Dammit - I went a zero too many, human civilisation ~ 20,000 years worth of "settled" building, agriculture, slowly increasing in scale as climate variations decreased in scale.

Everything that is "modern human civilisation" from, say, early Egyptian onwards (following the formation of the Sahara some 6,000 years past) has taken place in a period of climatc stability.

Point being, come climatic change on that scale again, the planet and various eco systems will adapt and move on, human civilisation patterns as we know them from history will be heavily jarred.

Cheers for that.