The Elephant In The Room - II
Randolph Femmer
Saturday, 19 September 2009 14:13 UTC
This topic is a continuation of posts begun in The Elephant in the Room discussion that began in the Theoretical Population Dynamics forum several weeks ago.
The topic, which was just one of thirty in the TPD forum, developed into a lively discussion and became one of the busier topics on nature network within a week or two.
We keep the topic and the posts going here and look forward to your insights and assessments. We request everyone to please keep posts polite and to offer support or rationale for positions taken.
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This first comment in The Elephant in the Room – II is taken from, and is a continuation of, a forty-seven-item previous discussion that has been taking place in the Theoretical Population Dynamics forum elsewhere on this network and which is offered for continuation here.
I hope to comment on several problematic aspects of current Demographic Transition Theory here in a short time. For now, however, we continue with a discussion that was underway at the original Elephant in the Room.
Dear members and contributors – Thank you to everyone for your coninuing posts. As you know, the elephant in the room in this forum has generated a lot of contributions (and has for some time been one of the busier topics on nature network).
To Sidney and Seth – Your points concerning strictly theoretical aspects of population and population dynamics are certainly understandable. On the other hand, some of us who perceive ourselves as pragmatic, real-world, or big picture people think it is nearly incomprehensible that, given the problematic nature of multiple biospheric and humanitarian trajectories, that we should continue to focus only on theoreticals and minutia as opposed to pragmatics.
In one respect, your criticism that the elephant in the room has become overly-dominant in the TPD forum is certainly true. (Although it is just one topic out of thirty, it has drawn a lot of attention – which may, or may not, be to its credit.) (And certainly a number of forum members and visitors have been stimulated to comment – which may, or may not, perhaps, be to its credit)
The theoreticals-only position, however (despite a dismissive comment or two that border on name-calling), has some degree of merit in that the elephant in the room has drawn attention away from the twenty-nine other more purely theoretical and modeling topics in the forum. (No one, of course, is forcing anyhone to read the elephant posts, nor forcing anyone to comment on the posts, as such reading and commenting on the topic are entirely voluntary.)
In a way, I think that the elephant topic is appropriate in the TPD forum because it forces those whose interests are primarily or purely theoretical to face up to some of the uncomfortable truths suggested by dozens of today’s troubling trajectories. (And I don’t think that suggestions to somehow banish the elephant from mention and discussion within TPD is appropriate.)
If there are theoretical and/or practical reasons to suppose that there are no limits, no near-term limits, or higher limits to earth’s carrying capacity for an industrialized humanity, then let contributors who hold such positions so state – and then offer evidentiary or analytical support for their position, or undermining evidentiary or analytical support for the lower limit that this topic has had under discussion for some days.
Having said all of the above, however, I note that I might be amenable to some arrangement to “close” the elephant topic in this TPD forum to further posts and direct further comments and posts to The elephant in the room – II which I have already opened in the Population and Carrying Capacity Forum elsewhere on Nature Network (provided of course that all of the existing TPD elephant posts and its period of existence are preserved for visitors to see).
Two footnotes: (1) The reference to Ehrlich – Commoner assessments refers to a time when world population was nearing four billion while today we are nearing our seventh billion with what one would think to be even more troubling biospheric and humanitarian trajectories, and (2) If there are those who disagree with suggestions of a long-term planetary carrying capacity somewhere in the vicinity of 1.5 to 2.5 billion or so, please state your position as such and offer us analytic and/or evidentiary support for your position (instead, perhaps, of trying to silence assessments that you do not support). (We are, after all, just one tiny topic out of thirty.)
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Ok, let’s continue/begin afresh.
First, I’d like to proceed with minimal reference to “theory”.
Put simply, after looking around at the (to me overwhelming) evidence, I’m one of those convinced that there are somewhere between “too many” and “way, way, too many” people struggling to support themselves, and that this is causing tremendous unnecessary suffering, both for people and the other inhabitants of our planet. Since many in this forum have written books on just this subject, I feel I can safely stop with this. The latest scary evidence to come my way is from the UN Pop. Division via Worldwatch particularly, the three graphs at the bottom.
