As none of us were there at the time - we must be guided by all the evidence. I would suggest that folk far more qualified than either of us - do still have different views on the details and history of climate variation but are probably too polite to describe each others opinions as rubbish.

Within the past 32,000 years, human cultural evolution has sped up dramatically. About 10,000 years ago, the evidence shows that people first began to farm and it follows that the climate in this period must have been settled enough to allow this practice to spread.

It most probably follows that if the world's climate had been settled enough to allow this previously - this cultural change may have started earlier? It may not have been the case and there may have been many other factors. But a suitable climatic period - free of the effects of comet collisions and super volcanos etc - is an important factor that does rather tend to be taken for granted?