Resolution and Hockey Sticks, Part Deux: Carbon Dioxide

Guest geological perspective by David Middleton

In Part 1 of this series on resolution in signal processing, we discussed the integration of high resolution instrumental temperature records and lower resolution paleoclimate proxy data in climate reconstructions. In Part Deux, we will look at the integration of high resolution instrumental carbon dioxide records and lower resolution paleoclimate data.

Carbon Dioxide Hockey Sticks

The image below is an example of fake science.

Figure 1. A 100% fraudulent Hockey Stick, older is toward the left. (NASA)

Ancient air bubbles trapped in ice enable us to step back in time and see what Earth’s atmosphere, and climate, were like in the distant past. They tell us that levels of carbon dioxide (CO2) in the atmosphere are higher than they have been at any time in the past 400,000 years. 


According to the NASA narrative, the paleo-CO2 was from the Vostok ice core…

Data: Luthi, D., et al.. 2008; Etheridge, D.M., et al. 2010; Vostok ice core data/J.R. Petit et al.; NOAA Mauna Loa CO2 record. Some description adapted from the Scripps CO2 Program website, “Keeling Curve Lessons.”


The NOAA Mauna Loa CO2 record would be a single data point at the same resolution of the Vostok ice core. It would be the average atmospheric concentration over the past 1,500 years, not the sharp blade of a hockey stick.

Most Antarctic ice cores are not capable of resolving century-scale COshifts.  ice cores cannot resolve CO2 shifts that occur over durations shorter than twice the bubble enclosure period.

According to Neftel et al. (1988), CO2 fluctuation with a duration of less than twice the bubble enclosure time (equivalent to approximately 134 calendar yr in the case of Byrd ice and up to 550 calendar yr in Dome Concordia) cannot be detected in the ice or reconstructed by deconvolution.

McElwain et al., 2001

Here is a schematic diagram of bubble trapping process for the Law Dome, Antarctica DE08 ice core:

Figure 2. Schematic diagram of the bubble enclosure process.

The gas enclosed in ice core bubbles is always younger than the enclosing ice. The gas-age/ice-age difference is a function of the snow accumulation rate. The higher the accumulation rate, the smaller the gas-age/ice-age difference, the shorter the gas age distribution and the higher the resolution. The bubble enclosure period for Law Dome DE08 is about 10 years, indicating a resolution of 20 years. While it’s possible that the resolution of the DE08 core is as fine as 10 years, it could also be as low as 30 years. MacFarling Meure et al. 2006 presented the highest resolution analysis of the Law Dome cores as a 20-yr spline fit. While the exact resolution is uncertain, even at 30-yr, it should “see” the Mauna Loa record and it does.

This composite Antarctic ice core record would seem to confirm that CO2 is indeed higher than at any point in the past 800,000 years:

Figure 3. Composite CO2 record (0-800 kyr BP) from Bereiter et al. (2014).

The composite was constructed from the following core intervals:

  1. -51-1800 yr BP:’ Law Dome (Rubino et al., 2013)
  2. 1.8-2 kyr BP: Law Dome (MacFarling Meure et al., 2006)
  3. 2-11 kyr BP: Dome C (Monnin et al., 2001 + 2004)
  4. 11-22 kyr BP: WAIS (Marcott et al., 2014) minus 4 ppmv (see text)
  5. 22-40 kyr BP: Siple Dome (Ahn et al., 2014)
  6. 40-60 kyr BP: TALDICE (Bereiter et al., 2012)
  7. 60-115 kyr BP: EDML (Bereiter et al., 2012)
  8. 105-155 kyr BP: Dome C Sublimation (Schneider et al., 2013)
  9. 155-393 kyr BP: Vostok (Petit et al., 1999)
  10. 393-611 kyr BP: Dome C (Siegenthaler et al., 2005)
  11. 612-800 kyr BP: Dome C (Bereiter et al., 2014)

These ice cores are of vastly different resolutions.  Petit et al., 1999 indicate that the CO2 resolution for Vostok is 1,500 years. Lüthi et al., 2008 suggest a CO2 resolution of about 500 years for Dome C.  It appears that the high resolution Law Dome DE08 core was just spliced on to the lower frequency older ice cores.

If I apply a 500-yr smoothing filter to the DE08 core to match Dome C, I get this:

Figure 4. A 500-yr smoothing filter totally removes the Hockey Stick’s blade. Figure 4. Hockey stick vanishes in a puff of resolution. Older is toward the left.

Century scale CO2 shifts on the order of the modern instrumental record would not be resolved by most Antarctic ice cores.

Application of a 130-yr smoothing filter indicates that it would be detected, but not resolved in the medium resolution Byrd ice core (Neftel, et al., 1988):

Figure 5. DE08 at 130-yr resolution. Older is toward the left.

Somewhat like my seismic fault resolution example in Part 1, ice cores with at least a 130-yr resolution could detect the anomaly, but not fully resolve the Mauna Loa record.

Atmospheric CO2 is almost certainly at its highest level in 2,000 years.  It may even be higher than any time in the past 5,000 years… It might actually be higher than at any point in the past 800,000 years, as routinely depicted by climate “scientists”.  However, every method of estimating pre-industrial CO2 levels, apart from Antarctic ice cores, indicate that Late Quaternary CO2 levels were frequently in the 300-350 ppmv range and possibly occasionally over 400 ppmv.

Greenland Ice Cores

Very little has been published about CO2 concentrations in Greenland ice cores. Anklin et al, 1997 is the only publication that I have been able to obtain. In the following figures, I have overlaid the composite Antarctic ice core record over two images from Anklin:

Figure 6. Greenland GRIP (Anklin et al., 1997) compared to Antarctic composite (Bereiter et al., 2015). Older is toward the right.
Figure 7. Greenland Dye 3 (Anklin et al., 1997) compared to Antarctic composite (Bereiter et al., 2015). Older is toward the right.

Greenland generally has a much higher snow accumulation rate and therefore its ice cores are of much higher resolution than most Antarctic ice cores. As such, they should see higher and much more variable CO2 concentrations. However, the so-called “consensus” rejects Greenland ice core CO2 data because…

The discrepancies between the CO2 profiles from Greenland and Antarctica can be explained by in situ production of excess CO2 due to interactions between carbonate and acidic species…

Anklin et al, 1997

The discrepancies could also be explained by resolution differences… And the higher, more variable CO2 concentrations of Greenland ice cores are supported by another method of estimating paleo-CO2 concentrations.

Plant Stomata

This was the subject of my first post for WUWT back in 2010.

Stomata are microscopic pores found in leaves and the stem epidermis of plants. They are used for gas exchange. The stomatal density in some C3 plants will vary inversely with the concentration of atmospheric CO2. Stomatal density can be empirically tested and calibrated to CO2 changes over the last 60 years in living plants. 

Middleton, 2010

There’s very good agreement between plant stomata and the highest resolution segment of the composite Antarctic ice core.

Figure 8. Finsinger and F. Wagner-Cremer (2009) compared to composite Antarctic ice core. Older is toward the left.

The agreement deteriorates with age…

Figure 9. Kouwneberg et al, 2005 compared to composite Antarctic ice core. Top x-axis is in years BP (1950). Older is toward the left.
Figure 10. Jessen et al, 2005 compared to composite Antarctic ice core.
Figure 11. Wagner et al., 2002 compared to composite Antarctic ice core.

Note that two stomata chronologies indicate sharp spikes in atmospheric CO2 near the end of the Late Pleistocene Bølling-Allerød interstadial/GI-1 (230-320, 240-430 ppmv) and the onset of the Holocene (210-330, 170-300 ppmv).

Figure 12. McElwain et al., 2002 compared to composite Antarctic ice core.
Figure 13. Steinthorsdottir et al., 2013 compared to composite Antarctic ice core.

The spike at the onset of the Holocene is even supported by an example of “Chicken Little of the Sea”…

Figure 14. Figure 3 from Kubota et al., 2014 “(a) Reported δ11B values of planktonic foraminifera with 2σ uncertainty from ERDC-92 (ref. 10). Age model is from the original publication. (b) In situ pH reconstructed from δ11B of fossil Porites spp. using our new calibration. Red and green circles are from Tahiti by this study and Douville et al.11, respectively. Blue circles are from Marquesas by Douville et al.11after correction by +0.04 pH units. (c) Derived pCO2 of surface water around equatorial South Pacific Ocean (same colors as b) and atmospheric pCO2 on the GICC05 timescale1. All error bars are 2σ. YD, Younger Dryas; B/A, Bølling/Allerød; ACR, Antarctic Cold Reversal; HS1, Heinrich Stadial 1; LGM, Last Glacial Maximum.”

The same relationship holds true for the last Pleistocene intreglacial stage (Eemian/Sangamonian):

Figure 14. Rundgren et al., 2005 compared to composite Antarctic ice core during Eemian interglacial stage.


The plant stomata chronologies falsify the notion of a stable 270-280 ppmv pre-industrial atmospheric CO2 concentration.

In contrast to conventional ice core estimates of 270 to 280 parts per million by volume (ppmv), the stomatal frequency signal suggests that early Holocene carbon dioxide concentrations were well above 300 ppmv.


Most of the Holocene ice core records from Antarctica do not have adequate temporal resolution.


Our results falsify the concept of relatively stabilized Holocene CO2 concentrations of 270 to 280 ppmv until the industrial revolution. SI-based CO2 reconstructions may even suggest that, during the early Holocene, atmospheric CO2 concentrations that were >300 ppmv could have been the rule rather than the exception.

Wagner et al., 1999

The plant stomata chronologies are reproducible…

The majority of the stomatal frequency-based estimates of CO2 for the Holocene do not support the widely accepted concept of comparably stable CO2 concentrations throughout the past 11,500 years. To address the critique that these stomatal frequency variations result from local environmental change or methodological insufficiencies, multiple stomatal frequency records were compared for three climatic key periods during the Holocene, namely the Preboreal oscillation, the 8.2 kyr cooling event and the Little Ice Age. The highly comparable fluctuations in the paleo-atmospheric CO2 records, which were obtained from different continents and plant species (deciduous angiosperms as well as conifers) using varying calibration approaches, provide strong evidence for the integrity of leaf-based CO2 quantification.

