Curious if anyone has info on this? It's obviously a finite number.

The United Nations projects that population will level off at 9 billion and remain there indefinitely.

From what I've read about 9 to 10 billion.

Would require a lifestyle change tho. No more driving around in an SUV and then eating a nice steak at dinner when you get home. We all need to become hippies basically.

Lol now that's funny. Interesting

The projection is based on our current level of technology. Although it's more than likely that one gets severely diminishing returns after a point due to space consideration and ecological reasons.
If we magically discover a safe clean and practically unlimited form of energy production along with a way to mass synthesize nutritious food for really cheap and great advances in medical technology then the number is probably much higher. (yeah I know.. good luck with that). On the other hand, the odds of some massive
plague coming along and wiping a large portion of the population out increases as population increases...

9 Billion is what I have read as well. But like Magellaan said some lifestyle changes would need to be made. And then we are pretty much out of space. If our population grow we start living on land we use for food. I suppose it could keep its self in check that way.

Space? I recall hearing somewhere that we can fit the world's entire human population in Texas with like 1000 square feet for every person. If this is true, then space won't be the dominant limiting factor. It will be resources.

When space does become a limiting factor, we can just all move to Canada.

Well, we could probably support more if we start eating each other instead of cows, because you can fit more people in that space. Cows are so big after all.

So that would result in a permanent underclass of "food" humans and a permanent overclass of "eating" humans.

We could all draw lots for it at age 18 if you're not accepted to a university or in the military, etc.

Heres a video about demographics. http://youtu.be/2vr44C_G0-o

The number of people we add to the planet has begun to slow since 1965.

Globally, total replacement would need 2.1 children.

In 2003 half of all the women in the world are having 2.1 or less, which was very different stat in 1950s, which the norm was 5 kids.

The change is still going from 2.5 to 2.1

When the poor countries get developed, the number will skew to 2.1 as more time goes on.

Population will be 9.1billion by 2050 if the change still goes on, but if it doesnt pop will be 12b

I dont want anymore people on this planet.. their are already enough fluffs here already. Why in hell would we want more people to compete with for resources. Is it selfish of me to think this way or rational?

Well, think of it this way:


If we didn't have enough resources for the people we have now, the people you know and/or love would probably be the ones to try to kill you for that moldy loaf of bread they saw you smuggle from your basement to your kitchen. And, of course, you'd probably want to kill others for their resources as well.

42.

Canada's population: 34,482,779
Canada's land area: 3,855,100 sq. mi.

Nearly as many people as the state of California (38,041,430), and they fit it all into 163,696 sq. mi. :P

if the machines get their way, humans will only need space about the size of a coffin to live in. and medical technology will probably advance far enough such that you get to live there forever. they'll just make it feel like you died and will just give you a new virtual life to live. oh wait, that's like reincarnation... hmmm...

Been watching the Matrix lately, Dibs?

We're about due for another plague-like illness to strike and decimate (m|b)illions.

when replicators will get invented then food and water (and other drinkables) won't be problem.

yeah, a couple weeks ago. the Matrix trilogy were the 3 movies that i purchased to test my phone's download ability. $71 to get them delivered in an hour.

Soviet wins btw

well.. 50% of global food production goes immediately to waste so if 9 billion is the limit, food is probably not the limitting factor. As an aside, we could probably feed way more than double what we can now with a little bit of creativity although food choices would rather suck. Also because of the food choices in many 1st world countries we are actually being far less efficient than we could be in terms of resources/nutrition.
Also corn isn't exactly biologically friendly in terms of a mass scale. So if we were allt o give up certain things (like beef and corn) we could probably increase global food production even further (not that we really need to, just saying). That's not to mention that we could grow algae and other yucky things along with easier to raise animals such as rats and rabbits:P

I find it interesting that a biproduct of prosperity has been smaller family sizes and a slower population growth rate. Mind you, even if somehow the whole world went to a one child policy, it would take a *very* long time before one would witness significant population shrinkage.

According to the Movie cliche "The world isn't big enough for the both of us", the answer is clearly 1.

-Fooglmog
Guy with no clue.

Depends on technology ...

It is a good debate. The leaders of this world will have to manufacture a war soon(15-30 years) in my opinion.

I overeat thats pretty wasteful.

There are a lot of projections based on various assumptions for quality of lifestyle and technological development. For a steady-state population the highest I have heard is 13B and the lowest is 6B (yes, like if everyone wanted to live like an American we'd have to cut back on the number of people already alive.)

Around 9B is the most common projection I have heard.

Around 9B is the most common projection I have heard on this thread.

Research suggests we may actually face a declining world population in the coming years.

http://www.slate.com/...lining_not_exploding.html

I read this a couple weeks ago, seems relevant to this topic...

prosperity is the end of the struggle to get there. what's left to do once you're there?

pandemic

Well, theoretically isn't the answer to this question whatever the volume of the Earth is including the atmosphere divided by the average volume of a human being? There's no reason to believe that it is impossible for us to develop technology that would allow humans to continue to live in some sort of Matrix type world while huddled together side by side in some sort of stasis. And if we develop this technology there's no reason to believe we can't put it in orbit. And there's no reason to believe we can't replace the function of the Earth's core so that we can use the entire volume of the planet. Or is all this a little too far-fetched?

@hawkeye: and then we can all have a group dream?:P
And at that point why not just build colonies elsewhere:P
And "in orbit" isn't on the earth:P

World oil production is the real problem.

Modern agriculture is essentially an oil-to-food conversion; when oil prices start increasing (because of diminishing supply, or marginal production is more expensive, or flat supply with growing demand) then you get serious problems for food production.

