Your post is the most valuable lesson from this thread. And it goes for burning wood for heat as well. The Carbon cycle used to be taught in school (photosynthesis was the hard part to understand.) But car emissions are actually not part of the closed cycle. The reason that livestock are being looked at now is that car emissions are relatively under control and the regulators need to move on.
No, the regulators need to find another line of work.
“But car emissions are actually not part of the closed cycle.”
They certainly are part of the cycle, although not a natural part obviously.
The CO2 from auto emissions comes from hydrocarbons in petroleum, and those hydrocarbons were trapped from the atmosphere by plant life. When we burn the petroleum, the carbon goes back to the atmosphere.
It make take many years for that cycle to close, but it’s still a cycle.