Zipperfish Zipperfish:
Current CO2 concentration:  402.8  ppm
And it was about 2000 ppm during the time of the Dinosaur.
Submarines don't warn of Toxic levels until, I think, it's 12,000 ppm.
Under 180 ppm all life on earth dies. At one point we were down almost to CO2 starvation levels. I think close to 200. 
I'd double check all that if I were you, but I think it's more or less correct. If it is, 
"Current CO2 concentration:  402.8  ppm," so what?