Pharyngula

I also find it odd that you rule out major biological changes through genetic engineering. I grant that straight evolutionary mechanisms won't do it. I also grant that the technology to really engineer a specific outcome isn't there and the politics that prevent applying it to humans may well last out the next 100 years. But conceivably there could be very minor modifications to the human genome that might increase intelligence or longevity significantly. These might not have been as important traits for survival compared to others during most of our history, but the results would be very different if we had the conscious choice to select them for our kids.

Posted by: PaulC | May 15, 2006 9:17 PM

Space isn't an option. Even if we make some assumptions about advanced technologies (space elevators, etc.), the costs involved with building and supplying habitats in space or on other bodies are absolutely prohibitive. We *might* be able to establish very small, stable, self-supporting populations, but that would only serve to spread humanity, not lessen the burden on this planet.

***

Advanced tech only for the elite? Yeah, just like cellphones and personal computers. The whole point of technological development is that things that were once expensive and rare become cheap and ubiquituous.

Posted by: Caledonian | May 15, 2006 9:38 PM

The population is double what it is now or more

My guess is that the human population might stabilize around 9 or 10 billion - about 50% larger than the current population.

What about the chances of us exporting excess population to other planets / orbital habitats?

Keep in mind the scale of the problem. 2.7 billion people have been born since 1970 - approximately 75 million people per year. We'll have to send that many people into space every year (the equivalent of the population of the US every four years) in order to stabilize earth's population. That doesn't seem very viable. Reducing population growth rates is definately a much more viable way to stabilize earth's population.

Advanced tech only for the elite? Yeah, just like cellphones and personal computers. The whole point of technological development is that things that were once expensive and rare become cheap and ubiquituous.

I don't know. It depends on the technology. Liposuction might be an interesting technology, but I'm not sure that it's for anyone but the elite, and it's unlikely to solve the US' problems with being overweight. Cellphones and computers are external devices, and I would expect that genetic engineering would be much more similar to liposuction.

Posted by: BC | May 15, 2006 10:02 PM

"Advanced tech only for the elite? Yeah, just like cellphones and personal computers."

I think for the purpose of this discussion, if you own a cellphone and/or a computer you are part of the elite. There are (as of 2004, according to the CIA World Factbook) 1.8 billion cell phones in the world. Obviously this is a lot, but it's still not quite 30%, assuming (probably incorrectly) that each phone had a unique user. The things that many readers of this website take for granted (such as, reading a website) are still out of reach for the majority of people on earth, and even as things get better and the rising tide raises all boats (at least before flooding the town) there will always be things that only a fraction of the planet can have.

Posted by: Jethro Gulner | May 15, 2006 10:13 PM

I'm much more optimistic than P.Z. This is because the environment is generally better protected in rich nations than poor ones and rapid economic growth in China and India makes me think that it may not take too long for the bulk of humanity to become rich enough to care about the environment. I know some people might think my optimism is foolish, but I'm confident that people in United States wouldn't be feeling so grim if President Gore had been in the Whitehouse for the past five years.

Posted by: Ronald Brak | May 15, 2006 10:32 PM

Last time this question was put here I believe it was in a political context. (What we should do with the environment.) That is already bad, since politics aren't much factual. now, it is futurism, which is even worse.

Well, extrapolating trends we should see a stabilised poulation (probably not the peak level), democracy, free trade, less poverty, most people living in cities, less wasting technology but less genetic and ecological diversity.

OTOH we will destroy or deplete some easy access resources like oil, and we may do it too quickly which may impact living conditions. If we believe old trends we are back to the city or civilisation destruction of older civilisations. But speaking of the latest trends I see no fundamental reason why the replacements we continue to find wont suffice. I guess that places me besides Ronald.

Posted by: Torbjörn Larsson | May 16, 2006 12:12 AM

BTW, looking at these comments I do hope compass or Jason go by in their trolling, since they always claim that Pharyngula are used by sycophants or at least likeminded people. Maybe they finally learn something...

Posted by: Torbjörn Larsson | May 16, 2006 12:37 AM

A pessimistic view to your optimism: I don't see option #3 becoming viable until we're up to our noses in #2. If we were capable of restraint before the point where the consequences of our actions significantly impaired daily life, something tells me we would have started using it a long time ago.

Posted by: CJS | May 16, 2006 4:47 AM

The human race would have slowed down to a crawl....

Posted by: Arun Gupta | May 16, 2006 6:58 AM

I think we'll still be here.

The big questionis what state will 'civilization' be in?

For fairly obvious reasons, most of us look at this question from a western outlook.

