Several comments can be made on the reconstruction of the historical CO2 data made by the late Ernst Beck (Beck, 2010, published in SCC 2022 [21]). While most chemical methods used were fairly accurate (+/- 10 ppmv), many places where was measured were completely unsuitable for “background” CO2 levels and in many cases too few measurements were made at high wind speed to have a sufficient convergency of the data towards a “background” CO2 level.
Moreover, the late Ernst Beck made several mistakes in the interpretation of the available data. Finally, the possibility of huge CO2 levels around 1940 is physically impossible and contradicted by several other proxy’s and contradicted by CO2 levels as measured in high resolution ice cores.
Continue reading: About Historical CO2 Levels. Discussion of Direct Measurements near Ground since 1826 by E.-G. Beck Ferdinand Engelbeen.