What Is Your Single Greatest Fear?

But just out of these options:
1- Robots killing all the humans
2- Small pox/ebola or some kind of virus killing us
3- Gray Goo
4- Israel bombs Iran and starts WWIII
5- Computers are used in the future to control everyone
6- Runaway global warming killing us
7- The singularity taking too long to happen

They've made movies about 4 out of the 7 (that I know of).

I'm a #7 guy, like Peter Thiel, because I know that if I can imagine amazing technology that would eradicate hunger, extend lives, and help us colonize space, then the stuff I can't even imagine yet must be so much more awesome.  When I describe the time in the future when our current problems don't exist, my sentence tends to start with "If we don't kill ourselves first."  The Singularity has to happen before we blow ourselves up. 

The one I'm least worried about?  #6.