The world population was so low
The world population was so low after the last Ice Age, and conditions so depressed, that it took humanity 8,000 years to recover itself to a major presence. That's what we are heading back to by facing the Ice Age with us being unprepared for it, such as by building 6,000 new cities in the tropics with new agricultures.
Of the course the present course can still be changed with advanced science ant technology. Modern society became a 7 billion world population with the advance of science, technology, and energy intensive processes. Unfortunately, this is precisely the feature of humanity that is presently being squelched for the political of power, property, and profit. Without science, technology, and energy intensive processes preparing the way for building a new world, the coming Ice Age unfolds as a death trap instead of as a renaissance opportunity.
My point is that humanity has the potential to awake from its death-spiral slumber, and live again as an intelligent species, as it has amply demonstrated to be capable of. But what do we see? We see the hustings empty. The evidence of the Ice Age challenge is hugely around us, but society prefers to remain asleep, obediently and politically correct.