Guest essay by James McCown
Oxford economists Felix Pretis and David Hendry (henceforth Pretis), published a critical paper, with a very patronizing and sanctimonious tone, in 2013 in Earth System Dynamics to comment on earlier research by Beenstock, Reingewertz, and Paldor (2012), (henceforth Beenstock) in the same journal. Amazingly, they didn’t bother to note that their criticisms, if accurate, also invalidate the results of previous researchers who support the AGW theory.
Beenstock’s research concerns the issue of whether or not there is a statistical relation between the radiative forcing of greenhouse gases (GHG), and atmospheric temperatures, using advanced statistical methods that were developed by economists. There have been a number of researchers who have previously used this methodology to discern a relation between the GHGs and temperature, including both climatologists and economists. The latter include James Stock at Harvard, one of the foremost experts at time series econometrics.
Beenstock’s paper was in response to earlier papers by pro-AGW researchers Stern and Kaufman (2000), Kaufman and Stern (2002), Kaufman, Kauppi and Stock (2006), and Liu and Rodriguez (2005), and several others, who claimed to have found an equilibrium relation between radiative forcing from GHGs and atmospheric temperatures. The main contribution of Beenstock was to show that there cannot be an equilibrium relation between temperatures that are integrated of order one, I(1), and GHGs integrated of order 2, I(2), unless they are polynomially cointegrated. And Beenstock show they are not polynomially cointegrated.
Beenstock’s conclusion (from their abstract) is:
…greenhouse gas forcing, aerosols, solar irradiance and global temperature are not polynomially cointegrated, and the perceived relationship between these variables is a spurious regression phenomenon.
Pretis criticize Beenstock’s use of spliced data for atmospheric CO2 and N2O, and criticize them for not stating that this data comes from a variety of different sources. However, they do not criticize the previously mentioned pro-AGW researchers who used the exact same data.
Pretis criticize Beenstock for finding the time series properties of the radiative forcing of the three human-emitted GHGs to be integrated of order 2, I(2), even though the pro-AGW researchers came to the same conclusion. And they don’t bother to mention that the pro-AGW researchers also found the GHGs to be I(2).
Pretis’ comment shows dismayingly flawed logic. To give an analogy to what they have done: Suppose that Kaufman claimed to have built a house, from the foundation to the roof. Beenstock claim that Kaufman could not have done so, by proving that they never shingled the roof. Pretis reply that Beenstock are in error, because Pretis prove that the foundation was never laid. Therefore Beenstock must be wrong and Kaufman is right! The more I think about it, the more ridiculous it sounds.
Pretis point out there is a structural break in the annual data for CO2 at 1957 (Hardly surprising since that is the point at which the data were spliced from the different sources), then they run Augmented Dickey-Fuller (ADF) unit root tests (Said and Dickey, 1984) on the first differences of the data for the two subperiods from 1850 – 1957 and 1958 – 2011 (See Table 1 of Pretis), and conclude that the CO2 radiative forcing series cannot be I(2). However, Pretis omitted tests of the levels of the series, which would enable the researcher to determine whether the GHGs are I(1), which could potentially be cointegrated with the I(1) temperature series, as the warmist researchers have claimed.
I tested the CO2 radiative forcing for the two subperiods in levels, first differences, and second differences. I used the ADF test, and also the test by Kwiatkowski, Phillips, Schmidt, and Shin (1992) (KPSS). For the latter 1958 – 2011 period, I conclude the series is I(1), as did Pretis. However, for the earlier 1850 – 1957 period, which uses CO2 data from ice core measurements by Etheridge et al (1996), I got the following results:
| ADF with Trend & Constant | ADF D-lag | KPSS with Trend & Constant | |
| Levels | -3.496* | 2 | 0.126 |
| 1st Difference | -3.807* | 0 | 0.078 |
| 2nd Difference | -13.288** | 0 | 0.039 |
* Rejects null hypothesis of a unit root at 95% confidence
** Rejects null hypothesis of a unit root at 99% confidence
The ADF D-lag is the number of lags included in the ADF test, selected using the Schwarz criterion.
