A challenge in making people care about techno-apocalypse is that most of the proposed technologies which could cause it exist in the future, not the present.

There’s all-out thermonuclear war, sure. If the Bush administration is dumb enough to attack Iran before he leaves office, then we could have serious problems with Russia (the country my family left when the Communists took over), whose minister of defense has cautioned the US not to lay a hand on Iran. If Putin’s successor is as gangster as he is, then Cold War part II (or Hot War part I) can’t be ruled out.

But would this kill everyone? Not too likely. Although burning cities do create black clouds which can initiate widespread crop failure, this effect is temporary. The world is a big place, and you can’t nuke it all.

So, in examining possible sources of human extinction risk, we have to look to the future. In a way this is reassuring, because we have time to prepare, but in another way it’s not, because some of the scenarios are too futuristic for people to take seriously.

I suppose the step after global thermonuclear war is genetically engineered plague. I’ve talked to four separate recombinant geneticists who say they would have a good chance at wiping out 90% of the human population in a decade if they had several million dollars and complete secrecy. (Their claims were more or less in tune even though they don’t know one other, to my knowledge.) Are they exaggerating? I don’t know, I’m not a biologist, but I think I’d rather err on the side of trusting them on this one.

What I do know about is history. The Black Death, which was possibly not the same thing as the bubonic plague, killed as much as half of Europe. Perhaps modern-day hygiene would prevent this from ever happening again, but the Spanish flu happened in conditions of nearly-modern hygiene, still killing 50-100 million, and spreading as far as the Arctic and remote Pacific islands (those are the two regions you need to watch if you care about extinction risk).

Would nuclear war threaten Tristan da Cunha, the most remote archipelago in the world? No. But a sufficiently powerful plague might. Especially a plague that spread to hundreds of millions of people before they started to display symptoms. Would such a thing be possible to genetically engineer? I’ve been talking with scientists about it since I got out of school but they often contradict each other, so I’m still confused.

My intuition tells me that when mankind can engineer something from scratch, it opens a vastly wider design space than nature alone could access. This is why humanity came up with computers, supersonic planes, and rocket ships, and the fastest swallow can’t even break the sound barrier. That’s why the Luddites got angry — because specialized looms could create textiles way faster than they ever could. Perhaps specialized microbes could kill people faster than any conventional weapon, or even nuclear weapons. I’d rather not watch it in action to find out.

I like thinking about the genetically engineered bacteria because it’s a happy medium in its future shock between thermonuclear war (which most accept as a possibility) and AI/robotics (which people have bizzare reactions to). There’s also nanowar, but that is also more futuristic.