There are many western countries who have managed to reduce, and in same case, even drastically reverse the environmental impact of their lifestyle and still maintain a standard of living comparable to that of the US. Germany comes to mind as a good example. Germans have managed to halt both population increase and environmental impact, and have even reversed much of both. After the fall of the wall, the cleanup of Eastern Germany (which is still ongoing) significantly improved the environment of that part of the country. Other European countries are following suit, and hopefully, this half of the globe will learn from their experience.

And then, there are the small, 'native' populations in various parts of the world that the passing of technological civilization will hardly impact, unless we really do a number on the climate. Tribes of indiginous peoples who live in remote parts of South America, Australia, Tibet and much of Eastern Asia may not even notice the passing of technology if it comes to that. Then again, we of the technological civilizations could probably learn a thing or three from those 'primitive' peoples. Don't get me wrong, I don't have some romantic notion of an idyllic life that they live, but at least they seem to maintain a balance with the world around them.

So I think it could be a combination of all the scenarios mentioned above, or some as yet unforeseen and completely unexpected result. Imagine what might change if we were finally contacted, or made contact with, a true technologically advanced alien civilization. (Via radio telescopes or some similar means, I don't foresee actual physical contact for centuries, if ever.)

Cheers.

Posted by: Fastlane | May 16, 2006 8:27 AM

BTW, I agree that it's silly to envision humans migrating into space, but it's also clear to me that off-world resources are going to be hugely important if we ever achieve a sustainable technological civilization.

I'm not betting on 100 years, though as an optimist I'm not ruling it out. I will bet that if we don't do something in 1000 years, we'll be wallowing in our own waste and may have even missed the window for ever improving matters.

I expect self-replicating machines to be a reality in the next few decades--in my lifetime I hope. Once this is possible, we can set up off-world automated industries (e.g. in the asteroid belt) starting with small payloads. These can potentially dwarf the theoretical productive capacity of earth. There are tons of roadblocks, clearly, both technological and ones completely beyond our control such as finding the right elements in the right places. One thing that is not scarce is solar energy. We don't even need a very efficient way to collect it provided we have an automated way to produce the collectors with available materials. In short, there is no physical impossibility. Getting the goods to earth will also not be energy intensive provided the source is located at a higher potential energy from earth's orbit (I'm not saying it'll be easy).

One thing that is true is that even if you imagine all these payloads of goodies parachuting into earth from our robotic benefactors, there could still be a waste problem to solve. I don't have a great answer to that, although if I wanted to extend my optimism a little, I think it would not be an immediate problem and eventually we could do something about it (again, no physical impossibility given existing solar energy--just send the junk up on the space elevator; hook your barge on a solar sail and send it back to the recycling center in the asteroid belt, maybe with some human tourists).

Next hundred years? Nah, I guess not. Eventually? I don't see any substantially different possibility that doesn't lead eventually to a Malthusian nightmare.

Posted by: PaulC | May 16, 2006 9:05 AM

"But I don't see any reason to believe that people have gotten a lot smarter about nukes or that the existing arsenals aren't sufficient to wipe out most major cities, destroy arable land with fallout, and lead to global meterological consequences that aren't fully understood."

Standard disclaimer: saying that nuclear weapons are not necessarily End of Days devices is not the say as saying we should use them promisciously. Also, when I say "we", I really mean "someone else" because Canada unaccountably gave up the Bomb in the 1980s.

Bear in mind that fallout isn't really a problem with airstrikes (because much less material is pulled up into the debris stem), although since you need groundstrikes to destroy hardened targets, this may not be that much of a comfort: many scenarios include ground strikes.

Fallout decays very rapidly. You could build expensive condos for Yuppies [1] on ground zero of a groundstrike within about ten years of the detonation. That initial period of intense radiation is going to be hard on much of the plant and animal life, so I'd expect what we saw ten year later (assuming no human intervention) to be a mix of things that recolonized the region and species whose biology or lifestyles preadapted them to survive: yes to things that can grow back from deep roots or from seeds, animals that live in warrens or can travel great distances but no to things like conifers, which are not noted for their speed and which have a resistance to radition about the same as ours (If I remember my Cold War texts, deciduous trees are much more resistance to radition than conifers, but I don't know why that would be).

1: Judging by his comments on strontium-tainted milk, Kahn would suggest low rent public housing but I prefer to maximize my returns on Teller Estates.

