The Future of Cities

Re your comment about future farmers coming out of cities and suburbs rather than being born on and inheriting the farm: I wonder if this might not be an advantage in the future? I suspect they might be much more open to new technologies (i.e. equipment and ways of doing things) than the old traditional farmers. Old-time farmers were in general strongly reputed to be very conservative and traditional, slow to adopt new (i.e. better) ways of farming. Now I know I'm operating from a stereotype, but from all that I've read, there was a lot of truth to it, in part for good economic reasons, given the variability in weather and economic circumstances. But the future may require greater adaptability, willingness to change, which perhaps these urban farmers may exhibit more freely. Anyway, it's an idea that occurred to me as I read your piece.

Thanks for the links to the old posts! I especially like "Reconsidering Cities," and especially this line:

"If not very many people lived there until air conditioning or until we stole water from somewhere else, that might not be so good."

I never thought about it in those exact terms before, but it's an excellent point.

"If not very many people lived there until air conditioning or until we stole water from somewhere else, that might not be so good."

I never thought about it in those exact terms before, but it's an excellent point.

Guess you never thought much about Phoenix, Az, then.

My take on cities is that they'll turn into death traps, for a variety of reasons, such as:

People will starve en mass once transportation infrastructure breaks down.

Population density will allow water & rat borne disease to become rampant once sanitation infrastructure becomes defunct.

Some of the major cities will end up being nuked as famine induced social unrest escalates.

Cities will be plundered by the undisciplined armies of marauding warlords.

Population collapse impends & cities won't be the place to look for any survivors, if there are any.

Sure, because no-one lived in cities before the advent of cheap oil... Except for, you know, all those people living in cities for the last 7,000 years or so.

Cities aren't going anywhere. OK, some cities are, but the concept of the city in general is not.

What are all those millions of northern Europeans living in high rise flats going to do in winter when the Russian natural gas runs out, Dunc? After all the furniture has been burnt, I mean.

Be cold and not freeze to death, realistically. Seriously, DD, there wouldn't be any human beings if we couldn't live in sheltered places without heat. That said, one of the major concerns I have about cities is the fire danger of cold climate cities not prepared to adapt. But they are hardly likely to *all* burn down.

The most important point is that there are cities and cities - there's Pheonix, which just plain doesn't have enough water to support its population and will have to get a lot smaller (and cities do this even without nukes, consider the history of Buffalo and Detroit) and then there's a city like Portland ME, with a major ocean port, agriculture within the city limits and enough elevation that at least part of it should survive climate change.

Cities ain't just one thing.

Sharon

I'm not saying there aren't going to be big changes, I'm just saying that urban living in general has a long history and it's not going to disappear.

And high-rise flats are so 1960s... The few that are left 'round here are all being pulled down anyway.

Well said, DD. Tribal living arrangements may be all we will be able to keep together.

With a few notable exceptions, the world's great cities are located along sea coasts. Where are all those urban refugees going to go when the West Antarctic Ice Sheet abruptly collapses and sea level rises nine meters or so over the span of but a few years? 18K yrs BP sea level was 120 m lower than today. A 9 or 10 m further rise isn't much, not even along with that much again due to thermal expansion, Greenland's contribution, and the loss of virtually all mountain glaciers outside the Arctic & Eastern Antarctic. A 20 m or so marine ingression isn't much, except that it's sufficient to inundate all the coastal cities, driving billions of refugees inland. I have a painting I stole off the internet of a baleen whale and her calf serenely swimming near the surface, seen from below, with the top of the Empire State Building in the foreground. Maybe those in Upstate New York, struggling to survive themselves on human powered subsistence agriculture, can kindly accommodate the hordes of desperate, clueless climate refugees & ghetto toughs that come prowling around looking for something - anything! - to eat. Maybe Sharon can "pass the cup, pass the ladle, pass the plate to all who hunger.." as Tull puts it, when that day comes. Maybe you Brits can simply rebuild London in the Pennines or Scottish Highlands, then.

By the same token, what am I going to do when I catch kids from the trailer slums up the ditch or from the extensive newer and extremely cheaply constructed apartment complexes nearby, down in my woodlot with hand saws & hatchets, stealing wood to drag home for mama to cook their frijoles with? Or down there with slingshots & BB guns intent on poaching a rock squirrel or Gambels quail? Do I shoot them? Do I attempt to befriend them, feed them, even arm them perhaps, in the hope that they will help defend the neighborhood when troops of truly dangerous bandits show up? Ooops, probably won't be able to feed them once the ditch quits flowing.

