CO2 by the numbers

THE KEELING CURVE
Can you see where renewables kicked in? No?

Mona Loa Research Station
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CO2 concentrations do go down. It is not always up.

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Tons of CO2 in the atmosphere
The atmosphere "weighs" [5.2 x 1000**5] metric tons
(5.2 quadrillion metric tons)
CO2 is 410 ppm or .410/1000 molecules by count
converting count to weight: (.410/1000) x (44/28.8) = .627/1000
explanation of 44/28 factor. CO2(44) is heavier than N2(28)
[5.2 x 1000**5] x [.627 x 1000**-1] = [3.26 x 1000**4]
410 ppm CO2 = 3.26 trillion metric tons

1 ppm of CO2 is about 8 billion metric tons
6 ppm of CO2 is about 48 billion metric tons
40 billion metric tons is 5 ppm (2019 emissions)
250 ppm of CO2 is about 2.0 trillion metric tons (pre-industrial)

Conversion from tons of Carbon to tons of CO2: (44/12) or 3.66
Conversion from tons of CO2 to tons of Carbon: (12/44) or 0.27

See James Lovelock. He is clearly unaware that man has emitted 2 trillion metric tons in the last 250 years, a blink geologically.
A billion metric tons he calls a gigaton
A trillion metric tons he calls a teraton.
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CO2 world emissions since 1750: 2,120 billion metric tons

Not all of that ended up in the atmosphere.
It looks like 1.3 trillion metric tons, about 60%, did.
calculation: 1.3 trillion metric tons = 3.3 (410ppm) - 2.0 (250ppm)
I think the claim that CO2 never comes out of the air is too strong a claim.
Could we get the split between fossil CO2 and biologic CO2? Maybe nuclear testing in the air has made that impossible, with the creation of unnatural amounts of C14.
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Is this true? Or false.

How long CO2 stays in the atmosphere is a crucial issue. The flip side is how fast does it clear?