withrespect2x's posterous

You need to stop using this phrase

Dear everyone who uses the term "carrying capacity" in debates about human population, as in "Australia's carrying capacity is probably a little less than 20 million...."

Stop it, please. I know your intentions are good, but you're talking out of your anus. Yes, really, even most of you professors of environmental science/biology etc who employ it in public policy debates, from what I've seen.

Now I'm a stupid crazy Cornucopian[1] on these issues, but fortunately you don't need to agree with my overall views to accept the argument I'm about to make...

What is a Carrying Capacity?

Essentially a carrying capacity is a number that derives from certain kinds of biological models of population growth. The first and simplest such model, which will do for the purposes of explaining the relevant concepts, is the logistic equation[2]:

dN/dt = rN[K-N]/K

In this equation K is the carrying capacity.

I know, Calculus is hard and boring, but this model isn't too hard to understand for non-maths people.

Its about predicting how the population of a given lifeform grows. It says the more lifeforms there are, the more lifeforms get born, which leads naturally to exponential growth[3]. However at a certain point, the ecosystem the lifeform lives in can't provide enough of some critical resource (energy, potassium, territory, etc) to sustain any more growth; so the population obtains a natural maximum value, our much beloved K.

While a massive oversimplification of most populations outside of bacteria on a petri-dish, its nonetheless a reasonably successful model; it predicts some things quite well, and is the basis of most of the more sophisitcated and accurate models that we have.

OK, so far so good.

Is the logistic model applicable at all to humans?

In a sense, yes. Based on what we know about physics, there are is an upper bound on the the amount of humans that can live in a given segment of space.

However, applying the model (or any of its variants) naievely to homo sapiens is useless, because basic biological models make simplified assumptions about living things that work reasonably for most organisms, but simply don't work for us. Its important to stress that I'm not saying that humans aren't subject to the basic laws of biology; I'm saying that our current understanding of the laws of biology are only an approximation, that break down especially badly in the case of humans, just as Newtonian physics breaks down for really small things, really fast things, and really heavy things.

So what's broken?

The model assumes that two important things are fixed: the environment, and the nature of the organism (technically, the species' phenotype).

Both of these assumptions are wrong. However they typically work well enough in practice. A lot of the time, the environment doesn't change very quickly relative to the growth of the organism whose population you're trying to predict. Sometimes there's a megavolcanic eruption or whatever and the environment does change rapidly, but no scientist who uses the Logistic Model would pretend it works in those scenarios.

Thanks largely to Darwin we understand that phenotypes also aren't fixed. Organisms make technological innovations, in the forms of experimental mutations to their genome, that are passed on via vertical and horizontal gene transfer. But, and this is a critical point so I will chuck in some emphasis, genetic evolution is generally slow when compared to the timescales of population growth.

Actually, to be honest, I gather biologists increasingly are of the opinion that both ecosystems and genes nearly always change fast enough to matter for any reasonable model of population in the real world. But the intuition, that the effect of population size dominates these other variables and so they can be approximated in our equations as a constant, is what most people mean (even if they don't realise it) when they talk about Carrying Capacities.

And humans...?

Modern humans don't just challenge the assumptions of environmental change and evolution happening very slowly relative to population growth; they shatter them.

I shouldn't have to tell "we're overpopulated and the environment is dying" types that our environment is changing very rapidly due to our presence in it.

What a lot of people miss though is that the reason our physical environment is changing so fast is because we're causing it to, by virtue of evolving orders of magnitude faster than any other species in Earth's history.

The trick is that we no longer depend on genes alone to pass on our neat discoveries to our peers (horizontal transfer) and descendents (vertical transfer). We have what Richard Dawkins called memes. Before everyone changed the word to mean "amusing YouTube video", it was supposed to express the concept that the information contained in a human idea replicates, spreads, mutates, combines and evolves in a way that is related (but different) to a gene.

This is the defining feature of humans as organisms. It sets us apart from other animals. There are of course some quite striking examples of similarities between human intelligence and the intelligence found in other animals - the agriculture of Ants, the tool use of Chimpanzees, the puzzle solving of Octopuses - but none of them can be said to have culture.

They can't learn how to make a hand-axe or a fibre optic cable from a diagram. They can't change how they think about their co-species members by reading a Bible or a Tao Te Ching. They don't write songs or novels or advertisements or newspapers, they don't make speeches or status updates or scultputres or blog posts.