The KPSS test has the null hypothesis of stationarity with a trend and constant, versus the alternate hypothesis of a unit root. The results fail to reject the null hypothesis of stationarity at 95% confidence or higher.
The results of both tests indicate that time series of the levels of CO2 radiative forcing from 1850 to 1957 is well-modeled by a trend stationary process with no unit root. That is, I(0). An ordinary least squares regression of the series on the year gives the following relation:
RFCO2 = -9.935203+0.005346 x YEAR
where RFCO2 is the radiative forcing from the concentration of carbon dioxide in the atmosphere, converted to radiative forcing using the method of Myhre et al (1998). This regression has an adjusted R-square of 0.988 and the slope coefficient has a t-statistic of 41.34.
The CO2 radiative forcing series is very close to a straight line. Since it does not have a unit root, it cannot be cointegrated with the nonstationary temperature data for the period from 1850 to 1957. See the following graph of the series:
Kaufman and Stern (2002) give their economic justification for the nonstationary time series of global average temperatures:
…changes in radiative forcing might introduce a stochastic trend in temperature if the radiative forcing variables have a stochastic trend. This is likely because the concentrations of trace gases and sulfate aerosols are driven by anthropogenic emissions, which are determined by the stochastic trends that characterize many macroeconomic time series.
But as can be seen in the graph above, and the tests of stationarity of CO2 I have conducted for the 1850 – 1957 period, the GHG that is widely viewed by the warmists as the primary culprit has a trend-stationary process. This leads me to believe that if the CO2 concentration is accurately measured by Etheridge et al (1996), then it is more likely the result of a natural process than from industrial sources.
The editors of Earth System Dynamics did not allow Beenstock to publish a response to Pretis’s comment. Beenstock made an informal response here: http://www.earth-syst-dynam-discuss.net/4/C118/2013/esdd-4-C118-2013-supplement.pdf.
The last two sentences of Beenstock’s response are telling:
The main difference between this [warmist] literature and our paper is that we do not think that greenhouse gas emissions have a long term effect on Earth’s climate. Perhaps this is why HP waited until 2013 to voice their criticisms rather than 1997 when this literature was pioneered by Stern and Kaufmann.
Pretis have opened up a can of worms through their comment, and have likely done more damage to the warmist cause than help.
Furthermore, as an economist who has done research on pre-World War II data, I am struck by something I don’t see in the above chart. If the increasing concentration of carbon dioxide in the atmosphere is caused by burning fossil fuels, which has increased significantly during the industrial era, then why don’t we see any decrease, or at least a deceleration, during the great depression of 1929 to 1933?
The great depression had severe effects on two of the largest industrial economies: the USA and Germany. Industrial production in the USA, from 1929 to 1932, dropped by 46%. Coal production in the USA dropped from 608 million short English tons in 1929 to 359 million in 1932. In Germany, industrial production dropped by 42% from 1929 to 1932. German coal production dropped from 163 million metric tons in 1929 to 104 million in 1932.
And yet, according to Etheridge et al (1996), the concentration of carbon dioxide in the atmosphere increased from 307.2 ppm in 1929 to 308.9 ppm in 1933. And the concentration kept increasing every year after that until 1942. There was no deceleration in the increases. Either the theory that burning fossil fuels adds to the atmospheric concentration of CO2 is flawed, or perhaps Etheridge’s estimates of the concentration of this GHG are inaccurate. I don’t know which is the case.
References
Beenstock, M., Y. Reingewertz, and N. Paldor (2012). Polynomial cointegration tests of anthropogenic impact on global warming. Earth Syst. Dynam., 3, 173–188.
Etheridge, D. M., Steele, L. P., Langenfelds, L. P., and Francey, R. J.: 1996, ‘Natural and anthropogenic changes in atmosphericCO2 over the last 1000 years from air in Antarctic ice and firn’, J. Geophys. Res. 101, 4115–4128.
Liu, H. and G. Rodriguez (2006), Human activities and global warming: a cointegration analysis. Environmental Modelling & Software 20: 761 – 773.
Kaufmann, A., Kauppi, H., and Stock, J. H.: Emissions, concentrations and temperature: a time series analysis, Climatic Change, 77, 248–278, 2006.
