Atmospheric CO2 Increase Not Due to Humans: Alarmism Baseless

Written by Anthony Cox on April 23, 2017. Posted in Current News

This is a key issue: whether humans are responsible for all or most of the increase in atmospheric CO2. If they are not then it does not matter if alarmists believe that CO2 is the dominant ‘greenhouse gas’, which it is not because the increase is natural. Human CO2 is a very small {154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} of the total CO2 going into the atmosphere, The {154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} of human CO2 going into the atmosphere is shown by Figure 7.3, AR4, 3.67{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} (218.2 GT divided by 8 GT):

Fig 7.3 AR4:

Of the total CO2 emissions 98.5{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} are reabsorbed:

EIA, Table 3 2004:

The reabsorption of CO2 does not distinguish between human and natural CO2, so the human contribution to the increase is 3.67{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} of 1.5{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117}. This amount, the human contribution has not changed in 150 years. The human contribution to the increase in atmospheric CO2 is called the airborne fraction. The AF has not changed:

https://wattsupwiththat.files.wordpress.com/2009/11/knorr2009_co2_sequestration.pdf

This paper by Knorr finds 40{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} of human emissions remains in the atmosphere. This is NOT sufficient to explain the increase in CO2 in the atmosphere:

In this graph by Ian Hill based on Knorr’s paper, the yellow line shows the AF of human CO2 remaining in the atmosphere. It is below the level of growth of CO2 shown by the green line. Human emissions cannot be the cause of all of the increase in CO2

A new paper by professor Hermann Harde estimates the human contribution to the increase in CO2 as between 4.3 – 15{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117}:

The other part of the alarmist argument for humans being the cause of atmospheric increase is the isotope distinction between C12 and C13. Alarmists argue that the increase in C12 relative to C13 CO2 proves emissions from the burning of fossil fuel is the cause of the increase in CO2. However, this cannot establish human responsibility for the increase in CO2 as professor Tom Segalstad explains at section 10 of his paper:

From the measured delta-13-C values in atmospheric CO₂ we can by isotopic mass balance also calculate that the amount of fossil-fuel CO₂in the atmosphere is equal to or less than 4{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117}, supporting the carbon-14 “Suess Effect” evidence. Hence the IPCC model is neither supported by radioactive nor stable carbon isotope evidence (Segalstad, 1992; 1993; 1996).

Professor Salby notes:

that while fossil fuels are richer in C12 than the atmosphere, so too is plant life on Earth, and there isn’t a lot of difference (just 2.6{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117}) in the ratios of C13 to C12 in plants versus fossil fuels. (Fossil fuels are, after all, made in theory from plants, so it’s not surprising that it’s hard to tell their “signatures” apart). So if the C13 to C12 ratio is falling (as more C12 rich carbon is put into the air by burning fossil fuels) then we can’t know if it’s due to man-made CO2 or natural CO2 from plants.
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It is therefore the case that humans are not responsible for the bulk of the increase in CO2 and therefore all the policies directed towards reducing human CO2 are simply an enormous waste of money and resources.