I'm scared of a terrorist organization dropping a bomb in NYC (probably the most likely city right) and then me and everyone I know and love dying slowly from radiation poisoning
I'm concerned about the short and long-term impact that ISIS and their terrorist ways will have upon their victims in the Islamic world, the possibility that right-wing nuts like that Rick Perry bozo want to use this as an opportunity/excuse to start another war, and the way in which this (as well as the problems in the Ukraine and Gaza) will continue to damage international relations.
The only things I'm worried about are ISIS, the Ukrainian war, and to a lesser extent: global warming. I'm expecting Ebola to stay contained and the USA riots will be over with soon.
Almost nothing on that poll is really an international threat You're probably safe from everything on that list except you live in the affected/target areas.