Before the break, mankind was restricted to operating in a very narrow tropical band on a small fraction of the globe's land surface. Every where else the climate marched back and forth very quickly over several degrees making agriculture totally impossible with the possible exception of some herding. And the carnivores made that pretty dicey.
Today, that same temperature swing is a half degree or so every century, and we still yell.
When the ice age ended 12,500 years ago, the northern ice melted raising the sea level 300 feet over a number of centuries. This sank the edge of the continental shelf below sea level everywhere, inundating coastal plains everywhere.
This certainly explains the Bronze age traditions of a great flood that humanity fled. The rest of the story means little in the face of the universality of this coastal inundation that destroyed most of the human habitat of the time.
My own small contribution is to attempt to understand the crustal shift mechanism that brought these changes into been. In any event, the actual collapse of the ice age is a historic reality, regardless of causation. At least my causation mechanism has the benefit of promising us a continuation of the Holocene (or Antropocene) for millions of years. Does anyone understand just how incredibly lucky we are to have the current crustal configuration that we have?
The Arctic is a nearly closed sea that could easily become an icecap again if any number of significant shifts took place . How did we end up with the right configuration in the first place? It has been suggested that the crust shifted several times in order to get it right. I find this difficult to subscribe to because it seems so unnecessary. Once by accident seems good enough. However, if the dynamic causation model in fact predominates, then multiple shifts become natural until the exact configuration emerges that eliminate the northern ice cap.
I also note that the southern ice cap is stable on a large land mass, but is tightly bounded ensuring any excess ice finds its way into the ocean long before there is enough build up to endanger global crustal balance.
I suspect that this configuration is stable until plate tectonics finally changes the configuration, millions of years from now.
This still begs the question of why are we not making more of the dramatic change that occurred a mere 12500 years age. It undoubtedly made it possible for the human animal to populate the globe as an agriculturalist. And it seems strange that the promoters of biblical studies do not jump on this, although it queers any more recent middle eastern scenario. However, they usually have no difficulty in questioning the age of anything.
My publication of the Pleistocene Nonconformity a few months back covers the causation problem in some detail for the interested reader. It can be found on the View Zone.