Often I get the impression that people haven't thought through the implications.

Abrupt collapse of the WAIS? Not entirely beyond the bounds of possibility, I'll grant (for suitably geological values of "abrupt"), but it's a long way towards the tail of the probability distribution. (By which I mean "about as likely as a complete collapse of the thermohaline circulation"...) And even if it does, it's only good for ~5m of SLR. I wouldn't hold your breath waiting on that one.

Don't take this the wrong way DD, but from what I've observed of your comments elsewhere on Sb, you'd do well to say less about AGW, as you don't appear to understand it very well.

Still, if it's hot enough for the WAIS to collapse, we're probably not going to be as worried about freezing to death, right? If you want to make apocalyptic predictions, it's probably better to just pick one apocalypse and stick with it.

It's true that I'm not a climatologist, Dunc. Not sure if I've told this story before on here, but about ten years ago I received an email asking my opinion about the impact on the Peruvian anchoveta fishery of the collapse of the West Antarctic Ice Sheet. I was like, "wtf, what do I know about the Peruvian anchoveta fishery or the WAIS, either one." But wanting to be helpful, since I was asked, I did some reading.

See, for example, West Antarctic Ice Sheet collapse â the fall and rise of a paradigm [David G. Vaughan; Climatic Change Volume 91, Numbers 1-2, 65-79; August 2008]: "Only a few glaciologists consider it likely that complete collapse of WAIS could occur in less than a few centuries, although most agree that a thousand-year timescale for collapse is possible (Vaughan and Spouge 2002)."

I've just posted a link to a recent study on the topic, but it's stuck in moderation... Summary: "abrupt" in this context means at least several centuries.

(For your Googling pleasure: "West Antarctic Ice Sheet collapseâthe fall and rise of a paradigm", DG Vaughan - Climatic Change, 2008)

What I discovered was that the WAIS rests on unconsolidated glacial till on the sea floor, and that it has collapsed & reformed repeatedly over the course of the Cenozoic. How close to collapsing it is today is anyone's guess but when it does collapse it does so rapidly, over the course of years to decades. When sea water infiltrates beneath it, it floats free, breaks up & the fragments drift northward & rapidly melt. While it's true that no one knows when this may happen again there are plenty of troubling signs that it may happen sooner rather than later. Floating ice shelves attached to the ice sheet are collapsing. The loss of these ice shelves, per se, don't contribute to sea level rise but may contribute to the ice sheet's stabilization. Also, coastal glaciers are surging to the sea, contributing, along with sublimation, to net mass loss. And the temperature of the southern ocean is rising. I don't know how imminent the collapse of the WAIS is but there are well regarded climatologists & glaciologists who are worried about it, and you don't know that collapse is unlikely anytime soon, either.

The WAIS has collapsed in the past when the mean temp. was only a few degrees C warmer than it is today. It's specious to claim that given a lack of affordable heating fuel people in northern Europe won't be freezing in winter since it's warm enough for the WAIS to collapse. You know this.

Collapse of the WAIS undoubtedly would have an effect on the thermohaline circulation of the southern Pacific but just how that effect would impact the Peruvian anchoveta fishery is too complex & contingent for me, or anyone else, to have a cogent opinion about, so I couldn't help the person who emailed me about this very much. Btw, when I did this reading there didn't seem to be much concern about the East Antarctic or the Greenland Ice Sheets contributing much to rising sea level. Since this time the GIS, at least, has shown an unexpected amount of mass wasting, the point being that as time goes on it becomes increasingly clear that sea level is rising at a more rapidly accelerating rate than anyone would have predicted only a decade ago. It's becoming clear that IPCC estimates have been understated.

(Sorry for this comment appearing as two posts. I hit "Post" instead of "Preview.")

Thanks for a more recent reference about the WAIS than I read ten years ago, Dunc. That ice sheet dynamics are more complex than initially realized comes as no surprise. It was especially interesting to read in the abstract: "In the last few years, however, satellite studies over the relatively inaccessible Amundsen Sea sector of West Antarctica have shown clear evidence of ice sheet retreat showing all the features that might have been predicted for emergent collapse. These studies are re-invigorating the paradigm, albeit in a modified form, and debate about the future stability of WAIS." Perhaps the WAIS won't collapse in one piece, after all. Perhaps the Amundsen Sea sector will go first, destabilizing the rest of the WAIS which will then rapidly follow course. In any event, it's clear that concern over the stability of the WAIS is warranted.