Posted by: JamesNicoll | May 16, 2006 10:13 AM

I'd say the most drastic hazard facing humanity over the next century or few is climactic "tipover", where for whatever reason (greenhouse effect, nuclear dust, deforestation, ocean biodisaster) the planetary climate makes a chaotic transition into some regime that's flatly unsurvivable for humanity. Even if it only lasts decades, something like 120% cloud cover, or glaciation to the equator, would wipe us out, and likely most of the ecosphere to boot. (Of course, there's also a huge biomass on ocean bottoms and even the lithosphere, that would be more or less unaffected.) The actual risk of this is almost unknowable, but we're certainly "playing with fire" (heh) lately.

Next most drastic would be global ecosystem collapse. This might be triggered by global warming, CO2 increase (aside from the warming), a "perfect storm" of exotic-species mixing, overharvesting of fish or forest, pollution, and probably other ways. This would be less of a sure killer, but even our agricultural systems have many hidden dependencies on the ecology-at-large. This probably would take more than 100 years to kill us, and we might well be able to patch together a simplified but stable ecology, at least for our own territories and support systems.

A large-scale nuclear exchange, of the older MAD style, might well scatter enough radiation to make the earth unlivable for humans, with effects similar to one of the previous two scenarios. These days, that would need to be a U.S./Chinese exchange, since I doubt Russia could even manage a full launch of the former Soviet arsenal. Now, there doesn't really seem to be a reason for such an exchange, but with the madmen we've got in power, who knows?

Almost anything less sweeping than the above would certainly kill many humans, but not all of them. We might well regress to earlier technology levels, but if there was some warning, we might be able to maintain a smaller technology base, perhaps in "tech cities" studding a mostly low-tech world.

As noted above, space provides resources, but not an outlet for excess population. (AFIK, no nation has *ever* managed to dump its surplus people to a colony.) Von Neumann Nanotech would work a lot better in vacuum and/or microgravity conditions, but even so, there will certainly be natural limits to what they can accomplish. Just another tool, not a miracle....

Posted by: David Harmon | May 16, 2006 10:27 AM

JamesNicoll:

Standard disclaimer: saying that nuclear weapons are not necessarily End of Days devices is not the say as saying we should use them promisciously.

Just to clarify, are you saying we should use them sparingly? I would readily concede that they work wonders as game theoretic bargaining chips and that they might very well explain why we haven't had another World War in the past 60 years. It's a high risk equilibrium, though (though the longer the "War on Terror" lasts, the better the cold war starts to look). I'm not sure nukes are good for much of anything and should be used at all. I am sure we built way too many of them.

As a youth, I took it as an article of faith that a US-Soviet war would spell doomsday. In retrospect, I admit I never even did a back of the envelope calculation taking the scale of the earth into, so I'm unsure. Here's one:

Earth's land-area is about 150x10^6 km^2 (http://hypertextbook.com/facts/2001/DanielChen.shtml or take 30% of the area given a sphere of radius 6400 km)
If you wanted to drop enough bombs to put every land location within 100 km of a bomb site, you'd need to cover that with disks of area pi*100^2 km^2 or about 31000 km^2. That's only 5000 bombs. I realize we're not targeting them like that and maybe the ones we have would not be big enough to make those areas inhabitable, but it's too close for comfort as far as I'm concerned.

It seems to me that it is technologically feasible to commit this kind of species suicide if we just set out minds to it. :)

Species extinction might not be the most likely result of global nuclear war. Again, I would like to think it is not. However, I think it would be very difficult to prove that species survival would necessarily be the outcome.

Any surviving population would face widespread starvation and disease. The climate would probably be altered significantly (I guess nuclear winter has fallen into disfavor, huh?, but that doesn't mean we know things will stay as they are.) If we were talking about any other animal, we'd have to consider extinction as a very possible result of habitat destruction. I would not assume that once we've been knocked back into worse than stone age conditions that our big brains are going to set the population back on a growth curve. The extinction doesn't even have to happen at once, but could be the result of generations of less than replacement level birth. Humans are well adapted to a resource rich earth just waiting to be used. We would be living on a very different planet after a nuclear war.

Posted by: PaulC | May 16, 2006 10:52 AM

"If you wanted to drop enough bombs to put every land location within 100 km of a bomb site, you'd need to cover that with disks of area pi*100^2 km^2 or about 31000 km^2. That's only 5000 bombs. I realize we're not targeting them like that and maybe the ones we have would not be big enough to make those areas inhabitable, but it's too close for comfort as far as I'm concerned."

There may or may not be another comment by me coming along: something odd happened as I was typing.