The speed of evolution of all these other species is limited to the speed at which genetic mutations appear, can be tested for fitness by nature, and can be spread amongst a population. This is normally such a glaically slow pace that it took until Darwin for us to even realise that it happens.

In contrast, consider a tiny little bit of memetic information, a Martin Luther King Jr quote [4]. Look at how quickly, with ze power of teh interwebs, it was accidentally mutated, spread, and then the faultiness of the mutation was identified and counteracted.

OK, enough ranting about memes

The point is that:

dN/dt = rn[K-N]/K

is, to use the technical term, an idiotic model to apply to humans. Thanks to memes that store their information in your brain and your iPhone instead of your genome, our species is not only changing fast enough to effect our population growth (and in a nice little feedback loop the size of our population in turn effects the speed of memetic evolution), we, and as a result our environment, are actually changing faster than our population is growing. Contrast for instance the rate of change of per GDP over human history with the rate of change of population.

Now there are naturally still constraints, and there are still going to be constants of various descriptions in whatever the correct model of human population growth is, including one that might resemble a carrying capacity: maybe something like

(dN/dt) = rN[K-N][C-M(N,T)]/CK

where M(N,T) is total memetic information [i.e. our collective cultural knowledge] as a function of population size and time. But the constant CK here is a very, very different beast from the K that models a limit on the amount of available grass for a cow to eat.

And furthermore you may think we're going to rapidly evolve to a dead end where we nuke or pollute one another out of existence (eventually N -> 0), or to a triumphant program of galactic colonisation (eventually N -> Lots), or any one of a million scenarios in between. And that's fine, we can disagree about that, its kinda hard to say at this point who is right, since we don't have any other memetic species to study for clues. Scientific reasoning is sadly of little help in understanding unique data points.

In conclusion

If you continue to try to treat N as the only variable in our own population equation, and approximate all other relevant factors with a constant K, and if you further try to guess what that K looks like based on a vague intuition formed from other, non-memetic species, you're going to end up looking very, very silly. Some otherwise quite respectable biologists[5] keep making this mistake, because scientists love to take a model that works for the phenomena they've studied, apply it to a superficially similar but actually far more complex phenomenon, and then act puzzled when it doesn't seem to work so well. That's ok; learning why the models don't carry over, and updating them, is what science is all about.

But please don't try to tell me Australia can only "biologically sustain" 20 million people, as opposed to 10,000 people, or 10 billion people. You made the number up, based purely on the remarkable coincidence that we happen to have a little over 20 million living here right now. Its fictious; it has no basis in scientific reality.

And, if you try and use your bullshit number to justify preventing people fleeing corruption, poverty, war and genocide from moving here, I reserve the right to first mock you as clueless, and second attack you for using terrible reasoning to inflict a moral outrage.

So yeah, STFU with the "carrying capacity" phrase already.

----------------------

EDIT: Fixed some tyops, tidied wording in a couple of sentences slighly, clarified the language concerning what changes in genetic evolution (species wide phenotype, not individual organisms.)

Footnotes, because I'm old fashioned, and wanted you to read my argument in full before following the links.

[1] http://en.wikipedia.org/wiki/Cornucopian

[2] http://mathworld.wolfram.com/LogisticEquation.html

[3] http://en.wikipedia.org/wiki/Exponential_growth

[4] http://www.theatlantic.com/national/archive/2011/05/anatomy-of-a-fake-quotation/238257/

[5] http://en.wikipedia.org/wiki/Paul_R._Ehrlich

Useless regulator

Posting again! Huzzah!
 
This one is something topical with a "here's opinion that I prepared earlier" flavour. But I have a heap of stuff writtren recently that could be publishable pretty soon, about all sorts of fun topics so this is as much as anything else an excuse to get the ball rolling.
So anyway, dear reader, I refer you to the pissweak findings of the communications regulator in the David Campbell went to a sex club case:
 
 
Funnily enough I think my contempt for their conclusion is completely encapsulated in the following letter of complaint that I drafted to them at the time the story broke, but sadly never sent.
 
According to section 4.3.5 of the Commercial Television Industry Code of Practice, broadcasters of News and Current Affairs programs

"must not use material relating to a person’s personal or private affairs, or which invades an individual’s privacy, other than where there is an identifiable public interest reason for the material to be broadcast"

There was and is no identifiable public interest whatsoever in the Channel 7 news broadcast of material pertaining to David Campbell's visit to the club Ken's at Kensingtons.

