Hi everybody!

I've checked the Time animation by Valery and I concluded that indeed the icecaps are rather rare if we view the whole history of earth.

But,

when the globe was young volcanic activity was more intense. There were ages when lots of CO2 and other greenhouse gases filled the atmosphere due to vulcanic activity. Therefore the global temperature was higher those ages.
The globe is older now, volcanic activity is not elevating its temperature anymore, what changes the climate today is: human activity.