Wagner et al., 2004

The discrepancies between the Antarctic ice cores and stomata chronologies can largely be explained as functions of ice core resolution…

The discrepancies between the ice-core and stomatal reconstructions may partially be explained by varying age distributions of the air in the bubbles because of the enclosure time in the firn-ice transition zone. This effect creates a site-specific smoothing of the signal (decades for Dome Summit South [DSS], Law Dome, even more for ice cores at low accumulation sites), as well as a difference in age between the air and surrounding ice, hampering the construction of well-constrained time scales (Trudinger et al., 2003).

Kouwenberg et al., 2005

The resolution difference can be quantified…

Atmospheric CO2 reconstructions are currently available from direct measurements of air enclosures in Antarctic ice and, alternatively, from stomatal frequency analysis performed on fossil leaves. A period where both methods consistently provide evidence for natural CO2 changes is during the 13th century AD. The results of the two independent methods differ significantly in the amplitude of the estimated CO2 changes (10 ppmv ice versus 34 ppmv stomatal frequency). Here, we compare the stomatal frequency and ice core results by using a firn diffusion model in order to assess the potential influence of smoothing during enclosure on the temporal resolution as well as the amplitude of the CO2 changes. The seemingly large discrepancies between the amplitudes estimated by the contrasting methods diminish when the raw stomatal data are smoothed in an analogous way to the natural smoothing which occurs in the firn.

Van Hoof et al., 2005
Figure 15. Panel A is stomatal frequency curve. Panel B is the D47 Antarctic ice core. The dashed line on Panel B is the “synthetic” ice core generated from the stomatal frequency curve. (Van Hoof et al., 2005)

The effect of resolution on the amplitude of the CO2 signal can even be demonstrated using Antarctic ice cores

Figure 16.  From Ahn et al., 2012: “Smoothing an imaginary atmospheric CO2 ime series (green line). The synthetic atmospheric CO2 time series has slightly larger decrease of CO2 than Law Dome records at ∼1600 A.D. To better compare magnitude of CO2 decrease at ∼1600 A.D., we subtracted 3 ppm of CO2 concentration from WAIS Divide core record (blue line) and compared with three synthetic smoothing curves (purple lines).”

Yet, this is all ignored and climate “scientists” continue to push this narrative…

Ancient air bubbles trapped in ice enable us to step back in time and see what Earth’s atmosphere, and climate, were like in the distant past. They tell us that levels of carbon dioxide (CO2) in the atmosphere are higher than they have been at any time in the past 400,000 years. 

The effects of resolution on the CO2 signal render all but impossible to definitively state “that levels of carbon dioxide (CO2) in the atmosphere are higher than they have been at any time in the past 400,000 years.” 

As I previously stated:

Atmospheric CO2 is almost certainly at its highest level in 2,000 years.  It may even be higher than any time in the past 5,000 years… It might actually be higher than at any point in the past 800,000 years, as routinely depicted by climate “scientists”.  However, every method of estimating pre-industrial CO2 levels, apart from Antarctic ice cores, indicate that Late Quaternary CO2 levels were frequently in the 300-350 ppmv range and possibly occasionally over 400 ppmv.

From a climatic perspective, 400-500 ppmv is not significantly above a natural background which routinely rose to 300-400 ppmv in response to Earth’s natural cycles of warming.

Here is MacFarling-Meure’s higher resolution Law Dome CO2 reconstruction, Mauna Loa (MLO) plotted on Figure 3 from Kouwenberg et al., 2005…

Figure 17. “Reconstructed CO2 mixing ratios based on stomatal frequency
counts on Tsuga heterophylla needles for A.D. 800–2000.
Black line connects means of 3–5 needles per sample; thick white
line shows three-point moving average. Gray area indicates confidence
interval of 61 root mean standard error” (Kouwenberg et al., 2005). The blue line is MacFarling Meure (lower resolution DSS before 1800). The orange line is a 20-yr average of MLO.

While it does appear that atmospheric CO2 is currently higher than any point in the last 1,000-2,000 years, when all of the data are examined, it’s not nearly as anomalous as indicated by the Antarctic ice cores.

Higher frequency data have a lower signal-to-noise ratio than lower frequency data. In seismic data processing, we strive to preserve as much of the high frequency component as possible. In climate “science” there seems to be a tendency to disregard the high frequency component of the pre-industrial carbon dioxide record, while also disregarding or mishandling the low frequency component of the pre-industrial temperature record (Esper et al., 2005). This leads to overestimating the climate sensitivity (Lorius et al., 1990) and almost certainly underestimating atmospheric carbon dioxide’s sensitivity to temperature changes.


Ahn, J., E. J. Brook, L. Mitchell, J. Rosen, J. R. McConnell, K. Taylor, D. Etheridge, and M. Rubino (2012). “Atmospheric CO2 over the last 1000 years: A high-resolution record from the West Antarctic Ice Sheet (WAIS) Divide ice core”. Global Biogeochem. Cycles, 26, GB2027, doi:10.1029/2011GB004247. LINK

Anklin, M., J. Schwander, B. Stauffer, J. Tschumi, A. Fuchs, J. M. Barnola, and D. Raynaud (1997), “ CO2 record between 40 and 8 kyr B.P. from the Greenland Ice Core Project ice core,” J. Geophys. Res., 102(C12), 26539–26545, doi: 10.1029/97JC00182.

Bereiter, Bernhard.  Sarah Eggleston, Jochen Schmitt, Christoph Nehrbass-Ahles, Thomas F. Stocker, Hubertus Fischer, Sepp Kipfstuhl and Jerome Chappellaz. 2015. Revision of the EPICA Dome C CO2 record from 800 to 600 kyr before present. Geophysical Research Letters. . doi: 10.1002/2014GL061957. LINK

Esper, J., R.J.S. Wilson,  D.C. Frank, A. Moberg, H. Wanner, & J. Luterbacher.  2005.  “Climate: past ranges and future changes”.  Quaternary Science Reviews 24: 2164-2166.

Finsinger, W. and F. Wagner-Cremer. “Stomatal-based inference models for reconstruction of atmospheric CO2 concentration: a method assessment using a calibration and validation approach”. The Holocene 19,5 (2009) pp. 757–764

Kubota K., Yokoyama Y., Ishikawa T., Obrochta S., Suzuki A.  “Larger CO2 source at the equatorial Pacific during the last deglaciation.” (2014)  Scientific Reports,  4 , art. no. 5261.

Lorius, C., J. Jouzel, D. Raynaud, J. Hansen, and H. Le Treut, 1990: The ice-core record: Climate sensitivity and future greenhouse warming. Nature, 347, 139-145, doi:10.1038/347139a0.

Lüthi, D., M. Le Floch, B. Bereiter, T. Blunier, J.-M. Barnola, U. Siegenthaler, D. Raynaud, J. Jouzel, H. Fischer, K. Kawamura, and T. F. Stocker. 2008. “High-resolution carbon dioxide concentration record 650,000-800,000 years before present”. Nature 453(7193):379-382, doi: 10.1038/nature06949.  LINK

MacFarling Meure, C., D. Etheridge, C. Trudinger, P. Steele, R. Langenfelds, T. van Ommen, A. Smith, and J. Elkins. 2006. “The Law Dome CO2, CH4 and N2O Ice Core Records Extended to 2000 years BP”. Geophysical Research Letters, Vol. 33, No. 14, L14810 10.1029/2006GL026152. LINK Data

McElwain et al., 2001. “Stomatal evidence for a decline in atmospheric CO2 concentration during the Younger Dryas stadial: a comparison with Antarctic ice core records”. J. Quaternary Sci., Vol. 17 pp. 21–29. ISSN 0267-8179.  LINK

Neftel, Albrecht, H. Oeshger, T. Staffelbach & Bernhard Stauffer. (1988). “CO2 record in the Byrd ice core 50,000–5,000 years”. Nature. 331. 609-611. 10.1038/331609a0.

Petit J.R., Jouzel J., Raynaud D., Barkov N.I.,  Barnola J.M., Basile I., Bender M., Chappellaz J., Davis J., Delaygue G.,  Delmotte M., Kotlyakov V.M., Legrand M., Lipenkov V., Lorius C., Pépin L., Ritz C., Saltzman E., Stievenard M., 1999. “Climate and Atmospheric History of the Past 420,000 years from the Vostok Ice Core, Antarctica”. Nature. 399, pp.429-436. LINK

Rundgren et al., 2005. “Last interglacial atmospheric CO2 changes from stomatal index data and their relation to climate variations”. Global and Planetary Change 49 (2005) 47–62.

Steinthorsdottir, Margret & Wohlfarth, Barbara & Kylander, Malin & Blaauw, Maarten & Reimer, Paula. (2013). “Stomatal proxy record of CO2 concentrations from the last termination suggests an important role for CO2 at climate change transitions.” Quaternary Science Reviews. 68. 43-58. 10.1016/j.quascirev.2013.02.003.

Van Hoof et al., 2005. “Atmospheric CO2 during the 13th century AD: reconciliation of data from ice core measurements and stomatal frequency analysis”. Tellus (2005), 57B, 351–355.

Wagner et al., 1999. “Century-Scale Shifts in Early Holocene Atmospheric CO2 Concentration”. Science 18 June 1999: Vol. 284. no. 5422, pp. 1971 – 1973.

Wagner F, Kouwenberg LLR, van Hoof TB, Visscher H, 2004. “Reproducibility of Holocene atmospheric CO2 records based on stomatal frequency”. Quat Sci Rev 23:1947–1954.  LINK

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Robert of Texas
July 2, 2019 7:30 am

Arguing over the level of CO2 in the atmosphere through multivariate proxies is useless, especially when it has not been determined if the level of CO2 in the atmosphere is harmful, or even beneficial.

