Some don't think CO2 levels of 550 ppm is enough:
"Luckily in the smoggy cities, the CO2 level can be as high as 500 PPM, and by just having a good circulating fan, the plants should have enough CO2 for a medium-light indoor garden.
A high-light indoor garden with the carbon dioxide amount increased from an ambient level of 300 PPM to a high level of 2,000 PPM can nearly double plant growth."
http://www.hydroempire.com/store/hydroponic-carbon-dioxide.php
What if you are say growing Xmas trees or growing trees for pulp. It seems like forests in particular if there isn't much wind will have shortage of CO2. If these producers could get CO2 cheap and say pump in the CO2 during daylight hours so levels were around 1000 ppm, they might get significant increase in production.
Space/Science » in reply to re: The gods are laughing
re: The gods are laughing