Kaufmann, R. K. and Stern, D. I.: 2002, ‘Cointegration analysis of hemispheric temperature relations’, J. Geophys. Res. 107, D210.1029, 2000JD000174.
Kwiatkowski, D., Phillips, P. C. B., Schmidt, P., and Shin, Y.: Testing the null hypothesis of stationarity against the alternative of a unit root, J. Economet., 54, 159–178, 1992.
Myhre, G., Highwood, E. J., Shine, K. P., and Stordal, F.: New estimates of radiative forcing due to well mixed greenhouse gases, Geophys. Res. Lett., 25, 2715–2718, 1998.
Pretis, F. and D. F. Hendry (2013). Comment on “Polynomial cointegration tests of anthropogenic impact on global warming” by Beenstock et al. (2012) – some hazards in econometric modelling of climate change. Earth Syst. Dynam., 4, 375–384.
Said, S. and Dickey, D.: Testing for unit roots in autoregressive moving average model with unknown order, Biometrika, 71, 599–607, 1984.
Stern, D. I., and R. K. Kaufmann, Detecting a global warming signal in hemispheric temperature series: A structural time series analysis, Clim. Change, 47, 411 –438, 2000.
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James McCown an economist with Toltec Group, an economic consulting practice in Oklahoma and has a PhD in economics from Ohio State. You can see some of his research here: http://papers.ssrn.com/sol3/cf_dev/AbsByAuth.cfm?per_id=154208.
That 1940 drop really, really bugs me. How can CO2 drop in the middle of the European and Asian (Japan/China) wars? Wouldn’t there be LOTS of burning stuff, and LOTS of fuel and coal being used?
So I went looking for something in 1940…Hmm, weird:
“Sunspot cycle…There is another well-known, super-imposed variation of annual sunspot numbers, of about 85 years. This irregular variation affects the length of the sunspot cycle, ranging from 9.8 to 12.0 years. Maxima of sunspot-cycle length occurred [SIC] in 1770, 1845 and 1940.”
http://www-das.uwyo.edu/~geerts/cwx/notes/chap02/sunspots.html
Sure enough there appears to be a dip around 1845 as well – hard to tell from the graphs I can find but there is at least a deceleration around that year. I can’t find any good information about 1770 – maybe just a coincidence since this seems rather obvious and SOMEONE would have looked at it.
But then WHY would CO2 levels go down in 1940? Measurement error? Different methods? How the heck could it go down if it isn’t ocean temperature?
you know we actually have direct co2 measurements pre 1957. These are ignored in favor of icecore data. They seem to imply co2 followed the temps up in the early warming of that century, and then back down to where it was in 57, to rise from there. I could never find satisfactory answers as to why all this was ignored. Wouldnt it be hilarious if temps dropped in future decades and pulled co2 levels down as well?? lol, after all this “undeniable” nonsense we hear.
Randy:
Can you please give me a link to the direct CO2 measurements pre-1957? Thanks.
@ur momisugly james… http://www.biomind.de/realCO2/ This link is to prof. becks site. He has a few published papers on the topic. If you dig though, you can find the raw data he used to come up with his charts.
Doug Proctor says:
June 24, 2014 at 11:15 am
Good question, Doug. You are looking at the net respiration of our green friends in the northern hemisphere. Starting the spring we get growth, growth, growth, with a corresponding decrease in CO2 starting in April, as the CO2 is converted to leaves and stems and such.
By the fall, however, growth slows or stops, and we get the rotting and decomposition of the results of the growth cycle. This, of course, frees up the CO2 that was bound up in the earlier growth, and so the CO2 levels rise until April, when the season starts over again.
You also ask, is that the only cycle? By no means. It’s just the biggest one. The carbon cycle has lots of pathways.
Regards,
w.
Randy says:
June 24, 2014 at 4:14 pm
Randy, those measurements are not “ignored”. The problem is that they are LOCAL measurements, made in areas where there are significant local CO2 sources (industry, plants, roads, cities, etc.)
As a result, they are not useful for estimates of the “background levels” of CO2, meaning the levels at a large distance from the CO2 sources.
Georg Beck, who made many of the measurements you refer to, actually stated this in a post which I’d written about CO2 levels. He commented to say that his measurements were not suitable as estimates of the background levels, for the reason I list above. I was much impressed.
w.
