h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Heh... Reminds me of some classic B.S. from Rush Limbaugh, probably 30 years ago. He was blathering about conservationists concerned about deforestation. He made a factual but completely misleading statement that there were more trees in North America currently, than there were in the colonial period. I believe that may be factually true. But that's misleading because many of the new trees were planted by lumber companies. They're monoculture tree farms that replaced the old growth forests. There's much less biodiversity in areas that have been clear-cut and replanted, obviously.

"Sorry, no offence but you are missing one really crucial thing - total human population." [orcus]

I am not at all offended. I didn't think of that angle, and it's good to know. I'm assuming that after the apocalypse, population levels will fall drastically, making my earlier comments more feasible. But maybe even that assumption will turn out to be wrong?

Suppose that the world population goes up to 15 billion before the apocalypse happens, and then gets cut back to 6 billion. (I'm not saying that it *will* do so, only that there might be a future in which this happens). Six billion is still a lot more than one billion or 500 million, or whatever.

As a species, we are helped by the ways we've developed of remembering what earlier generations did. Maybe some people *will* try horse-drawn vehicles; if they have the right conditions in their area, this might stick. In other places, who knows?

In any event, we don't currently have one homogeneous world where the same4 solutions are equally valid everywhere. Chances are, after an apocalypse there will be even more separation. The Internet will likely be one of the last things we restore. Paper mail might still be delivered thanks to sailing ships, but as in the past people on one side of the Atlantic would likely have to wait six to eight weeks for mail form the other side -- longer when there are Atlantic storms.

As time went by, more things would be restored. Would we get *everything* back, though? That depends on whether, a few generations down the road, the people who are alive then will want to. This is their story, not ours, though I'm sure most of us would wish them well and try to leave as much helpful info as possible.

Re: population - for there to be any point to the thought experiment the dieback would have to be BIG.

There was some ridicule earlier this year about Thanos's plan in Infinity War. People like me pointed out that if you're idea of saving resources is to wipe out half the population, you're not saving much at all, not least because the world population was half its present number IN MY LIFETIME.

Leave six billion people alive and the human resources available are indistinguishable, really, from today. Leave even one billion alive and I think we could reasonably not even notice that much of a change. (Things would be less convenient for a while, but nothing would actually STOP.) Seriously - look around you. Six out of every seven people you see could disappear and your life would probably actually get better overall, assuming the removals were evenly distributed and you got over the loss of loved ones.

No, I'm talking about a BIG dieback. I'm talking about a situation where only one out of every THOUSAND people is left alive. That's the entire UK reduced to the population of Shrewsbury. The entire US reduced to the population of Honolulu. About the same number of people in all of Australia as currently live in Alice Springs. Assuming those people are relatively evenly distributed across the country, it's a non-trivial consideration of how (or IF) they even FIND each other.

Seriously - if a global pandemic killed basically everybody you know, would you try to stay put, or go somewhere else? And if the latter - where would you go? (I wouldn't go to Shrewsbury, for example. I mean, it's a lovely town and I loved living there, but I can't see it being a hub of civilisation.)

Pandemics can (and sometimes do) kill 99% of a population (whether you're talking about rabbits or cockroaches or the unfortunate indigenous peoples of North and South America who caught smallpox, etc. from European invaders).

I totally agree with you, Hoo. I'm just not sure that I would deserve to be one of the few survivors. I can live with that. My life has been pretty good, and I have few regrets.

Heck, we would only be able to feed four billion if the technology for making nitrogen-rich fertilizers had not been developed in the 20th century. (I read that somewhere. I hope my source was correct.)

" I'm talking about a BIG dieback. I'm talking about a situation where only one out of every THOUSAND people is left alive." [Hoovooloo]

A lot of apocalypse scenarios are that drastic, and I'm sure there are good reasons for thinking that an actual apocalypse, when it comes, will reduce the world's human population well below one billion. Going lower, to maybe 100 million would give the Earth's environment to recharge and recover. That's all for the good.


But it's not what I had in mind when I speculated about going up to 15 billion and then down to 6 billion. Anybody can speculate. How is one person's speculation better than someone else's, when the proof of accuracy lies decades or even centuries down the road? We're not trying to *make* things turn out a certain way. We couldn't do that. Neither are we trying to score points by being the one who got the most accurate answer. We're going to be dead! What reward would we get for being right?

I have quite a lot of humility, really. I'm going to be wrong lots more times before I shuffle off into the sunset. Therefore, since I'm almost certain to be wrong anyway, how would it hurt to at least be wrong in an interesting way? Or a different way from those around me? If you have a group of people who all know the same things, or think the same way, you probably have a pool of ignorance. Perhaps there's some advantage in being the one who *didn't* assume that that large, hungry snake lying n your path was just a harmless vine.

