What'll the world population be in 2100?

[Stolen Rutters]

The number of people who can reasonably leave the planet, with any energy source concievable, is too small to materially change the results, and the economics of population growth should keep a collapse in numbers too unlikely.

The 10 billion mark should be the ballpark... so which side do I like?

Many nations have seen population growth slow down so...

7-10 billion

 

[luiz]

Around 9 billion people, according to the UN's estimates. Not that much, and before the malthusians say we can't feed that number let me say that we can feed many times that number if it becomes necessary.

And as masquerouge pointed out it's not like we're running out of space, we actually only occupy a tiny portion of the world's landmass.

As an interesting note, I recently read a study by the World Bank which suggests that the brazilian population will peak in 2050 at 233 million people (not that much more than our current 190 million) and then start declining, a patter which I imagine will also occur in many other countries.

 

[tomsnowman123]

That is completely and utterly false. 6 billion square meters is actually 6,000 square kilometers, a very small piece of land, 1/6 of Switzerland.
10 times that, 60 billion people and thus 60 billions square meters, is still only 60,000 square kilometers, a tenth of France.

This is all I could find, but I first read it on Wikipedia some where. I want to say it wa like 2750.

 

[Cannae]

I think that due to golbal warming and nukes we will have much less population than today.To be exsact it will be around 1-3 billon people after these events start to occor on a large scale.

 

[luiz]

Do you really believe that Global Warming will wipe out 2 to 5 billion people by 2100? No offense, but that's completely crazy.

 

[Narz]

3 to 5 billion. Closer to 3. To make a long story short, due to global warming, which is a fact, therell be widespread famine, breakdown of the current global economic system, disease, displacement of huge numbers of people,and wars as a result of all of these climate change related factors. When the smoke clears Im saying around 3 billion will be left. Im being optimistc.

Pretty much agree. Except closer to 1 billion.

The planet is only able to hold so many as it does now due to the proliferation of cheap oil and imported goods, also keeping in mind that without fossil fuels the current agricultural system would not function.

 

[El_Machinae]

Do you really believe that Global Warming will wipe out 2 to 5 billion people by 2100? No offense, but that's completely crazy.

Not so much 'wipe out' but prevent replacement-levels of breeding.
We have such a large population because we have stable food sources and an integrated economy. As the agricultural source change, the food sources will change too, in a less-than-pleasant way.

 

[Shaihulud]

Mutants and Giant ants will rule the world, the rest of the untainted humans having fled to Mars.

 

[Tee Kay]

Population growth will slow down as our resources dwindle and as global warming et cetera take effect. But even so, world population in 2100 will not be lower than today, unless something apocalyptic happens for example a decade-long nuclear war (highly unlikely), an epidemic on the scale of the black death (unlikely, and with the medical technology we have we should be able to cope) or an invasion by genocidal aliens (laughable). I guess the world's population in 2100 will be around the 8 billion mark, may be a little over 9 billion.

 

[azzaman333]

When there is only a little oil left on the planet, WWIII will occur killing off many, many people. This will most likely severly stutter the humans race, leaving us with 1-3 billion people left at the turn of the century.

 

[MOTH]

I believe that a major asteroid strike will happen. This will either be a random or thrown at the earth by some sort fo extreme faction that happens to get out to the asteroid belt.

 

[Bozo Erectus]

Do you really believe that Global Warming will wipe out 2 to 5 billion people by 2100? No offense, but that's completely crazy.

Not really that crazy if you stop and think about it. The current global system which keeps billions of people fed, every single day, in its scale, is unique in human history. In order to deliver lets say 2500 calories a day to every person on the planet (I know, in some areas they never get that much) a million things have to go right, everywhere, not just every day, but literally every minute and hour. Its an insanely complex web that requires, among other things, cheap plentiful energy not just in the form of oil. Predictable weather patterns are also vital, in order to produce all of this food. Keeping billions of people fed isnt easy during peaceful, stable periods. Imagine how difficult it'll be during the catastrophic changes that are on the way.

