Interesting storage idea....

[Kenyth]

I would think something nice and inert, like nitrogen, would work better...

CO2 is neutral enough under these circumstances. The plus is that it's a nice big heavy molecule in comparison to other gases. It tends to settle out at the bottom of containers it's stored in, displacing other gases to the top. It's also very easy to contain because of this. It's also toxic in high concentrations to most life, including many that cause spoilage.