Let me be different, even if you're certain I am wrong. The history of predictions has been upended time and time again by game-changers. I don't want to go of-topic by making a very long list of them, but they're out there. Our predictions will be foiled at least once and maybe more times by some game-changer.

If predictions have such a poor chance of turning out to be right, wouldn't it make sense to aim for the recovery agenda to be applicable to as many different scenarios as possible?

The back-stop recovery agenda is evolution.

Amen to that.

Perhaps we could write a series of recovery books for different possible futures? These could be more precisely tailored on particular conditions. To make them as useful as possible, we could print them in the five or six most widely-spoken languages in the world, and send copies to *everyone* currently alive, with instructions to keep them where future generations could find them.

Even with those precautions, chances are not many will have access when the books are needed. But if even a few copies survive, chances are they might be read by a lot of people.

"how would it hurt to at least be wrong in an interesting way? "

It wouldn't. But I'm respectfully suggesting that "what if there were only six billion people in the world?" is *not* an interesting question. We know what it would be like if there were six billion people in the world - that was the world population in 1999.

Possibly marginally more interesting is "what if there were 15 billion and it suddenly dropped to six?", but even that doesn't strike me as posing any particularly interesting challenges. If anything, going suddenly from 15 billion to 6 billion would be a pretty much unalloyed good thing for most of the 6 billion. Given how much most of modern tech is automated, I'd be surprised if there was any noticeable difference from the loss of nine billion lives, apart from less crowding. Infrastructure would breath a sigh of relief but carry right on working as before.

Drop the population to 6 MILLion, worldwide, however, and life for many of them becomes nasty, brutish and short. *That*, to me, is an interesting question in recovery. Drop the population that much and there's nobody to mine the coal, pump the gas, refine the petrochemicals, operate the power stations, purify the water, do so much of what we take for granted.

Like I said - Thanos's plan in Infinity War always seemed comic-book simplistic to the point of being wrong, simply because the population of earth has DOUBLED in MY LIFETIME. Getting rid of half of all life means, oh, it's 1969 again, big deal. My prediction would be that immediately post-blip (assuming the Avengers didn't fix it) there'd be a baby boom and we'd be back to seven billion a good deal quicker than we managed it the first time, because we'd got so much more agricultural and informational infrastructure already in place, plus new tech like GM foods and IVF that weren't around in '69. With half the population still here, assuming a random cut, you've still got basically everyone who understands how everything works, more or less close to where the things are. Do a more savage cut, and just the logistics of getting the right people where they're needed becomes an issue.

Sorry, going to correct you again Paulh - thanks for not taking it personally - it's not easy to be told you are incorrect. Respect for that - I don't like it either

>Pandemics can (and sometimes do) kill 99% of a population (whether you're talking about rabbits or cockroaches or the unfortunate indigenous peoples of North and South America who caught smallpox, etc. from European invaders).<

No they don't. It's *much* less than that. The worst disease ever to hit humanity is probably the Black Death and that was half the population even in the worst hit places. In total number the 1918 Spanish Flu could also be described as that and that was only about 20% of the people infected who died. (that's a MASSIVELY bad disease).

Think about how Ebola works - it's so darn deadly that it wipes out everyone in the local area. That makes it actually terrible at spreading as it creates a dead zone around it and then it dies off itself as it runs out of hosts. A disease is an organism like anything else, it will evolve to be less virulent so that its own population can increase more. Not a conscious process of course, just what happens in evolution.

The very worst mass extinction in Earth's history is the Great Oxygen Catastrophe - about 2 billion years ago. That killed (it is estimated) about 98% of life - but we're (well by bod we hope) not looking at anything that drastic. That's actually an interesting one as that was when photosynthesis began and the only things that survived were those that could rapidly destroy that toxic-deadly chemical - oxygen gas. Now of course, we descend from them and rely on it
A worst-case scenario currently is that methane-clathrates deep in the oceans (that's frozen methane-water mix) get released explosively due to global warming and lead to a runaway greenhouse warming. There's certainly enough of it down there and its' what's thought to have cause the (iirc) Cambrian mass-extinction that led to pretty much all land based life dying and life had to re-evolve out of the sea again (about 95% of life wiped out in that one). Both of those were waaaay worse than the one that wiped out the Dinosaurs.


Anyway, I digress. Population would undoubtedly die off drastically under an apocalypse scenario. Our population is only sustained but things like factory farming - using plant manufactured ammonia and such to provide enough fertiliser for our food crops. A big city would start starving in days due to lack of transportation of food and then it would be followed up by there just not being enough food. This would happen quite fast. I have no idea about an accurate estimate of population drop off either, but I think the ball park would be pretty much what Hoo is saying.

