Ice in Dino Land

Even when there were significantly higher levels of CO2 in the atmosphere, (50 to 100 million years ago) there was still ice in the polar regions.
Now, considering the elevated levels of the greenhouse gas and the elevated temperatures as shown by the presence of dinosaurs just exactly how is all the current ice supposed to disappear again? And let's not discuss the lower sea level.

On the other hand, this study showed CO2 levels to be much lower than today 650,000 years ago. They measured the levels in gas bubbles in Antarctic ice.

And this report (sorry, LA Times, free registration required) of the interglacial periods also done using and ice core suggests we have altered the interglacial period (time between ice ages) since we are now 12,000 years from the last ice age and the next should have happened after 10,000 years. The research (according to the report) suggests we are 15,000 years form the beginning of the next ice age. When times between ice ages have fluctuated wildly, just exactly how can you predict when the next one will start?

I remember reading (many years ago and the source long lost)
1-If temperatures rose only a few degrees, the Arctic Ocean would not become ice covered during the winter
2-If the Arctic Ocean were to remain unfrozen for just two or three years evaporation from its surface would create additional snow that would accumulate upon the Ocean's shores
3-This added snow would be so deep so as not to melt in the summer before the next winter's snows fell. (It would only take a few inches of residual snow.)
4-As the snow accumulated, it would reflect more sunlight from the surface and temperatures would begin to decrease and an Ice age would be born.