No the proof is in the yeild. 1500ppm is not a "high co2 condition" for a plant or a human.
Can you cite the top parameter of co2 ppm you think causes a plant harm?
The bottom is around 200ppm where your plants will actually stop growing.
I guess that co2 is plant food. Thanks for helping me realize that as I set my grow room to 1500 ppm which let's the temps run hotter without hurting the plants.
Cheer up impeachment coming any day now. Yep any day now, could be within the hour even. And the supreme court will be dealt with like next week just watch and see.