Approximately, what is the Earth’s carrying capacity? I’ve read several articles saying people need to be killed of in order for humanity to prevail. What are your thoughts on this? If you agree with this statement, what do you think is the most human/efficient way to kill people a and how would we decide who gets to live or die?
Sorry if this is too gory of offensive…I don’t intend to harm anybody. I am merely curious to the point of insanity. 
That’s a very tricky question because any answer you give depends on a lot of assumptions. If we assume a hunter-gatherer lifestyle, then the carrying capacity of Earth is probably between 200 million and 500 million. But if we assume the current lifestyle of factor farms and cities with suburbs, it may be 10 billion or 20 billion. Yet there are lots of analyses which conclude that this system isn’t sustainable. For example, factory farming relies heavily on artificial fertilizers, and the raw materials to keep making artificial fertilizers may run out in a matter of decades or centuries. So, it greatly depends on what time scale you’re looking at. If we assume sustainable farming methods and a major shift in our use of energy and human power (such as turning all the lawns in the world into organic gardens and expecting everyone to spend a few hours per day gardening) then maybe the answer would be around 5 to 10 billion. But if we assume that we could cut back on meat consumption, that figure could go up to 10 or 20 billion. Conversely, if we assume no more irrigation using water from underground aquifers, then it would drop to perhaps 2 to 5 billion. And then there’s the whole question of how much land you want to put aside for non-farming uses. Would you cut down all the forests to make room for human crops? Would you drive to extinction all plants and animals that don’t directly feed humans? That would increase the capacity. But it would increase the danger that the entire system could collapse.
I think 2 billion is a reasonable answer, if we decide to give up non-sustainable technologies.
Seriously? I’ve never seen any articles like that, except from people who are being facetious, arguing that it’s an impossible choice. Can you give some links?
Letting them die of old age is the easiest and most humane way to do it. Nobody has to be actually killed. Just lower the birth rate and let the older population die off when they get old. If we just cut the birth rate down to 1 child per adult woman (instead of 2+ children per adult woman) and let the death rate stay the same as it already is, our population would drop below 2 billion in less than a century.
Letting everyone die of old age also sidesteps the question of deciding who dies. There is no deciding. Everyone dies eventually.
This is already happening:http://brilliantmaps.com/fertility-rates/
It may be humane, but it is not without problems. As the birthrate drops, so does the ratio of pensioners to young productive workers. In a country like the UK, where state pensions are funded by current contributions, this means that young people have to pay more towards their pensions, and start drawing them later in life.
The US will depend a great deal on immigration to fill low paid, menial jobs, just as the UK does currently.
The maximum population for the Earth has been an active topic since the days of Malthus, who was himself responding to Godwin and Condorcet. Anton Van Leeuwenhoek was apparently the first to put a number to it, sending the Royal Society of England a letter putting his estimate at 13,385,000,000. This was in 1685.
The best overview of estimates comes from How Many People Can the Earth Support? by Joel E. Cohen, which provides estimates of up to 1 trillion.
That number may seem ridiculous. Yet few pundits in the past would have predicted that the earth would today hold 7 billion and that they would have the highest overall standard of living of all history. Famines and mass death were always supposed to have happened by that number.
Short answer. The world will probably double in population. After that, nobody knows.
I haven’t checked the links yet, but we could try something like this for a cap:
(surface irradiance)(photosynthetic efficiency)(crop caloric yield)/(energy needed per person)
Until someone comes along to tell me I’m wrong (I am), let’s play WAG the numbers:
surface irradiance: Discounting albedo and atmospheric adsorption, we have about 51% of 173 PW, or 88 PW. That of course includes everything that hits the ocean and isn’t reflected, so is too large.
photosynthetic efficiency: Theoretical is 11%, but let’s say 6%
crop caloric yield: I have no idea. WAGging 50%.
people: 100 W each
So that gives us 88 PW * 0.06 * 0.5 / 100 W = 2.6E13, or 26 trillion people!
If we try again with 29% of the solar irradiance to account for only land area (ignoring the distribution of land by latitude), that gives us a lower number. Plants don’t grow year round. That gives us a lower number. Etc. Just using that 29% and saying 3% for photosynthesis drops us down to under 4 trillion, which is approaching the previous post with the link I still need to read.
I’ve always said that people who think the earth is overpopulated haven’t traveled much.
Montana, North Dakota, South Dakota, Texas, Idaho, an even California have millions maybe even billions of undeveloped or un-utilized land. There is no shortage of places to live or grow food.
Consumable water may be a different story
I’ve often heard people say that the Earth can only support 7 billion people with 1 billion starving.
These people seem to forget that the other 6 billion are overfed.
By the time the population of Earth becomes a problem, we’ll have developed multi-level artificially lit farms, farms on the ocean, and a way to turn hydrogen and oxygen into water, as well as built a completely self sustainable power system. In 1000 years when this would become an issue, it will have been solved long before.
I’m pretty sure Australia is about 96% uninhabited, and is the size of the US. Easily fit 1 billion + here.
Through out history earthlings have been stricken by pestilence, plague, famine, cosmic events etc. Nature will take care of the problem.
