Extinction means zero humans left, which is highly unlikely as we are a very resilient species. A global collapse is more likely sometime in the future, but even then some countries and communities might just keep going on.
Probably what the dinosaurs thought too... an asteroid made the planet unlivable and they are gone now. We are making our planet unlivable bit by bit. My entire life is built around seeing patterns, and this is a pattern i cannot unsee. The only thing that could potentially extend our stay is the low birth rates, for which we can thank portal media devices and social media.