Absent a ground strike, 100 km is far enough that for most of the warheads we use the main risk would be serious eye injury. The largest device the US deployed was between 10 and 15 megatons, which could ignite fires out to 30 km (if I am reading my slide-rule correctly) and knock domestic dwellings down at 15 km. Even windows would only break out to around 60 kilometers.

15 MT is an exceptionally large bomb. Despite the push to develop the Supers in the 1950s, it turns out the combination of the geometry of nuclear weapons effects and the payload limits on rockets means that a lot of small warheads are far more useful than a few large ones. What I mean by geometry is that EMR effects like thermal damage are surface effects and scale as the inverse square of the distance while things like overpressure scale with the volume effected. As a result, if you're trying to crush a target, halving the circular error probable is just as effective as building a bomb eight times as large.

Posted by: JamesNicoll | May 16, 2006 11:25 AM

You know, just reading through these posts, it occurs to me that, wow, what a bunch of rays of sunshine we are. I have young kids, born in 1994 and 1997, and in 100 years, they may face scenarios 1 or 2? Great. Then why'd I have kids? So they could fall off the end of the earth? So they could watch part of our de-evolution back to cave-dwelling and hunter-gatherers before Conan gets 'em?

Wonderful.

When should I send them to Summer Survivalist Camp so they'll have advantages over the rest of their peers? That's a completely realistic question, isn't it?

I'm not saying scenarios 1 and 2 cannot happen. But let's just turn the clock back to 1906. What was the population then? Had computers been postulated yet? Using silicon to make our lives easier? Penicillin? Turbochargers?

I was listening to a piece on NPR's Weekend America last week where there's this tendency to screw around at the beginning of projects before getting down to the real work, and as deadlines approach, we roll up our sleeves and pull all-nighters and get the job done. The economist who talked about this said this is pretty normal for humans to do, and she even had a name for it (I can't remember what she called it).

I think it's possible the same thing could happen here.

It makes sense. While I'd love to see windmills and solar energy production, for example, it won't happen until they're cheaper and easier to do than oil. In spite of us knowing that oil will be unaffordable one day, we won't do a thing about it until alternatives are cheaper; then oil will rise catastrophically in price, we'll suffer, we'll work hard, and viola, that long stretch of road between Barstow and Las Vegas will suddenly have thousands of facilities to generate electricity and split water into hydrogen and oxygen for our fuel-cells.

But it won't happen until oil gets catastrophically expensive.

I just hope my kids don't have to watch society dissolve. No Road Warrior endings for my kids, please.

Posted by: MikeM | May 16, 2006 11:44 AM

PZ: ...some cultures practice restraint, using technology to control population growth and develop sustainable food and energy resources. They work to bring about scientific and technological advances that improve their chances for survival and progress.

Finally! PZ writes something good about the United States on his blog.

Posted by: NatureSelectedMe | May 16, 2006 11:49 AM

I think we're pretty close. Don't you?

1. ..using technology to control population growth

Since we're wealthly from technology advances and wealthly people have fewer childern, We're all over that.

2. ..develop sustainable food and energy resources

We grow so much that we can use our corn for energy. E85?

3. ..They work to bring about scientific and technological advances that improve their chances for survival and progress..

We do this too.

Posted by: NatureSelectedMe | May 16, 2006 12:27 PM

100 years is now a very LONG time. In terms of the accelerating rates of change in our de facto environment (which is technological and increasingly virtual) it's probably equivalent to 30,000 years of pre-10K BCE living.

I can't imagine any ecosystem catastrophe that would wipe out humans. So the options are:

1. Wild tech: Gray-Goo nano disaster, some weird vaccum energy thingie, etc. I'd put these all down as unlikely.

2. Engineered plague: A pimply 15 yo in southern China is upset by social rejection and engineers a virus using his home biotech kit that wipes out humanity. I'd put this at 20% when you consider all the folks that might try this.

3. AI: If we ever did produce a sentient AI, and if it turned out that "intelligence" scaled to an IQ of, say, 100,000, then all bets are off on everything. I'd put that down as a 40% probability over a course of 100 years.

Since we have to survive both 2 and 3 to make the 100 year mark I'd say:

.8 * .6 = .48 or less than a 50% survival probability.

PS. The Fermi Paradox (aka the great silence) is not comforting here.

Posted by: John Faughnan | May 16, 2006 12:32 PM

John Faughnan:

100 years is now a very LONG time. In terms of the accelerating rates of change in our de facto environment (which is technological and increasingly virtual) it's probably equivalent to 30,000 years of pre-10K BCE living.