You have multiyear gas mixing in the bubbles, unknown gas chemical interaction and travel through the ice, and the ice may become nearly exposed (more than once), or even layers removed by wind. You can’t even predict how many years to average as the snow and wind patterns can change over time.

Proxies are dangerous when used this way – to reinforce an essentially political argument. They can inform in a limited way, but without direct measurement they are open to bias.

Reply to  Robert of Texas
July 2, 2019 8:22 am

Precisely, and gas bubbles two miles under cold pressure are natured to the chemistry of ice, and fractionation of both ice and gas. And that variance from base ice to surface is singular to that specific region — not a ‘Globe’. Is colder gas not dense?

Reply to  Michael
July 2, 2019 9:45 am

Some of those graphs show CO2 levels dropping to 180ppm at the bottom of the cycles. I believe plant life stops at about 150ppm. That is the real climate emergency.

Reply to  David Middleton
July 2, 2019 7:02 pm

Hi David,

I have used the argument that CO2 was much higher in the past and we didnt have run away warming then, and have seen this and similar graphs showing the periods of greater than 2,000 ppm. Yet every time I try to follow to the the original papers I do not see these graphs.

Can you please assist with where I am going wrong in finding the original papers and the data that shows this.

Thank you

Reply to  David Middleton
July 3, 2019 4:14 am

Thank you David

Reply to  David Middleton
July 3, 2019 7:49 am

CO2 declining over last 50 million years from inexorable tapering off of volcanic eruptions combined w/ongoing carbon sequestration. Perhaps eventual cause of end of life other than extremophiles.

Charles Higley
Reply to  Robert of Texas
July 2, 2019 8:18 pm

It is a joke to even pretend that ice cores yield absolute CO2 concentrations of ancient atmospheres. LOL.

These cores suffer egregious decompression and trauma during extractions and easily lose 30-50% of their contents to microfractures. Thus, ice cores provide general trends, but they simply cannot provide absolute values. If you back-calculate a 40% loss rate, past CO2 concentrations were easily the same or much higher than our present concentrations.

The political narrative that CO2 has been low for thousands of years is a political myth, with absolutely no basis in fact.

We do have chemical CO2 bottle data going back 200 years but the IPCC prefers to ignore it. Bottle data shows that CO2 was much higher than now three times over the last 210 years. It was much higher in the 1940s and dropped down to 1950, where perchance Mauna Loa data started to be generated. It’s funny how they love Mauna Loa data and ice core “data” but shun direct chemical and contemporary CO2 data. Why would that be? Oh, it does not fit the political narrative, while spurious indirect ice core data is gospel.

Stop pretending we know what CO2 was back more than 200 years. It’s laughable.

Reply to  Charles Higley
July 3, 2019 11:00 am

Charles Higley,

CHemical methods were relative accurate (+/- 10 ppmv), but the main problem is where was measured. Most CO2 levels were measured in towns, in forests and other places with very high contamination. There are two series which make most of the 1942 “peak”, one was measuring CO2 under, in between ad over growing crops (Poonah, India), thus has nothing to do with “background” CO2 and the other, the longest, was at Giessen, Germany.
At a few km from the historical measurements, a modern station takes CO2 samples twice an hour. That shows already some 40 ppmv (positive) bias over background, up to hundreds ppmv with zero wind and an inversion layer. Here for monthly averages at Linden-Giessen:

I had a lot of discussion with the late Ernst Beck about the historical data and in my opinion, only the historical data that were taken on seaships of coastal with wind from the seaside have some interest: these are all around the ice core CO2 levels of the same age…
See further:

Scott W Bennett
Reply to  Ferdinand Engelbeen
July 4, 2019 3:45 am

“thus has nothing to do with “background” CO2 – Ferdinand Engelbeen ”

Of course it matters what was measured then and there is no reason why a coastal or ocean location is any better place even today. It is the total effect of CO2 concentration on AGW that is at issue; is it not. And if you are arguing that altitude matters then you point is equally mute! Even today, the gridded global average does not add up to that measured at Mauna Loa. It has to be fudged to match their “well mixed” figures!

Scott W Bennett
Reply to  Scott W Bennett
July 4, 2019 6:49 am

“The chemical sampling methods cannot be adequately controlled for local effects. The signal-to-noise ratio is simply too low for these data to be useful. – David Middleton”

Unless of course, by local effects you don’t mean Mauna Loa; were everything is fine and there’s “nothing to see” there!

So, you don’t actually mean local! And point locations really aren’t the issue. What matters – it seems – is that the chosen location is deemed to be representative of the globe.

Houston, we really do have a problem! 😉

Reply to  Scott W Bennett
July 4, 2019 1:18 pm

Scott W Bennett,

There is a lot of day/night variability over land and even extreme levels under inversion layer conditions with no wind. That is only over the first few hundred meters. That hardly exists midst the oceans or coastal with wind from the seaside. Neither if you take samples over 500 meters over land.
That are current conditions for most stations are situated. If there are local conditions which interfere with the measurements, like for Mauna Loa wind form the volcanic vents, these are marked an not used for daily to yearly averages, but still can be downloaded from the NOAA web site. It doesn’t matter much if you use all data or only the selected data, the difference is less that 0.1 ppmv over a year in trend.
See further:

There is no fudging necessary, because CO2 levels in 95% of the atmosphere match each other within +/-2% of full scale, despite the fact that some 20% of all CO2 in the atmosphere is exchanged over the seasons. I call that well mixed.
The assumed “global” CO2 level is the average CO2 level of 10 surface level stations, not including Mauna Loa, but it really doesn’t matter: the trend is the same within a few ppmv worldwide.

Local CO2 levels don’t matter either. You can calculate the theoretical difference in outgoing IR for 410 and 1000 ppmv in the first 1000 meters of the atmosphere with Modtran which needs 0.1 C change to overcome the extra IR retention. No big deal at all as effect on such a short distance.

John F. Hultquist
July 2, 2019 7:46 am

Thanks David.

Seems the null hypothesis (Ho) remains, not disproven.

July 2, 2019 7:53 am

Stomata measurements are as reliable to measure past CO2 concentrations as tree rings to measure past temperatures. Those that accept one while reject the other should check themselves for cognitive bias.

Stomata-inferred CO2 data is more useful to measure changes than to measure actual concentrations. Plant stomatal response to CO2 has plenty of issues of linearity, adaptation and genetic variation.

Everybody understands that ice-core CO2 data is filtered by the firn compaction into ice process losing short term variability, but this is a small issue because high resolution cores show the baseline increasing rapidly in recent times. The hockey stick in CO2 is real and we know its cause because we know how much fossil fuels we have extracted and we know how much CO2 its combustion should produce and it is about double what is needed to produce the increase in CO2, so it is not a mystery where the CO2 is coming from.

So you defend that similar increases might have happened in the past and not be detected due to the low resolution of ice cores. I seriously doubt that. Where would the CO2 have come from? And where would it have gone to produce a spike that would not be detected in ice cores? We know once CO2 levels increase, it takes from hundreds to thousands of years for those levels to go down. Check Vostok ice core. After the Eemian there was a delay of thousands of years from the time the interglacial ended to when CO2 levels decreased. The present CO2 spike will be clearly detectable in Antarctic ice cores for hundreds of thousands of years.

I have no problem with CO2 levels. It is their climatic effect that is very debatable.

Reply to  Javier
July 2, 2019 8:19 am

So how can your “hockey stick’ explain the fact that human-produced CO2 is only 5%of the total CO-2 emissions today? 5% is still only 5%.

The climate is warming, as it has, on average, been doing for the last 16K years. A warming climate results in natural CO-2 emissions increasing, due to off-gassing from the oceans, where most of the world’s CO-2 resides as a natural sink, and also offgassing from the land and its vegetative matter.

Warming causes CO-2 to rise, not the other way around.

Reply to  David Middleton
July 2, 2019 9:19 am

Isn’t that resequestered back into the geological system via increased photosynthesis in vegetation? Why doesn’t that create equilibrium?

Clyde Spencer
Reply to  David Middleton
July 2, 2019 9:59 am

According to Wikipedia, ” Global coal fire emissions are estimated … to represent three percent of the world’s annual CO2 emissions.” Something that humans are not entirely responsible for, and have little ability to prevent, is approximately equal to the amount of CO2 from fossil-fuel energy production.

Reply to  David Middleton
July 2, 2019 1:12 pm

Where it moves right back into sequestration, with a big of geologic lag time.

The point is, we are not creating any new carbon on Earth. We, but actually, mostly the planet itself, simply cycles the same carbon round and round and round again. When the oceans warm up, more of it gets put into atmospheric circulation, temporarily, until a new equilibrium between atmosphere and ocean and crust is reestablished … until the next perturbation of planetary temperatures up or down resets the new equilibrium.

Reply to  Duane
July 3, 2019 8:09 am


The point is that human emissions indeed are partly removed by growing vegetation and the (deep) oceans, but that needs time. The e-fold removal time for any excess CO2 (volcanic, human,…) above the current dynamic equilibrium between the ocean surface temperature and the atmosphere (around 285 ppmv) is about 51 years, very linear in the past 60 years. Or a half life time of around 35 years. That is not fast enough to remove all human extra input in the same year as emitted, which makes that the total CO2 increases with about half the human input:

Krishna Gans
Reply to  Javier
July 2, 2019 8:25 am

In general you are right, but you forget the implication, lower CO2-cold, more CO2 warm.
So if the stomata values are right, why was it colder with a comparable CO2 level ?

Reply to  Krishna Gans
July 2, 2019 9:57 am

I don’t subscribe that implication. The correlation between CO2 and temperature in the paleorecord is quite poor actually, that is if we believe CO2 proxies from millions of years ago.

Krishna Gans
Reply to  Javier
July 2, 2019 10:36 am

I don’t subscribe it too, but as argument against the warmist ideas is it a good one, that was what I thought.

