Estimation of 14CO2 amount in the atmosphere

Carbon from fossil CO2 emissions, without a significant presence of 14C, causes dilution of 14C in the carbon isotopic mixture (Suess effect). Reported 14C activities are usually connected to radiocarbon amount in the carbon isotopic mixture. Our paper is aimed on estimation of 14C/14CO2 amount in the atmosphere (and its trend), utilizing calculation of a 14C activity concentration. A parameter connected only with a 14C quantity in the volume or mass unit of air is not influenced by a fossil carbon amount. Such a “robust” parameter can be influenced only by processes connected with 14C emissions/depositions.