Why do you think its possible for a few punks in Nigeria to adversely impact the global economy merely by blowing a hole in one oil pipeline? Because our 'just in time' society has to depend on the assumption that everything, everywhere will go right, every single time. So if one ruptured oil pipeline has an impact on the world economy, what sort of impact do you think it will have on the global economy if all of the worlds coastal cities are underwater because of the melting ice caps?

And thats just looking at one narrow range of things that will be adversely impacted by global warming.

It would be crazy to think anything else

Pretty much agree. Except closer to 1 billion.

The planet is only able to hold so many as it does now due to the proliferation of cheap oil and imported goods, also keeping in mind that without fossil fuels the current agricultural system would not function.

And instead of planning and preparing for the catastrophic climate changes which are already locked in and inevitable, the world wastes its time with nonsense like the Kyoto treaty. Natural selection is still at work on us, though we thought we left it behind in the jungle. If we're too stupid to prepare, then we deserve our fate.

 

[Cannae]

Do you really believe that Global Warming will wipe out 2 to 5 billion people by 2100? No offense, but that's completely crazy.

How would you know if that's unlikely to happen? Are you a top metioralogist and cilmeatetologist? (sorry for my spelling)

 

[Masquerouge]

This is all I could find, but I first read it on Wikipedia some where. I want to say it wa like 2750.

I don't understand. If you give one square meter to each person on Earth, you have 6 billion square meters, and that's 6,000 square kilometers, a ridiculously small amount of land (you know it's ridiculously small when the majority of European nations are bigger than it).
There's no way around that.
So either you switch square meters for square kilometers, but that would not make sense since 1 square kilometer is pretty big for just one dude, or... I don't know actually.

 

[Godwynn]

How would you know if that's unlikely to happen? Are you a top metioralogist and cilmeatetologist? (sorry for my spelling)

Are you...?

 

[Cannae]

Are you...?

No...I am not...

 

[CIVPhilzilla]

I think we'll level off around 10-12 billion as China and India's birthrates decline once industrialized.

 

[tomsnowman123]

I don't understand. If you give one square meter to each person on Earth, you have 6 billion square meters, and that's 6,000 square kilometers, a ridiculously small amount of land (you know it's ridiculously small when the majority of European nations are bigger than it).
There's no way around that.
So either you switch square meters for square kilometers, but that would not make sense since 1 square kilometer is pretty big for just one dude, or... I don't know actually.

I don't know.... I tried looking for it on wikipedia. I swear it was under something like "over population", "end of the planet", "population growth", or something similar.

 

[mdwh]

I don't understand. If you give one square meter to each person on Earth, you have 6 billion square meters, and that's 6,000 square kilometers, a ridiculously small amount of land (you know it's ridiculously small when the majority of European nations are bigger than it).
There's no way around that.
So either you switch square meters for square kilometers, but that would not make sense since 1 square kilometer is pretty big for just one dude, or... I don't know actually.

I think he's just doing that thing where you plug in the numbers to work out what the population will be by a given date *at the current growth rate*, and then claiming it'll be some absurdly high number in a few hundred years.

Let's work it out:

From Wikipedia, the Earth's land area is 148,939,100 square km, or about 150 million million square metres. The population needs to increase by a factor of about 23,000. From http://geography.about.com/library/faq/blqzworldgrowth.htm , the growth rate is about 1.3%. According to my calculations, that means we have to wait about 778 years.

So, not something going to happen soon, and clearly the growth rate will fall before then.

I've read similar things like "by such-and-such date, the mass of all humans will be more than everything in the Universe".

This is basically just fun with the numbers of exponential growth - it has no relevance to the reality of population growth.

 

[Eran of Arcadia]

In the year 2014, every single human being on the planet will spontaneously and independently lose interest in sex. Thus by 2100 there will be fewer than 100 million left, and they will all be at least 86 years old.