This is correct, but there's also a constant metabolic process that makes (most) plants breathe in oxygen and release CO2. This is cellular respiration, and it's shared with animals. It does occur during the whole day/night cycle, but since the volume of gas processed by respiration is sensibly smaller than the volume of gas handled by photosynthesis, the CO2 emission during light hours is relatively irrelevant for us. During night, though, photosynthesis shuts down and respiration continues, so plants do consume more oxygen than they release and release more CO2 than they consume. Hence the classic recommendation of not keeping plants in the bedroom. But you would need a lot of plants in a closed space to raise CO2 levels to a dangerous degree.

Scientists have “hacked” photosynthesis, and it could help them speed up food production
https://richarddawkins.n...peed-up-food-production/

Shadow, I was unable to get your link to work (it might just be me), but from your excerpt I'm assuming you're referring to a story that is complemented by this paper published in Nature

For the convenience of those unable to access the full text, I have attached it below

Attached

Lin, M.T., Occhialini, A., Andralojc, P.J., Parry, M.A., & Hanson, M.R. 2014. A faster Rubisco with potential to increase photosynthesis in crops. Nature.

I've updated the link, it was linked to a redirect.

Thanks for the paper colour (I like how you correctly spell your name btw - hehe)

Actually, looks like the link I provided was based on the link you provided. Your link is better. Cheers!