That I posted may be a little deceiving.

In the past 400,000 years Co2 has varied from 180ppmv to 300ppmv, worryingly in the past view decades it has risen to near 480ppmv which is unnaturally high amount.

However I've heard before that it's temperature that controls the amount of C02 in the atmosphere due to the effect it has on plant life :\ ......not the other way round