Coastal cities are at risk of inundation whether the WAIS collapses or not. The IPCC predicts a "plausible" increase of .8 m over the course of the 21st century, with a "theoretical maximum value" of 2 m. Even a .8 m increase will put major infrastructure stresses on coastal cities, stresses nations can ill afford during times of economic hardship and fossil fuel depletion. The problem with these estimates is that they most likely understate the degree of sea level increase that will occur, by failing to take into account positive feedbacks that have already, are being, or soon will be triggered. Hence, these estimates are almost certainly overly conservative. It behooves people living in coastal regions to prepare for sea level increases in excess of current predictions - and such preparation may involve getting out while the getting's good. And if the WAIS does collapse, it will be all over for these regions.

For urban areas, how about calling those "right to farm" laws "right to EAT" instead?

I concur that us city dwellers will not all become a rioting cannibal zombie horde needing to be nuked by the PTB. First, there are hundreds of millions of hungry and even starving people in the world today, and even when they are together in large groups, as in refugee camps, they do not generally run amuck like vicious animals (okay, the Rwandan genocide excepted). Generally speaking, malnutrition makes one weak and apathetic, so sufferers don't make a good horde even when an outside observer can see that killing and eating the nearest rich folks would be righteous.

Second, your average small-town resident doesn't produce much more of the goods he personally consumes than I do. If I and my neighbors were "starving en masse," a lot of good rednecks would be starving in small groups - and just as in the Depression, food distribution to the cities would be prioritized both because it's easier to set up bread lines for dense populations, and 'more importantly,' because that's where the powerful people live. Yeah, our crime rate now is higher than in the countryside and will continue to be, but I doubt that the rate of outright banditry will escalate faster among us because we will already have a dominant gang in place (e.g., the NYPD or LAPD, which are well armed and numerous enough to resemble a third-world army battalion, and often behave like it).

A few thoughts on the apocalyptic scenarios.

I know quite a few people now, who have been to cities where the relevant countries were in the middle of a full-scale war. Civil war, in some cases. The kind where you read about bombings all the time. (Yeah, these people are reporters for the most part).

One of the things you notice is that life for the most part seems remarkably normal. In Beirut, for instance, as I was told it, people still went to the market, people still drove to work, people still put their pants on one leg at a time.

During WW II, if you were walking around Paris, you would have been able to have coffee in some fine cafe's throughout the war, and would only have noticed the ration cards occasionally. In Germany, things didn't get crazy until the troops showed up, and even then not every city was a bombed out wasteland. (And it should be noted that the bombs were dropped beforehand). Had you lived in Prague, same thing. The civil war in Spain did not result in starving hordes killing each other.

In Northern Ireland, people weren't getting shot every day. In Southeast Asia, even in war-torn Vietnam, it wasn't until very late in the game you'd have noticed the war. The combat scenes were all outside the city in the countryside until 1968-69 at least.

And during the Depression, with 25% of the whole working population out of work (a much higher percentage than now) taking out a third of the dollars in circulation, with people going hungry everywhere -- nobody went in for banditry all that much. The closest thing we had to the apocalypse was the bonus Army march on Washington. And that was primarily because the future General Douglas MacArthur disobeyed orders and decided to shoot folks. (He was only a Colonel then, I think, and should have been cashiered).

What about countries that are really starving? In Ethiopia, at the height of the famine, the cities were actually okay. It was the countryside where the bloated kids with bellies were. Simple enough, really; a combination of war and the rural transport links getting broken, and no spare parts or fuel for the farm machinery was getting there.

In all of these cases society had major disruptions to deal with. Usually war, but that's a pretty big one.

So I think, any collapse will be a mite slower than that in the movies. Rome fell, and it wasn't like you got up one morning and said "Hey, the Empire is gone!" It took a good couple of centuries at least. If you were there at the time you'd not have noticed -- it would just be daily life and politics as usual.

I dunno, dewey, "..a rioting cannibal zombie horde needing to be nuked.." describes the gangs of East St. Louis pretty well already, unless things have really changed since my days in the Midwest.

