No, that would mean the warming of 800 years ago would be causing the CO2 values of today to go up. It was warm in the year 1200CE.<quoted text>
No external source of warming is needed to explain the increase in CO2. Humans activity, even if the Earth would otherwise be getting colder, is sufficient to explain the increases in CO2.
You are drawing a very bizarre conclusion here.
Ice contains air bubbles, that is why ice is less dense than the same amount of water.
If you were to do this experiment: Encase a piece of ice in air tight plastic, then allow it to melt.
The result would be this: A plastic container which is ~3/4 water and 1/4 air.
That means that as the ice shelf melts, air trapped within the ice is released.
Now, you could say that since the air in that ice has CO2 at 100ppm less than the atmosphere, it's lowering the average, but the amount of atmosphere vs the amount of air reduced from melting ice is so ridiculously disproportionate that the overall effect if you were to melt all the ice would cause an insignificant change to the global average ppm.
If that were true, then your conclusions would require that the ice shelf for the last 100 years shows a massive increase in warming and no corresponding increase in CO2.
That's not what we see. We see a MASSIVE increase in CO2 over he last 100 years, with that increase growing consistently.
I happen to think CO2 in our atmosphere is far more variable than the ice core data from antarctica demonstrates. Plant stomata proxy studies show far more variablity.