Most of us sleep soundly in our beds at night, not even thinking about the possibility that the world could end in horrible fiery death at any minute.
This is probably a good thing.
Luckily, however, there are people out there who have made it their business to protect us from the apocalypse. These heroes have taken every eventuality into account and are currently figuring out various genius schemes to prevent them. These scientists are nobly sacrificing their sleep and sanity, pondering the ultimate fate of humanity, so that you don't have to.
We all have a zombie apocalypse survival strategy (right?), but as with all things, prevention is usually better than cure as you can't perish in an apocalypse that doesn't happen.
Whether the threat to Earth comes from above in the form of an Idaho sized space rock, from below in the guise of an explosive super volcano, or even from within, in the shape of some explosively virulent disease that will either turn us into a horde of zombies, or dehydrated husks. Regardless of the source of the threat, you can rest safe in the knowledge that there are some very clever people working on it.