Before the , the content in the air remained quite steady for thousands of years. Natural is not static, however. It is generated by natural processes, and absorbed by others.
|CO2 concentrations in the atmosphere over the past 400,000 years|
More than 90,000 accurate chemical analyses of CO2 in air since 1812 are summarised.
The historic chemical data reveal that changes in CO2 track changes in temperature, and therefore climate in contrast to the simple, monotonically increasing CO2 trend depicted in the post-1990 literature on climate-change. Since 1812, the CO2 concentration in northern hemispheric air has fluctuated exhibiting three high level maxima around 1825, 1857 and 1942 the latter showing more than 400 ppm. Between 1857 and 1958, the Pettenkofer process was the standard analytical method for determining atmospheric carbon dioxide levels, and usually achieved an accuracy better than 3%. These determinations were made by several scientists of Nobel Prize level distinction.
Following Callendar (1938), modern climatologists have generally ignored the historic determinations of CO2, despite the techniques being standard text book procedures in several different disciplines. Chemical methods were discredited as unreliable choosing only few which fit the assumption of a climate CO2 connection.
|Figure 5: CO2 concentrations in 2 m sampling height (0; 0,5;14 m available) at the
meteorological station near Gießen (Germany) 1939/41 
|Figure 7: CO2 concentration at museum of Rostock, Baltic Sea (Germany) 1863/64, |
1465 samples, 4 m height in western direction
The close relationship between temperature change and CO2 level exhibited by these results is consistent with a cause-effect relationship, but does not of itself indicate which of the two parameters is the cause and which the effect. The greenhouse hypothesis of IPCC argues for CO2 being the cause (through radiative feedback) of the temperature rise. My (Beck) results are equally if not more consistent with temperature being the forcing that controls the level of CO2 in the atmospheric system. In support of this causality, ice-core data consistently shows that over climatic time scales, changes in temperature precede their parallel changes in carbon dioxide by several hundred to more than a thousand years. (bold added)
DISCUSSION AND CONCLUSIONS
During the late 20th century, the hypothesis that the ongoing rise of CO2 concentration in the atmosphere is a result of fossil fuel burning became the dominant paradigm. To establish this paradigm, and increasingly since then, historical measurements indicating fluctuating CO2 levels between 300 and more than 400 ppmv have been neglected. (bold added)Read More here - http://www.liberterre.fr/gaiasophia/gaia-climats/dioxyde-carbone/z-pdf-carbone/analyse-dioxyde.pdf
Anthony Cox continues:
Human CO2 is a tiny % of CO2 emissions.
|Figure 7.3. The global carbon cycle for the 1990s|