We came to different understandings regarding becks work willis. He seems to think the measurements were from others. http://www.biomind.de/realCO2/persons.htm He also seems to clearly make the case he expects co2 to follow temps, not lead them. http://www.biomind.de/realCO2/statements.htm He clearly does not think the ice core data truly represents historical co2 levels. Guy callendar seems to have been the guy who set the modern stance on these earlier measurements.
@ur momisugly Doug Proctor says:
June 24, 2014 at 11:15 am
All good questions. But why does the cause have to be biotic, and why confined to either hemisphere? The Earth reaches perihelion in December. The peak could be a process, the results of which have a lag from the event, and the source of the CO2 rise could be sub-oceanic basalt volcanoes reacting to the increase in the sun’s gravitational effect due to the reduced distance between the Earth and the Sun. Other apparently chaotic effects in the cycle could be modulation of the signal by the gravitational effects of the other planets as their configuration constantly changes due to their motions in the solar plane.
I’ve no evidence at all to point to at the moment; this is just a notion at the moment, sparked by one of Willis’ posts the other day that I’m still mulling over.
But it’s no secret that not much is known, certainly not enough, about the output or behavior of sub-oceanic volcanoes, it is well established that gravitation varies as the square of the distance, and as we can plainly see from tidal effects, and the very motions of the planets, the most powerful force at work in the solar system is not the sun’s radiation, but it’s gravity.
It’s simply not as obvious…
Again, just thinking out loud, and haven’t thought any of it through yet.
Sorry: and the most obvious artifact of the power of gravity is the thermodynamic processes of the sun which result in the radiation in the first place. And as long as there is fuel for that process, it will achieve equilibrium with gravity. But once the fuel starts to run out, gravity will win.
…certainly not enough, about the output or behavior of sub-oceanic volcanoes.
Here, here!
Willis,
I follow you with great respect…but this is BS:
Randy, those measurements are not “ignored”. The problem is that they are LOCAL measurements, made in areas where there are significant local CO2 sources (industry, plants, roads, cities, etc.)
Most all relied-upon CO2 measuring sites are local under your same definition. The excuse for this is given as: homogenization of Co2 is very rapid – and indeed, it is.
Those prior measurements were accurate to 3% and more reliable for accuracy than what we rely upon today as regards data older than infrared absorption.
It’s the temporal sampling limitations and inter-layer diffusion of CO2 that enormously bias the ice-core records.
The big issue is that climate is influenced by the equivalent of a black box- various factors beyond our control whose effect on climate can not be predicted. By extremely sharp, contrast, the effect of changes in the concentration of carbon dioxide in the atmosphere on global temperatures is easily predicted by a simple equation.
If we could somehow isolate the black box, and make carbon dioxide concentration the sole determinant of temperature, then an increase of concentration from 300 to 400 would yield an increase of 1.12 degrees Fahrenheit- no more, no less. But in the real world, we can not isolate the black box and thus can not predict climate change.
Ron Voisin says:
June 24, 2014 at 8:21 pm
Thanks for the reply, Ron. When you agree with me I get “great respect”, but when you don’t I’m spouting “BS” … funny how many people look at the world that way. Next time it happens, you might at least consider the possibility that you’re wrong.
For example, you’re wrong when you claim the “relied-upon CO2 measuring sites are local “, unless you consider e.g. the South Pole as being “local”. The main CO2 measuring sites are Barrow, Alaska; Mauna Loa, Hawaii; Samoa (another Pacific island), and the South Pole. All of these were carefully chosen because they are not local, they are remote from centers of industry, and so measurements of the background CO2 levels can be obtained there by using appropriate precautions.
The problem is not the accuracy, it’s the contamination of the record from local sources. Look, as I said above, Ernst-Georg Beck amassed many of the measurements you are referring to, and he himself said they were not a measure of background CO2 because of local contamination. Is there some part of that you didn’t get? I’m not making this up, and it’s not “BS” in any sense. It’s the claim of the man who amassed the data. Here it is:
So if you have a complaint about Beck’s CO2 data being “ignored”, you should go tell him that he’s wrong.