Reply to  Krishna Gans
July 2, 2019 10:29 am

“lower CO2-cold, more CO2 warm”

That is only true as a general tendency, not in any strict sense. In the past climate has been very different at times with identical CO2 level. There has even been ice ages at times with several times more CO2 than now.

Reply to  tty
July 2, 2019 5:29 pm

Which is cause and which is affect.
As sea waters cool, they absorb more CO2. In fact when you look more closely at the CO2 vs. temperature curves from the glacial records, you see that CO2 changes trail changes in temperature, they do not lead them.

Reply to  David Middleton
July 2, 2019 10:25 am

The problem with stomata is that they record the local CO2 level, and CO2 is not well mixed as usually claimed. If the leaves comes from a plant growing in a ravine it is likely to record a significantly higher CO2 level than if it was growing on top of a hill.

Reply to  David Middleton
July 3, 2019 12:52 pm


As said below, you can compensate for the local/regional bias in CO2 levels by calibrating the stomata data with ice cores and direct measurements over the past century, but you have no knowledge of any changes in local bias over the centuries, except by comparing the average of the stomata (index) data with the average of the ice cores over periods longer than one or more resolution periods of the ice cores.

The WAIS DIvide ice core has a resolution of about 10 years in the past 1000 years and a yearly ice layer resolution over some 30,000 years. In the period of the Younger Dryas event the resolution might haven been a somewhat longer, nevertheless much shorter than even the stomata data resolution.
The WAIS core data shows an average of about 265 ppmv during the whole Younger Dryas period, the stomata data about 400 ppmv. That simply means that the local bias at the point where the plants did grow changed with 40 ppmv and that the stomata data need to be recalibrated…

Reply to  tty
July 4, 2019 2:11 pm

The high resolution WAIS divide ice core indeed was not the same deep core, as drilled down to over 3 km deep, the 10 year resolution over the past 1000 years was from a shallow core:
Still searching for the resolution of the deep core…

The shallow core shows about the same resolution as Law Dome and shows the same dip around 1600 as the DE08 core.

Interestingly, they also compare with the stomata data in the period 1000-1500 AD:

Atmospheric CO2 records during 1000–1500 A.D. reconstructed from leaf stomata are 20 to ~23 ppm higher on average than those from the high-resolution Antarctic ice core CO2 records [van Hoof et al., 2008]. It is difficult to compare these reconstructions with the ice core record because of the very high variability (30 ppm) and high uncertainty (6 ppm (1s)) for those records during preindustrial times [van Hoof et al., 2008].

The 20-23 ppmv bias in the stomata record in any case should be corrected for by recalibrating the stomata data with the ice core data, the 6 ppmv uncertainty should be taken with a grain of salt…

Reply to  David Middleton
July 2, 2019 10:36 am

Both stomata and tree rings are effective proxies when they are properly controlled for other variables.

You can’t control for what you don’t know that affected your proxy. There are lots of assumptions going into proxies’ analysis. Biological organisms have a huge plasticity and one of the main assumptions with stomata is that plant response to CO2 levels has little plasticity.

A clear example was the famous decline in tree rings response to temperature that certain climate scientists believed it had to be hidden. Without instrumental measurements to contrast what had happened we wouldn’t have known that the proxy was not behaving correctly. The assumption was shown to not be true.

We might have to do with unreliable proxies for lack of better ones, but ice cores are many times more reliable than stomata. Stomata might add information about rapid changes, but it will not be accepted as a superior proxy, and rightly so in my opinion.

The ocean

No. The ocean can provide about 8-16 ppm per °C of warming. Getting >100 ppm from the ocean would require a warming equivalent to a deglaciation.

The industrial age spike in CO2 has occurred over a roughly 100 year period.

Yes, but CO2 levels will remain above prior levels for hundreds of years if not thousands. This means the spike will remain detectable in future records. We don’t see anything like that in past records.

Anthropogenic CO2 has been moved from fossil stores to the carbon cycle where it will have to remain for a long time cycling through different stores before being buried at the sea bottom.

Reply to  Javier
July 2, 2019 5:31 pm

“You can’t control for what you don’t know that affected your proxy. ”

Are you now arguing that we should not use any proxies?
If not, how we know that the unknown unknowns are invalidating all of them?

Reply to  David Middleton
July 3, 2019 11:19 am


On millemmial scales, there is a quite good response of CO2 to temperature changes in the Vostok record of about 8 ppmv/K (the latter for Antarctic temperatures). On global scale that is about 16 ppmv/K over the past 800,000 years:
where most of the discrepancy is caused by the long lag of CO2 changes after T changes.
Even today, there is only some 4 ppmv/K change on short term (seasons, ENSO,…).
In all cases the atmosphere follows Henry’s law with a rather fixed ratio between the pCO2 of the ocean surface and the pCO2 (~ppmv) in the atmosphere. The pCO2 of the ocean waters changes with about 16 ppmv/K around 15 degrees, which is the current average ocean surface temperature…

Reply to  Javier
July 2, 2019 10:29 am

“We know once CO2 levels increase, it takes from hundreds to thousands of years for those levels to go down.”

This is true only if the Bern’s model hypothesis is proven to be right.

Some scientists do not agree with the Bern’s model :

Ed Berry :

Murry Salby :

Tom Segalstad (geologist) :

Reply to  Petit_Barde
July 3, 2019 11:29 am


The Bern model indeed is wrong, because it assumes that all other reservoirs get saturated with CO2. That is only the case for the ocean surface, the top 100-200 meter where most sunlight and bio-life is active. That is the layer which shows a rapid exchange with the atmosphere for all gases, but the CO2 buffer capacity of the surface is limited to about 10% of the change in the atmosphere.
For the deep oceans, neither for vegetation there are no such limits, at least not in the far foreseeable future.
On the other hand, both Segalstad and Ed Berry are wrong too, as they use the residence time to calculate the decline of any extra CO2 in the atmosphere.
The residence time only shows how much CO2 is exchanged each year, but that doesn’t change the amounts of CO2 in the atmosphere, only the difference between inputs and outputs does that and that is a much slower process…
Dr. Salby is wrong for other reasons, but that goes too far to explain here – again…

R Shearer
Reply to  Javier
July 2, 2019 4:05 pm

Volcanoes and biology both act at high frequency compared to the time constant of ice cores.

Reply to  Javier
July 2, 2019 5:26 pm

The problems with using trees as thermometers has been discussed to death.
Why don’t you clue us in on why you believe that stomata can’t be used to infer CO2 levels?

Dan Sudlik
July 2, 2019 7:54 am

Yeah! Our plants love it and we will all eat well again tonight.

July 2, 2019 8:20 am

In climate “science” there seems to be a tendency to disregard the high frequency component of the pre-industrial carbon dioxide record, while also disregarding or mishandling the low frequency component of the pre-industrial temperature record (Esper et al., 2005).

I had to read that a couple of times before I got it. So, they apply a low pass filter to the CO2 and a high pass filter to the temperature. I wouldn’t accept that from a student unless she had a PhD statistician in tow. On the other hand, climate scientists don’t seem to know any statisticians.

Steve Keohane
July 2, 2019 8:21 am

Great post, thanks David

July 2, 2019 8:28 am

What’s the position of climate scientists when it comes to plant stomata chronologies?

Reply to  David Middleton
July 7, 2019 6:50 pm

OK. I found the arguments of the climate scientists.

At least it references and links to the Wagner study and the reaction you mentioned as McCarthyism. I’ll have to go through their arguments.

Thomas Homer
July 2, 2019 8:50 am

We know that CO2 is integral and necessary to the Carbon Cycle of Life.
– Life consumes CO2.
– CO2 feeds life.

We know atmospheric CO2 levels of three sister planets:
– Venus 95%
– Earth 0.04%
– Mars 95%

And we’re supposed to be alarmed that Life-Food has increased to 0.04% on Earth because ancient air bubbles trapped in ice apparently reveal details after they are “reconstructed by deconvolution”?

We know that we are unable to detect the “Greenhouse Gas Property” of CO2 on Mars where it is 95%.
We know that we are unable to measure the “Greenhouse Gas Property” of CO2 here on Earth.
We are unable to advance the theory of “Greenhouse Gases” because we are unable to measure anything of significance. We cannot derive any Laws, Axioms, Postulates, nor formulae because we have not been able to measure the purported “Greenhouse Gas Property” in the real world.

Which of the three sister planets: Venus; Earth; Mars; do we know supports Carbon Based Life Forms which consume CO2 when considered as a whole?

Johne Morton
July 2, 2019 8:58 am

So anthropogenic CO2 has pushed the concentration above levels seen during the last several hundred thousand years…so what? I’m sure if there were a way to measure contrails in the stratosphere or upper troposphere over the same time span, we could say that the 20th-21st centuries were “unprecedented”, too. Who cares? CO2’s ability to absorb outgoing longwave radiation is already mostly saturated. I bet we have far more asphalt and rice paddies nowadays, too.

William Astley
July 2, 2019 9:18 am

What are the competing theories? Can someone please prepare a summary of the problem situation that includes the recent paradoxes? Why are there still dead theories in Geology? Are there no thinkers in Geology?

There are a dozen independent current observations (not proxy data) that show that atmospheric CO2 levels is currently tracking planetary temperature changes not human CO2 emissions and that human CO2 emissions are responsible for less than 5% of the recent rise in atmospheric temperature.

The finding that atmospheric CO2 is tracking temperature not anthropogenic CO2 emissions is only possible if there is a massive unaccounted for source of CO2 into the biosphere and a massive accounted for sink of CO2 out of the biosphere.

As noted below there has been the very recent discovery (C14 found in shells of deep ocean life) of a massive fast sink of CO2 into the deep ocean and there has been a recent finding of a massive sink of water into the mantel. Three times more water is being dragged into the mantel by ocean plate than is coming out in volcanic gases.

The current observations show the Bern model of CO2 sinks, sources, and resident times is a fake model that was created or there would be no AGW/CAGW.