I am therefore very much in favor of the efforts say, of the UN Population Fund, and am very disturbed that worldwide funding for family planning has been falling drastically (see the third graph)
I am aware that this issue was adressed as policy 40 years ago, e.g. in NSSM 200 and that in the intervening period these policy recommendations have been largely reversed or forgotten.I am particularly interested in the nature of this political reversal, and the reasons for it. I have recently been studying various websites which espouse views directly contrary to mine, and particularly the arguments they advance. These range from reasonable (what are the economic consequences of a demographic transition, which groups get smaller first, how does this affect transmission of local cultures) to the truly weird (it’s all a plot of the worldwide conspirators, whose real goal is to destroy the traditional family).
Furthermore, as I have previously mentioned, there are generally sound psychological reasons to be slow to respond to declarations of doom, although they do not apply in this case. Finally, whatever the obstacles to increasing say, UN family planning funds are in the advanced countries, there will be equally strong arguments in the developing countries. This leaves out cultural and religious obstacles, for now.
In summary, I would like, as a minimum, to strongly increase UNFP donor funding in the near future as a gentle and collaborative way of reducing the harm, as a prelude to facing the more difficult problems, and am interested in obstacles thereto, both intellectual and especially psychological, sociological, and political. I would appreciate whatever insight others can offer in this regard.
PS. Let’s not get caught by our using terms from current theory imprecisely, e.g. using terms like “carrying capacity” without a definite time frame, applying it (dubiously) to humans who are so innovative, etc. Since this is going to eventually be a political and policy argument, seemingly minor errors of this sort will not be excused or forgiven. Furthermore, better arguments now exist (although these also need sharpening by comparing the models with data), e.g. dynamical systems projections, ecological footprint arguments, etc. In other words, we can make a stronger argument by modeling the next few centuries’ ecocatastrophies, without invoking any general theory. Better short and medium term models (say up to 2150) should mean stronger arguments. I am also looking for these, but they seem very hard to build and test.
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Refs:
See UNPF home page,
esp. the upcoming 26th International Population Conference next week. It’s a pity there isn’t more specialist and non specialist journalistic coverage, e.g. Youtube video’s etc. Maybe Nature could/has appoint(ed) someone. -
A very interesting 2009 paper “Why Do People Become Modern? A Darwinian Explanation” on the “kin influence hypothesis” as an explanation for how economic development becomes a cause for demographic transition is freely available as a pdf . The abstract is here
I recommend it for discussion perhaps later. -
Hi Seth,
Hmmm, you refer to it as an error to use the term “carrying capacity” without a definite time frame, possibly an error to apply the term to humans in the first place. Okay, I have some “issues” with that. :-)
Maybe I’m wrong, but here’s how I see it. First, many respectable definitions of carrying capacity use terms such as “indefinitely” or “permanently” or make no reference to time frames at all. I’ve always assumed the unspoken assumption is that we’re talking about a long to very long time, but that we understand it is not literally infinity.
And that seems appropriate. It seems to me that if we stipulate too short a time frame, then “carrying capacity” loses its meaning and become indistinguishable from overshoot. Isn’t it clear, that is, that the size of some population that an area can support is often much larger over short time frames than over long periods because for the short term the population can simply use resources faster than they are renewed until they are severely depleted? This can happen at a rate that seems so slow that it provides a temporary illusion of “carrying capacity,” as has been the case with human depletion of oil, for example. But as Alan pointed out in a post in the other thread, that is not carrying capacity.
Catton goes so far as to say, “Since ‘carrying capacity’ is by definition the maximum permanently supportable population, the expression ‘permanent carrying capacity’ is redundant.”
I don’t think anyone would object though to the stipulation of rather long, finite time frames. There are aboriginal cultures which have lived in place for tens of thousands of years without degrading their local ecosystems. Perhaps that would hint at the kinds of time frames one might use. Nevertheless, I don’t see how it improves particularly on “indefinitely.” It may be necessary to stipulate shorter time frames when working with mathematical models, but when discussing the issue in a general sense, looking at questions such as the sustainability of civilization itself, I don’t think so.
