Natural pandemics like the Black Death will seldom wipe out more than half the people in an affected area and never everybody. It's possible that someone might

Natural pandemics like the Black Death will seldom wipe out more than half the people in an affected area and never everybody. It's possible that someone might genetically engineer a plague to be dormant but transmissible for a year then suddenly kill its host but even with something like that you're probably going to miss pockets of people as large as were left after the Toba supervolcano 70,000 years ago. Nuclear war probably won't wipe out humanity either. Lots and lots of people would die in the countries involved and a few hundred miles downwind of the fallout but other locations would probably only see increased cancer rates. I say probably because while it looks like fears of nuclear winter were probably oversold there's still a fair chance that they weren't and we'd be looking at 5 years with no plant growth after a nuclear exchange. In which case, hey, there's this charity called ALLFED[1] working on how to feed people in the event of a nuclear winter or meteor impact or supervolcano eruption causes a global years long winter. Things like how to operationalize turning dead trees into edible mushrooms at a huge scale. [1]https://allfed.info https://allfed.info