I was going to ask in GQ, but I think that this one is up for debate, as opposed to being a clear-cut question of fact.
I’m not just talking about filling the world to it’s maximum volume, but what is the most we can have and still feed and shelter them. I know everybody in the world isn’t fed or sheltered at the moment, but as I understand it that’s a problem with distribution/economic systems as oppose to supply/space. Feel free to correct me if you think I’m wrong.
I’ve heard guestimates from 12 billion to 30 billion. That’s a pretty wide range. Let’s narrow it down.
My guesstimate is that it’s way way more than ecology enthusiasts believe. In fact, I find 30B to be rather low. Of course, this is merely my (un-expert) opinion.
That opinion is based on a couple of fundamental observations:
a) I’ve been around, and I’ve seen an enormous amount of unused land. Some of it may be considered inhospitable, too desert or too icy, but there were times not that long ago that most of what is currently comfortably inhabited was not for the same reasons.
b) Farming could reasonably be condensed, but there’s not any real economic need to do so. Farm land is relatively cheap. If we increased the human population by 5 fold to that 30B number and farm land became much more expensive, the market would create ways of producing food in smaller spaces. Also, food prices have plummeted since farming was invented, and there’s no reason to believe they won’t continue to drop due to technological improvements.
c) The market will solve other problems as well, increased pollution, lack of oxygen, etc. If there is a problem that people are willing to spend to fix, the market will create solutions. Rain forests are beautiful and species are wonderful, but they aren’t required for human survival. at all.
The following thread does not specify the holding capacity. It does (around pages 3 and 4) deal with a number of issues surrounding holding capacity. I post it not to thwart this thread, but to provide a ready reference when the issue wanders into certain previously identified areas. 6 billion?
For those of you unfamiliar, arcologies are cities specially designed to house a massive number of people in a small area. The architecture is usually varied and built vertically in order to maximize efficiency in energy and water use.
I bet the earth’s holding capacity would increase if cities were designed like arcologies. More info - http://www.arcosanti.org
More than that is too many for the Planet to comfortably support; and too many for those 60,000,000 humans to comfortably get on with the business of living life.
Well…I’ve heard that the population density of Manhattan (the city, not the moderator) is around 50,000 people per square mile. If 20,000,000,000 people (20 billion, for those who have trouble counting that many zeroes) people live at that density, they could fit in an area of 400,000 square miles. That’s definitely smaller than the state of Montana. If we had the rest of the world available for farming, I don’t think we would have to worry about producing food. FWIW.
It is also said “It is better to keep quiet and let people wonder if one is an idiot than to speak and remove all doubt.” We can exchange irrelevant aphorism all day, but that would not address the issue in the OP.
The fact is that the world holds 6 billion people today, and even in areas of great poverty, the numbers of people succumbing to famine and disease are proportionately lower (and, in most cases, absolutely lower) than when the population was less than half its current level.
The question of the OP was “How many is too many?” Throwing out an unrealistically low number will not advance the discussion. It will only serve to maginalize your attempts at contribution.
ultrafilter, I was obviously not replying to your post.
I will note that figuring how many people we can pack into Manhattan (or Mexico City, Calcutta, Tokyo, or wherever) does not really answer the question. We still need to deal with the issues of moving the food to the population centers and removing the waste. (In a realistic scenario, we would also need to address how to persuade people to jam themselves into small areas. Obviously, many people are willing to do that. Equally obvious is that a great many people are not willing to live in large cities.)
Everything you’ve said is true. Unfortunately, those back of the envelope contributions were all I could contribute at that point.
But, if we could fit 20 billion people into the state of Montana, we could distribute those 20 billion people across the entire world without too much discomfort. This would allow for food and waste to be dealt with at a local level.
Sixty million is sufficiently large to [ul][li]easily maintain the knowledge base[]maintain the necessary equipage to defend against an asteroid[]advance “useful” technology[]continue research into [list]* science[]ethics[]archeology[]paleontology[]ecology[/ul][]accomplish “needful” (altruistic) activities ( :eek: ) provide food, clothing, shelter, etc. for ourselves.[/list][/li]Enough is enough; too many is too many."
Since the OP asked what the highest number would be, supplying a much lower number (than we have already seen be successful) as the highest number is unrealistically low.
Of course, if you think you are contributing to excessive population. . . .
