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"The carrying capacity of a biological species in an environment is the maximum population size of the species that the environment can sustain indefinitely". This definition is consistent among dictionaries and it is excellent. It is very useful and we need to comprehend what it actually means. "indefinitely" means "unlimited or unspecified period of time". This means that when the species is consuming resources (that enable more to live at one time) faster than they renew, the species is over the carrying capacity. This is a time independent concept that is dead useful. It tells us about the potential for premature death. It tells us nothing about the premature death that might or might not be happening right now. If we use accounting as an analogy, exceeding the carrying capacity is like having a debt. It does not tell us whether the bills are being paid today. It tells us that a bill is due sometime in the future. Notice what happens when we properly comprehend this. In order to avoid those future premature deaths, we have to ensure that we either 1) discover methods of providing for our numbers without relying on resources that will become scarce, or 2) average less than 2 babies until we no longer require the use of resources faster than they renew. Obviously the first solution is speculative (don't waste time explaining your favorite future technology that will save the world). As others on this talk have pointed out, humans are the only species that can really contemplate executing either of these choices. Other species always suffer the killing back down to the level that the renewable resources can sustain. Also note that this means it is rare that we observe any species above the carrying capacity. This includes humans. The past several hundred years of human existence is that rare situation. We have discovered a stockpile of resources (fossil fuels for example) and how to burn them to increase food production.
The problem with the current article is that it confuses this simple and useful concept described in the previous paragraph with another concept. That other concept is the premature death that is happening today. This would be like an accountant failing to differentiate between the profit/loss and the debt. In this case the profit/loss is the ability to keep our numbers alive today. Let me clarify what I mean by premature death. When discussing reproduction in a finite environment, we must recognize that environmental destruction and reduced quality of life are secondary issues. All the other factors, except child mortality, mentioned in the "overpopulation" and "carrying capacity" articles are simply optional. Children must die at the rate of (x-2)/x where x is how many babies the adults average. If we average 3 babies, then 1/3rd of the children must die. Notice that we don't mention this brutally simple and obvious math formula. Population scientists always discuss some arbitrarily short time span where one of the 4 following factors are changing allowing more (or less) children to live during that finite time span. The factors are 1) increasing food supply, 2) increasing age that the babies are created, 3) reducing adult life expectancy, and 4) reducing income differential. Notice that these factors must be changing in order for more (or less) children to survive than the formula dictates and obviously none of these factors can be changing for long. They are all bounded. The bottom line is that the other concept that is being confused into "carry capacity" is the side effects of attempting to avoid the child mortality caused by averaging too many babies. The child mortality happens when the population is at the limit of what can be kept alive right now. If we properly separate these 2 concepts, carrying capacity and the limit, these articles become short and simple and dead useful.
We are at the limit right now and have always been at the limit. Averaging too many babies creates the groups of people that suffer starvation related child mortality. These groups of people have always existed. The fact that the population is increasing just tells us that the limit is increasing and therefore we don't expect to see (x-2)/x deaths right now. Most people will argue that we can easily keep the ones that died alive if we improve sustenance distribution. This logic fails the most basic sniff test. It is saying that we are not at the limit now because we can behave differently in the future. Furthermore that argument is using the existence of other people, which is fundamentally bogus. This can be seen when I rephrase the statement. "we are not at the limit because the other people that had the subsistence could have shared it properly". If those other people did not exist, then what stops the victims from simply picking the food up off the ground? The existence of 7.3b people forces us to have distribution systems. "other people" is exactly what is created when we average too many babies.
Several years ago I changed the "carrying capacity" and/or the "overpopulation" article to state these simple concepts. My changes were immediately removed because I cited no scientific sources. I then reviewed the rules for Wiki and concluded that the removal was correct. The goal of Wikipedia is to state the current conventional wisdom. These 2 articles are properly stating the current conventional wisdom. That wisdom is confused and these articles are confusing. For example: "the use of fossil fuels has been alleged to artificially increase the carrying capacity of the world by the use of stored sunlight". "alleged"? Are we really confused about the fact that fossil fuels enable the production and distribution of more food? "artificially"? What is artificial about that increase? It is very real. What's really going on with this sentence is the confusion of what "carrying capacity" really means. That confusion is very real in the scientific community and this article is properly reflecting that confusion.
