Anthropogenic CO2 accumulation in the atmosphere

This is my proposal for the report of U.S. Department of Energy by the name "A Critical Review of Impacts of Greenhouse Gas Emissions on the U.S. Climate"

Addition to 3.2.2

The report concludes on page 18 about the anthropogenic CO₂ portion in the atmosphere: ”The carbon cycle accommodates about 50 percent of humanity’s small annual injection of carbon into the air by naturally sequestering it through plant growth and oceanic uptake, while the remainder accumulates in the atmosphere (Ciais et al., 2013).” This same conclusion can be found in the study of Crips et al. (2021), which has been used as the updated basis of CO₂ circulation of the DOE report: ”… but now, CO₂ 'sinks' the land biosphere and ocean also remove about half of the anthropogenic CO₂ emissions”. The AR6 reports in the same way that the increased CO₂ in the atmosphere since 1750 is totally anthropogenic in origin, which means that nowadays about 31 % is anthropogenic by origin (100*260 GtC / 850 GtC).

There are three pieces of evidence that this is not the case. Firstly, the removal rate of different CO₂ molecules from the atmosphere happens at the same percentage. Figure 5-2 in AR6 represents different fluxes of the CO₂ circulation for the period 2010-2017. The table below shows the anthropogenic CO₂ fluxes of Figure 5-2, and the percentages have been calculated from these values.

	Phase/flux	CO2 total	Anthropogenic CO2
	GtC or GtC / year	GtC	percent
Atmosphere	870	279	32.1
From atmosphere into the ocean	79.5	25.5	32.0
From atmosphere into the land plant	142.5	29.0	20.4

According to the table, the anthropogenic concentration of CO₂ in the atmosphere in 2017 was 32.1% and the anthropogenic concentration of the CO₂ flow from the atmosphere to vegetation was only 20.4%. This is against the laws of plant chemistry, because plants prefer anthropogenic CO₂ in their photosynthesis process, since it contains a little bit more 12C molecules.  When something is wrong in the theory, the balance sheet will reveal the errors. So, the IPCC's material balance does not work, since something in fluxes and compositions has been violated.

Secondly, there are continuously carried out permille (δ¹³C) measurements which show univocally that the present atmospheric CO₂ composition is in direct conflict with this atmospheric CO₂ composition.  The observed permille value of the atmospheric CO₂ composition is about -8.6 ‰. The permille value depends linearly on the CO₂ concentration, and the permille value of the CO₂ mix can be calculated based on the portions of different CO₂ volumes. The permille value of fossil fuels and present-day plants is, on average, the same -28 ‰. By assuming that the present-day CO₂ is a mixture of 31 % (= 260 GtC / 850 GtC) of anthropogenic CO₂, the rest 69 %  can be called ”natural CO₂”, which originates from the ocean and the land plants.

The present-day permille value of the atmosphere's CO₂ can be achieved only by assuming that the permille value of the natural CO₂ is about zero: 0.69 (0.0 ‰) + 0.31 (-28 ‰) = -8.6 ‰. The natural atmospheric CO₂ portion originates from the land plants with the permille value of -28 ‰, and the rest originates from the ocean, which has the permille value of about -8.0 ‰ according to several studies. It means that the permille value of the atmospheric CO₂ with these values would be about -13.0 ‰.

Thirdly, the most important carbon cycle research studies omit this permille issue. The studies of Friedlengstein et al. (2020) applied in the AR6 do not mention the permille measurements at all, and in the same way, the comprehensive review study of Crisp et al. (2021) referred to in the DOE report does not refer to this issue. In the AR6 is a short curve named δ¹³C (permille) in Figure 5.6 c without any explanation, what it means. These evidences mean that the researchers have a skeleton in their closets. One can ask: Are the research studies and reports of big scientific groups or organisations too big to fail?

There are studies with quite different results about the division of the anthropogenic CO₂ emissions between the atmosphere and the sinks, namely Ollila (2023) and Berry (2021). Both studies applied different methods, but the amount of the anthropogenic CO₂ in the atmosphere was about 70 GtC in 2020. This result means the model-calculated permille value for atmospheric CO₂ is the same as the observed. The removal rate of the anthropogenic CO₂ from the atmosphere is about 64 years, which is exactly the same as that of radiocarbon, which has now practically disappeared from the atmosphere after stopping the nuclear tests in 1964 (Ollila, 2023). The radiocarbon is the only full-scale test of the climate by humanity, and it fulfils the requirements of a tracer test for the anthropogenic CO₂ removal rate assessment. The radiocarbon case shows that all the different CO₂ molecules have been removed at the same speed from the atmosphere, even the heavy 14C, which is less attractive for living cells in the plants and in the oceans. If this were not the case, the radiocarbon method would not work.

The increased atmospheric CO₂ since 1750 is about 250 GtC. It is not mainly anthropogenic in origin, and it will disappear about the same time as it has accumulated, which is about 270 years (Ollila, 202). It should be remembered that the increase of anthropogenic CO₂ in the ocean is about 200 GtC (Crips et al., 2021), which is only about a 0.5 % increase in the total mass of CO₂ in the oceans. The sequestration capacity of the oceans is not near saturation.

References

Berry, E.X. (2021). The impact of Human CO₂ on the atmospheric CO₂. Science of Climatic Change 1.2: 213-249. https://scienceofclimatechange.org/wp-content/uploads/Berry-2021-Impact-of-human-CO2.pdf

Ollila, A. (2023). Testing Carbon Cycle Models and Budgets. Science of Climate Change, Vol. 3.5, pp. 463-486. https://scienceofclimatechange.org/antero-ollila-carbon-cycle-models-and-budget/