Graphs and sciency analysis are purposeless/blocks progress if the data is incorrect/fake and if observational paradoxes and the obvious forced solution is ignored.

There are past direct atmospheric CO2 measurements that support the assertion that short term atmospheric CO2 levels track planetary temperature and the past short term rises in atmospheric CO2 are not recorded in the proxy CO2 record.

‘Callendar (1938) revived the hypothesis of “Greenhouse Warming” due to Man’s activity, proposed by Arrhenius (1896). Callendar may truly be regarded as the father of the current dogma on man-induced global warming (Jaworowski et al., 1992 b).

In order to support his hypothesis, Callendar (1940, 1958) selected atmospheric CO2 data from the 19th and 20th centuries. Fonselius et al. (1956) showed that the raw data ranged randomly between about 250 and 550 ppmv (parts per million by volume) during this time period, but by selecting the data carefully Callendar was able to present a steadily rising trend from about 290 ppmv for the period 1866 – 1900, to 325 ppmv in 1956.’

“Callendar was strongly criticized by Slocum (1955), who pointed out a strong bias in Callendar’s data selection method. Slocum pointed out that it was statistically impossible to find a trend in the raw data set, and that the total data set showed a constant average of about 335 ppmv over this period from the 19th to the 20th century.

Bray (1959) also criticized the selection method of Callendar, who rejected values 10% or more different from the “general average”, and even more so when Callendar’s “general average” was neither defined nor given.”

‘13-C/12-C isotope mass balance calculations show that IPCC’s atmospheric residence time of 50-200 years make the atmosphere too light (50% of its current CO2 mass) to fit its measured 13-C/12-C isotope ratio. This proves why IPCC’s wrong model creates its artificial 50% “missing sink”. IPCC’s 50% inexplicable “missing sink” of about 3 giga-tonnes carbon annually should have led all governments to reject IPCC’s model.

Politically correct in science is called confirmation bias where proxy data is altered to agree with a theory.

This recent observation that C14 is making to the deepest ocean with no delay is another observational fact that disproves the CAGW team created absurdly non-physical so-called Bern model of CO2 sinks and sources and resident times.

The Bern model assumes that ocean circulation (with hundreds of years delay) is the only method for deep sequestration of CO2 in the ocean.

The alleged long lifetime of 500 years for carbon diffusing to the deep ocean is of no relevance to the debate on the fate of anthropogenic CO2 and the “Greenhouse Effect”, because POC (particular organic carbon; carbon pool of about 1000 giga-tonnes; some 130% of the atmospheric carbon pool) can sink to the bottom of the ocean in less than a year (Toggweiler, 1990).

Bomb C14 Found in Ocean Deepest Trenches

‘Bomb Carbon’ from Cold War Nuclear Tests Found in the Ocean’s Deepest Trenches

July 2, 2019 9:31 am

These graphs seem to be as much about an art form as about a form of science.

There seems to be creative wiggle room in how a person arrives at a picture. I call that “art”.

Can we really know what the past was like at the desired level of detail, … as in parts per MILLION of a gaseous atmosphere for an entire planet? We just have not lived and do not live long enough to know, and I think that it’s this inability to really know that keeps the argument going.

Sometimes it seems that we are arguing about which style of art is best.

Walt D.
July 2, 2019 9:33 am

Perhaps the hockey stick Climate Alarmists could learn from the great Wayne Gretzky, who said ..
“I skate to where the puck is going to be, not where it has been.”
Climate Alarmists are 100% wrong when forecasting “where the puck is going to be”.
Climate Alarmists always wait until something has happened before they forecast it.

Reply to  David Middleton
July 2, 2019 5:34 pm

I have a rule of thumb that says rules of thumb are only good up to a point.

Michael S. Kelly LS, BSA Ret.
Reply to  MarkW
July 2, 2019 9:44 pm

I wouldn’t count on that.

William Astley
July 2, 2019 10:04 am

Geology is interesting as it is a simple constrained field of science (solutions are forced analogous to a chess forced move where the physical problem constraints provides a simple force solution) that has mature observations and piles and piles of paradoxes.

The following are a couple of papers that support the assertion made above that the recent changes in atmospheric CO2 was caused by the increase in temperature, not by anthropogenic CO2 emissions.

Sources and sinks of CO2 Tom Quirk

The yearly increases of atmospheric CO2 concentrations have been nearly two orders of magnitude greater than the change to seasonal variation which implies that the fossil fuel derived CO2 is almost totally absorbed locally in the year that it is emitted.

A time comparison of the SIO measurements of CO2 at Mauna Loa with the South Pole shows a lack of time delay for CO2 variations between the hemispheres that suggests a global or equatorial source of increasing CO2. The time comparison of 13C measurements suggest the Southern Hemisphere is the source.

This does not favour the fossil fuel emissions of the Northern Hemisphere being responsible for their observed increases. All three approaches suggest that the increase of CO2 in the atmosphere may not be from the CO2 derived from fossil fuels. The 13C data is the most striking result and the other two approaches simply support the conclusion of the first approach.

The phase relation between atmospheric carbon dioxide and global temperature
Summing up, our analysis suggests that changes in atmospheric CO2 appear to occur largely independently of changes in anthropogene emissions.

A similar conclusion was reached by Bacastow (1976), suggesting a coupling between atmospheric CO2 and the Southern Oscillation.

However, by this we have not demonstrated that CO2 released by burning fossil fuels is without influence on the amount of atmospheric CO2, but merely that the effect is small compared to the effect of other processes.

Our previous analyses suggest that such other more important effects are related to temperature, and with ocean surface temperature near or south of the Equator pointing itself out as being of special importance for changes in the global amount of atmospheric CO2.

Reply to  William Astley
July 2, 2019 6:25 pm

A fairly recent story, maybe in WUWT, said that earlier IPCC publications, compiling natural CO2 sources, concluded that termites produce about 4X as much CO2 per year as all human activities. It went on to say that in many parts of the world termite populations are growing rapidly, frequently due to invasive species. It also said that there have been some recent discoveries of previously unknown ,very large, termite colonies, such as an area in the Amazon that is, if I recall correctly, about the size of New Hampshire. This area has been pretty much totally taken over by largish termite hills. Such population growth, apparently, has not been taken into account by the consensus bodies.

If the above is true, that could account for some significant part of the atmospheric CO2 increase

Reply to  AndyHce
July 3, 2019 1:10 pm


Termites are part of the biosphere and no matter how much CO2 they produce, they only can produce what was first removed out of the atmosphere. Thus that has zero effect on the amount in the atmosphere.
The biosphere as a whole currently is a net sink for CO2 and absorbs about 1/4 of what was emitted by humans. The latter CO2 was part of the atmosphere some millions of years ago, thus that affects current CO2 levels…

Reply to  Ferdinand Engelbeen
July 3, 2019 10:45 pm

It the long term termites may make no significant difference but termites often eat things that have been around for some longish time and/or may have otherwise been around for some longish time into the future. Thus on the time scale of a few decades a big growth of termite populations could have a noticeable effect on atmospheric measurements.

Reply to  William Astley
July 3, 2019 1:23 pm


We (Jack Barrett and me) have written a response to that work of Tom Quirk in E&E, as he have made several errors.
One of his errors is in:
“A time comparison of the SIO measurements of CO2 at Mauna Loa with the South Pole shows a lack of time delay for CO2 variations between the hemispheres”
Where he forgot that seasonal variations show the same “lag” at 12, 24, 36,… months.
There is certainly a lag of about 6-12 months between ground level and height and 12-24 months between the NH and the SH, both in CO2 levels and d13C decline:
Thus the source of that extra CO2 is certainly in the NH, where 90% of human emissions are going on…

Reply to  William Astley
July 8, 2019 4:31 am

William Astley – thank you for this paper by Tom Quirk, previously unknown to me. While I am still agnostic on this hypothesis, it is gaining momentum – here is some of the relevant material.


“Sources And Sinks Of Carbon Dioxide”
By Tom Quirk, Energy & Environment, 2009

Murry Salby, Video at the Sydney Institute, Aug 3, 2011 and subsequent works–9I&

“Scrutinizing the carbon cycle and CO2 residence time in the atmosphere“
By Hermann Harde, Global and Planetary Change, May 2017

“What Humans Contribute to Atmospheric CO2: Comparison of Carbon Cycle Models with Observations”
By Hermann Harde, Earth Sciences, June 2019

“Human CO2 Emissions have little Effect on Atmospheric CO2”
By Ed Berry, International Journal of Atmospheric and Ocean Sciences, July 4, 2019,

Reply to  William Astley
July 8, 2019 6:08 am



My paper was posted Jan.31/08 at

“Carbon Dioxide in Not the Primary Cause of Global Warming: The Future Can Not Cause the Past”

Despite continuing increases in atmospheric CO2, no significant global warming occurred in the last decade, as confirmed by both Surface Temperature and satellite measurements in the Lower Troposphere. Contrary to IPCC fears of catastrophic anthropogenic global warming, Earth may now be entering another natural cooling trend. Earth Surface Temperature warmed approximately 0.7 degrees Celsius from ~1910 to ~1945, cooled ~0.4 C from ~1945 to ~1975, warmed ~0.6 C from ~1975 to 1997, and has not warmed significantly from 1997 to 2007.

CO2 emissions due to human activity rose gradually from the onset of the Industrial Revolution, reaching ~1 billion tonnes per year (expressed as carbon) by 1945, and then accelerated to ~9 billion tonnes per year by 2007. Since ~1945 when CO2 emissions accelerated, Earth experienced ~22 years of warming, and ~40 years of either cooling or absence of warming.

The IPCC’s position that increased CO2 is the primary cause of global warming is not supported by the temperature data. In fact, strong evidence exists that disproves the IPCC’s scientific position. This UPDATED paper and Excel spreadsheet show that variations in atmospheric CO2 concentration lag (occur after) variations in Earth’s Surface Temperature by ~9 months. The IPCC states that increasing atmospheric CO2 is the primary cause of global warming – in effect, the IPCC states that the future is causing the past. The IPCC’s core scientific conclusion is illogical and false.