How do we convince population scientists to understand these 2 concepts I have stated? How do we clear up this confusion?
@Avram Primack, see above. Yes, carrying capacity is not a constant. We don't need to attempt to discover that number for any particular time period. Knowing that number is not useful. We just need to know whether we are, or are not, consuming resources faster than they renew. That tells us whether we have a premature death debt. Furthermore attempting to put a time frame on carrying capacity is a mistake. It will add confusion and disagreement and solve nothing.
@Esker7, yes, your second definition is essentially what the definition of carrying capacity is already stating.
Johntaves (talk) 18:25, 1 November 2016 (UTC)
First, environmental carrying capacity is not a number. It can only be a number in theory, and then only represented by a variable, K. In the real world, carrying capacity is a complex interaction of environmental factors that vary from year to year, so I suppose that we could next discuss the correct and relevant time scale for determining the number. In any case, carrying capacity is not a constant, and varies from time to time and place to place. Second, taking this into account, it is not necessary to have birth or death rates increase or decline in order to reach it. This may happen in extremely controlled experiments such as are reported in introductory ecology text books, but not in real life. Third, any species that has the ability to lower its carrying capacity in nature either has done so to the point where they no longer exist, or only exists by escaping into uncolonized patches of habitat. Certainly humans are not the only species capable of changing their own carrying capacity, either up or down. To assert this is to claim more place for humans than is our due. I could go on... Avram Primack
This page should link to http://en.wikipedia.org/wiki/Sexual_selection , which provides additional information on r-Selection and K-selection.
-- Nick Gall (nick.gall@metagroup.com)
"Humans are the only species known to possess the ability to increase their carrying capacity."
This isn't really true, as the Gaia Hypothesis states that all life tends to improve the chances for continuation of life (thus increasing carrying capacity... right?)
-booyabazooka
The first two paragraphs of this article give two distinct definitions of Carrying Capacity, namely:
and
The first definition allows the population (say of humans) to sink into poverty, a condition that must be considered to have a significant negative impact on the organism! The second definition rules that out. Frankly, I like the second definition better, but it is probably not consistent with the original intent of the person who first applied the term to biological populations, and thus should be removed.Esker7 (talk) 14:37, 2 August 2009 (UTC)
Humans are the only animals that kill their competiors. That takes us outside the realm of natural selection. That begins artifical selection. What is left out of the human ability to increase carrying capacity for our own species, is our near total lack of concern for the animals whose habitat we destroy.
So it could be argued that we don't increase the actual carrying capacity at all, we just shift it to the crops we enjoy. If the deer that were in the area before the farm came along, happen to like our corn crop, we simply shot them as well. Hence increasing the monoculture, and make it more possible for locust (for example) to alter the carrying capacity to their benefit. Sounds like Human carrying capacity should be added to the article.
Restated from the book Ishmael by Daniel Quinn
--Lee Wells 03:34, 18 June 2006 (UTC)
Amazingly, the logistic curve is not mentioned here at all, even though carrying capacity is actually a property of that curve. :-P This is akin to not mentioning the greenhouse effect in an article on global warming, or forgetting to mention that earth is a planet. ;-) Kim Bruning 09:15, 20 July 2006 (UTC)
(And lotka-volterra can also have a carrying capacity for each participant, of course, I last did this stuff years ago. ) Kim Bruning 09:27, 20 July 2006 (UTC)
Maybe that's because the current state of Wikipedia contributions is so overburdened with the fear of copyright infringement that everyone is afraid of trying to upload the graph. [I know I am]
I tried to start a Human Carrying Capacity article and managed to upload the wonderful table put up by a university from Joel Cohen's book 'how many people can the earth support' it was 'found' illegal in less than a day. Since I was dumb enough to include the reference of where it came from it was found to be 'copyrighted' and therefore unusable -- even though i gave the copyright reference. yes it is a grave injustice not to include the curve in the article, i even know of a couple of websites that include the article, but why put it in if some yo-yo is going to pull it for fear of 'copyright infringement' then you get accused of trying to 'piss someone off' if you put it back.
welcome to the world of NPOV. Sucks doesn't it?