Isn't it the case that the majority of humans live in cities, and that the percentage is increasing?

What strikes me, Jesse, is what you exclude. Like Leningrad, 1943, when a million and a half died and another million and a half were made refugees, most of whom died later. Or Warsaw, that same year, when nearly half a million Jews & Romani starved, died of typhus, were killed outright or sent to Treblinka to be murdered. I notice that you fail to mention the fire bombing of Dresden and Hamburg ("..not every city was a bombed out wasteland"). Hiroshima & Nagasaki you leave out, too. Then there was Rwanda, 1994, of course.. And that's just the past 70 years or so..

Heck, to hear you tell it, genocidal warfare sounds almost pleasant. So long as the cafes stay open & ordinary people can still get a coffee, guess everything's cool, right? Just pay no attention to the corpses piling up. Things could be worse. At least no one is eating anyone else, at least not around here, at least not today.. Guess we can all relax.

darwinsdog, the point I was making is not that genocidal warfare is pleasant. Just that as often as not, the process of collapse is not terribly noticeable as you are going through it.

ANd yes, there are plenty of examples of cities that were bombed out ruins. The point is not every city has to collapse that way. Saying X doesn't always happen Y way is not the same as saying Y way never ever happens.

And all of the examples YOU cite are huge, relatively sudden cataclysms. They aren't really collapses of the kind posited for our civilization. I stand by the statement that it would if anything resemble the fall of Rome more than the siege of Leningrad. Rome's collapse took a long time.

Heck, look at the Easter Islanders. IT wasn't like the movie "Rapa Nui" where one melodramatic day the last tree was cut down. Odds are nobody noticed what was happening at all. Until it was rather too late.

What strikes me, Jesse, is what you exclude. Like Leningrad, 1943, when a million and a half died and another million and a half were made refugees, most of whom died later.

And yet it's still there, isn't it?

To re-interate my earlier comment: "I'm not saying there aren't going to be big changes, I'm just saying that urban living in general has a long history and it's not going to disappear."

Cities, wherever they are created, will be the future of humanity, but not like the cities we have now. The cities would be more like the urban permacuturists of the Amazonian Basin in pre-contact times. Ubanism in the current context implies asphalt, concrete and orders of activity far removed from the production of our basic needs, but we are living in a time when cities can be the way they are, and not because cities are the way they must be. Verticle farms for vegetables and animal protein are the kinds of solutions that imply carefull management of the processes to fully capitalize on the advantages and resources that cities inherently have; proximity to labor and markets, access to transportation, energy, and the skills of management to organize necessary activities.

#21:

And all of the examples YOU cite are huge, relatively sudden cataclysms. They aren't really collapses of the kind posited for our civilization.

Who says? Posited by whom? Complex systems often totter along as interactions between stressors accumulate, until some, often minor, event triggers abrupt collapse. This is the scenario I and many others posit in terms of human population dynamics.

Heck, look at the Easter Islanders.

I've been looking at them riot as the Chilean government attempts to turn their island into a theme park. Then again, if food wasn't shipped & flown into them, they'd likely be extinct by now.

#22:

And yet it's (Leningrad) still there, isn't it?

Well, Sankt Peterburg is there but not so sure about the "still" part. The modern city was built, using fossil fuel energy, and populated after Leningrad had been depopulated and destroyed during WW2.

I think that people fall into the trap of assuming that the future will largely follow the examples of the past. This view discounts the facts that human population is immensely greater than it ever has been, environmental degradation has largely destroyed the carrying capacity of the biosphere sans fossil fuel inputs, and that fossil fuels are rapidly being depleted and will be unaffordable or unavailable in the future. Because collective human enterprise was able to accomplish something in the past doesn't guarantee that it will be capable of doing so in the massively resource base degraded future.

If you want to know what a post collapse city looks like, read "The Gangs of New York", which is actually a non-fiction book about what the city was like from pre-revolutionary times until modern times. It was a festering hell hole ruled by thugs, where the line between government and organized crime was non-existent.
Or go into any of the shanty towns in any "developing" country in the world. Unless you were/are one of the rich elite, its a dirty, dangerous way to live.

It (New York City) was a festering hell hole ruled by thugs, where the line between government and organized crime was non-existent.

So what's changed?