I purposely didn't get too interested in the mechanism of getting from here to population x 0.001. There are plenty of ways of doing it, as stated, but again, the details hold no particular interest to me. Mostly if you start discussing it you immediately and inevitably start to argue ways round it to explain why in fact it would NOT wipe out 99.9% of people. Much better, for my purposes, to flat out state that the Event - whatever it is - has happened, and take it from there. What are the immediate challenges? Shelter, water, food etc. are reasonably easy if you assume the pre-existing infrastructure hasn't gone anywhere, and assuming also that you're fortunate to live somewhere nice (e.g. England) and not somewhere intensely inimical to human life (e.g. quite a lot of the rest of the world).

But once you've addressed the immediate basics, what's next? What SHOULD be the priorities, if your ultimate goal is getting back to a 21st century level of tech? And how long, realistically, would it take?

My guess would be that it would be measured in centuries rather than decades, but not millenia - I reckon two or three hundred years. I have no hard data to back that, I just can't see how you could do it in much less and don't feel like it could take that much more.

Hi, Orcus.

You're right about the Black Death die-offs, as far as I can tell. What I was talking about withb the post-Columbus die-offs in North and South American was probably 90% or more. Some estimates of the population there are as high as 90 million, which became maybe 9 million. A die-off of 90% We will never know the exact numbers for sure, so there will probably be plenty of discussion for some time to come.

I've heard of rabbit populations dying off by up to 99% due to some virulent disease. The populations recovered eventually.

Thank you, Hoovooloo.

Having recovery take centuries but not millennia sounds about right. I read somewhere that the eruption of a volcano in the Mediterranean around 1600 B.C. set civilization back 1,000 years. We now know that civilization did get back on track, though with some bumps along the way (the Dark Ages, the Black death, etc.).

I enjoy reading about biology and history. Throw in science fiction, and my mind has gotten kind of crowded. (I won't let that stand in my way, though ).

Others have suggested fictional accounts of post-apocalyptic times. Maybe "City of Ember" would resonate here. The City of Ember was buried deep underground to protect it from whatever apocalypse was taking place on the surface. There were all kinds of magnificent technologies there to keep everyone alive and get them back to the surface when all was clear. But.....generations passed and people didn't know these things. The original people died.

The apocalypse we are talking about here may not be sudden and then gone. Maybe it will take generations for the dust to settle. When it finally becomes possible for people to start recovery (whatever that will mean then), even the people who survived the first disaster may be long dead. I hope that language will not have evolved so far that no one will be able to understand the book we are writing, asusming that any copies have survived the apocalypse.

>I purposely didn't get too interested in the mechanism of getting from here to population x 0.001.<<

Sorry, can't help myself - that's what I get off on

Paulh - yeah that's a good point about the native US die off due to smallpox etc. (got their revenge with syphilis a little . However I think those figures are not-well supported. As you say, nobody really knows. Must have been a horrific holocaust to the native Americans

Ebola has a near 100% death rate in infected areas... but doesn't spread too far. It doesn't kill of 100% of people globally. Same scenario for the rabbit populations - might have been that locally, not the same as globally, that's my point.

(and sorry, yes I did say I digress - the question just got begged which is why I answered it - it is certainly peripheral so we should probably stop and reboot to the main tenet of the thread)

Here's a skill that it just struck me would be useful and very much not intuitive - beekeeping.

Amen to that.

Native bees are enough for agricultural purposes in some areas, though. North America managed without honeybees for about 10,000 years, though agriculture was minimal for much of that time.

Just sayin'

"North America managed without honeybees for about 10,000 years, though agriculture was minimal for much of that time."

Perhaps those facts are connected.

I've seen it said that the UK was unusually well placed to be the cradle for an industrial revolution because of a combination of temperate climate, fertile soils, relatively docile indigenous wildlife and *extremely* varied geology meaning easy availability of a very wide variety of ores and minerals. There's more geologic variation in Shropshire alone than there is in all of Australia, for instance.

I sometimes come across accounts of people earnestly trying to build up native bee populations (Mason bees for pollinating orchards, for instance) so that the die-off of honeybees won't doom the people who depend on pollination for their food supply.

Bees fascinate me. I have at least one book about bees native to different parts of my country. It astonishes me to see a field full of wild asters (or maybe they are Fleabane?) that have *all* been pollinated, for the seeds are blowing everywhere. The Mulberry tree in the back of my neighbor's yard must have thousands of blossoms every Spring (I don't even notice them, but the bees apparently do), all of which become plump, juicy berries later on. Icelanders have tried (often without success) to import honeybees, but there are four native species of Bumblebees already there, doing their work.

There are harbor islands offshore form Boston, and many or them have sixty or seventy different species of bees. How did the bees get there? probably form the mainland, though they must have flown a mile or two, which is theoretically hard if not impossible for small bees to do.

But then, by our standards, it ought be aerodynamically impossible for bumblebees to fly at all.And yet they do!

You'd be amazed how easy it is to fly a mile if you've got a tailwind and even a little bit of altitude.

I'm glad to hear that.