-Lee Wells 13:43, 30 July 2006 (UTC)
P.S. you are more than welcome to try and upload the graph if you are succussfully, maybe you can tell me how i can reupload the table I spoke of.
"Amazingly, the logistic curve is not mentioned here at all, even though carrying capacity is actually a property of that curve." -- I don't agree at all. The logistic curve might apply in the situation where the population limit (the max that can be kept alive in the environment) is a fixed number and the species was introduced into that environment such that its numbers are below the limit. In that very rare situation the population might follow a logistic curve. Regarding the human situation, this is useless on both counts. 1) Humans have existed in the environment for plenty of time for our numbers to have hit the limit. Indeed the bulk of human history is characterized by no growth in the population and therefore the population must have been at the limit (unless you are going to invent some magical fertility rate regulator that prevents us from cramming too many humans into the environment and thus causing death). And 2) we obviously have managed to discover plenty of ways of increasing the limit. Farming, and refrigeration are a tiny fraction of the discoveries that have increased the limit. Notice that this is why Joel Cohen failed to fit any simple math curve to human population numbers. He's trying to fit a math curve to resulting population changes from immeasurable technology discoveries. Johntaves (talk) 21:59, 1 November 2016 (UTC)
Critiques of application to humans will be folded into humans for the VERY simple reason that carrying capacity is (as i understand it anyway) a NUMBER -- NOT A POLICY the 'forced sterilization' argument may have usefulness under Population control, (oh wait surprise it's already there!) but in any case references need to be included. This is supposed to be a reference tool, people can't find what they need if it's mislabeled. If anyone has any problems with this please discuss here. [a google search only turned up forced sterilization and carrying capacity in Wikipedia] that should tell you something.
Lee Wells 23:40, 24 August 2006 (UTC)
Completed. Rereading for about the fouth time it seems a little uneven, but I tried to group statements about the same idea in the same place. Statements that seemed obviously in error I tried to correct (like ecological footprint says nothing about population size),
Lee Wells 18:56, 4 September 2006 (UTC)
i have moved the following sentence not connected to any thought pattern to this talk page until someone can sort out its role (if any) in the subject article:
"Used in accordance with Fair use<ref>http://williamcalvin.com/bk5/bk5ch6.htm</ref>."
Anlace 18:21, 10 September 2006 (UTC)
Hi - I've been resolving a dispute over this article over the past few weeks, and would like to present my recommendations for the article (or at elast those which are relevant) here. Note that they are only suggestions, but I'd hope that in time they'd serve to improve the article as a whole.
I hope this can help to bring this article forward, and make it a better resource for thouse who look for it. Please direct any repsonses to my comments here (or to my talk page). I will try to help out with these changes when I get time. Thanks Martinp23 19:45, 17 September 2006 (UTC)
the graph for carrying capacity can be found nowhere on earth. WHo has taken this jewel from among us??
it was a jew. a black one
Perhaps carrying capacity should be broken into GENERAL i.e. bandwith (even telephone wires have a 'carrying capacity') & BIOLOGICAL. Then again both are so similar, the GENERAL term sim & BIOLOGICAL serve to explain each other.
Unfortunately THE EARTH IS FINITE and the author of this section fails to understand this SIMPLE point. Human migrations aren't possible across national boundaries anymore. Unfortunately the Earth is one large 'bounded space' which includes arable land which by ALL accounts is shrinking. Saying that carrying capacity doesn't apply to humans implys humans aren't animals thus they are immune from the law of evolution, and natural selection. [Thus this article discredits evolution, another term that is having enough problems in American public schools, without this 'Critique']
If Wikipedia editors feel that Critiques should be a seperate section, then I feel a 'response to critiques' is necessary. However I feel this solution would make the article less readable, so I'm asking for other ideas.
Lee Wells 21:57, 14 January 2007 (UTC)
Well I don't know if I fixed it to everyone's satisfaction or not but then again that's why Wikipedia has those [edit] links.