I've seen estimates of ~1B without fossil fuel inputs.

http://www.theoildrum.com/node/9718

Also, world population growth tends to follow energy growth:

http://www.theoildrum.com/node/9452

So it's possible in a diminishing energy environment that population would also head that way.

There are alternate fuels to oil. It is just a matter of costs...

Well, none of the alternative can be scaled up to replace fossile fuels. That is, at least not for the coming decades.

Seeing as we'll be looking at $9bil population in 2050 that probably will be close to max at that time. Who knows what technology will bring us though.

it's irrelevant. fossil fuels are static and can't be replaced conveniently unless you have a couple million years to sit around on your hands while you do nothing. we're goong to have to learn an efficient way to harvest beer farts that don't smell like pot.

It is bullfluff to say no alternate fuel can be scaled up to replace oil. It can't at current prices. If the price situation changes, the market adapts very fast. Most of the tech for biofuels, hydrogen fueled and eletric vehicles already is out there.

How fast is very fast according to you? I think Id consider at least a couple decades for new technologies to be developed/implemented and upscaled as rather fast.

Biofuels, doesn't make a lot of sense to use agricultural land for fuel if you need to feed 9bil+ people. You could use algea maybe but if current technology would be upscaled that would make up only a couple % of transportation fuel at most right now. Still has a long way to go.

Hydrogen fuel, it's not very efficient as is. Then you also need to produce the hydrogen first which makes it even less efficient.

Electric vehicles, we'll be seeing more and more of these of course but it will also take a time before they can be produced at the same rate as 'fossil fuel' cars. And even then it will take time to replace all current cars. Easily takes a couple decades..
It would make sense too to change land use policies and actually walk and bike more and use mass transit.

Also, you need to produce your electricity using something else than fossil fuels. Maybe we'll have nuclear fusion power plants in the futures, but thats still decades away. Renewable energy.. takes a while too. Germany is looking at 20-30% renewable energy in 2020 but that will have taken them 2 decades to get there even though they created very favorable market conditions for it.

Now don't get me wrong, I think a lot is possible and we don't necesarilly have to panic but I really do think 'very fast' still means at least a couple decades with something as huge as this issue.

Nono. No humans in orbit. The things in orbit would be the technology required to keep us alive so that it doesn't take up valuable space on Earth.

We likely already can feed 9 billion people, considering the world has over 7 billion, government's regulatory stock and plenty of fatties. Plenty of countries actually pay their farmers to not produce or to produce less than they can. Feeding is a no issue, the real problem is distribution (as in some of the poor can't afford to buy food).

During my life I have seen Brazil change a big part of its fuel source several times. Each round took a couple of years for full conversion. I don't expect it to take more than five years or so, tbh. Free markets do tend to be efficient and, like I said, the technology already is out there. We have vehycles on the streets using eletric, hydrogen and biofuels today.

To say that some or all of them aren't efficient just bring us back to the price issue again.

To say that a lack of energy production will be a problem is correct. But the solution for that is out there too. From nuclear power to alternate energy to coal power or hidro power. We will have to build them. It bets the hell out of watching the end of modern civilization.

And lets keep in mind that in real life oil won't end in the blink of an eye. As its supply dwindles, its price goes up, opening space to other techs.

i don't really see energy production as being a limiting factor. might effect quality of life. maybe people will get grouchy and start killing each other when they can no longer vent their anger via video games.

Just be careful. Don't let the "9 to 10 Billion" be a hard limit that "has" to be enforced. That can lead to some pretty terrible things.

The technology is there, but it doesn't scale quickly enough I think. The EIA estimated that even with high prices and an immediate switch, the US car fleet would still only be 80% electric by 2050. Which is super slow if we're to have a serious slowdown in oil.

Another big problem is our EROEI (energy returned on energy invested) in the economy is currently plummeting due to things like shale oil, some of which are break even at like $70-80/barrel. Coal-to-liquid is not exactly the best EROEI as well.

Electric is fine if you power it with coal =/ but even peak coal is likely to happen by 2050; better to go with nuclear.

The problem with nuclear (traditional, uranium) is that if we were to convert *ALL* the energy we use in oil yearly to nuclear production, we'd blow through all the recoverable uranium on the planet in like 10 years.


Thorium breeder reactors are the way to go. I'm not sure anybody's made any yet though tbh; maybe as a research reactor somewhere.


But the capital investment for nuclear is HUGE. And the build out time is HUGE. Can we build enough capacity fast enough to replace oil (even if the peak doesn't happen, supply isn't scaling up as fast as demand, so there's still a net shortage if we want to maintain current prices). And if oil goes through the roof, the economy will probably go into recession again, and then there won't be the capital to invest in building out an alternative....

9B is only a 28% increase over what we have now. In the developed world, the growth will not likely approach that level. I doubt if lifestyles will change all of that much in Sweden or Canada. Most of the growth will take place in countries that are already abysmally managed. Their lifestyles are already pretty miserable, it will just get worse.

I'll still be eating steak.

yes, but will we even be able to sustain our current population in 50 years?

probably. but it might require people to get off the couch. well, if i don't have heat, hot water, refrigeration and air conditioning. got to pick my own food? and hand wash my clothes?
hmm, starting to think we only got rid of slavery because of industrialization.

Absolutely; what is the point of a slave if you have a machine that can do the work of 20 of them for cheaper?

@qz: more than likely baring a plague. Standard of life is a different question.

we will colonize another planet when the time comes

think the aliens done stole all the required raw materials for us to be able to do that efficiently. though i haven't worn my tinfoil hat in a while, so i might've missed some activity. maybe we have some left that they couldn't get to efficiently enough for it to be valuable to them.