Mr Campbell was not improperly making use of a government funded car; as has been widely acknowledged, the Ministerial code of conduct condones the use of Ministerial cars for private use, and there is no serious argument that this policy is a controversial one, or that other commonplace private use of these vehicles is newsworthy.

Mr Campbell has not breached any duty of trust to the parliament or to his constituents. There is no onus on elected officials to publicly disclose details of their sex lives. Mr Campbell has not misrepresented himself in any way; there is nothing dishonest about his decision to keep his private life private. Any suggestion that his sexuality somehow requires public discussion is implicitly and repulsively homophobic, as it is grounded in the assumption that silence somehow constitutes deception - that gay and bisexual men, and only gay and bisexual men, must actively announce their sexual orientation to the world.   

There is no suggestion that Mr Campbell's execution of his duties as a Minister were in any way affected by his private affairs. The notion that his sex life left him unacceptably vulnerable to blackmail is absurd. By such a standard, any public figure who wished to maintain privacy with regard to any detail of life whatsoever would be fatally compromised.

Stripped of spurious justifications, it is obvious that the story broadcast by Channel 7 constituted a gross breach of Mr Campbell's personal privacy, for no reason other than to increase program ratings. Channel 7 has done a tremendous disservice to the quality and tone of civic discourse and the state of journalism within this country. This was a reprehensible piece of reporting and a clear violation of the Code. Those members of the Channel 7 news team directly responsible for the broadcast of this material should lose their jobs.     

So yeah, I think that pretty much sums up how I feel about this case! Still! Even though the ACMA bought into the bullshit blackmail argument, I still find it pretty thoroughly unconvincing.
 
In conclusion - screw you Channel 7 for your pathetic grubby gutter journalism, that makes it that much less likely that any talented young kid growing up in our society could ever actually aspire to be a hard working and successful Minister of the Crown. Just so you could get a ratings boost for a single night.
 
And screw you, ACMA. for being a useless piece of crap regulator that took however many months only to ultimately agree with a weasley excuse so stupid it took me about 15 seconds to see through. I'm sure you'd find some tortuous sophistry to justify the media publicising a politician's kid's best friend's dog's medical conditions, if the circumstances arose.
 

The main reason I'm not voting for the Greens this election

Take what follows with a grain of salt - I wrote it as an angry polemic. I completely standby the substance of the argument, though.

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People are keen to blame Julia Gillard for the demise of Kevin Rudd, and berate the ALP for its failures on climate change. 

People have short memories, or poor reasoning faculties.

A little while ago Kevin Rudd and Malcolm Turnbull were leaders of their respective parties. Both are highly intelligent men who's people skills turned out, in retrospect, to be a little lacking for what's required at that level in politics.

Both are by inclination centrists and pragmatists. 

Both are wholeheartedly convinced that Anthropogenic Global Warming is real, and that a carbon price would clearly be the best measure to address the issue.     

Between them, they almost brought about a bipartisan Act of Parliament to implement an Emissions Trading Scheme for Australia.

It would have been a truly historic occasion. Admittedly, the final scheme that ended up on the table was a paltry and mangled effort, far short of what's actually needed to address the magnitude of the problem.  

Yet, it would have been a scheme, and resulted in a fewer emissions than the absence of one. The law, once in place, could not conceivably have been repealed. Other countries stalling on taking any action would no longer be able to cite Australia as a richer and more selfish fellow hold out; international consensus would be that much marginally easier to reach. Potential investors in alternative energy would have had some much needed regulatory certainty. It would be subsequently a great deal simpler, with the populace given the chance to directly witness that the ETS did not spell the doom of Western civilisation, to put the case for a tightening of the inadequate original emissions caps.

It would, indeed, have been an almost inconceivable political triumph; for politics is the art of changing the world, one shitty compromise at a time.

This great hope for anyone who cares about Australia's role in the future of the planet was burned to the ground, in part by the fringe Senators Xenophon and Fielding, but chiefly, by two deceitful ideologues and their supporters. 

One was Tony Abbott, who thinks climate change is crap, held that argument within his party room against all the mountains of scientific evidence and the pleading of the moderates, and then set about spreading some unholy the mixture of confusion and lies to the electorate concerning the Coalition's newfound, so-called climate policy.

The other was Bob Brown, who unilaterally decided that only a perfect scheme was acceptable, that by some inconceivable paradox of logic a medicore and flawed scheme that did not reduce emissions enough was somehow worse than a non-existent scheme that did not reduce emissions at all.

