here's a little thought experiment. suppose that terrorism is not not a bizarre mentally-ill aberration of an infinitesimal percentage of fanatics, but something sort of built in to the human organism; or the massacre at columbine etc. suppose that it grew in pervasiveness through a few decades. compared to that, global warming might be relatively minor. like it might make airline travel impossible. it might make cities untenable; already you could shut down any city in the first world with a few backpacks and clock radios. it might blow up the internet in one direction or another.