which is within the accuracy of the ice core measurements, the rest of the observed increase is due to human emissions.
My formula works for any time period in the past near million years, your formula changes per period and doesn’t hold for long periods of sustained high/low temperatures (ice ages / interglacials, even the MWP/LIA), because you have no limit in time… Thus simply said: your formula is wrong.
Further, as also sent to Dr. Spencer the mass balance doesn’t hold at all for the past 50 years (Dr. Spencer attributed 52 ppmv increase to temperature):
attributed to temperature: +52 ppmv
added by humans: +110 ppmv
observed: +60 ppmv
to be removed by unknown (natural) sinks: 102 ppmv
Thus some natural sinks must remove more CO2 from the atmosphere than the increase of CO2 which is attributed to the temperature increase…
With other words, nature as a whole doesn’t add one gram of CO2 (as mass, not as individual molecules) to the atmosphere, as long as the increase in the atmosphere is less than human emissions…

Dear Ferdinand 🙂
Ok your answer came “late” but then, you did not waste time 🙂
will go through your writings soon, for now i would like to briefly return to what my article was about: The strong correlation between temperatures and CO2 rise / year.
With temperature changes as marked as in the first half of the twentieth century, with temperature changes as seen in Dalton minimum, Maunder minimum etcetc, we againg and again are dealing with major temperature changes in just a few decades.
When CO2 is shown to be so strongly dependent on temperature, we see big changes in the Antarctic CO2 graphs for the years i gave in my examples.
As i earlier showed, these differences should be at least around 50 ppm.
Therefore the Antarctic graphs are not in compliance with Mauna Loa + UAH data. In fact if we in stead use Mauna Loa + Hadcrut, we see a CO2-dependence even bigger.
In all these writings i have seen your main argument against this, that you accept that the CO2 is dependent of temperature as we see in my writing, but you say that this oscillation would only last so short that we never would see bigger deviations from Antarctic curves.
This i find to be wrong, as you know. Its true that the Connection between CO2 rise/year can change. But the relation is seen to remains for 3 decades with just minor change in relation between temperature and CO2 rise relation ship.
Therefore there is no weight in your claim that the relationship should only last 2-3 years so that bigger deviations of CO2 should not accumulate in the past.
Important is also to remember that it takes higher and higher temperature to achieve the same CO2rise/year (!)
This means, that this very big rise in CO2rise/year is NOT being stronger in connection with still higher human outlet of CO2. That is: The CO2rise/year temperature-dependency is not something that appears human-strengthened.
Beck told me that hes working on a new writing on some of the issue you mention, i look forward to that.
Another thing: When tops seems wrongly not to appear on Antarctic graphs, what is then the likelyness that the average of the Antarctic graphs is correct? Well, it COULD be, if for some reason just as many dives as tops where removed, but non the less its rather optimistic on this base to claim that Antarctic curves in average shows correct level. That should be a pure coincidence.
K.R. Frank

@ferdinand meeus:
You write:
“The CO2 dependence on temperature is between 2-4 ppmv/°C, that is based on the effect of the cooling caused by the 1992 outburst of the Pinatubo and the 1998 warming of a strong El Niño. ”
No no. You have seen clearly that the dependence is valid all the way from 1978 to 2008! Its certainly not just a one-two year dependence! If you want to claim this, you definitely MUST come up with some solid argumentation for this, please. Then I will 100% try to understand your viewpoint.
Only slight changes in dependency over the whole period 1978-08 Please see the graph again.
And if you look af the hadcrut-maunaLoa, you will see that the temperature dependency is at least as big in 1958 as it is in 2008!!
And very interesting, as I said, it takes more and more temperature to achieve raise in CO2 today than in 1958 or 1978. I say this because there are some who thinks that this CO2-dependency is only getting stronger due to human outlet of CO2. But, its just not what the data indicate in any way.

Dear Frank,
It is a pity that we can’t publish graphics here. But have a look at:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/temp_co2_1900_2004.jpg
This shows that a huge change of 0.5°C gives a change of about 4 ppmv/°C, or in average 3 ppmv/°C for any year over the full 100 years. Over the full trend, the change is about 80 ppmv/°C. That are two very different mechanisms at work: a short term influence and a long term influence. We agree on the origin of the short term influence, but we disagree that the 80 ppmv/°C (60 ppmv over 50 years) increase is caused by temperature (as you assert) or is a spurious correlation, because emissions, temperature and CO2 levels all go up in the past 50 years and the increase is mostly the result of the emissions (as I assert).
Thus let is compare the temperature-CO2 correlation to the emissions-CO2 correlation:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/acc_co2_1900_2004.jpg
Thus either the trend is caused by the emissions or the trend is caused by the temperature increase, or it is a mix of both. One can’t rely on the correlations alone, as the correlation between temperature and CO2 increase is the same, wether you detrend the CO2 data or not, and in fact the emissions correlate much better.
Thus we need other data to be sure:
1. The physical/(bio)chemical processes involved:
Higher temperatures means more CO2 emitted (tropics) and less absorbed (poles) by the oceans and more absorbed by mid-latitude vegetation. But that process is limited for both: an increase of CO2 means more (partial) pressure in the atmosphere, which limits the emissions from the warm oceans and increases the absorption of the cold oceans. This is a simple first order equilibrium process, where a temperature increase will increase the CO2 content of the atmosphere until a new equilibrium is found where the release of CO2 and the absorption of CO2 again are equal. Thus the oceans show a simple ratio between temperature and CO2 levels over time, not a constant change for at a fixed temperature difference.
Something similar for vegetation: increased temperatures will increase plant growth (but at the same time plant decay), which will give a short time extra growth, besides a long time shift in total growth area. But once that is established, plant growth and decay will be in equilibrium too.
2. The d13C decline:
Huge releases of CO2 from the oceans by higher temperatures would increase the d13C level of the atmosphere (currently at – 8 per mil), and huge amounts of CO2 absorption by vegetation, caused by higher temperatures would increase the d13C level too. But we only see a decline of d13C in the atmosphere ánd the upper oceans over the past 150 years:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/sponges.gif
3. The mass balance:
If the full CO2 trend is caused by temperature, then a lot of CO2 must be absorbed by some unknown sink, to restore the mass balance as the CO2 increase is less than the emissions + the alleged increase caused by temperature. That counts for about 100 ppmv (210 GtC) over the past 50 years. There is only one fast source/sink available: vegetation. That should mean that vegetation should have increased with about over 30% in the past 50 years. Not really what is observed:
http://earthobservatory.nasa.gov/Features/CarbonCycle/Images/carbon_cycle_diagram.jpg
Conclusion:
The good correlation between temperature and CO2 levels only holds for the influence of temperature on CO2 increase rate fluctuations and is not responsible for the trend itself. The trend is caused by the emissions.

Engelbeen, in my 2)
the formular should be
CO2 growth (ppm/decade) = 3,5 * Temp.anomaly(K) – 10

Dear Frank,
About point 1:
As I have tried to show, there is physical evidence from oceans/vegetation, d13C levels and last but not least from the mass balance, that temperature doesn’t play an important role in the long term trend. Thus it doesn’t take higher and higher temperatures to maintain the increase in CO2 in the atmosphere, it only needs higher and higher emissions. The increase in the atmosphere, measured over the full 104 years of emissions data (1900-2004) is 50-55% of the emissions. Modulated year by year by short term temperature changes. But temperature has NO influence on the long-term trend beyond 3-8 ppmv/°C. That is maximum 7 ppmv for the about 0.8°C temperature increase 1900-2004. Simply compare the temperature and emission trends over 1900-2004 with the increase in the atmosphere:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/temp_emiss_increase.jpg
Thus the long term increase of CO2 in the atmosphere has little to do with temperature and much to do with the emissions. And the higher temperatures are just coincidence. Temperature variability only has a high influence on the rate of increase, not on the increase itself.
About point 2:
As temperature has little influence on the long term trend of CO2, there are no high variations of CO2 levels in the ice cores to be expected. The MWP-LIA cooling of about 0.8°C caused a drop of 6 ppmv ( 8 ppmv/°C in the ice core air bubbles. The 420,000 years Vostok ice core also shows a ratio of 8 ppmv/°C, a little more than the 3 ppmv/°C which is seen in the modulation of the CO2 increase today. That is completely different from the 3.5 ppmv/°C/year in your formula, which doesn’t contain a time constraint.
Thus the ice cores show that your formula doesn’t hold, not the opposite…
Further, your example over a decade: the emissions over a decade are about 40 ppmv. That makes that the emissions factor is larger than the increase attributed to temperature… Which shows my point that the mass balance is impossible to close without a sink which is larger than what temperature allegedly causes + a part of the emissions together… Thus nature is a net sink for CO2, no matter what temperature does (within limits of course).
About point 3:
I completely agree with this: humans don’t influence the temperature sensitivity of CO2. That still is the same now as near a million years ago: 3-8 ppmv/°C, NOT 3.5 ppmv/°C/year! The problem is that you expand this to that temperature is responsible for the current trend, which is caused by something else (emissions), while the sensitivity only holds for the variability around the trend and a (small) part of the trend, depending of the temperature difference between begin and endpoint.
Have a look at the variability graphs at Allan MacRae’s paper on Icecap:
http://icecap.us/images/uploads/CO2vsTMacRae.pdf
and in particular figure 1 and 2. In figure 1, the variability of CO2 increase is around 1.5-2 ppmv/yr, with a high influence of temperature on the variability. In figure 2, MacRae detrended the CO2 increase, that means that the average increase rate is around zero, while the variability remains the same. And more important, the correlation between temperature and CO2 variability remains the same too. Thus even if temperature has nothing to do with the trend, it still is responsible for the variability around the trend.
What you have done is including the 1.5-2.0 ppmv/yr and attributed that entirely to temperature (variability + trend), while in reality only the variability is caused by temperature.
I hope that this made clear the differences in point of view.
Regards,
Ferdinand