Lee Wells 15:46, 28 January 2007 (UTC)
I got rid of the point/counterpoint format, and removed the unsubstantiated claims of the original editor. I also deleted the last several points completely, as they were purely argumentative, and in some cases, even the responses were misguided. (1) It's a misapplication of Occam's razor to say a simplistic argument is superior. (2) It's a gross oversimplification to suggest Rwanda was caused by population pressure. (3)Carrying capacity is not the basis of evolution, but one of many selective pressures. People would be subject to carrying capacity even if they hadn't evolved, as long as they have to compete for finite resources. (After all, Malthus came before Darwin.) At any rate, the points to which these errors responded were purely philosophical and unsubstantiated, so I deleted both point and counterpoint in these instances. JoeFink (talk) 17:20, 30 January 2008 (UTC)
The article states: "If the average American today owned 40 acres of arable land, there would be about 11.3 million Americans, instead of over 300 million, conversely our living standard would be higher. Most Americans would probably be farmers"
That statement is false for two reasons.
First, farming productivity in the U.S. is high enough today so that only 2% of the population needs to be farmers. This is true, regardless of whether the U.S. has 11 million people, or 300 million people.
Secondly, a long time ago, when almost everyone worked on farms, the standard of living was lower, not higher. If everyone is working on a farm, then there would be no one to build washing machines, refrigerators, telephones, or light bulbs. Without these things, our standard of living would be lower, not higher. Grundle2600 19:15, 14 May 2007 (UTC)
This part of the article is what makes it correct: One can also argue that if the United States of America have lost World War II if its population been that small compared to the rest of the world, so living sustainably when the rest of the world does not would have its drawbacks.
Notice the word SUSTAINABLY the reason that 2% of the American population is all that it takes to feed the rest of the United States is that it is done UNSUSTAINABLY the entire article is on CARRYING CAPACITY which by definition is what you mean by SUSTAINABILITY.
the only thing that is wrong with the statement is that it only implied sustainability a problem i will fix right now.
Lee Wells 02:26, 20 May 2007 (UTC)
All that really is wrong is it uses the term living standard rather than quality of life which would hold true.
Does anyone else here think it might be a good idea to inclue a bit of information of the use of carrying capacity in modelling? For one the theory of carrying capacity is applied widely in Applied Ecology and conservation though the use of population viability analysis etc. Surely this article is a little too centered on humans? --Philthemancunian 23:30, 5 October 2007 (UTC)
Under the mathematics/modelling section, a simple program I found to show carrying capacity is the WATOR: Predator-Prey Simulation game. I did not know where to put this information in the article but I believe it to be a worthwhile inclusion.Septagram (talk) 16:33, 9 July 2009 (UTC)
I don't understand what citations are required in this section. It certainly could be written better, but the point seems so simple that there is nothing to cite. I'll try some other ways of explaining it.
If an organism consumes the resources that it requires to sustain its current population faster than those resources can renew, then its population is by definition above the carrying capacity. I don't see how anyone can disagree with this. I didn't figure out how to state this concept in the definition of carrying capacity. It seems to be a natural conclusion from the definition.
Coal and oil are renewable resources, yet humans are clearly burning them faster than they can renew. Maybe we should cite that coal and oil took hundreds of millions of years to create. Coal and oil are not necessary for human life, but one must agree that humans require those resources to feed the current 6.7 billion population. In other words, coal and oil are necessary to support the population. I don't see a need to cite anything for this observation.
You can make an argument that it is possible to feed 6.7b humans without coal and oil, but that position would certainly be built on a lot of speculation and simulation. That position would need citations. That would be theory - a situation that does not exist, so it can't be used to say humans are not past the carrying capacity. It could be used to say that the carrying capacity will rise to meet and exceed the population, but still we are left with the fact that right now we are above the carrying capacity.
You can argue that oil and coal will last a long time and therefore "temporary" is "a long time", but so what? Carrying capacity is not about "long time" or "short time" it is indefinite. In other words as long as the conditions remain the same, it will go on forever. Clearly coal and oil will not go on forever so unless something else is invented (which could be as complex as a completely solar based energy system serving everyone) to allow us to produce the required food without using resources faster than they renew, the population must shrink.
