This figure in Jaworowski’s statement is reprinted from his article in The Science of the Total Environment 1992, and his related argument seems as odd as it did then. About the figure he says:
In Figure 2 encircled values show a biased selection of data used to demonstrate that in 19th century atmosphere the CO2 level was 292 ppmv[12].
Figure 2 has been widely reprinted:
Now let’s pause a moment to let Jaworowski’s description sink in. Look at that cloud of data points pre-1900, and compare those to the more modern values. Without knowing more about the data, it seems reasonable to suspect that atmospheric CO2 measurements before 1900 were highly variable, and may have been systematically high, compared to modern measurements. Jaworowski is trying to say that rejecting the outliers shows “a biased selection”! This seemed so preposterous that I looked up what he and his colleagues said in their 1992 paper. Yes, they actually do make that claim:
Slocum [1955] pointed out that, from a set of twenty-six 19th century averages, Callendar rejected 16 that were higher than the global average of 292 ppm, and only two that were lower. On the other hand, from the 20th century data set Callendar rejected three averages that were lower than his global average of 317 ppm, and none that were higher. This shows a bias in the selection method.
In fact, Jaworowski et al. get little comfort from Slocum, who in his 1955 paper
All this does not refute Callendar’s thesis. The available data merely fail to confirm it. The positive evidence that the CO2 has increased is inconclusive, but seems strong enough to reward further study, and the time seems ripe for new research.
In the intervening 50 years, new research has been performed that nicely vindicates Callendar’s selection criteria, as Tim Lambert showed by superimposing data sets from Antarctic ice cores and atmospheric measurements taken at Mauna Loa. Both data sets independently confirm the trend observed by Callendar. They were available to Jaworowski when he prepared his statement, but he ignored them.
Jaworowski’s accusation of bias is surprising, just taking the evidence on its face. But let’s go the extra mile.
A reasonable person, trying to be fair, might wonder if the paper by Fonselius et al.[2], whence the figure originated, had suggested some bias in data selection. OK, let’s have a look at Fonselius. Here’s the original figure:
Note that the sources of the selected data are identified; these are discussed in the paper. Now, did Fonselius et al. suggest that Callendar’s choice of data was biased, and that he should have taken an average of the whole cloud of data points from before 1900?
You can probably guess the answer to that one. No, they didn’t. They said:
This scatter … probably depends on the rather crude and incomplete techniques of analysis used during the first fifty years, possibly with systematic positive errors.
Fonselius et al. go on to discuss how CO2 measurements might be improved and collection extended, remarking that
In the diagram, the values used by Callendar and our mean values are encircled and we can see that our values fit in quite well.
Yet, Jaworowski has taken the figure from this paper, redrawn it, and used it to support his argument that Callendar used a “biased selection” in his choice of data. Now, that’s chutzpah!
[1] Slocum, G., Has the Amount of Carbon Dioxide in the Atmosphere Changed Significantly Since the Beginning of the Twentieth Century? Monthly Weather Review, December 1955, 225-231
[2] Fonselius, S.; Koroleff, F. and Wärme, Carbon Dioxide Variations in the Atmosphere, Tellus VIII (1956), 176-183
Dear sir,
do you have an original Fonselius et al. paper? If it’s possible, can you send me a copy?
Best regards
Gus
Gus –
If the original 1956 paper is now in the public domain (as it probably is), I will be happy to attach a copy to this post. Let me check.
I think Lambert had a poor method. He was comparing samples from a region that historically has always had a lesser rate of exchange from other regions of the planet, and is confounded with global precipitation. In fact, his “samples” are encased within ice, which is a clear indicator of how sparse plant life was in the Antarctic at the time the sample was captured. If you are able to follow this point and you support global warming on an ideological stance then it would be easy to state that this would only solidify his point further. By doing so however, you are ignoring several laws of physics and chemistry OR lack the ability to apply them in a viable scientific method. Take into account several other lurking variables, such as the diffusion rates of CO2 around Mauna Loa and the displacement of slipstreams. Both are greatly affected by temperature (solar activity for example), which means that one could as easily assume that an increase in temperature could cause a shift in slipstreams and affect the diffusion/out gassing of CO2. Then it could be hypothesized that temperature is simply increasing the perceived concentration of CO2 at the site of observation and not that CO2 is increasing the temperature. It is relatively accepted that a portion of the pollution in California is actually from China which is also a confounding variable since it passes over Mauna Loa. If you really want to understand the threshold of CO2 exchange I would think comparing the deviation of molar fractions between seasons in the northern hemisphere would server as a more relative observation. And then compare many seasonal deviations. It should be noted that of all the known possible contributors to global warming, the regulation of so called greenhouse gases is the only one that fits within an economic model; the regulation of CO2 stands to provide, any government which implements it, a tax generating mechanism and an expansive market (alternative technologies) which will again provide more tax revenue. This would explain the exuberance seen in the governments of the world to ignore the prime factor of global warming, and the reality that no scientist in the world has stated as such with an equivalent certainty.
If you are a proponent of greenhouse gases causing global warming, then the writing in the following link may convince you, that you’re interpretation though wrong: does not dismiss your concern. What it will remove is the deduction that government intervention is able to prevent global warming and thus possibly raise an anxiety over understanding there is nothing that we can do about it. This apprehension can be addressed by simply asking one’s self if they believe that following this train of thought and neglecting the global warming ideology will lead to a diminished lifestyle because of this neglect.
http://motls.blogspot.com/2006/07/carbon-dioxide-and-temperatures-ice.html