World Atmospheric CO2, Its 14C Specific Activity, Non-fossil Component, Anthropogenic Fossil Component, and Emissions (1750–2018)

Abstract

After 1750 and the onset of the industrial revolution, the anthropogenic fossil component and the non-fossil component in the total atmospheric CO 2 concentration, C(t), began to increase. Despite the lack of knowledge of these two components, claims that all or most of the increase in C(t) since 1800 has been due to the anthropogenic fossil component have continued since they began in 1960 with "Keeling Curve: Increase in CO 2 from burning fossil fuel." Data and plots of annual anthropogenic fossil CO 2 emissions and concentrations, C(t), published by the Energy Information Administration, are expanded in this paper. Additions include annual mean values in 1750 through 2018 of the 14 C specific activity, concentrations of the two components, and their changes from values in 1750. The specific activity of 14 C in the atmosphere gets reduced by a dilution effect when fossil CO 2 , which is devoid of 14 C, enters the atmosphere. We have used the results of this effect to quantify the two components. All results covering the period from 1750 through 2018 are listed in a table and plotted in figures.These results negate claims that the increase in C(t) since 1800 has been dominated by the increase of the anthropogenic fossil component. We determined that in 2018, atmospheric anthropogenic fossil CO 2 represented 23% of the total emissions since 1750 with the remaining 77% in the exchange reservoirs. Our results show that the percentage of the total CO 2 due to the use of fossil fuels from 1750 to 2018 increased from 0% in 1750 to 12% in 2018, much too low to be the cause of global warming.

Comment on “World Atmospheric CO2, Its 14C Specific Activity, Non-fossil Component, Anthropogenic Fossil Component, and Emissions (1750–2018),” by Kenneth Skrable, George Chabot, and Clayton French

“…On the basis of the several arguments presented here, we conclude that the paper of Skrable et al (2022) should be retracted in its entirety.…”

“…R ecently Skrable et al (2022) published a study based on analysis of 14 CO 2 (radiocarbon) in the atmosphere that concludes that CO 2 emitted from fossil-fuel combustion, which contains no 14 CO 2 , contributes only 36% to the observed increase in atmospheric CO 2 over the industrial era, with the balance due to non-fossil-fuel sources. In this Comment we demonstrate that the paper by Skrable et al is fundamentally flawed in at least four respects: (1) erroneous history of 14 CO 2 in air that is at odds with direct observations; (2) neglect of the consequences of the large input of 14 CO 2 into the atmosphere from nuclear weapons tests in the 1950s and 1960s; (3) failure to account for isotope exchanges between the atmosphere, ocean, and land biosphere that occur independent of net change in amount of atmospheric CO 2 ; and (4) neglect of multiple independent lines of evidence that CO 2 emitted from fossil-fuel combustion is the principal contributor to the increase of atmospheric CO 2 over the industrial era.…”

Comments on “World Atmospheric CO2, Its 14C Specific Activity, Non-fossil Component, Anthropogenic Fossil Component, and Emissions” by Skrable et al. (2022)

“…The relationship of 14 C behavior to global climate behavior has no characteristic of radiation protection. The Journal was not the correct venue for the content of the paper by Skrable et al (2022).…”

“…Despite the venue of publication, I feel confident that the paper of Skrable et al (2022) will receive scrutiny from the atmospheric science community.…”

Comments on Skrable et al. (2022)

“…But one can hardly look at Fig. 2 and argue that 14 C produced in nuclear testing can be ignored in understanding 14 C levels in 2004–2012, the only period from which Skrable et al (2022) took specific activity data. Net 14 C dilution is suppressed, not because anthropogenic carbon in the atmosphere is lower than conventional models suggest as Skrable at al.…”