I did a fair bit of work on Palaeoecology and Palaeobiogeography with an Australian university, climate change, including faily dramatic change is normal, a static climate for any geologically significant period of time is rare depending on the degree of change considered.
Reasons vary including vulcanism, solar activity, atmospheric gas and variations, bolide impacts, albedo changes, and many other factors.
Magnetic poles move creating magnetic polar wander curves and can change the shape of the Van Allen Belt but geographical pole variation is so very rare.
Plate drift rates vary but two million years is not much in geological time.
Northern Hemisphere climatic variation is higher than the Southern Hemispre due to the proportion of continental surface to ocean.
There are many papers on the Greenland topic you can choose your poison with those.
I will NOT be drawn to comment on anthropogenic climate change models.