Ways the Human Race could Destroy Itself :: Apocalypse

The End of Humanity: Could the Human Species Destroy Itself? There are lots of ways humanity could be wiped out - although I don't think any of them are particularly likely. Natural causes - An extinction-level asteroid impact would probably be sufficient, although not much else would - a disease epidemic, major climate shift, etc. would still leave many survivors to rebuild within a few hundred years. The window for such an impact is, however, extremely short, because it's extremely likely that within 300 years or so we will have the means to predict and avert all dangerous impacts. And the chance of that happening is, from historical comparison, 0.001% or less. There are a few other possibilities that would be much more catastrophic, though. One is a supernova very nearby, which would blast Earth with intense gamma radiation and most likely kill all macro-organisms. However, there aren't any stars large and old enough for this to be a risk for hundreds of thousands of years. Another is orbital destabilization of Earth (such as ejection from the Solar System) by a close-passing star - but the chance of that is extremely remote, and in addition we'd have thousands of years of warning. And the last that I can think of is alien invasion†¦ which is really out there, obviously. The eventual solar threats to life on Earth are not really relevant to humanity/posthumanity. The Sun is not large enough to supernova, but it will eventually engulf the Earth when it runs out of internal fuel and swells into a red giant. That's a good 4-5 billion years away, but well before that, though, the Sun will have become bright enough to heat Earth's surface enough to trigger a major atmospheric shift by overwhelming the "cloud effect" (which keeps temperatures on Earth stable) with a runaway greenhouse gas effect, boiling the oceans and making the planet Venus-like, uninhabitable except by micro-organisms. But even that is about 2 billion years away, plenty of time for posthumanity to rise and either avert the problem or simply head elsewhere. Accident - A scientific experiment run awry, or an unexpected side-effect of some new technology could potentially wreck some serious havoc. One possible horribly catastrophic scenario would be the unforeseen generation of a miniature black hole somewhere on Earth. If the hole did not evaporate instantaneously (and it would have to be pretty large not to, so I don't know how it would be possible to generate one accidentally) it would quickly bore a hole to the center of the Earth, absorbing more and more mass as it went, and eventually implode the planet.