There is almost no event that will wipe out humanity with certainty. Our species could survive for millennia in hermetically sealed caves, huddled around underground breeder reactors. There is however a very real risk of wiping out our current way of life; civilization is quite brittle. That would of course mean that we no longer have the means to sustain eight billion people, and most of them would die. The latter is what most people refer to when they say that climate change is an existential risk, because there is a very real danger that our population drops massively over the next hundred years or so. And not because we finally figured out how to use contraceptives.
> danger that our population drops massively over the next hundred years or so. And not because we finally figured out how to use contraceptives.
According to the evidence from Brazil and India, because we watch TV. According to the evidence from China, because of access to basic healthcare[1].
(I don't know of any evidence about video games, but they'd contribute too.)
[1] China's "one child policy" is blamed for the drop in fertility there, but if you look at the charts, fertility started trending down with the "barefoot doctor" campaign (someone with basic hygiene knowledge in every village). The one child policy coincides with a slight pause in the decline.
0.05c 2km asteroid. Grey goo. Fast UFAI takeoff (e.g. paperclip maximiser). Nuclear holocaust damaging our infrastructure enough that we don't survive the next big asteroid (speaking of which, we have no anti-asteroid infrastructure). Bioweapons causing widespread infertility, airdropped over uncontacted tribes.
