Oh, thanks for that. There are better, more reliable sources.
Interspecific variation in the growth response of plants to an elevated ambient CO2 concentration
The effect of elevated CO2 on the chemical composition and construction costs of leaves of 27 C3 species
This is kind of old news, really. I can't even find an article for this more recent than about 10 years ago. -_- It would be nice to have more than the abstracts available without subscriptions, ugh.
I grow plants as a hobby, something few people without such an interest know is that the roots of plants need oxygen greatly, as do plants as a whole. Humans need some carbon dioxide as well, as it is what stimulates us to breath, not the need for oxygen. If you can happily expel excess CO2 from your body in a low oxygen, low CO2 environment, you'll start to suffocate without realizing it until it's too late.