And that was with a much smaller population, when people were used to living that way. They had horses and sailing ships and river barges that didn't require gas. Kitchens were equipped to cook with fire without burning down. We've forgotten a lot.

I recall an article in Scientific American, many years ago, about survival and functioning of cities bombed in WWII. The thesis was that the cities kept functioning much better than one would have thought. I don't recall which cities were studied. I've been to Hamburg, and saw no sign of it having been firebombed. Only city where I saw any real evidence of WWII was in the former East Berlin and surrounding countryside.

Because collective human enterprise was able to accomplish something in the past doesn't guarantee that it will be capable of doing so in the massively resource base degraded future.

Fair enough, but if you want me to believe that our most successful form of social organisation is going to disappear, you're going to have to provide some pretty solid arguments in favour of that idea. "You can't prove it won't" is not a convincing argument.

I think that people fall into the trap of assuming that the future will play out in basically the same way everywhere - and it always happens to be whichever way best sits with their own preferences and prejudices. The future, like the past, is going to be complicated.

..our most successful form of social organisation ..

People have lived in cities for like, what? Three percent of the time since speciation? 8K yrs out of 250K yrs, or thereabouts? Not sure how that qualifies as "our most successful form of social organisation (sic)." In fact, before a certain minimal population density is reached, communicable disease can't propagate. In a very real sense, epidemic communicable disease is an artifact of urbanization. The same can probably be said of slavery. I'd call the extended family or clan in a foraging/scavenging society "our most successful form of social" organization. This was a viable way of life for a couple hundred thousand years, compared with less than ten thousand years of diseased city life.

In ecology, when a new species rapidly displaces an existing species which has been around for a long time, which would you consider more successful?

Oh, and I also notice that you're using your assumption that urban living is over ("less than ten thousand years of diseased city life") as an argument in favour of the idea that city living is over. That's blatant circular reasoning. We don't yet know how long city living is going to last.

"In ecology, when a new species rapidly displaces an existing species which has been around for a long time, which would you consider more successful?"

City man, Homo citifus, displacing tribal man, Homo tribalus. Yes, I think I read something about that somewhere.

In ecology, when a new species rapidly displaces an existing species which has been around for a long time, which would you consider more successful?

The only rational, non-arbitrary criterion for assessing "success," in this context, is Darwinian fitness. A long established species is likely an integral component of the ecosystem it functions in, and its coevolutionary integration contributes to the stability of that ecosystem. An invasive species may rapidly displace an established species and thereby enjoy enhanced fitness but this fitness intensification is liable to be short lived because such rapid displacement is likely to destabilize the ecosystem, leading to less than optimum ecosystem functional efficiency and reduced fitness for all components besides saprophytes. It may even lead to ecosystem collapse. Invasive species typically proliferate for awhile before going locally extinct.

By analogy, if not homology, to human societies, a tribal foraging/scavenging culture maximizes fitness over the long run by maintaining its population at or under the carrying capacity of the ecosystem it operates in and partially comprises, doing nothing to destabilize said ecosystem thereby precipitating its own demise. A culture that devises an innovation such as practicing agriculture, taking slaves, living in cities.. may well obtain for itself a magnified fitness - but not for long. Such intensified reproductive success results in carrying capacity overshoot and consequent ecosystem and population collapse. Over time, the most "successful" strategy is the one that maximizes fitness by maintaining optimum ecosystem functioning & stability.

Hence, tribal foraging/scavenging societys' persistence over hundreds of millenia. Hence, urbanization is seen as an inviable social & ecological pathology contributing to carrying capacity overshoot and consequent population collapse towards extinction - the ultimate "failure" in terms of fitness.

Shorter darwinsdog: "I think urbanisation is doomed because I think urbanisation is doomed."

You can't use your prediction of collapse as supporting evidence in your argument for collapse: it's circular reasoning. Also, I note that your first para rightly contains a number of hedges and qualifiers ("liable to", "likely to", "may even") whereas your second para does not. Given that it's an argument by analogy, it must be at least as uncertain as the example it's based on.

Anyway, I see no point in continuing with this. You're clearly unwilling to even consider the possibility that your chosen scenario might not be both perfectly accurate and universally applicable, and from experience I know that arguing with such a position is futile.

Still, at least you're able to recognise an analogy when you see one, unlike Mark there... ;)

Shorter Dunc: "I think urbanisation is eternally viable because I think urbanisation is eternally viable."

