Recently a compilation of almost 100.000 historical data about chemical CO2 concentration measurements between 1826 and 1960 has been published as post mortem memorial edition of the late Ernst-Georg Beck.
This compilation can give important insight in understanding natural CO2 emission processes, but it has been criticized, in particular a documented significant increase of the atmospheric CO2 concentration around 1940. In this contribution we do not respond to any criticism of more or less suitable places for sampling or the interpretation of respective data, but concentrate on the CO2 data around 1940 and the variations over the last century. We show that the observed concentration changes not only correlate with observed temperatures, but can also quantitatively be explained, mainly in terms of the temperature dependent soil respiration.
Continue reading: About Historical CO2-Data since 1826: Explanation of the Peak around 1940 by Hermann Harde.