So what will kill off human civilization?
Will it be:
1. Nuclear War.
2. Ice Age.
3. Meteorite hits Earth.
4. Other and provide reason.
BTW: I believe the cockroach will still live on they survived the extinction of the dinosaurs when a meteorite killed them off 65 million years ago. Cockroaches have also survived many, many Ice Ages. Cockroaches would even survive a Nuclear war.