So with Global Warming: I don't think it will destroy the planet. I do think humans will come through in the end. Furthermore, I think the rich will be the ones who do it but we'll see. I say this because in the end the wealthy care about two things, losing their money... and their lives. As such once they realize environmental catastrophes are not cost effective and they destroy the planet they will likely work to fix them.
Basically the problem is these disasters need to affect the wealthy. As the wealthy live in such a bubble, the vast population will be greatly destroyed first before the wealthy are affected at all. They can end up in bunkers and they'll manage to survive however they manage to, they can afford it. Once the wealthy start getting screwed they'll stop, but this takes time. Time, for some, is a luxury.
So in the end humanity will survive. The question though is just one of how much of it. If the public can mount serious offense to the status-quo, get organized and realize that all of us, including our children and their children, are fucked or saved by what WE do NOW there is potential. Otherwise the question just comes down to...
How many of us are left to live on whatever is left of the planet?