How big a loss of life could civilisation survive?

This is a very big question with many subquestions. I know that it’ll need Una Persson’s input and a lot of other people’s as well.

Let’s say that a lot of people die suddenly. To make it as simple as possible, let’s call it a death ray from space, striking the entire Earth at once and immediately killing a certain percentage of people, picked at random. If the kill ratio is ten percent, we’ll assume we still have ninety percent of the policemen, ninety percent of the farmers, ninety percent of the lit majors, and so on. The ray has no other effects and isn’t built in the style of any particular decade.

How big a percentage hit could civilisation take and keep functioning in a way that we’d recognise? How many people could be lost without the power grid going down, the food supply chain ceasing to work, garbage lying rotting in the streets, violent gangs taking over, petroleum becoming unavailable, and so on?

I think we can safely assume that the ten percent figure above is too low; civilisation could certainly survive that. Also, if some ridiculously high amount like 99 percent died, civilisation as we know it would certainly be history. But where’s the limit? Could we lose fifty percent of the population and pull through?

Of course, we could lose almost any percentage and eventually come back to where we are now. I want to know how many we could lose and just keep going, barring some initial speed bumps.

I think we could lose 2/3 to 3/4 of our population without a total collapse. Oh, it would be massively disruptive, of course, but we could maintain our levels of technology and the essential social/economic/other connections well enough to weather the shock.

I base that on the historical experience of things like the Black Death in Europe - horrible thing, massive loss of life, profound effects on society… but things did not fall completely apart.

it also depends on who dies
3/4 people die randomly? It’d set us back, but we’d regroup, rebreed, and be back.

Everyone who has a university education dies? Well, we’ve got a problem.

Also it depends how we die. A nuclear war that somehow kills most of the population of earth will probably scare the rest shitless into being part of any organised government or civlisation… but I guess some still would.

Have been to Cleveland? :smiley:

Seriously, I think that we could take a much bigger hit than 10%. If 80% of the US were wiped out, there would still leave 60 million people. More than enough to bounce back pretty quickly. IMHO, of course

Depends on who dies. If the elderly who are retired or children die then it won’t really hurt civilization.

Also you have to consider that if there are 3/4 less people then there only need to be 1/4 as much oil, food, etc.

Also it seems that alot of people work in fields that are novelties rather than necessities. Cell phones, computer games, broadband, tv shows, passenger cars with 300hp engines, etc. All these things are novelties. The internet ‘may’ be a necessity but broadband is not. If something drastic happened then people in these fields would switch to more necessary fields like communications, electricity, food production, transportation, etc.

There are foreign countries that have had a major loss of life. Russia lost (i think) about 20% of its population due to Stalins purges and WW2 and they survived as a civilization.

I’d agree to a point about those with an education in medicine and engineering. But those with an education in liberal arts or computer science? I don’t think we’ll notice a difference. I mean, of course there will be a difference, with 3/4 of the people gone and all. But to gain ground in breeding, health, transportation, power and all that happy stuff, IMO, 20% of advanced education is all we’ll require. Everything else is grunt work.

As postulated in my original post, the deaths are completely random. Let’s assume that we lose approximately the same percentage of each category of people you can think of.

Yeah, Europe survived the Black Death… but Europe in the 14th century wasn’t relying on technology to anywhere near the extent that we do now. Also, this is sudden and unexpected by everyone, not like Stalinist purges.

When 75% of all nuclear power plant personnel fail to turn up for work, what happens? 75% of all policemen are gone. 75% of all doctors are gone. 75% of all farmers, truck drivers, garbagemen, train drivers, janitors… all gone. Could we handle that? What about 90%?

Tapioca Dextrin: This is about the world, not the US. This happening to any single country would be a doddle to clear up.

if 75% disappeared there would be short term anarchy followed by martial law and a return to the old way of life with more emphasis on producing and catering to needs and less on novelties. Also if 75% of police disappeared it wouldn’t matter much as there would be 75% less people to police around. Same with all the other categories, 75% less garbagemen doesn’t matter if only 1/4 as many people are producing garbage.

