That really doesn't answer my question at all. I asked why so many people are terrified of terrorism, and all you tell me is that they're afraid of some nebulous future. Well yes, obviously they're afraid of the potential future, as it would be pretty odd if they were afraid of the past. But why does terrorism get so much emphasis compared to other potential dangers?
Partly it's the immediacy. In the long term, China poses a threat to American hegemony, but they're not actively trying to blow things up at this very moment. The other part is the narrative. Environmental disaster should rank higher in peoples' minds, but people are intrinsically drawn to narratives that involve other people. Terrorists are like comic book villains as far as narrative goes. Not only do they behead people, but they brutally oppress women!