@Engelbeen,
Then you write: “But temperature has NO influence on the long-term trend beyond 3-8 ppmv/°C.”
Yes im aware that you claim that, but is it not true that this claim is based on the very Antarctic ice core CO2 data that my data shows is incorrect?
So, down to earth, I prove to you that Antarctic data has errors. Then you say to me, “No, because if you assume Antarctic data is correct, then…”.
In that way your are not dealing with the info I give you.
Anyway your claim that temperature has NO influence on the long-term trend beyond 3-8 ppmv/°C.
What I have shown you is that within decades, the CO2rise-temperature link is strong and VERY LITTLE affedted by long term trends! So within decades your claim is false onless you really produce an actual solid argument.
BUT, if you with long term trends meane longer than perhaps 50-100 years, you MAY be right. You ARE right that the log term trends definitely tends to omit short term trends. But as we can see from 100% solid data (Not just proxies) then the long term trends takes several decades to omit short term trends. And therefore we MUST se much more variability in CO2 graphs than you can imagine.
Heres again the Mauna Loa / hadcrut graph:
http://www.klimadebat.dk/forum/attachments/co2hadcrut.jpg
Look very carefully at the long term trends. These does change, and on this hadcrut they change MORE than using UAH. But still it is VERY clear, that changes in long term trend is likely to take decades! Therefore the temperature mediated changes in CO2rise MUST have a magnitude corresponding to the CO2rise/year that can be accumulated over decades. And as I have shown, 50 ppm is a size of variation that we will expect to see in the correct CO2 data. This kind of variation in CO2 (or bigger), should be seen in connection with Maunder minimum, Dalton minimum etc. Big temperature changes over few decades.
Obviously the biosphere grows when we have more CO2, and therefore pulls out more CO2 when more is available. Therefore the long term trend will always seek to omit the short term trends. But it obviously takes several decades to occur.

Indeed I did write:
” it doesn’t take higher and higher temperatures to maintain the increase in CO2 in the atmosphere, it only needs higher and higher emissions.”
Because despite a drop in temperature, the CO2 levels still increase with in average 55% of the emissions, but modulated by temperature changes. The formula for any single year to one million years is approached by:
dCO2 = 3*dT + 0.55*emissions
For sustained temperature changes the factor 3 can expand to 8 for the influence of temperature.
For e.g. the period 2004-2007 that should give:
dCO2 = 3*(-0.35) + 0.55 * 16 ppmv = 8.05 ppmv or about 2 ppmv/year in average. Have a look at your graph of the trends…
Thus even if one does attribute only very little influence of temperature on long term CO2 levels, it is simple to match the data.
Thus we have two competing theories: the bulk of the CO2 increase is from the temperature increase (or reverse!), or the bulk of the increase is from the emissions. Both match the direct data for the past 50 years of direct measurements.
My theory matches all known observations.
Your theory doesn’t match several observations:
1. the mass balance:
In your formula the increase of CO2 over 10 years is:
dCO2 = 35*dT + 1
Where 1 (one ppmv!) is all what is left as possible contribution from human emissions. But human emissions in ten years are about 40 ppmv. So where does that go?
For each year of the past 50 years, the emissions are higher than the supposed increase caused by temperature and about double what is observed in the atmosphere. Where does the rest go?
2. The ice core measurements
My formula matches with the ice core measurements, your formula not, despite a 20 years overlap between SPO direct data and ice core CO2.
3. d13C and d14C measurements
Warmer oceans increase d13C of the atmosphere (measured!), warmer climate means more vegetation and that uses preferentially 12C (measured!), thus increasing the d13C level in the atmosphere too. We measure a continue decline of d13C in the atmosphere and upper oceans. While d13C is a NOT a proxy for CO2 levels, it gives a clear indication of the source of CO2 changes. In this case it proves that neither oceans, nor vegetation (if there is more growth than decay) are the cause of the increase.
Similar remarks for d14C measurements.
4. O2 deficit.
The oxygen measurements show that less oxygen is used than calculated from fossil fuel use. Thus there is more vegetation growth than vegetation decay. Thus vegetation is definitely not the cause of the increase.
If your theory should be true, then some unknown mechanism must sink near all human emissions, the ice core measurements must be wrong, and the d13C/d14C measurements must be wrong.
For a new theory to be proven, that is a little difficult to explain…