I would say around 90% could disappear before any real problems occured. If you got above 90% then you’d have a shortage of experts and international nations would have to start cooperating and swapping experts just to keep basic supplies running. Globally i’d say 98% is a good estimate, there’d be martial law at first and population redistribution but things would go pretty much back to normal soon. Overall I don’t think it’d matter much as each time X% of doctors, engineers, scientists, power plant operators die the amount of services these people need to provide goes down too.

The means of destruction need to be defined and considered before any further speculation. If this death ray could destroy 75% of human beings, is it fair to assume it would have destroyed a huge percentage of arable land? What about climatic changes? Communication networks? If all you intend to do is postulate a sudden decrease in 75% of population one not-so-fine morning without any “event” as such, then of course, civilization should survive. But, if there needs to be a plausible mechanism to carry this change out, then the total sum impact needs to be known.

There’s also the psychological effect of 3/4s of your friends and family going poof.

Just to keep this thread on target:

Say the aliens abducted x% of all humans. They beamed them up without hurting any of the surroundings. The only materials that we lose are the clothes those unfortunates were wearing. The aliens, being scientists, got an even x% of all groups (they’ve been watching us long enough to know how we divide things). The humans they took are, for all intents and purposes, not coming back. (The aliens will all get tenure in a couple of centuries based on this research, and they don’t care if all of the test subjects have died in that time. Some research groups might deliver mummified remains that are no longer required for dissection.)

I say, 33% would be survivable. That’s how many Europe lost overall in the Black Plague. It would cause labor shortages and a huge spike in wages for those left around, causing a large increase in pleasure-seeking behavior. Being a hooker or a drug dealer would suddenly be very profitable. 50% would probably do the same thing, but 75% would, to me, be too much. You’d end up losing essential knowledge, even given that more and more of it is written down now. Any more than 80% and you have too few, in my opinion, to keep essential systems up and running.

As postulated in the original post, the death ray has no other functions than killing people. Ignore the ray itself, it’s just a MacGuffin. Call it an incredibly infectious quickly killing plague (that some people happen to be immune to, The Stand-style) if you prefer that.

Yes, the garbage volume would go down by 75% when 75% of the people died and so forth, but the people needing all those services would be spread out. Take the building I live in, for example. It is inhabited by approximately 25 people and serviced by two garbagemen every week. After the 75% death ray, the building is still inhabited by 6-7 people, but the city garbageman crew has gone down by 75% and they’ll have a dickens of a time to get every building serviced. In the same vein, 75% of the world’s power plant personnel can run 75% of the world’s power plants, but they cannot run every power plant in the world (I assume; Una Persson, feel free to pop in at any moment).

The answer is simple: group the people together. However, this will take time and in the meantime, civilisation isn’t functioning very well. That doesn’t count as civilisation keeping going, barring minor speed bumps. A power blackout lasting a day is a minor speed bump. A power blackout lasting a week is on the verge of turning into a major speed bump, and a power blackout lasting a month is definitely too much.

Ahem, I have to take issue with this, and I’m qualified to speak because I have a liberal arts education, but have spent most of my working life as a programmer. The use of computers is so basic to the way business, science, and technology is conducted now that the absence of people who can design, build, and program them would be a very severe shock to the system, even if you still had an adequate supply of doctors and engineers. At the very least, it would take immensely longer to get the infrastructure up and running.

As soon as we need any significant time to get the infrastructure up and running, we’ve lost according to the frame of the question.

See, I don’t buy this at all. Dump 75% of the population, and you have to do a total regroup. Major cities would be abandoned for the countryside. There would be a tremendous shift of the remaining population to areas closer to food production.

I think we could lose 50% without much of a bobble. 90% of the computer programmers out there are working in non-essential areas anyway. Civilization doesn’t need Doom 4 to survive, and the ones that are left will be very busy doing necessary tasks.

So, based on historical references and my own SWAG, the bright-line between speed bump and total reboot is somewhere between 50% and 75%. Call it 66.6%, just for giggles.

