''The Vikings left Greenland after first colonising it - both instances due to climate change changing what was possible for them. The Vikings later started giving up farming and raiding others and colonising other lands such as France and England - again due to climate change this time - cooling.
Such is normal.''
seen any Viking villages have you nip?
I have.
what would be easier to move -------- a 100 unit high rise or 1000 mc mansions - or a Viking village?
take all the time you need
you just might start to get the idea that this is not exactly what humans have experienced in the past as 'normal'