Second, there is the objection to applying “carrying capacity” to humans because we are so innovative. (This is a favorite argument, BTW, of many folks who wish to squelch discussion of population as an environmental stressor. I know you’re not one of them… just sayin’.) I can’t help thinking this sounds like an instance of the very natural tendency to think in terms of “human supremacy,” if you will. Many animals are innovative. Many have abilities we humans don’t. The more evidence we gather on animal behavior the, the fewer the differences we find between us an other animals. To suggest that humans are not as subject to carrying capacity as any other species is to suggest we have figured out how to overcome basic natural limits. I submit that were we that smart we would not be in the ecological mess we’re in today. I think we have not overcome, but have merely temporarily circumvented the process which, in all species, keeps population numbers in check. It has done nothing more than put us remarkably deeply into overshoot.
I have no problem, by the way, with defining carrying capacity not purely in terms of numbers but as “sustainable load.” Catton does that, and I do think it’s a better definition. But it’s important to bear in mind that the evidence suggests that the numbers themselves are far too high regardless of any remotely realistic level of per capita consumption. Here’s one way I’ve looked at that. There are other ways, such as a pure “phantom carrying capacity” analysis or the simple argument that we are fundamentally a “patch disturbing” species.
At any rate, to me a key topic in the other thread was the simple question of whether we could agree the human population was in overshoot. There is no need there even to concern ourselves at all with the question of time frames going into the future; we’re just looking at the question of overshoot. And there the evidence seems clear.
By the way, my own best guess for human carrying capacity happens to be even a good deal lower than Randolph’s 1.5 – 2 billion. If I get the chance I’ll lay out the reasoning in a future post. It’s not intended as an airtight argument as there are potential weak links which I have not sufficiently researched, but I do believe I can offer some thought provoking observations which, when pieced together, make a case for a surprisingly low human carrying capacity. More later…
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Anonymous
I’m confused. I just posted twice to “The Elephant in the Room” and now find that it has been renamed, apparently because of objections of some kind. How is whatever that problem was “cured” by starting “The Elephant in the Room—II?” I must confess that I tend to scan past material irrelevant to the subject, so I may be missing something crucial . . .
Please tell me/us by what/whose authority this was done and why? Is Femmer just capitulating to pressure or did he violate some Forum rule?
Is discontinuity an improvement over continuity or ? Does this mean that I should have started a new discussion heading called “Wooly Mammoth in the Room?” That, it would seem to me, to be ridiculous. It seems to me that there was nothing unseemly or subversive about Femmer’s discussion topic—on the contrary it seemed to be calling for a statement of the fundamental principle upon which the entire Forum is based, and that does not seem to have run its course, regardless of the number of posts.
WT
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Dear John,
As a complete amateur who has used the term “carrying capacity” in this context myself, I’m actually not competent to respond to your question.
Doesn’t use of the term CC always imply a series of particular simplifying assumptions and idealizations? If we look at the resulting simplified dynamical (e. g. stochastic differential equation) model, doesn’t CC mean that the model tends to a (meta)stable limit, or limit cycle, or chaotic variation between definite upper and lower bounds, presuming again enough temporal stability in the assumptions to suppose that we can extrapolate to long term behavior? Furthermore, isn’t the basic idea of CC that if the population of the model species in question exceeds some number for a sufficiently long time, then the ecological substrate for the species, i.e. food or habitat, is itself degraded?
On the other hand, if these caveats and preliminary understandings are introduced, I suppose that the powerful reifying metaphor of CC can be effectively used in arguments as a shorthand for all of the the above.
These idealizations deal with the objections that all species are always only metastable, environments change in the long enough run, etc.
Questions which have crystallized in this (nomadic) thread for me include
1. Although Carrying capacity is a powerful metaphor, like sheep destroying a meadow they’re overgrazing, maybe it’s too fragile for heavy use in policy arguments about humans, i.e. we need to revert to direct demonstrations of resource depletion, ecological unsustainability, ecological footprint calculations, etc., reserving the use of carrying capacity itself a capstone metaphor.
2. The most convincing arguments for human population overshoot is not the loss of a particular individual limiting resource (such as might be more relevant in a CC model), but the near simultaneous degradation of so many resources, water, soil, atmosphere, forests, fish, ocean bottom life, terrestrial wildlife, seashore and wetland life, mineable elements, societal infrastructures (from migrations), increase in pollution of many forms, etc. This is what gives these arguments what Philip Morrison used to pun as “The Ring of Truth”.PS. I very much liked your 2008 article and its conclusions. Can you speculate as to why discussions of population is somewhat “taboo” in some circles, and to which circles that disinjunction applies?