Ice-core records have problems, but I wouldn’t say that they are “enormously biased”. Where the Ice core records overlap with the instrumental observations, the correspondence is good.
You might enjoy taking a look at a couple of my posts discussing Beck’s CO2 measurements, among other CO2 questions.
Under the Volcano, Over the Volcano
Some people claim, that there’s a human to blame …
Regards, and please … lay off the accusations of “BS”, and at least consider the possibility you might be wrong …
Here’s how it stands. I’ve been at this game a while, I don’t make things up, I’m skeptical as hell, I do my utmost to call them as I see them, and I have a good nose for bad numbers. Yes, I might be wrong, I have been more than thrice … but it is likely a mistake to declare BS on my claims unless you have researched the subject very, very well. I go to great lengths not to be wrong, and I’m usually successful. Not always, no one is … but I’d advise you not to bet against me unless you’re triple-sure of your facts.
Anyhow, read the linked posts, and the comments, you should find them interesting.
All the best to you,
w.
Randy says:
June 24, 2014 at 6:37 pm
Well spotted, Randy. Re-reading, I see that you are right, I had erroneously said that he TOOK the measurements, whereas in fact it’s obvious that he COLLECTED the measurements … be hard for him to have taken a CO2 measurement in 1900, for example, and some of his measurements are from well before then.
As well he should, since CO2 does follow the temps in the long term. In the short term, however, it moves in opposition to temperatures because increasing temperatures lead to plant growth which depresses CO2 levels … go figure.
Mmmm … all data contains both errors and biases, and is only sampled at discrete times, so I’m not sure what you mean by “truly represents”.
CIte? Thanks.
Regards,
w.
Willis Eschenbach:
At June 25, 2014 at 12:15 am you say
Sorry, but that is not true.
Changes in CO2 follow changes in temperature at all time scales.
At the shortest time scales the lag is by between five and eight months depending on latitude. The first determination was by Cynthia Kuo, Craig Lindberg & David J. Thomson which they published in Nature magazine on 22 February 1990 (Nature v.343, pp.709 – 714). Their paper was titled Coherence established between atmospheric carbon dioxide and global temperature and its Abstract says
This does not mean that CO2 has no affect on temperature, but it shows the effect of temperature on CO2 is discernible at all time scales.
Richard
Willis Eschenbach says:
June 25, 2014 at 12:03 am
“So if you have a complaint about Beck’s CO2 data being “ignored”, you should go tell him that he’s wrong.”
Unfortunately, Mr. Beck is no longer amongst us.
richardscourtney says:
June 24, 2014 at 10:26 am
…
If the assumption that the equilibrium of the carbon cycle system has been disturbed and the system is adjusting to the new equilibrium is correct, then the observed rise in atmospheric CO2 concentration is a result of whatever has caused the equilibrium to change. The most likely cause is the rise in global temperature which is observed as recovery from the Little Ice Age (LIA), but other causes are possible and the anthropogenic emission of CO2 is one of them.
Hence, it is possible (although unlikely) that the anthropogenic CO2 emission is causing the rise in atmospheric CO2 while it is also possible that Etheridge’s estimates are correct.
The problem lies in the word “equilibrium.” There is no geological evidence at any time scale of a planetary equilibrium state in either atmospheric CO2 or planetary mean temperature, nor is there any historical (last two millennia) evidence of such an equilibrium. One seriously important issue that I have not seen addressed is that CO2 in all available geological field derived data lags d-O18, suggesting that the most probable driver for changes in atmospheric CO2 is ocean temperature. The scale of the lag, minimally several centuries, indicates a great inertia marine temperature changes great enough to affect atmospheric CO2. Empirically, it is reasonable to hypothesize that human CO2 sources might affect isotope mix without seriously affecting the efficiency of the planetary carbon sinks. The simplest explanation based solely on empirical evidence without modeling is that recent increases in modern CO2 levels is that we are seeing the rebound associated with Medieval Warm Period.
Duster:
At June 25, 2014 at 1:20 am you say to me
Yes, but I see no “problem” because I never said there was.