Review my post #3 for a list of reasons why I think living in dense clusters is inviable Dunc. This list only scratches the surface, of course. Nothing circular about it.

Those are all arguments which, if true, would have prevented us from ever developing urbanisation in the first place (well, except for "Some of the major cities will end up being nuked as famine induced social unrest escalates", which just looks like a blatant non-sequitur). Given that we clearly did, I must conclude that they are not entirely accurate. We know that it's possible to build cities without the use of fossil fuels, because we spent over 7,000 years doing it.

Now, if you're arguing that the complete extinction of the human race (or something very close to it) is inevitable, then sure, urbanisation goes along with it. My position is simply that, short of near-complete extinction, people are going to keep organising themselves in whatever ways best serve them. In some (but not all) circumstances, that involves at least some degree of urbanisation. People in the future will build cities for exactly the same reasons the ancient Mesopotamians did, and with at least as much success (probably more, since we've learned a thing or two since then).

As for sanitation systems breaking down - do you realise there are cities in Britain which are still using sewers originally built by the Romans? And that it is actually possible to build and maintain this stuff with nothing more sophisticated than picks and shovels?

I'm perfectly happy with the idea that many individual cities will disappear for one reason or another - that's just history - but the idea that humanity as a whole will abandon the concept is absurd. People have gone to incredible lengths to build cities in the past, and I see no reason to believe that our fundamental motivations will change to such an extent that we will stop doing so in the future.

As long as there are people, there will be agriculture. As long as there is agriculture, there will be cities.

You know, Dunc, when you say things like, "Shorter darwinsdog: 'I think urbanisation is doomed because I think urbanisation is doomed,'" you remind me of creationists who claim that selection is tautologous because, "Some organisms have greater reproductive success because they're the most fit, and they're they most fit because they have greater reproductive success." This is ridiculous, of course, because the most fit organisms have greater reproductive success by virtue of them happening to be better adapted to the constraints & opportunities provided by their environment, than are their competitors. What these constraints & opportunities are can be investigated and quantified, as can the adaptations to these parameters the organisms possess. Likewise, it isn't that 'I think urbanisation (sic) is "doomed" because I think urbanization is doomed,' it's that I think living in situations that rely on food and other resources trucked in from elsewhere is inviable on account of the reasons I've repeatedly listed, as in post #3 above, and elsewhere. Since I have listed these fatal drawbacks to clustered living in an energy constrained future, your charge of circular reasoning is as specious as similar charges leveled towards selection by biblical literalists.

Also, I note that your first para rightly contains a number of hedges and qualifiers ("liable to", "likely to", "may even")..

Is this what bothers you? That I write in a declarative style and don't often bother to qualify my statements with weasel words? It goes without saying, or ought to, that the future will be complicated, that circumstances will unfold in different ways and at different rates according to local or regional happenstance, as you say, at least at first, and that relict populations may well huddle down in the ruins of once great population centers until these populations become extinct. If you want me to concede all this, I'm happy to do so.

Given that it's an argument by analogy..

I wrote: "By analogy, if not homology.." because the comparison of humans in cities to deer on islands or rats in a cage is at least analogous, thinking this would be less contentious, more differential to population collapse denialists, less likely to be a point of contention, thereby making my argument easier to swallow by those frightened by it. Upon reflection, I realize that I shouldn't be such a wimp. The situation goes beyond analogy to homology. Humans are organisms functioning in ecosystems as much as deer & rats are. Human populations that exceed carrying capacity crash just as surely as deer & rat populations do. Heretofore, when human population has locally exceeded carrying capacity the situation often has been resolved by emigration. Deer on an island or rats in a cage don't have that opportunity. Now humans have expanded population globally, into all conceivable habitats. The Earth has become an island. Now when I speak of exceeding the carrying capacity of an ecosystem the ecosystem I speak of is the entire biosphere. The only way human population has exceeded the carrying capacity of the biosphere so massively has been by means of utilizing the potential energy of reduced fossil carbon. Mining of reduced fossil carbon deposits is entering into terminal decline, even as population continues to swell. Meanwhile, anthropogenic environmental degradation continues apace. The result is as inevitable for humans on Earth as it is for deer on an island & rats in a cage. Human population will collapse. It will collapse worldwide and as the collapse gains momentum cities will become death traps for billions. Any survivors, any relict populations, will be found in the tropics or subtropics of the Southern Hemisphere, living as dispersed foraging/subsistence agriculturalists, if there even are any survivors. The situation humans face goes beyond being merely analogous to deer & rats. It is the same situation.

