Let me get this straight. You are saying that from the ice minimum CO2 of ~200 ppm to the intra glacial maximums of the past of `280 ppm that the temperature went up 9 C from -9 to 0. Man enters the picture and raises CO2 from 280 to 400 ppm (delta 120 ppm which is 50% more than the min-max shown) and our global temperatures go up much much less than the 9-13 C expected by a linear relationship (<2 C by most authors).
You could conclude one of the following:
Temperature follows CO2 but is not linear (more CO2 now is causing less delta temperature than at lower concentrations).
CO2 does not strongly control temperature (and thus the time lag of CO2 behind temperature and the extra CO2 man has added is not the driving force in the recent minor temperature increase (compared to the glacial cycles).
The least likely conclusion is that CO2 controls temperature in a linear way and this is proved by ice core data.
