Correlation does not necessarily imply causality. In fact, it is just as reasonable to conclude that warm periods result in increases in greenhouse gases rather than the other way around.
Of course.
But also you realize, of course, that such a view does nothing to contradict the idea that carbon dioxide could be leading to global warming....right?
After all, it's not like we have an example from the past in which man pumped CO2 into the atmosphere at our current rate, raising the atmospheric concentration to its current level (that is, raising it above the quasiequilibrium level and potentially making CO2 become a forcing element, not reactive). It's not like Homo erectus was buring THAT much stuff, even after discovering fire! :-)
Additionally, the temperature increase could very well have been the result of feedbacks, following initiation by a change in insolation.