I knew this would come up. I’m not trying to slam college in anyway. My point was that if 3/4 of the world population were wiped out right NOW, a degree in liberal arts, or computer science (and many others) is meaningless. As there would be many, many people that can handle these tasks without a college education for the type of catastrophic incident that has just occurred. Programming and infrastructure design can be accomplished without a college education.

I’m not saying that it’s useless now, in an unaffected world. I’m just saying if it happened, the skills would be there to get the job done, college or not.

Mmm…complicated issue.

Methodology and percentage mean a lot. If fifty percent of the population croaked, I’d certainly head for the country, closer to where the food is grown. If ninety percent or more died, I’d head for the city, where there would theoretically be lots of resources lying around for my collection and use. Of course, considering that ninety percent of the city is dead and rotting, I likely wouldn’t stay there long.

We’d also have to take ancillary deaths into consideration – this is something Stephen King touched on when he rewrote The Stand. A great many children would die if their parents suddenly dropped dead, don’cha think? I mean, I’d certainly want to check on my friends and relatives’ kids, but if X% of the population suddenly turned to orange powder or something, I should think I’d have problems of my own, assuming I wasn’t one of them.

There is also the matter of people not able to handle the sudden change, and either committing suicide or simply going insane, and performing actions counterproductive to their own survival… or yours, or mine. Or, for that matter, the people who weren’t too stable before the plague. In The Stand, Trashcan Man was a good example.

Seems to me that if ANY large percentage of the population were to suddenly die off within a week or so, we’d have to plan for some major upheavals among the survivors. Hell, it’s bad enough losing a relative or loved one, without losing a major hunk of your neighborhood!

I agree, I’m not sure I could go on without my neighborhood’s major hunk.

Didn’t we do a similar thread quite recently?

Since the OP’s condition was in a way we recognise rather than in current form then I reckon we could lose 99% of the population, probably more. Unless a strong leader quickly appears society would likely revert to the groupings of the Dark Ages. Keeping the infrastructure working is going to be a major task.

The population of the UK is approx 60,000,000 so a 99% loss would leave 600,000 people. India and China would still have over 10,000,000 people. At this level, people are going to be able to find other people. At 99.9% loss, I think the UK would be in trouble, but India and China would be fine. A 99.99% loss would leave 6,000 people left in the UK and unless a significant proportion could band together, that would be that. India and China with 100,000+ apiece would have a much better chance of recovery.

Assuming society as we know it can be kept reasonably functioning, life will be hard. The most obvious change will be the role of women: state welfare will be exceedingly limited and pensions worthless, many of the labour-saving electrical appliances may no longer work (no central heating, no washing machines …), so more work will have to be done at home and people will have to be supported by their children, which means many more children. The greater the population loss, the more likely women will revert to pre-industrial revolution roles. Large families will again be the norm until the population recovers. This won’t last for long - the population will rebound rapidly: if you assume 8 children per family of whom 6 survive to adulthood, the population will recover from a 99% loss in a little over a century.

I’m finding it hard to believe that so many people mentioned the Black Death, and nobody thus far mentioned the influenza epidemic of 1918. :smack:

The 1918 flu epidemic was effectively worldwide, and killed millions of people. From the Center for History:

ISTM that, so long as there were no bodies to deal with, civilization “as we know it” would survive a 50% population loss. However, I believe that a greater loss than that would seriously affect living standards in the “first world” (infrastructure and various “essential” occupations). Other, less-developed countries, would, IMO, cope much more handily, and the regions with the least technology could survive 75% - or perhaps even more. The greater the technology base, the more vulnerable it is.

Speaking of technology, from a page at Kansas University:

(emphasis added) What’s that saying? “The more things change, the more they remain the same?” Sheesh.

And (slight hijack), just to scare the stuffin’ out of those who’ve noticed all the bird flu quarantines this year … 1918 Flu Linked to Birds

I refer you to a review of a book (America’s Forgotten Pandemic : The Influenza of 1918 by Alfred W. Crosby). The review, by Earl Merkel, is halfway down the page. Also on this page is a reference to another book on the subject.

Finally, commentary in Journal of Translational Medicine (and which I strongly recommend anyone who cares about this subject read) starts out: