How to prevent the extinction of the human species?
Humans are vulnerable to many different cataclysmic events. 
One way is to migrate and reside in other planets, solar systems and even galaxies. Earth is a single point of failure. 
Another consideration is to merge with AI and exist in virtual reality as a non-biological species. 
Preserving human genetic material in doomsday vaults, so that humans can be revived/resurrected in the future.