We already are in an "ice age" its just that this is the warmer period of the ice age.
The basic rule is
Ice age = we have poles full of ice
non ice age = we dont have ice there. (natural iceless poles)
There is some other aspects to concider but we are in an ice age and if the poles will melt thanks to global warming we will still have the ice age since the melting was not natural etc and "ice on poles" is not the only thing required for having an ice age.
P.S. Ice age also means that there is ICE somewhere on the planet. So when there is no snow in the Alps but no snow at the poles we still have the ice age.
Ice age doesnt refer to a white frozen ball thats flying around in space its just talking about temperatures and chance of frozen water etc. Distance to sun etc.
