Our systems of civil society are fairly robust, but at some point those major problems become greater than our ability to cope. Unfortunately, "almost no chance" and "no chance" are not the same thing.
Or as lifeformed put it elsewhere: "Destroying all civilization doesn't mean destroying all humans, but just the structures that hold society together. A runaway heating scenario may be a pretty effective way of doing that - all crops die, wars for food, nukes get used."
Again, I am not saying these things are OK. We should worry about displacing millions of people and probably wars but civilization dying seems overblown and damaging to the argument that we should be doing something.