The truth is, just about anything in high enough concentrations becomes a pollutant, that is, life threatening. Remember, the solution to pollution is dilution.
Instead of pegging the level at some arbitrary time (what, 1960s levels?), they should take data from over the last 65 million years, or if they want to, since the lower Paleolithic (about 2.5 million years ago - you should at least include a couple of ice ages) and look at the highs a lows of CO2 in the atmosphere.
Then, find the mean and calculate two standard deviations out. Anything higher and the EPA could get involved to lower the levels. Anything lower than two standard deviations from the mean and they could get involved to try and increase CO2 levels. Terra-forming at its best.
But this idea is completely separate from the idea of global-warming. That's all about the sun.
Their idea is all about control.
“highs and lows”
Why do I always see it after I post?