[Garth Tater]

"Just keep reminding her that every bit of food on the table was atmospheric carbon dioxide just a few short months ago."

"All biomass is converted CO2. No exceptions."

Are you forgetting about mushrooms Mom, which take in oxygen and give off carbon dioxide as they grow? Better take the shiitake off the table before you make a blanket statement like that.

[exDemMom]

As I said, no exceptions.

Fungi, like animals, consume plant material. Every biomolecule in plants was converted from atmospheric carbon dioxide through the process of photosynthesis. Everything that consumes plant material, directly from plants or through the intermediary of animals—and yes, fungi—is consuming atmospheric carbon dioxide.

No exceptions.