How have you reached your conclusions, Sea Sorbust? What studies are you calling upon to conclude that 60,000,000 is “sufficient” to undertake all those activities? And why are you concluding that the “bare minimum” is also the “absolute maximum”?
If the earth’s population was 60,000,000, clothing and shelter could easily be provided by scavenging what’s left of the 99% of the world that got killed off.
Let me put this as clearly as possible. The question was “what is the largest number of people that the world can support?”
You answered with a figure that is a mere 1% of the number that the world currently supports.
This is obviously wrong. Incredibly wrong.
Or are you advocating killing 99% of the world population?
I like the 60 million number. It would certainly make it possible to find places where you couldn’t see the smoke from your neighbors cooking fires. Everyone would once again be able to burn their own yard waste, and even pee in an occasional stream, without having to worry about crashing the whole darn ecosystem.
On the other hand, it probably takes a few billion people to maintain much in the way of technological convenience.
I’m not optimistic enough to think that we can find acceptable and renewable substitutes for all the raw materials needed to maintain our current technological civilization at its current population so 2-4 billion seems like a reasonable long term compromise.
We might be able to hit 12-30 billion for a short time, but if anyone is really serious about numbers like that they need to come up with realistic estimates of the time frame involved in setting up power satellites, asteroid mines and double-decker cornfields or whatever sorts of technologies will be needed to support so many people over the long haul.
I’ve read the 6 billion thread and am reading this thread with great interest. I have nothing factual to add here, but I’d like to offer a small suggestion:
Do not pay the slightest bit of attention to those posters who believe the maximum holding capacity of Earth is less than what the Earth is currently holding.
I believe our highest bidder was 20 billion. Do I hear 25?
I can agree that, given our level of technology, we have not exceeded the carrying capacity yet. (For a hunter-gatherer technological level…we have definitely exceeded.) But I would add one question…is our current population level sustainable indefinitely? (In practical terms…not worrying about the sun heating up or burning out.) We have only been at this population level for a short time. No long-term data are available.
I think technology has a significant impact on what the carrying capacity is.
And then there is the question of what is the definition of holding capacity. The point at which there is not another square inch of land mass on which to put another person? Or when large portions of the population are starving to death even though all the arable is being used?
If using the population density of Manhattan as some sort of guide line, dontcha have to figure out how much land besides Mahattan itself is being used to support these people?
See, I told you I had nothing factual to add to this debate.
There are two different ways to take the question in the O.P. “How many people can the world sustain given a near perfect society” (the absolute maximum) or “How many people will the Earth sustain if humans keep acting pretty much the way they do now” (the true maximum). I believe the second one is more relevant and that is one I will address. (I’m also choosing that one because I haven’t a clue what the absolute maximum would be.)
vYield per unit of farmland improved by more than 30% between1947 and 1979. This was called the “green revolution” and was driven by the development of new seed varieties. The current population is about 6 billion. I estimate that, given our current agricultural technology, this number can double. If molecular biology produces a second “green revolution” increasing yield by 30%, and assuming this translates directly to population, we are left with a figure of 15.6 billion. For sake of convenience I’ll peg the maximum population at 16 billion.
I realize this may seem conservative to some, but I believe that certain restraints wil become apparent in population growth after we reach this level. Humans are animals and all animals have a niche in the environment. After the 16 billion level, environmental and human factors such as food shortages, low birth rates caused by malnutrion, disease caused by overcrowding, and wars brought on by the above factors will cause the population growth to level off. We will have reached saturation for our environmental niche and the excess will die off.
This of course assumes that we don’t screw something up royally between now and then. I am reminded of mesopotamian irrigation. The ancients used water from the Tigris and the Euphrates to irrigate their crops. This “fresh” water had a little bit of salt in it. Over time the salt turned the once fertile land into a desert and the population shrank as a result. We can see similar factors shrink population even today. Regions of Africa have experienced negative population growth in the last decade because of AIDS, malaria, drought, and civil war.
The more I think about it 16 billion might be optimistic as these Australian researchers believe: http://www.cosmiverse.com/science08030105.html
They believe the answer is 9 billion. Other researchers are all over the map. I’ll stick with 16 billion as my guess.
-Beeblebrox
Many were increasingly of the opinion that they’d all made a big mistake in coming down from the trees in the first place. And some said that even the trees had been a bad move, and that no one should ever have left the oceans.