I posted #38 before seeing your post #37.

People in the future will build cities for exactly the same reasons the ancient Mesopotamians did, and with at least as much success (probably more, since we've learned a thing or two since then).

We may have learned a thing or two since then (although this knowledge will likely be lost) but we have also largely destroyed the resource base the ancient Mesopotamians enjoyed. The floodplain of the Euphrates & Tigris was fertile & lush when Ur & Babylon arose, and the uplands were forested & full of game. Today the tanks rumble through a thoroughly degraded desert environment and the rivers are badly polluted.

Well, whilst I agree that the human population is highly likely to be quite dramatically reduced, I'm not yet convinced that it's going to collapse so completely and so universally as to render civilisation completely untenable across the entire globe.

It goes without saying, or ought to, that the future will be complicated, that circumstances will unfold in different ways and at different rates according to local or regional happenstance, as you say, at least at first, and that relict populations may well huddle down in the ruins of once great population centers until these populations become extinct. If you want me to concede all this, I'm happy to do so.

Yes, that's exactly what I've been getting at, only with the additional proviso that I'm not convinced that universal extinction is inevitable (in the short-to-medium term anyway - everything goes extinct eventually, one way or another). Concession accepted.

Nothing substantive to add to the conversation, just wanted to make the following observation -

Dunc appears to be a glass half full kind of a person here, which'd be all well and good if darwinsdog was a glass half empty kind of a person, but alas DD is more of a "glass, what glass? This here? This'll be a puddle in next to no time - and half full? This'll evaporate in the time it would take to evolve a twinkling eye." kind of a person. Which takes a bit of getting used to =p

DD - What is your basis for assuming that "any relict populations" after the apocalypse will be confined to the Southern tropics? If almost all humans magically vanished tomorrow so that "any survivors" were pretty much free to live a subsistence lifestyle wherever they could, much of temperate Eurasia is a heck of a lot better place to be a hunter-gatherer than central Africa or the Amazon jungle. There is not much big game now - nor is there in South America - but that would come back with time.

#41:

..alas DD is more of a "glass, what glass? .."

I'm a "the glass is about to be shattered" kind of a person here, Ewan.

#42:

DD - What is your basis for assuming that "any relict populations" after the apocalypse will be confined to the Southern tropics?

I agree that survival in the the tropics, per se, will be more difficult than in the subtropics or mild temperate zone, dewey. My rational for positing that relict populations will be limited to the Southern Hemisphere is:

1. The Southern subtropics are less densely populated, in general, than their Northern counterparts, and consequently less environmentally degraded.

2. I expect that strategic biological warfare and limited nuclear exchanges will be confined to the Northern Hemisphere.

Yes, but neither biological warfare nor limited nuclear exchanges would be expected to kill every human being on a continent, and there are plenty of places in both North America and Eurasia today where one could still make a living by foraging or pastoralism - in fact, where people would still be doing so if not for government coercion to settle. Those persecuted groups are usually in places remote enough that they are not high-value military targets, and they might experience a resurgence as the dominant culture that has suppressed their traditional lifeways destroys itself.

I don't expect biological warfare to be directed against people, except perhaps in numerically limited cases for the sake of psychological shock value. I expect staple cereal grains & soya to be targeted, rather. The loss of a given growing season's standing crop of rice or corn or wheat, for instance, would result in unprecedented famine. This famine would spark social unrest, lead to resource wars involving at least regional nuclear exchanges, the collapse of markets and trade networks, etc. Collapse of centralized government would release longstanding ethnic tensions from suppression, leading to Rwandan style ethnic violence becoming the norm. Collapse of sanitation services & medical care would allow communicable disease to become rampant. Foraging would become ubiquitous but not pastoralism. Grassland ecosystems have been almost wholly subverted to cultivation and livestock would be eaten virtually to extinction by the starving within just a few years. Trees, except in sparsely populated boreal & montane regions, would likewise be widely eradicated by fuelwood cutting. Already degraded ecosystems would be further devastated by desperate foragers combing them for anything edible or flammable, leading to their utter ruin & decimation of the biotia that form any survivors' resource base. A downward spiral of self-reinforcing ecological deterioration precludes any viable lifeway under such circumstances. Human extinction in the Northern Hemisphere will probably occur within a single generation or two or three at most.

