[Animats]

Some big threats:

- Something with the spread rate of COVID-delta, and a high lethality rate after a long incubation period.

- Enriching uranium in a rather small facility. This may already have happened and been kept quiet. Laser enrichment was talked about a lot in the early 1990s, and then suddenly, after some announcements from Lawrence Livermore, things got much quieter.[1][2] As high-powered lasers get better, this gets easier. There's now a startup in Australia working on this process again.

- Long term, a birth rate that's below replacement rate. That's the current normal in the developed world.

[1] https://www.nrc.gov/docs/ML1204/ML12045A051.pdf

[2] https://en.wikipedia.org/wiki/Separation_of_isotopes_by_lase...

[zh3]

Long conjectured, some disillusioned uni student with the latest tech combining the R number of measles withe the lethality of ebola (and a dash of HIV on the side).

As a twist, "The giving plague" by David Brin is an interesting (short) take on it.

[trinovantes]

If it's too lethal, it would probably kill all its carriers before spreading too far

I wonder if anyone's ever calculated the optimal parameters for a disease to end humanity

[erik_seaberg]

There’s a game about this: https://en.wikipedia.org/wiki/Plague_Inc.

[humanrebar]

It doesn't have to kill anyone. Just sterilize the young.

[mcswell]

Or it could kill off only males (or only females). There is at least one SciFi story based on that premise.

[neutronicus]

I don't think the birth rate thing is an actual existential threat

If it goes on long enough there will be opportunities and a baby boom

[hn_throwaway_99]

> Something with the spread rate of COVID-delta, and a high lethality rate after a long incubation period.

I sometimes think how "lucky" (obviously, luck is relative) humanity is that HIV is an STD and not an airborne virus with the transmissibility of Delta.

[forty]

For some reasons I feel HIV treatments would have been found much more quickly had it been the case. Just like I'm pretty sure mosquitos would have been eradicated (or another solution would have been found) if it had killed so many people in developed countries.

[hn_throwaway_99]

I think that's a good and fair point. Reagan famously didn't even mention AIDS publicly until 1985, 4 years after it was discovered. Urban gay ghettos in NY and SF were basically experiencing a plague with young, otherwise healthy men dropping like flies, and the world at large either (a) didn't care, or (b) was glad that AIDS was "killing all the right people".

[zzt123]

Your first point is something I’ve wondered as the biotech revolution gets under way.

I wonder how many years away we are from home hackers having the tools necessary to create a horror. Say, something with the spread rate of Covid Delta and which acts as an airborne prion disease.