[Robert A Cook PE]

There is a minute difference between C12 and C14, and the two have slightly different ratios in wood (plant life) and atmospheric ratios, but :fossil fuel" IS plant life-derived (so we are told by classic chemistry!) but that has no difference in the emissions of burning old plant life or new plant life ...

UNLESS you consider petroleum based oils are NOT from "plant-life" derivatives, in which case they come from ???? (underground biologics and microscopic (non-plant) bacteria and from the natural gases and rock... in which case NEW oil and natural gas IS being formed all the time and we DON'T have a oil-source crisis after all...)

[secret garden]

And that's why he never got anything higher than a C in science all through college.

[patton]

Now, Robert, don't confuse the discussion, by bringing up abiotic oil...LOL

[tioga]

I am sooo relieved that you cleared that up for me....the divinity school flunkie had me scared.

[spunkets]

"There is a minute difference between C12 and C14, and the two have slightly different ratios in wood (plant life) and atmospheric ratios, but :fossil fuel" IS plant life-derived (so we are told by classic chemistry!) but that has no difference in the emissions of burning old plant life or new plant life ... "

The isotope that's important is the stable isotope ¹³C. ¹²C is preferentially incorporated into vegitation, because the ¹³C/oxygen bond is slightly stronger, than the ¹²C/O bond. That results in an increased isotopic ratio of ¹³C/¹²C in the atmosphere, over the general natural abundance ratio. See #284. There's some corrections in 2 posts below it, a missing H for ³H...

" UNLESS you consider petroleum based oils are NOT from "plant-life" derivatives, in which case they come from ?"

¹⁴C would be irrelevant in this case, because the oil is millions of years old, and the half life of ¹⁴C i ~5700yrs.