There is strong correlation among three parameters: Surface Temperature (“ST”), Lower Troposphere Temperature (“LT”) and the rate of change with time of atmospheric CO2 (“dCO2/dt”). For the time period of this analysis, variations in ST lead (occur before) variations in both LT and dCO2/dt, by ~1 month. The integral of dCO2/dt is the atmospheric concentration of CO2 (“CO2”).

See also Roy Spencer’s (U of Alabama, Huntsville) take on this subject at


Earlier work by Kuo et al reached similar conclusions about the lag of CO2 after temperature.
“Coherence established between atmospheric carbon dioxide and global temperature“
By Kuo C, Lindberg C & Thomson DJ, Nature 343, 709 – 714, 22 February 1990.


The hypothesis that the increase in atmospheric carbon dioxide is related to observable changes in the climate is tested using modern methods of time-series analysis. The results confirm that average global temperature is increasing, and that temperature and atmospheric carbon dioxide are significantly correlated over the past thirty years. Changes in carbon dioxide content lag those in temperature by five months.

Keeling et al reached some similar conclusions in 1995.

“Interannual extremes in the rate of rise of atmospheric carbon dioxide since 1980”
By C. D. Keeling, T. P. Whorf, M. Wahlen & J. van der Plicht, Nature Vol 375, June 22, 1995

OBSERVATIONS of atmospheric C02 concentrations at Mauna Loa, Hawaii, and at the South Pole over the past four decades show an approximate proportionality between the rising atmospheric concentrations and industrial C02 emissions1. This proportionality, which is most apparent during the first 20 years of the records, was disturbed in the 1980s by a disproportionately high rate of rise of atmospheric CO2, followed after 1988 by a pronounced slowing down of the growth rate. To probe the causes of these changes, we examine here the changes expected from the variations in the rates of industrial CO2 emissions over this time2, and also from influences of climate such as EI Nino events. We use the 13C/12C ratio of atmospheric CO2 to distinguish the effects of interannual variations in biospheric and oceanic sources and sinks of carbon. We propose that the recent disproportionate rise and fall in CO2 growth rate were caused mainly by interannual variations in global air temperature (which altered both the terrestrial biospheric and the oceanic carbon sinks), and possibly also by precipitation. We suggest that the anomalous climate-induced rise in CO2 was partially masked by a slowing down in the growth rate of fossil-fuel combustion, and that the latter then exaggerated the subsequent climate-induced fall.

Veizer (GAC 2005) is very interesting, and was quite controversial when published.
“Celestial Climate Driver: A Perspective from Four Billion Years of the Carbon Cycle”

See also Veizer and Shaviv (2003):

“Celestial driver of Phanerozoic climate?”
Nir J. Shaviv and Ján Veizer, GSA Today, June 2003


The postulated causation sequence is therefore: brighter sun => enhanced thermal flux + solar wind => muted CRF => less low-level clouds => lower albedo => warmer climate.

The hydrologic cycle, in turn, provides us with our climate, including its temperature component. On land, sunlight, temperature, and concomitant availability of water are the dominant controls of biological activity and thus of the rate of photosynthesis and respiration. In the oceans, the rise in temperature results in release of CO2 into air. These two processes together increase the flux of CO2 into the atmosphere. If only short time scales are considered, such a sequence of events would be essentially opposite to that of the IPCC scenario, which drives the models from the bottom up, by assuming that CO2 is the principal climate driver and that variations in celestial input are of subordinate or negligible impact….

… The atmosphere today contains ~ 730 PgC (1 PgC = 1015 g of carbon) as CO2 (Fig. 19). Gross primary productivity (GPP) on land, and the complementary respiration flux of opposite sign, each account annually for ~ 120 Pg. The air/sea exchange flux, in part biologically mediated, accounts for an additional ~90 Pg per year. Biological processes are therefore clearly the most important controls of atmospheric CO2 levels, with an equivalent of the entire atmospheric CO2 budget absorbed and released by the biosphere every few years. The terrestrial biosphere thus appears to have been the dominant interactive reservoir, at least on the annual to decadal time scales, with oceans likely taking over on centennial to millennial time scales.

I think there are perhaps four cycles in which CO2 lags T:
1. A cycle of thousands of years, in which CO2 lags T by ~hundreds of years (Vostok ice cores, etc.)
2. A cycle of ~70-90 years (Gleissberg), in which CO2 lags T by ~5-10 years (this is contentious – Ernst Beck’s direct-measurement CO2 data supports, ice core data does not, and there is the important question of how much humanmade CO2 affects this cycle).
3. The cycle I described in my paper of 3-5 years (El Nino/La Nina), in which CO2 lags T by ~9 months.
4. The seasonal “sawtooth” CO2 cycle, which ranges from ~18 ppm in the North to ~1 ppm at the South Pole.
It is clear that T precedes CO2 in cycles 1, 3 and 4. For Cycle 2 we have conflicting and perhaps inadequate data…

Regards, Allan

Five years after my paper, Humlum et al (2013) provided the sequence:
Sea surface temperature changes, then surface air temperature changes, then lower tropospheric temperature changes, then atmospheric CO2 changes.

“The Phase Relation between Atmospheric Carbon Dioxide and Global Temperature”
by Ole Humlum, Kjell Stordahl, Jan-Erik Solheim
Global and Planetary Change. January 2013

– Changes in global atmospheric CO2 are lagging 11–12 months behind changes in global sea surface temperature.
– Changes in global atmospheric CO2 are lagging 9.5–10 months behind changes in global air surface temperature.
– Changes in global atmospheric CO2 are lagging about 9 months behind changes in global lower troposphere temperature.
– Changes in ocean temperatures explain a substantial part of the observed changes in atmospheric CO2 since January 1980.
– Changes in atmospheric CO2 are not tracking changes in human emissions.

In June 2019 I wrote a summary report on the subject of Climate and Energy, hypothesized why the lag of CO2 after temperature is ~9 months, and provided a credible rational for that lag – This ~9-month lag, +/- several months, averages 1/4 of the full-period duration of the variable global temperature cycle, which averages ~3 years.

“CO2, Global Warming, Climate and Energy”
by Allan M.R. MacRae, B.A.Sc., M.Eng., P.Eng., June 13, 2019
Excel workbook:


Global warming alarmism, which falsely assumes that increasing atmospheric CO2 causes catastrophic global warming, is disproved – essentially, it assumes that the future is causing the past. In reality, atmospheric CO2 changes lag global temperature changes at all measured time scales.

Nino34 Area Sea Surface Temperature changes, then tropical humidity changes, then atmospheric temperature changes, then CO2 changes.

The velocity dCO2/dt changes ~contemporaneously with global temperature changes and CO2 changes occur ~9 months later (MacRae 2008).

The process that causes the ~9-month average lag of CO2 changes after temperature changes is hypothesized and supported by observations.

The ~9-month lag, +/- several months, averages 1/4 of the full-period duration of the variable global temperature cycle, which averages ~3 years.

Based on the above observations, global temperatures drive atmospheric CO2 concentrations much more than CO2 drives temperature.

Climate sensitivity to increasing atmospheric CO2 must be very low, less than ~1C/(2*CO2) and probably much less.

There will be no catastrophic warming and no significant increase in chaotic weather due to increasing CO2 concentrations.

Increasing atmospheric CO2 clearly causes significantly improved crop yields, and may cause minor, beneficial global warming.

Atmospheric CO2 is not alarmingly high, it is too low for optimal plant growth and alarmingly low for the survival of carbon-based terrestrial life.

Other factors such as fossil fuel combustion, deforestation, etc may also increase atmospheric CO2. The increase of CO2 is clearly beneficial.

“Green energy” schemes are not green and produce little useful (dispatchable) energy, primarily because of the fatal flaw of intermittency.

There is no widely-available, cost-effective means of solving the flaw of intermittency in grid-connected wind and solar power generation.

Electric grids have been destabilized, electricity costs have soared and Excess Winter Deaths have increased due to green energy schemes.


Earlier conclusions by the author and others are reviewed that disprove global warming alarmism and the justification for CO2 abatement schemes.

Increasing atmospheric CO2 does NOT cause dangerous global warming. Humanmade global warming / climate change is a false crisis.

Atmospheric CO2 changes lag global temperature changes at all measured time scales.

The process that causes the ~9-month average lag of CO2 changes after temperature changes is hypothesized and supported by observations.

This ~9-month lag, +/- several months, averages 1/4 of the full-period duration of the variable global temperature cycle, which averages ~3 years.

July 2, 2019 11:30 am

Ok, so we assume they are correct and CO2 is higher. That then is demonstrable that CO2 is not a control knob as the Holocene Optimum was higher in temperature than now and the past interglacials were higher than now.

July 2, 2019 1:42 pm

I have always had doubts about the ice core results, led mainly by my observation of the collapse of plastic bottles over time as the contents migrate through the plastic. Different physics but a similar situation to air bubbles trapped in ice.
CO2 is far more solvent in water than either nitrogen or oxygen and this markedly increases with pressure; but whether this alters the ratio I don’t know; for it is a matter of partial pressure. Thus we have potential changes in the mix during the mixing/sealing zones which experience considerable movements and stresses over time.
Then we have the matter of diffusion about which I know little; but gather that the data input on this stems from theory and laboratory experiments giving diffusion rates under sealed conditions.
It is in my view that such experiments can in no way accurately mimic what happens over very considerable periods of time subject to variations in stress and movement. Osmosis is a powerful force.
Generally I can accept that data on anomalies can have value; but when it comes to establishing actual CO2 levels, I have my doubts.

I suspect that overall, the actual physics tends to result in an asymptotical progression towards a final result with time and it is this that is evident in the remarkable consistency in apparent levels of CO2 in the distant past leading to the apparent rise at the approach to the present.

