Published and referenced global temperature and atmospheric CO2 charts are presented for all of geological time. Some of this data goes back forty years, and has largely been unacknowledged or un-acounted for by climate scientists. The data indicates that outside a small number of relatively-short-lived ice-age events, the Earth's climate has been consistently 2-3 degrees warmer than at present, held there right up to very recent times by the sun's remarkably constant thermal output and a very stable, steady-state, dynamic earth-sun thermal equilibrium. All indications are that the earth will slowly return to these slightly warmer conditions as this thermal equilibrium readjusts after fully emerging from the Pleistocene glaciation event.   

The Earth's atmospheric CO2 history depicted in the first chart indicates a progressive and massive reduction in CO2 (some 85% absolute reduction) up until the present and that there is no consistent association between atmospheric CO2 levels and mean global temperature.  During the 85% CO2 reduction mean global temperatures have remained consistently at around 20 degrees outside the 4-5 short glaciation episodes. This is powerful evidence suggesting there is no correlation what-so-ever of CO2 and mean global temperatures.

The last 15 inter-glacial episodes 

The chart below presented he last 15 inter-glacial episode (labelled 1-15). Note that from 11,000 ya the chart has a significantly enlarged time scale. There seems little significant difference in the climate behaviour across the 15 inter-glacial episode, with the maximum temperatures for each little different from what is being experience today. This suggests that the current warming will probably follow a similar pattern. 

One significant difference is in the atmospheric CO2 behaviour in the present warming event (represented at the location marked "Present" below), where it extends to higher levels than for the other peaks (seen in earlier CO2 charts), reflecting the man-made (industrial), contribution, not experience in previous warming episodes.