The rate of change is not uniform, and it seems especially sluggish when it comes to infrastructure. Aside from computers, the internet, and mobile phones, many things seem similar to the way they were when I was growing up in the 70s. I live in a house that was built in 1954 and though you wouldn't build anything quite like it today, it's recognizable as a suburban single family house. The roads are still paved with asphalt. I'm surrounded by infrastructue such as electric transmission lines and the Hetch Hetchy aqueduct that was built many decades ago. I get out of the car and pump my own gas--too expensive to pay a human to do it, and nobody has bothered to invent and mass produce a robotic filling nozzle: i.e. a service once widely offered has now reverted back to household labor. There's some great progress for you.

I think that some kind of von Neumann replicator--nanotech or bigger--my be a genuine breakthrough since it would move the effect of technology away from manipulating pure information into productive capacity. However, I thought this 30 years ago too, and I am no longer holding my breath for it to happen.

Posted by: PaulC | May 16, 2006 12:50 PM

"I had a feeling I was oversimplifying, though this does make me wonder how anyone plans to arrange a return trip for a human mission to Mars. Send a big return rocket in pieces? How would you assemble it?"

Well, I simplified as well: It's easier to get off Mars than off Earth, so Earth's surface -> Mars surface will be easier than Mars' surface -> Earth's surface.

One way to reduce the amount of supplies you need is to live off the land. Mars is obviously somewhat dismal in its supply of Wallmarts and Safeways but you can make rocket fuel from its atmosphere, at least in theory. That would be very convenient.

Deimos and Phobos are low density, which could be that they have a lot of water-ice in them or alternatively that they are filled with cavities.

Posted by: JamesNicoll | May 16, 2006 1:27 PM

"Well, I simplified as well: It's easier to get off Mars than off Earth, so Earth's surface -> Mars surface will be easier than Mars' surface -> Earth's surface."

And by "easier", I of course mean "harder".

Posted by: JamesNicoll | May 16, 2006 1:44 PM

As a result, if you're trying to crush a target, halving the circular error probable is just as effective as building a bomb eight times as large.

i thought lethality went up as the fourth power of accuracy, not the cube? in contrast, as you say, lethality is only directly proportional to yield.

Posted by: ekzept | May 16, 2006 10:32 PM

JamesNicoll, with regards to why deciduous trees survive radiation better than conifers, I imagine it's because anything that is used to surviving desication is generally good at repairing damage to its DNA. Deciduous trees are presumably adapted to repairing damage they must suffer while dormant and frozen over winter.

Posted by: Ronald Brak | May 17, 2006 6:47 AM

I mean, it took computers 100 years to become as prolific as they are now.

I wonder what you're defining as a computer. There were electromechanical census tabulators 100 years ago, but the notion of a universal programmable computer was unknown even in theory until the 1930s and remained vaporware until after WWII when electronic computers were built with vacuum tubes.

Charles Babbage's analytical engine would have been a universal (Turing complete) computer, if he'd managed to get it built. It was first described in 1837.

Leibniz envisioned programmable binary digital computers in 1679, using punched cards, with the presence or absence of marbles in various locations to represent the bits.

There are no detailed designs---at least, none surviving---but I'm guessing that if Leibniz had had the resources and gone for it, he'd have eventually figured out how to build a Turing-complete computer, and done it. He was clearly thinking along the right lines at both low and high levels. (I.e., binary logic at the bottom, using combinatorial logic to implement a machine that could perform high-level logical inference in a universal formal logic language.)

It's really not hard to build a universal computer, by accident even, if you can build a programmable computer that can do simple arithmetic. In fact, it's hard to build a reasonably general computer that isn't universal.

Once you get the idea that the program is just more data, and make it modifiable like other memory, you're pretty much done. That's an inevitable hack---people will do it for convenience, whether or not they realize that they've just converted a very limited computer into a completely general one. (It's just so handy to be able to preprocess your program a little rather than having to re-punch all the cards or flip all the switches by hand...)

That kind of evolution happens in software all the time---a very limited, special-purpose piece of software plus a convenient "cheesy hack" becomes a Turing-complete, programmable system, without people even noticing.

In that regard, Turing mainly showed that any number of cobbled-together engineering hacks for programmable computing are in fact exactly equivalent, in terms of what they can compute, given enough memory.

I think that has a some interesting implications for biology. There are likely a some surprisingly general computing engines embedded in our genetic regulatory networks, etc. Even if they're only used for fairly specialized purposes in any given species, they could be highly exaptable. And because there are so many bizarre ways to make powerful or even universal computing devices, it's easy to miss that something is one, even if you're looking right at it.

Posted by: Paul W. | May 17, 2006 9:52 AM