We are discussing this "carrying capacity" concept to understand the current state and what we must do to deal with the future. If we somehow let ourselves be fooled into thinking that we are not way above the carrying capacity, then we are allowing ourselves to conclude that we don't need to do anything differently. We don't need to invent some new stuff that will give us the energy to feed 6.7b without consuming resources faster than they can renew. Do we need to cite something to comprehend this?
You might point out that the sun will burn out in 5b years, and therefore all species are over populated. This is true, and therefore over the next several tens or hundreds of millions of years we must reduce the human population so that we can live comfortably within the diminishing area that is still hospitable on the planet. Clearly this does not require immediate understanding and action. Oil and coal on the other hand will run out within a time span that is similar to a human life time (I agree that a citation is needed for this sentence, because it is not common knowledge when oil will run out). If nothing is invented or changed to raise the carrying capacity, then the population will drop as oil and coal become scarce. Johntaves (talk) 05:58, 19 September 2009 (UTC)
"The World3 model of Donella Meadows deals with carrying capacity at its core." What does this statement mean? Can someone put it in clearer language please? SweetNightmares (talk) 01:16, 25 February 2010 (UTC)
"Agricultural capability on Earth expanded in the last quarter of the 20th century. But now there are many projections of a continuation of the decline in world agricultural capability (and hence carrying capacity) which began in the 1990s." What is agricultural capability? Is the term synonymous with agricultural productivity? Is agricultural capability a measure of the biophysical capacity for cultivating crops? Whereas agricultural productivity simply measures the efficiency of crop production without considering the capability of lands to withstand said mode of production? I think a distinction should be made. Also, a citation should be added for the "decline in capability" statistic. --Daliposc (talk) 02:01, 31 January 2017 (UTC)
The last line of Ecological footprint section, "The authors overlook the fact that burning fossil fuels helps to create sustenance that keeps many more people alive than otherwise.", seems more like an opinion then a fact. It would be an interesting section to expand on but currently is completely unsubstantiated. Brennand97 (talk) 21:13, 11 February 2017 (UTC)
The section on ecological footprint was greatly expanded, using material from the Global Footprint Network, (http:///www.footprintnetwork.org) if at all. I don't think that's a reliable source. I haven't checked whether the material really was taken from that web site, as the reference tags are vague as to where on the site they were referring to. — Arthur Rubin (talk) 07:31, 1 March 2010 (UTC)
Hi, I've fixed a number of citations but half of the links in this article are dead and half of the citations are so vague as to be non-existent. In addition some are more than a little dodgy The Sex Lives of Cannibals is described by a leading internet bookseller as a 'comic masterwork of travel writing' for instance, which doesn't really fit in the the encyclopedia thang. I'm going to try to (slowly) work through the entire thing finding reliable, viewable, assertions for everything.
I've noticed that there is also a page Tourism carrying capacity (which I know nothing about). The section in Carrying capacity on this subject is almost as large, which is ridiculous and I would suggest either that the section in this article gets merged with it? talk tospy on Kae 18:32, 14 March 2010 (UTC)
As an addition to the above I have one question: How does "Chincoteague Pony Swim" 'example' pertain to carrying capacity? According to the quote they are artificially managed herds with restricted size so the carrying capacity of these herds are irrelevant...
Also Carrying_capacity#Differing_definitions has been lifted wholesale from the EU report (section B.1). I'll try and fix it with differing sources. talk tospy on Kae 23:01, 15 March 2010 (UTC)
The sentence "Supporters of the concept argue that the idea of a limited carrying capacity is just as valid when applied to humans as when applied to any other species." seems to be a valid point and a much talked about subject of this article but this sentence has no direct reference to it. Could one be found? Brennand97 (talk) 20:34, 11 February 2017 (UTC)
I think the scope of Optimum population is too similar to this one to justify separate articles. Optimum population could very well be a separate section within the Humans section in the Carrying capacity article, and any major differences between the two parameters explained there. Mikael Häggström (talk) 10:23, 3 January 2011 (UTC)
The first paragraph should define the concept and put it in context. Carrying capacity is a theoretical ecological concept. It involves a one dimensional model that includes no environmental or species factors. It has no operational definition that can be used to evaluate any real world situation.
