Suppose, through some biological disaster, humanity is basically reduced to a population of a couple hundred thousand naked monkeys strolling about the globe. At that point it’s unlikely anyone will reinvent the technology or that there will ever be enough thumbs to come close to maintaining an entire city. So stuff falls into disrepair, nobody puts out fires, etc. because they’re all too busy getting their next meal and enough firewood to last another night.
How long till a place like New York, London or Sydney is transformed into an unremarkable hunk of natural landscape? How long would those odd mounds yield evidence of having been constructed (let’s say the squirrels evolve and develop sonar/radar gizmos that can peak a short distance underground).
As a follow up, let’s throw in another pleistocene-style period of glaciation–would that effectively grind NYC into some odd but unperplexing mineral deposits?
Incidentally, if there are more than 200,000 people still living and there’s no effect on those survivors’ basic physical and mental health (and, as I think you’re saying, there’s no change to the physical infrastructure of civilization), they eventually will rediscovery the technology and build it back up to the present level.
Such a change would be gradual, and take place over thousands of years. It’s possible that New York would be slowly abandoned as the climate changes, and new economic centers emerge. Consider Rome after the fall of the Western Roman Empire and Detroit.
The remains of New York, Montreal, Boston, Toronto, and other cities, towns and villages would be absorbed into the oncoming glacier, and deposited along the landscape as the glacier recedes. There will probably be relics galore for the archaeologists of the next interglacial period.
A good place to see what would happen is the ruins around Chernobyl (since many towns were left undamaged but had their population wiped out/scared off by the high levels of radiation). I watched a documentry on exactly this topic a while back, but not a lot sank in.
That’s debatable. Some people feel that since all of the easily available resources have already been tapped, if our present civilization falls no technologically advanced culture will ever again be able to arise. They won’t be able to get what they need to bootstrap themselves up.
I would also recommend the book ‘The World Without Us’. Among other things the author talks about several city’s that have, for one reason or another, been abandoned.
Possibly related: I saw a show on PBS once on climate change. At one point they mentioned Angkor Wat, and how it was once part of a relatively huge city at one time. They then go out into the surrounding jungle where parts of the former metropolis can still be seen.
They basically overextended themselves and the whole city collapsed.
Hmm, I’m not sure I buy that. Sure, we’ve already used up lots of readily available energy sources. But the biggest pre-industrial (and early industrial) supply of energy was firewood. We’ve destroyed the vast majority of forests, but that’s mostly through clearing and maintaining land for agriculture or other uses. In a few hundred years, forests will grow back – at least enough to run a small steam-powered civilization until they rediscover coal or wind and solar power.
Furthermore, unless the OP is claiming that some sort of disaster has wiped out every book in the world, the present state of knowledge will still be there and can be recovered. Indeed, the knowledge available on computer media can be recovered (again, unless the OP is claiming that some particular disaster has wiped them out). If this disaster that wipes all except about 200,000 people happens were to happen right now, there will be plenty of oil and coal for them to rebuild civilization for a few decades before they have to switch to renewable energy. I think 1/3000-th of the present population can live on the remaining resources for a while.
Food sources. Survivors vastly better off than early humans due to widespread availability of a staggering variety of re-domesticable plants and animals. Some food types would be lost, but virtually no place on earth would be limited to the crop types they were limited to historically. I’d expect they wouldn’t lose agriculture entirely to revert to pure hunting and gathering. They’d be gardening and herding from the start.
Tools. Survivors even more vastly better off than early humans than in the first case. While easily available metal ores have indeed pretty much all been tapped, the metal they contained hasn’t been destroyed. It’s even easier for our survivors to obtain than the shallow mines of early history - pop into the ruins and do a little scavenging. Lots of it is even in the form of tools. But even if it weren’t, basic blacksmithing isn’t all that difficult. Though one does need:
Energy. In history, this meant firewood and, for metalworking, charcoal. Here our survivors might be in a bit of a pickle, but if the population has been diminished enough they’ll be fine. Forests will regrow. It’s not like primitive civilizations didn’t occasionally deforest a location to the point where their cities collapsed - obviously civilization as a whole can recover from this sort of thing. Eventually they’ll get back to coal mining, which shouldn’t be horrendously problematic as there’s still lots of it out there. They’re going to be SOL on petroleum, though.
Information. Depending on the timeframes involved, possibly very well off indeed. It really depends on how quickly they can get back to agriculture with sufficient food surpluses to support specialized labour. If they’re all generalist subsistence gatherers, I’d expect literacy to be threatened within a couple generations and then they’d have to more or less rebuild the knowledge base from scratch. Could take millenia. On the other hand, if they can maintain literacy and save a library here or there, well, that’s a whole different deal.
I do not understand the question. There is evidence that the entire human population almost died off and had only 5000 people. Those 5000 people managed to turn into us…I am sure we will mange. We also would have a huge jump start because we would not have to invent that whole language thing or maths or many other things.
Also at current rates of consumption the US can go 200 years with what coal we have.