I know that a greenhouse is not air tight so I imagine it breathes somewhat and exchanges gas with the outside. However, I also assume that it’s going to use up the co2 in it for plant growth. How does it not run out? I think you could vent it, but then wouldn’t that cool it off and thus defeat the purpose of a greenhouse? All my web searches either give climate change facts or co2 supplementation by farmers.
Not sure how they capture the carbon dioxide, but it’s delivered to the greenhouse itself from a giant tank outside the building. I realize that’s probably not the part of the process you were interested in, but it’s all I’ve got.