Even anatomically modern humans have gone through similar events several times in the history of our species, let alone our ancestors. Climate change itself will not be the end of humanity, but it may be the end of the current civilisation.
You already said these are massive geographic issues.
Yet these different, large, geographic problems are of a size that doesn’t end up having even a remote effect on human civilization?
How? Is there some geography which is not impacted at all? A geography where a massive portion of human civilization is situated?
You're driving at changes to how we live.
Changes to how we live, even large ones, does not equate to "the end of humanity."