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Seth,
Ah, okay, I think the confusion is just due to the variety of related but somewhat different definitions of CC. The kinds of precise simplifying assumptions you mention are required of the logistic equation, which is one (mathematical) definition of CC (and of which I have only a passing familiarity). But there have been a number of other, often non-mathematical definitions. (This article (PDF) gives something of a review.) A number of them are fairly closely related, and I think they do get somewhat mixed and rearranged to suit the user.
I know I sometimes use a very basic definition which is close to the very first usage (Hadwen and Palmer,1922) in the scientific literature. Theirs was apparently along the lines, “the number of stock which a range can support without injury to the range.” The one I’ve sometimes used is one I found which is simple but which combines what seem to be the two key elements when you examine various definitions: “The maximum number of animals that a specific habitat or area can support without causing deterioration or degradation of that habitat.” I’ve tended to assume a word like “indefinitely” is implicit after the word “support.”
But as I mentioned, I actually think the more accurate definition, for human carrying capacity, is something close to Catton’s: “the maximum persistently feasible load – just short of the load that would damage that environment’s ability to support life of that kind,: which he puts quantitatively as, “the number of us, living in a given manner, which a given environment can support indefinitely.” That helps by allowing for consumption or, essentially, the AT of the I=PAT equation. Note that these definitions put the emphasis on total environmental degradation rather than the depletion of, say, a single resource.
I have often stuck with the simpler definition in writing for a general readership, just to emphasize sheer numbers which I have come to believe are more important than they might seem when simply considered side by side with per capita consumption (though I do of course talk about how the two multiply etc.).
Something as you suggested, I use these kinds of simple definitions as a kind of shorthand containing a number of assumptions which I then discuss as necessary.
Many times I do think it’s most effective just to talk about demonstrable environmental impacts. But sometimes I think it can be very powerful to point out that we’ve exceeded the number of humans the earth can support for the long term, almost regardless of future changes in per capita consumption or other foreseeable factors. So I guess my view is that it just depends. But, speaking for myself, when I say we’ve exceeded the human carrying capacity of Earth, I’m using something like Catton’s definition, sometimes working backward from observed environmental degradation as I did in this little essay. Though such usage is certainly not as precise as a mathematical model, I do think it has useful, substantive meaning. And it seems to me that if we can’t come out and say we’ve exceeded carrying capacity, backing it up with simple, sound logic, it’s going to be tough to convince any of those who doubt the importance of the size and growth of our numbers that we’d better do more to address the issue.
And that leads into your question about the “taboo.” it’s late, so I’ll come back to offer some thoughts and info on that tomorrow.
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It seems relevant that a newsworthy, quite strong argument for increased family planning efforts which does not directly use the notion of carrying capacity is referenced today here .
Note, however, that the Optimum Population Trust, which funded the study,has (I believe) already been subjected to severe criticism (and even vilification) on the grounds that it merely represents upper class, liberal, meddlesome do-gooders. The study’s critics will presumably include climate change skeptics as well.
I don’t know that “taboo” is the right word for the critics. There also seems to be rather a misplaced rationalism, a suspicion of intellectual arguments and (post)modernism, a strong belief that family planning and education and jobs for girls and women represent an attack on the traditional family, conservative cultural values and clan power structures (perhaps well placed), and a deep suspicion of hyperrational rich strangers arguing from the possibility of imminent catastrophe, for openers. This leaves out political, short and medium term economic, moral (anti coercion), and religious arguments.
In short, carrying capacity arguments have been made very well several times. They have been answered with a varied responses ranging from widespread willful ignoring and neglect to enthusiastic seconding. Politically, in recent decades funding has been halved or worse. There is now the possibility of a more liberal political wave, which is faltering on economic grounds, but the underlying resistance remains very strong. How to work with it?
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I suppose that a more proper place for the (hopefully) extensive public discussions to come about the reasons for the apparent psychological and sociological obstacles to comprehension (what John called “taboos”) as well as the resistance and counterarguments to increasing family planning funding is in another thread in this forum, already started and entitled Population Growth – Why are We Ignoring the Elephant in the Room? , with a focus on who are the “we”, why, and what best to do about it.
Ordinarily, I would suggest continuing of the “Why resistance” sub-discussion there. On the other hand we are very few here. Too soon and disruptive?
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