coberst: "...while we have the brain power to prevent this we may well not have the necessary character traits to do so."
Supposing that's true - and I think it is - is there a pragmatic approach to dealing with the problem? You suggest:
coberst: "the only way to prevent this is for our species to become much more intellectually sophisticated than it is now"
Are you suggesting that better education would change the character traits inherent in our species?
I think it is these very character traits - which encompass instinctive behaviour - that answer your ultimate question:
coberst: "Do you think that the human species might extinguish itself within a few centuries?"
I think that (a) as TFF says above, our species would survive self-inflicted injury, though in what condition is another question (b) civilisation will be very seriously damaged unless population is controlled (c) adequate population control can only be achieved by coercive measures.
Most current threats to the survival of civilisation, short of a catastrophe like cometary impact, would seem to be either caused by overpopulation or intensified/exacerbated by it. Overpopulation is a common characteristic of underdeveloped regions, and it could be argued that accelerating the development of those regions would solve the problem. I think the critical limit will be reached long before such a plan could be effective.