In the Southern tropics and especially subtropics things shouldn't be quite so bad. Markets & trade infrastructure will break down but these regions won't be directly targeted with perhaps the exception of Argentine or Australian wheat producing regions. Ecosystems aren't as badly degraded, for the most part, south of the equator and there are even some aboriginal forager/subsistence agriculturalist cultures still functioning independent of the goods of civilization, in Irian Jaya & the Amazon basin. However, these populations will still be impacted by global environmental problems such as AGW & ocean acidification and will be isolated one from another prohibiting trade & gene flow. I expect such relict populations to persist for several generations before the consequences of rapid onset environmental degradation coupled with demographic stochastic events, such as Allee effects, to bring them down one by one. It's conceivable that these populations could persist indefinitely but I don't consider it likely.

It's said that the mean duration of species is about a million years. Homo won't last but a quarter of that period. The cleverness with which people released their population from natural constraints on its own growth constitutes our own downfall. The evolution of a hypertrophied cerebral cortex, of language & cultural transmission of acquired traits, mastery of fire, etc. - the things we are most proud of, in other words - must be recognized as supremely maladaptive in terms of persistent fitness. I guess it's pride or egoism that makes it so extremely difficult for most people to come to this recognition. And yet the truth of the situation is apparent.

Okay, I gotta go cut some firewood now...

Total extinction that soon would be letting us get off easy. I think we muck around in the ruins for a very long time, probably centuries, as a kind of cosmic payback for screwing things up so badly.

What about psycho-cultural aspects of high-density urban evolution? I live in a very urban center. I moved into my condo in 1988 and can't believe how it has changed since then. In 1988, we had GREATER diversity than today. In one jolly 49 unit building we had Industry people, academics, retired folks/white, black and latino/a minister and two top porn directors. NO ONE locked their apartment doors until bedtime because people were always popping in to say hello or borrow something or whatever (think Tales of the City). Then, in the 90's it began to change. Money became a bigger issue than ever before and folks began to cocoon. By 2000, the whole building was different: almost all white, wealthier, less creative, and socializing was limited to planned pool parties between 1 and 4pm on first Sun of the month. Now, no one knows their neighbor (few exceptions) and social time is limited to riding in the elevator together. A crisis is met, not with a rushing together to solve the problem, but "deer in the headlight, wtf" inactivity followed by finger pointing. In 1988, we could have overcome a lot more adversity and difficult change because we had each other and a different attitude. Today, I fear for the ability of the social group to weather change productively. WE has been replaced by ME. I assumed I would live and die in my little corner of la la land, but now I am making plans to retire out of state, in a more rural place. Me, Mr Urban Life is The Only Way, has become a convert to "see ya." I'm looking at lower density options far from the madding crowd. Am I just an older fuddy duddy? Has my POV become twisted by hindsight distortion and the crankiness of age? Or are the civic minded folks of yesteryear being replaced by more insular folks who are going to have to rediscover the kind of social magic required to make urban life good (and who may or may not be able to learn that lesson?) No technological advances can compensate for social disintegration which will destroy any urban future. Please, someone tell me not to worry. Tell me I've got it all wrong. These kids are swell in so many ways, but I see a dark future for urbanization in the next 20-30 years.

#46:

It isn't about karma, justice, retribution, or the Book of Revelations, Mark. It's about biology, biogeochemistry, & ecology. It's about the physical consequences of overpopulation & resource depletion. Humans exceed the carrying capacity of their environment, trash that environment and pay the consequence in population collapse & potential extinction. No remorse, no repentance.

#47:

Worry, Misha. You don't have it wrong. The social trend you outline is the result of fear. Given the circumstances, such fear is rational. Population density breeds social pathology. Get out while you still can.

Humor and imagination will be essential during a population collapse, DD.

Or are the civic minded folks of yesteryear being replaced by more insular folks who are going to have to rediscover the kind of social magic required to make urban life good (and who may or may not be able to learn that lesson?)

I'd say it depends on where you are and who you're hanging out with. There have always been selfish arseholes, and they're not limited to urban environments. At least in the city there are other people around if you don't like your immediate neighbours.