I said the carbon cycle system adjusts towards an equilibrium state (i.e. the state of minimum energy) and, of course, that can only be true. But it does not mean the system ever achieves equilibrium. As I said, and you quote me having said
So, I am saying that the observed continuing rise in atmospheric CO2 concentration demonstrates that equilibrium has not been achieved and “the system is adjusting to the new equilibrium”.
And I fail to understand your saying
I stand by my statements that said
Richard
This illustrates a problem with Economics as much as with Climate science – an over-reliance on increasingly “sophisticated” statistical methods.
Meanwhile, what use have economists been in predicting what will happen in the real world?
Pretty much zero. If your statistics can’t predict the future they are wrong..
They can predict the future, based upon certain inputs. However, Economists do not control those inputs (in the final analysis, no one person does – hence the social part of the science).
We can model what will happen based upon inputs of X, Y and Z. But we do not control those inputs, and they are not based upon any natural or scientific laws, but on the whims (and insanity?) of people. Try predicting which person you are going to see drive by on Saturday, June 27, 2015 at 10am.
That is what you are demanding of economists. They can tell you what will happen based upon a set of actions. But neither you nor they control the actions.
Thanks John Slayton for saying:
“No natural processes come to mind, but there is the matter of all those Northern Hemisphere residents who respond to cold weather by firing up their furnaces, or otherwise burning stuff to keep warm.”
Let’s kill that one dead: The change from Fall to Spring is about 5 ppm, not so? That is FAR greater than any human emissions variation could accomplish. It takes years to change it by 1 ppm.
When water droplets form in the atmosphere, they absorb CO2 within a few seconds. When the freeze or evaporate, they release it. Snow and ice forms in the NH from October to April. It kicks out the CO2. Then there is warming in the Southern Ocean which may emit CO2 then absorb it again later.
The CO2 mass change in 6 months is massive. Airborne water droplets (like clouds) transport CO2 from place to place. Does it leave the south to be released in the north when it is cold? Doesn’t seem likely. Case open.
I have seen several ideas floated about how ‘mankind’ creates the annual fluctuation, none of which hold water. We are CO2 Lilliputs.
Duster said
The simplest explanation based solely on empirical evidence without modeling is that recent increases in modern CO2 levels is that we are seeing the rebound associated with Medieval Warm Period.
I have heard this before. It makes me wonder what the time lag is between the warming of the oceans and the release of CO2. Obviously, some glob of water can’t release its CO2 if its one mile below the surface. So, the oceans have to turn over before the amount of dissolved CO2 can equilibrate. And how long does that take?
I’m just speculating here, but it seems to me would be more of a gradual process, just like warming of the oceans from the atmosphere would be a gradual process.
Economics is known as the inexact science for good reason dontcha know.
Willis,
I will be more diplomatic going forward…sorry. You might consider a thicker skin.
I might be wrong.
Have you evaluated Murry Salby’s work? http://www.youtube.com/watch?v=2ROw_cDKwc0&feature=player_embedded
Ron Voisin says:
June 25, 2014 at 9:24 am
Thanks, Ron. Unfortunately, writing for WUWT has abraded off most layers of my epidermis … and in any case, telling someone that their claim is “BS” when your level of knowledge is not up to the task is a mistake regardless of the thickness of my hide.
Regarding Salby, do you have something written by him? I don’t waste my time on videos for a couple reasons.
One is that movies, tv, and video are all passive media, and I don’t like looking at science with my brain turned off. I get sucked in by the graphics and the action and my critical thinking goes out the window.
Another is that they are generally neither detailed, concise, nor cited and referenced. Next, they are usually more in the nature of advertisements, trying to change our minds, rather than science. Finally, they are slooooooow … I get bored.
So I just give them a pass unless I’m told that they are truly extraordinary.
w.
The fact this paper was Hendry and Pretis, not the other way round, makes its awfulness even stranger. Particularly, the notorious figure 4, plotting temperature against CO2 forcing in a textbook case of ‘spurious’ correlation between time series where at least one is an integrated series. Prof Hendry was one of the pioneers in the 1970s in the development of detailed theory for these sorts of issues. He has authored textbooks on the subject. It’s like an experienced driving instructor blithely going through red traffic lights!
A case of AGW ‘red mist’ and an urge ‘to do something’?