Acreage and water are just two items on a really long list of finite resources which are required for factory farming. Other items include…
+enough sunlight
+not too much sunlight
+the right temperatures for your crops
+the right kind of soil (not too rocky or sandy)
+artificial fertilizer
+chemical herbicides
+chemical pesticides
+fences for keeping out animals
+tractors for plowing and planting
+harvesters (either machine or human)
+transportation to and from the farm
+a source for seeds (will they be GMO? how many research labs will you have?)
The list goes on and on. Many of those things require energy. Many of them require tapping into finite natural resources (phosphorus, for example).
OTOH, you could assume that we’ll go with organic farming and sustainable methods, and then the list of what you need gets a whole lot shorter, but then you suddenly have a lot less acreage to choose from because the soil isn’t right or the climate is too harsh, et cetera.
Physically fitting people onto physical land space isn’t the problem. The problem is essential resources including energy. Technology is a wonderful thing but it is uneven and can’t be guaranteed to keep up with the problems that a rapid population increase introduces. A failure of even one essential resource to keep up with demand spells disaster and already has in many cases.
The biggest understated long-term threat associated with overpopulation is water distribution. Much of the U.S. and the world depends on deep aquifers that have built up their reserves over literally thousands of years and will take that long to recharge again. It took less than 100 years to deplete them and the rate of depletion is accelerating. When they start to run out, agriculture has to shut down or find a way to drastically scale back or find a new source. California is already encountering this problem and will continue to do so in hugely significant ways. They are getting a brief retrieve now because this fall has had average rainfall and they just opened a new desalinization plant so the news stopped covering it but the underlying problem hasn’t been fixed and won’t be in any reasonable amount of time. That state of the art desalinization plant can only serves the needs of 400,000 households out of a total population 39 million people and household water use is insignificant compared to agricultural use. It is really hard to engineer your way out of that one problem alone.
However, that is mere child’s play compared to problems that overpopulation in China is causing. At least they were wise enough to institute birth restrictions early. Africa is expected to explode in population over the next few decades and that is for a continent that already can’t handle the problems it has at its current size.
The world is already greatly overpopulated. Anyone that denies that is also denying global climate change, mass species extinction, deforestation, general pollution and some regional unrest. All of those are a direct result of our current overpopulation problems and the totality of the problems that causes are not easy to fix even individually if they are possible at all.
The Earth isn’t going to suddenly collapse right now because we are so overpopulated but we are running a deficit on a very finite set of essential resources. I agree with the estimates that the long-term, sustainable carrying capacity of the planet is about 1 - 2 billion people, a fraction of what we have now. That is just academic though because we are apparently going to add about 2 billion more people to an already overstressed system before it starts to come back down again according to the experts. The population fall back to sustainability may be brutal if the system can’t take it.
‘Relax, perspectives on population’, is a brilliant documentary by a Swiss Statistician that will educate you on the actual math. I highly recommend it!
It is a good documentary but he mainly focuses on how population increases are leveling off in previously high growth areas and will continue to do so. That is true but it doesn’t address the sustainability of even that many people in a best case scenario. We are seeing very real effects of overpopulation right now and saying that it will only get 20% worse before it slowly starts to fall back to still unsustainable levels isn’t my idea of an optimistic message. He is looking at it as a strict function of the number of people in the world but that isn’t the threat. The problem is the resources those people have to consume to live a semi-decent life and the major question of how that can be done on a finite planet that is already running low on some of them.
From what I understand we have lots and lots of land left for people. I read all people in the would could fit in size of Texas!!!:eek::eek:
Problem is most cities are by the water and coast areas and are experiencing out of control population numbers. Well the in land is empty.
We are not building new cities these days but people moving to cities that are overpopulated that is the main problem.
If we build new cities we would not have places like New York, Miami and Los Angeles so overpopulated where middle class house cost $900,000 :eek::eek: And condo that cost $500,000 :eek::eek:
We also have enough water and food to go around but the problem is most of the food and water do not make it to the people because of politics. That why a lot of people today have little to no food and water.
Nope, sorry. The OP said “I’ve read several articles saying people need to be killed of [sic] in order for humanity to prevail.” but those 30 quotes do NOT say this.
#1 says we need to “limit our population growth”, doesn’t say anything about killing.
#2 suggests “reducing… the size of the population”, which you might infer to mean killing, but it doesn’t actually say it.
#3 gives suggests limiting parents to a maximum of two children, unless the second pregnancy is twins. Nothing there about killing.
#4 makes a metaphor that humans are a disease. Doesn’t say anything about killing.
#5 proposes a smaller population “would be ideal” but doesn’t say anything about killing.
#6 suggests that we should let medical patients with “serious illnesses” “hurry up and die”. Sounds to me like he’s talking about terminally ill patients and how wasteful it is to prolong their lives when they are dying anyway, nothing to do with population and nothing about killing otherwise healthy people.
#7 just says population growth has a “negative impact”. Nothing there about killing.
#8 points out that optimum population is not the same as maximum population. Nothing there about killing.
#9 does say “we need to promote death” but he’s specifically talking about suicide, not killing.