As for the excellent statistical analysis here I like to think that it somehow supports my views; but am not qualified to judge here.

Joel O'Bryan
July 2, 2019 2:14 pm

Exactly 5 years ago, July 2, 2014, NASA’s OCO-2 mission launched from Vandenburg AFB, CA.
This NASA OCO-2 polar orbiting spectrophotometer mission was to show where all that nasty “carbon pollution” was coming from. The expectation was it would validate the anthropogenic GHG warming paradigm.

The NASA web page lists 4 Big ‘Main Points’ for the OCO2:

“The main points for the mission are:

Message One: The burning of fossil fuels and other human activities are currently adding more than 36 billion tons of carbon dioxide to the atmosphere each year, producing an unprecedented buildup in this important greenhouse gas. OCO-2 provides a new tool for understanding the sources of carbon dioxide emissions and how they are changing over time.

Message Two: Less than half of the carbon dioxide emitted into the atmosphere by human activities stays there. The location and identity of the natural “sinks” that are absorbing the rest of this carbon dioxide are currently not well understood. OCO-2 will help solve this critical scientific puzzle.

Sub-message: Knowing what parts of Earth are helping remove carbon from the atmosphere will help us understand if they will keep doing so in the future. OCO-2 measurements will help scientists construct better models to predict how much carbon dioxide these sinks will be able to absorb in the future.

Message Three: The innovative technologies incorporated into OCO-2 will enable space-based measurements of carbon dioxide with the sensitivity, resolution and coverage needed to understand human and natural sources of carbon dioxide emissions and the natural sinks that control its buildup, at regional scales, everywhere on Earth.
Sub-message: To control carbon dioxide in our atmosphere, we need to be able to measure it. We can only manage what we can measure.

Message Four: OCO-2 will help assess the usefulness of space-based measurements of carbon dioxide for managing emissions of this important greenhouse gas.

(source: )

Right in #1 they start with the message they “expect” to find.
And then the “To control carbon dioxide in our atmosphere,…” is amazing hubris.

Before they had any actual OCO-2 data, this November 2014 article shows a much-hyped 2006 NASA simulation of what they “expected” to see:

But then real data started flowing in by December 2014.
The initial OCO-2 data, especially showing large sources in the Southern Hemisphere and Southern Ocean completely surprised, and blew away the validity of that previous simulation.
IOW, the first thing that OCO-2 showed NASA was their preconceived “expectation” of global CO2 sources and sinks was badly wrong:

Anthony covered it here at WUWT, the initial early surprise results here (from the Dec 2014 AGU conference):

And NASA in 2016 released this cool Supercomputer re-analysis of 1 year’s worth of OCO-2 data (September 2014 to August 2015) to show global CO2 movements:

If you actually compare that to their earlier “expected” 2006 simulation, it shows huge differences, especially in the Southern Hemisphere, which was totally unexpected.

But that last data product on the OCO-2 web page is now 2 years old. There have been zero CO2 updates from the OCO-2 team since July 2017. And there have been no OCO-2 monthly data product gallery visualizations provided.
see here:

The OCO-2 team had a big Science Mag paper in 2017 and a News telecon in the Fall 2017.

And there was this interesting snippet in that Oct 12, 2017 release:
“OCO-2 data show that in the first few months of the 2015-16 El Niño, the rate of carbon dioxide released from the tropical Pacific to the atmosphere decreased by 26 to 54 percent. That translates to a short-term reduction of 0.4 to 0.5 parts per million in atmospheric concentration, or close to 0.1 percent of total atmospheric carbon dioxide.”

My question
Why? Why has OCO-2 team gone dark on reporting CO2 products, it’s been “crickets”…. approaching 2 full years now?

My hunch is they have now strong data-based results that blows away much, if not all, of the presumed exclusive nature of fossil-fuel anthropogenic source paradigm for observed CO2 rise.

Further conjecture on my part:
As a result, the OCO team has been put on CO2 data lock-down, going on 2 years now. Imagine the implications of such a data driven finding. It would be as major a paradigm shattering event as the first 16th Century telescope observations to show the Jovian moons orbiting Jupiter, and not in some Earth-centric epicycle around the Earth. A telescope showed the existing consensus on geo-centrism was dead wrong. And OCO-2’s now peering at Earth may have found that the anthropogenic CO2-rise paradigm is dead wrong.

Yes, the full level 2 data is available for independent researchers to down-load and study on their own, but it is a huge amount of data that requires specialized IT tools, machines and expertise. That is not do-able for some Excel-geek PC desk jockey to take on. And so far I can’t find in searches any recent data from OCO-2 CO2 mission anywhere. The only thing they are reporting since 2017 on is the chlorophyll-derived Solar-Induced-Fluorescence (SIF) data from the OCO-2 mission.
Interesting, yes.
What their primary mission is? No.

Someone, anyone, please show me I’m wrong. Show me where the OCO-2 team is still putting out something other than the raw data (terabytes of the OCO-2 Level 2 data in raw form). I will accept that if you can show that OCO-2 data team has published graphics in usable form since 2017 (like they did in their data products gallery till July 2017).

If NASA’s OCO-2 CO2 team and their data products have been silenced by someone, then William Happer and his climate change commission should look into this matter on OCO-2 data.

Clyde Spencer
Reply to  Joel O'Bryan
July 2, 2019 8:57 pm

Incidentally, the data that they have been making available is very noisy, largely from missing data because of clouds. That leads me to conclude that the summary maps that they have produced have either been strongly average over time, or a lot of interpolation has been employed.

But, I agree that it is noteworthy how little has been released in the form of processed maps.

Martin Cropp
Reply to  Joel O'Bryan
July 3, 2019 3:00 am

Why don’t you just contact them through the website. I have found them very friendly and keen to help.

It will save a lot of speculation on your part.

Steven Mosher
July 2, 2019 8:41 pm

‘A stomatal frequency record based on buried Tsuga heterophylla needles reveals significant centennial-scale atmospheric CO2 fluctuations during the last millennium. The record includes four CO2 minima of 260 275 ppmv (ca. A.D. 860 and A.D. 1150, and less prominently, ca. A.D. 1600 and 1800). Alternating CO2 maxima of 300 320 ppmv are present at A.D. 1000, A.D. 1300, and ca. A.D. 1700. These CO2 fluctuations parallel global terrestrial air temperature changes, as well as oceanic surface temperature fluctuations in the North Atlantic. The results obtained in this study corroborate the notion of a continuous coupling of the preindustrial atmospheric CO2 regime and climate.”

control knob


Joel O’Bryan
Reply to  Steven Mosher
July 2, 2019 10:13 pm

Yes, I agree… temp controlling CO2. Simple.
Henry’s Law stuff.

Scott W Bennett
July 2, 2019 10:32 pm

“control knob thanks” – Steven Mosher

control knob
noun (slang, pejorative)
1. An obnoxious person, who feels an obsessive need to exercise control over others.
2. A person who believes CO2 is “the” climate control knob.
3. A climate alarmist

See also: globalist neo-marxist totalitarian 😉

July 2, 2019 10:39 pm

David: There is some interesting stuff in this post. You are correct that slowly accumulating Antarctic ice core like Vostok have little ability to detect quick large changes in CO2 – such as the change over the past century. However, that is why ice cores are still being drilled in fast accumulating regions of Antarctica. You are correct that Greenland ice cores should exhibit even higher resolutions, but the surface of Greenland often melts in the summer and then refreezes. That disturbs gas exchange within the firn before it compacts into ice.

I’m skeptical of the stomata data until someone provides a viable explanation for the large rapid changes in atmospheric CO2 stomata report. Right now, according to Mauna Loa and elsewhere CO2 is increasing about 20 ppm/decade and it was increasing about 10 ppm/decade in the 1960s. We know that we burned enough fossil fuel to cause twice the observed change in CO2 and that half of those emissions disappeared into sinks. (We can refine these estimates by adding emissions from limestone and deforestation.) Your Figure 9 with data from stomata shows a greater than 100 ppm increase in CO2 in about 30 years in the around 1540. Assuming the stomata record is correct and the ice core records are wrong, what happened to all of that CO2?

It is far too much to be taken up by “greening of the planet”.

During the 97/98 El Nino and 98/99 La Nina there was a major shift in the usual steady pattern of 2 ppm/yr de-seasonalized increase in CO2 in the atmosphere: There was a 3 ppm increase in 97/98 and only a 1 ppm increase in 98/99. So I think the extra CO2 came form outgassing of the warmer mixed layer of the ocean in 97/98 and uptake of CO2 by the mixed layer in 98/99. The change in SST was about 0.2-0.3 degK. So uptake by the mixed layer is only worth about 4 ppm/K of cooling. It takes about a 1000 years for the ocean to overturn, so only about 3% of the ocean was available to take up that 100 ppm of CO2 in Figure 9 over 30 years. According to Antarctic ice cores, the decrease in CO2 during the LIA was less than 10 ppm, consistent with the estimate from El Nino and La Nina.

The big rapid changes in CO2 reported by stomata are too big and rapid to be believable. That 1 ppm large and smaller rise and fall in 97-99 is the biggest deviation from a totally uniform de-seasonalized rise of CO2 in a half-century. Figure 9 shows large (50 ppm) irregular fluctuations for a millennium and then the biggest irregularity we detect with an accurate instrument is 1 ppm in the most recent half-century???? Perhaps I’m wrong, I choose to ignore this evidence.

I suspect that what you will find someday is that stomata vary for other reasons than just CO2, just like tree rings vary for reasons besides temperature. If we ever get a large number of stomata records, they will be consistent from 200-400 ppm at different locations at the same time. Of course, I don’t need to be right and I may be overconfident of the other thing I think I understand.

Reply to  David Middleton
July 4, 2019 11:27 am

David: Thanks for the reply. If stomata data are “noisy”, what changes are believable and what changes are not? Above I commented on a 100 ppm change over several decades in one of your graphs and questioned what physical process could remove so much CO2 from the air in such a short period of time. If you smooth the data, perhaps the change will be reduced to 70 ppm or 50 ppm. So what, if I find those changes equally hard to explain?