The first sentence is.... "The carrying capacity of a biological species in an environment is the maximum population size of the species that the environment can sustain indefinitely, given the food, habitat, water and other necessities available in the environment. " Better as....
Carrying capacity is a theoretical ecological concept that describes how a population responds to limits an otherwise stable environment in which resources and competitors are constant. It is formally defined as the maximal number of a species that can be supported by an environment. Mathematically it is the value of K in the logistic equation which is used to describe population growth in limited environments. In the real world resources and the population of competitors and food items are always changing, so it is difficult identify whether or not any species has reached or exceeded its carrying capacity. Still, the concept is useful in fisheries management in trying to identify maximum yield, and in ....
The next sentence is nonsensical and repetitive....what is the concept of population equilibrium and how is it different? Environmental maximal load is jargon for carrying capacity, and you cant use a word to define itself.
"In population biology, carrying capacity is defined as the environment's maximal load,[1] which is different from the concept of population equilibrium."
The next paragraph immediately jumps to humans without giving any discussion of whether or not there are any animal or plant examples of carrying capacity.
"For the human population, more complex variables such as sanitation and medical care are sometimes considered as part of the necessary establishment. As population density increases, birth rate often decreases and death rate typically increases."
The next paragraph is full of woulds...a signal that means that we are not really sure. To make it definite it should be couched in will... Avram Primack (talk) 19:04, 8 December 2011 (UTC)
An actual, verifiable scientific attempt at determining human carrying capacity of Earth requires you to set upper limits on innovation (which happens to affect resource discovery & utilization), information storage & sharing, and cooperation. Anyone who makes such claims has historically & inevitably always ended up looking like a fool. -Reticuli 71.72.161.102 (talk) 20:40, 6 August 2016 (UTC)
This article could be expanded to cover more information. I feel as though it has a shallow exploration of carrying capacity and could have more topics covered rather than just the factors that govern carrying capacity and the ecological footprint. Pipertownsend (talk) 06:04, 19 May 2017 (UTC)
@Beland: Although you added a cleanup tag to this article, I still don't know which part of the article contradicts the Human overpopulation article. Can you explain the reason for this cleanup tag? Jarble (talk) 20:11, 7 August 2017 (UTC)
RBlew (talk) 16:29, 3 February 2018 (UTC) Carrying Capacity is a multivocalic concept [] – which itself has a carrying capacity of how many different meaning a word can have. Depending on context carrying capacity can be in a closed system where a number can be applied as in engineering with the load bearing capacity of a bridge, the time till structural failure under given conditions, the operating envelope of a device. In some cases a number is applied when in reality this is more a mean of a variance in statistical distribution (z score). A recommended dose of a medicine, or what is a lethal dose of a toxin, depend on the status of the patient at the time. In open systems carrying capacity is subject to a wide range of factors, where a biome can have a higher carrying capacity than living organisms present, and then can be vastly exceeded by a rapid environmental change (hurricane, flood, fire, deforestation, oil spill), where a given population . Human carrying capacity is even more of a moving target and even reverses rules related to growth curves, for example a more affluent county may have a slower birth rate as more children survive to adulthood, and gathering wealth become more important that assure progeny. The human technology and cultural ability to exploit a wide range of environments, find new resources, create more energy, endure in less that optimum conditions, can push carrying capacity beyond apparent limits of finite resources. From looking over the article the current version is accurate and the dispute tag can be removed. Someone may want to the terms has a wide variety of meaning, though the See Also section convey with wide number of ways the term is used, though recommend Malthusianism [] and Malththusian Catastrophe, Criticisms [] be added to the article.
The human overpopulation article's uncited estimate of the maximum possible population that will ever exist on earth at 4 billion is clearly wrong, as evidenced by reality. The UN reference with a summary of estimates averaging at 10 billion used here is good. The editors of that article seem to be confusing terminology and using 'carrying capacity' incorrectly. I think what they mean is the K of a earth in which humans were completely sustainable, something which is not implicitly implied. Leo Breman (talk) 14:32, 8 May 2020 (UTC)
this assessment has recently been updated - see katherine richardsons report from last month ~~ 123.208.37.87 (talk) 03:41, 16 October 2023 (UTC)
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