#10 says we need to “get the birthrates in the developing countries to drop as fast as we can.” Nothing there about killing.
#11 says we need to “decelerate our population growth” by “reducing global fertility”. Nothing there about killing.
#12 says “ending population growth” is almost certainly necessary and “reducing current human numbers may be necessary”. (emphasis mine) So there’s one who actually mentioned the idea of killing people but he didn’t say we need to do it, he just said we MIGHT need to do it.
#13 says we’d be “much better off” with a smaller population. Nothing there about killing.
#14 specifically talks about “birth control” and “contraceptives”. Nothing there about killing.
#15 suggests that families should have fewer children. Nothing there about killing.
#16 talks about “allocating health care resources” because we have a limited amount of money. Nothing there about killing. But he’s not even talking about overpopulation at all, just the federal budget.
#17 also talks about health care spending and points out that, no matter how much money you spend, everyone dies eventually. This has nothing to do with overpopulation and he doesn’t say anything about killing.
#18 says the problem is “overbreeding”. Nothing there about killing.
#19 discusses Roe v. Wade. Nothing there about killing people who have already been born.
#20 actually does suggest killing infants, but in the narrow context of a “large family” and talks about it being “merciful”. Presumably, she means that a quick death is more merciful than slow starvation. There’s nothing here about it being necessary in order for humanity to prevail.
#21 talks about abortion, and specifically says we DON’T want to “kill your grandma”.
#22 suggests that it should be “permissable” to kill a newborn, but there’s nothing here about it being necessary in order for humanity to prevail.
#23 says we need to “continue to decrease the growth rate”. Nothing there about killing.
#24 discusses “sterilizing women after their second or third child”. Nothing there about killing.
#25 talks about mandatory contraceptives. Nothing there about killing.
#26 discusses the importance of reducing population “our way, through nice clean methods” (whatever that means) in order to avoid the bad alternative of “authoritarian government, even fascism”. He’s not proposing killing, he’s saying we need to take action in order to AVOID killing.
#27 talks about contraception and abortion, nothing there about killing.
#28 says we must “eliminate 350,000 people per day” in order to “stabilize world population”. But he doesn’t say it’s necessary for humanity to prevail. It seems to me that he’s just pointing out the difference between birth rates and death rates.
#29 speaks hypothetically about killing people, with the specific condition that the executioner also dies. There’s nothing here claiming that such killing is necessary in order for humanity to prevail.
#30 suggests that a deadly virus could reduce overpopulation and this would be a good thing. That’s not exactly killing, and he’s not saying it’s necessary in order for humanity to prevail.
Frankly, I have serious doubts about the accuracy of these quotes in the first place. I bet half of them were misquoted or taken out of context. Even so, out of all those 30 alleged quotes, only a few of them actually discuss killing at all; the vast majority of them merely discuss contraception. I didn’t see a single one that claimed that killing people off is necessary for humanity to prevail.
Nope, sorry. That one also does NOT say that killing people off is necessary in order for humanity to prevail. The article you’re pointing to seems to be a paranoid rant where the author claims that the New World Order appears to be making plans to kill billions of people in order to get the population down to “to a manageable level of between 500 million and 2 billion” but the author does NOT claim that such killing is necessary in order to for humanity to prevail. He doesn’t even seem to be claiming that the NWO (whoever that is) even thinks it’s necessary in order for humanity to prevail, just that these overlords think it would be more “manageable”.
Once again, this article is NOT saying that killing people off is necessary in order for humanity to prevail. On the contrary, the author is actively speaking AGAINST such an idea. But he does seem to believe that there’s a global conspiracy which thinks killing people is necessary, and he clearly HATES this alleged conspiracy.
That’s a rehash of more of the same. All of these links are to articles whose authors are arguing AGAINST killing, not supporting it. They each claim to have quotes from other people that (in their opinion) show that those other people think killing is necessary. But you haven’t shown me a single example of an article where the author of the article actually argues in favor of the concept that killing people off is necessary in order for humanity to prevail.
Paul Ehrlich notoriously got it wildly wrong in 1968.
Looking forward, I think almost any attempt to estimate an absolute ultimate ceiling is suspect, even those based on solar energy flux. Is there any final limit to human technology? Do we exclude a Dyson sphere around the sun? Modifying humans or post-humans to make them more energy-efficient?
It seems to me that the pressing issue is the rate of change, and in this respect we certainly can’t assume that predictions of doom are as unfounded as Ehrlich’s turned out to be. Is population growth temporarily out of control, will technology keep up before there’s some crash? Will technology itself cause a crash before other technologies are brought to bear (global warming)?
In any event, I don’t find the prospect of arbritarily large numbers of people particularly appealing. How soon will this all become moot? Does H sapiens 1.0 become obsolete, to be augmented with or replaced by artificial intelligence? Will we feel any loss if our direct descendants are the products of our technology, rather than simple organic replicas?
Cover the planet in a shell, grow crops on the outside. 126 billion acres; probably only half of it can grow food at maximum efficiency. At 0.5 acres per person to grow a mixed diet, that’s still a carrying capacity of 126 billion people.