If stomata data from different sites around the world show correlated and similar changes, then they may be real. Then we will need to find a smoothing process that can explain how these large changes in CO2 are smoothed in ice cores. But I doubt we will need to do this.

Today, we burn enough fossil fuel to raise CO2 4 ppm/yr and the extra 120 ppm currently present in the atmosphere result in a net 2 ppm/yr uptake. Back in the 1960s, emissions the equivalent of 2 ppm/yr were reduced to a net 1 ppm by the extra 50 ppm in the atmosphere. After seasonal changes are removed, natural perturbations in this process are barely detectable.

IIRC, scientists are looking into the changing ratios of gases in ice cores to understand how fast CO2 diffuses into the firn before it is compressed into ice, permanently trapping the gases. Argon is smaller than nitrogen and oxygen, which are smaller than CO2. Argon and krypton have similar radius and different atomic weights, while Neon and Argon have different sizes and weights. I’m not sure which gases can be detected and are being studied, but the idea is to better characterize diffusion and place constraints on the lag time between CO2 and temperature proxies dated by layer.

Reply to  Frank
July 3, 2019 1:00 pm

“It takes about a 1000 years for the ocean to overturn”

Correct, but you overlook the biological carbon transport to the deep ocean. Animals living at abyssal depth contain about as much C14 as surface biota. This admittedly only works one way – in decreasing CO2 near the surface and increasing it near the bottom.

July 3, 2019 1:18 am

When was the last time CO2 concentration rose at 3ppm pa?

Reply to  David Middleton
July 3, 2019 11:10 pm

Never mind, I found out for myself.

“Even if today’s CO2 concentrations are similar to the levels seen millions of years ago, the rate at which they’re currently climbing probably “outstrips anything we’ve seen in the geological record for at least 65 million years,”
Professor Gavin Foster,

… and still accelerating. Now thats what I call a hockey stick.

July 3, 2019 8:44 am


I nearly missed this one, just as I totally missed the previous one…

The resolution of the ice cores indeed is important, as we can miss some peaks that are short living.
Several remarks on that:
– Many ice cores with increasing resolution from 10-600 years overlap each other and show the same CO2 levels within 5 ppmv for the same average gas age. So you can bootstrap the past from the present and better than for any temperature reconstruction, the average CO2 concentration of the past is as good as for the present, but you can miss some peaks and drops of higher frequency.
– Greenland ice cores are not reliable, due to frequent acid dust inclusions of nearby Icelandic volcanoes. With the old CO2 measurements: melting ice under vacuum, you could find increasing CO2 levels over time as the reaction in the melt simply got further. Antarctic ice cores do have some dust inclusions, mostly sea salt near the coast and even from far away inland, but lack the acid component. Newer measurements don’t melt the ice and either crush it under vacuum or sublimate it just under the melting point and separate everything cryogenic.
– Stomata data are good to show fast changes, but are unsuitable for absolute levels: they grow on land with a variable bias against “background” CO2 levels. One can compensate for that bias by comparing with ice cores, firn and direct measurements over the past century, but nobody knows what happened with the bias over the centuries with land use changes in the main wind direction or even changes in main wind direction from more sea-side to more land side when climate changes between e.g. MWP and LIA.
Thus if the average of the stomata data differs from the ice core data over periods longer than the ice core resolution, the stomata data should be re-calibrated, not reverse…
– The 2 times the resolution is only applicable for full CO2 up-and-down cycles, not for one-way peaks, like the current is going. One way peaks like the current 110 ppmv increase over 165 years would be visible in the 600-years Vostok resolution as an extra 15 ppmv peak, still detectable with the 1.2 ppmv repeatability of the measurements…

Reply to  David Middleton
July 3, 2019 2:24 pm


What I remember from the Taylor Dome ice core is that it has a resolution of about 40 years over the past 75,000 years, but I have no direct reference. The WAIS divide at 10 years, at least over the past 10 years is more promising…

The current 110 ppmv spike in 165 years not only is detectable in the 560 years Dome C resolution over 800,000 years, it is also resolvable, as a 15 ppmv peak outside the 8 ppmv/K ratio over that period…

About the stomata data, my last word: stomata CO2 data are proxy’s not direct measurements. By definition they grow on land which includes a variable local (positive) bias against background CO2 levels which may change over the centuries with land use changes (human) or landscape changes (natural/climate related) in the main wind direction and even wind direction changes as result of climate changes.

Huge rapid changes in stomata data therefore are local/regional changes and impossible to extrapolate to global changes, as the speed of change, especially back to “normal” is impossible. There is no known process fast enough to do that.

Reply to  David Middleton
July 4, 2019 12:57 pm


The cooling around 1600 was worldwide, not only of the Southern Ocean, it was at the depth of the LIA.
Depending of which reconstruction you like, the overall temperature drop between the MWP and LIA was between 0,2°C (Mann et al.) and 0.8°C (Esper, Moberg and others). The drop was about 6 ppmv CO2 with a lag of about 50 years after the temperature drop. If you take Mann’s hockeystick for granted, then the ratio is about 30 ppmv/°C, take Esper or others as base and that ratio drops to 8 ppmv/°C. I expect that you don’t prefer Mann’s HS…

Thus all depends of the worldwide temperature changes and resulting CO2 changes. That the Vostok (and other inland) ice core(s) show the same ratio over many millennia which (not) by coincidence agrees with the change in solubility of CO2 in seawater with temperature changes is a good indication that the Vostok ratio is not far off.

Again about the stomata “spike” around 12.750 years BP:
That was over 100 ppmv up in 50 years and down again in about 50 years, according to the stomata data.
There are ice cores with a resolution of 22-40 years (Siple Dome) and 40 years (Taylor Dome) and recently probably 10 years (WAIS divide) which don’t show such a huge peak.

Reply to  David Middleton
July 5, 2019 2:30 pm


I don’t know where you have your ice core resolutions taken from.
What I remember is:
– Less than a decade for the DE08 and DE08-2 Law Dome cores over the past 150 years.
– 10 years for the WAIS divide shallow core over the past 1,000 years.
But I suppose that is more than 20 years as the resolution of the 1600 dip is less than for the DSS core (7 ppmv vs. 10 ppmv).
– 20 years for the DSS Law Dome core over the past 2,000 years.
– 20 years for the Siple Dome core (22 years at medium depth to 40 years at full depth including a theoretical migration in that “warm” core) over 65,000 years.
– 40 years for the Taylor Dome core over 60,000 years.
– 560 years for the Dome C record over 800,000 years.
– 600 years for the Vostok record over 420,000 years.

An over 100 ppmv “peak” in the stomata data over a period of 50 years up and 50 years down around 12,750 years BP would be visible as a peak of around 80 ppmv in the Taylor record, if it was global…

Reply to  David Middleton
July 6, 2019 1:41 pm


In your first reference they show in Table 1 the gas age distribution in the bubbles, which is already twice or so the bubble closing time.

The gas distribution is not only a linear function of the accumulation rate, seems more a log function, but also a matter of temperature of the core which is between -20 and -45 degrees C for different cores,

Further, the Dronning Maud ice core has an accumulation rate of 6.4 cm water eq./year and a gas age distribution of 59 +/- 5 years. Thus both Taylor Dome and Siple Dome should have a smaller gas age distribution…

Found a nice Gaussian gas age distribution graph for the Siple Dome at Fig. 5 in:
Where they expect a sigma of 12.74 years, thus depending of how many sigma you want you can make it as broad as you like…

I made a mistake by assuming that sample resolution of a decade for the WAIS devide shallow core was the gas age resolution… More small samples over the same period do give some better resolution, but can’t give better results that the real gas distribution…

July 3, 2019 10:54 pm

Mmm, a simple “I don’t know” would have sufficed instead of churlishness.

July 3, 2019 10:58 pm

You’re on point concerning resolution differences between ice core measurements compared to NOAA Mauna Loa CO2 record and of Greenland compared to Antarctica. The high frequency data with a higher standard deviation but short duration is a subset of longer term lower frequency data. The high frequency dataset should be averaged and smoothed not the other way around.

July 4, 2019 7:08 am

Ceci n’est pas une crosse de hockey

After (and apologies to} Rene Magritte

Howard Dewhirst
July 8, 2019 9:57 pm

I’d be interested in views on Parrenin et al’s 2013 paper (Synchronous Change of Atmospheric CO2 and Antarctic Temperature During the Last Deglacial Warming) which says “Understanding the role of atmospheric CO2 during past climate changes requires clear knowledge of how it varies in time relative to temperature. Antarctic ice cores preserve highly resolved records of atmospheric CO2 and Antarctic temperature for the past 800,000 years.
Here we propose a revised relative age scale for the concentration of atmospheric CO2 and
Antarctic temperature for the last deglacial warming, using data from five Antarctic ice cores.
We infer the phasing between CO2 concentration and Antarctic temperature at four times
when their trends change abruptly. We find no significant asynchrony between them, indicating
that Antarctic temperature did not begin to rise hundreds of years before the concentration of
atmospheric CO2, as has been suggested by earlier studies.” This paper is used by the Geological Society of London as support for their position that warming & CO2 changes are synchronous – and therefore CO2 ‘drives’ temperature – apparently

Howard Dewhirst
July 9, 2019 5:31 am

That’s my feeling to but as I’m told by some in the GSL I’m not a climate scientist, my opinion is zilch; thanks David

Howard Dewhirst
July 9, 2019 1:43 pm

The well tie syndrome has always been with us, confirmation bias, not necessarily dishonesty per se, but certainly log interpretation, and the rotary lie detector teaches you to be aware of. There is no recourse in this field – at the moment. The PETM nonesense is similar, a ‘massive CO2 influx has to be the cause of the heating … then reputations kick in and defensive walls are erected. Can I come back to you next time the GSL people try to push their PETM science on us, supported as it is by Parrenin et al?

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