He too lied and continues to lie to voters, maintaining the rhetoric that the scheme "would not have reduced emissions" - by which he presumably is referring to reducing emissions levels at some arbitrary point in the future below those at some arbitrary point the past, when the only valid comparison is whether the scheme would reduce emissions in any given year versus the alternatives of a stronger scheme or an absent one in the same year. We could be facing the end of the world as we know it, and every tonne of C02, just like every cigarette, is doing us damage. 

It was quite nauseating to see him interviewed recently - insisting that the Greens, with their consistent range of 5-10% of the primary vote, would have graciously condescend to lower themselves as far as a 25% target; and that it was the ALP - the duly elected party of government in Australia, with a popular mandate the Greens will almost certainly never match in our lifetimes - that was pigheaded in refusing to negotiate within the Greens' defined non-negotiable parameters of the debate, for senate votes that would not alone have seen the law passed anyway.

The pair of them got their way: Abbott wanted a weaker scheme or none at all, Brown wanted a stronger scheme or none at all, so we were landed with the natural reconciliation of those two views - no scheme at all, and an agreement to keep arguing about the issue. The centrists had been outflanked to both the left and right, and thus were lost.

Malcolm Turnbull chose to go down fighting. Kevin Rudd was content to retreat, but had already been mortally wounded. As a believer in climate change he had committed himself in no uncertain terms over the issue, but as a politician he knew or at least feared that the window of opportunity for a compromise had been lost.  He lacked perhaps the courage, or perhaps the patience, to fight another election over an issue he had already contested strongly at the previous election, to seek a second popular mandate for a policy when he had already won one. Unprepared or unable to fight on, he shelved the scheme - only to find the move an extremely sharp rock to the double dissolution's somewhat hard place.   

The ideologues got their sordid desserts. Progressives laud the Greens for their purity and heap scorn upon the machinations of the ALP, and how despicable it is they pay attention to opinion polls, when they should be "leading" - which is to say somehow unilaterally imposing progressive views on the electorate, perhaps by the Prime Minister spontaneously conjuring a PhD level understanding of science and economics during the 10 second sound bite the TV networks usually allocate to policy pronouncements.   

They weep for the knife Julia Gillard slipped into Rudd, to dispatch him quietly where he already lay in a pool of his own blood, surrounded by the spent shell casings of Bob Brown's semi-automatic. 

Abbott meanwhile was more than willing and able to seize the moment and drag the entire political debate in the country substantially rightwards. Moderates who saw Rudd's wounded dithering listened to Abbott's lines about great big new taxes and rewarded him in the polls. Rudd and now Gillard have had little choice but to chase after him, seeking the median point of voter opinion that determines the outcomes of elections. Cue more bitching and moaning about politicians with no vision or leadership, and the of course the progressives indignantly flocking to give their primary vote to who else but the Greens.

If the Greens had volunteered to vote for Labor's original ETS - while of course still prosecuting the case with voters that it was insufficient and would need to be strengthened - it is very likely none of this would have happened. The government could have focused its negotiations efforts entirely on Steven Fielding's uninformed climate skepticism instead of the entrenched anti-environmentalism of the Liberal Party's hard right.  

Abbott and Minchin would have had to steamroll the moderates knowing that afterwards a single rebel Senator crossing the floor - and their were several such votes in the version of reality we got lumped with - would pass the bill and leave them hugely damaged as a party.

Odds are something between Labor's first proposal and the one the parliament rejected would have passed.

Both major party leaders would have survived. Under a Turnbull led opposition against a Rudd led government, there would still be a debate about asylum seekers, but it would have been less audible and less vitriolic; no one would have proposed sending home those without papers. 

The election debate would have probably been about whether the BER was genuinely wasteful or largely successful stimulus; about just how culpable the government was for the failures in the Insulation scheme; about the merits of the start of a shift towards federal control of hospitals, measured against the abject failure to provide more substantial reforms in sectors like mental health; and possibly about more of the content of the Henry tax review, which could conceivably have achieved bipartisan backing for some of its simpler reforms with a less obstructionist opposition. In other words, about genuine issues of serious national concern and significant disagreement between the major parties. 

But instead, we have a polarised debate between vocal ideologues, and stuck in the middle Australia's first female prime minister suffering the indignity of trying to become the illegal immigration macaroon.

No wonder the Greens are so terrified of Nuclear Proliferation that they fear even Nuclear Medicine. They are of the ilk that would see the world burn rather than give ground and have their "principles compromised", and so of course it strikes them as highly likely that anyone given access to uranium would do the same.

I cannot protest the ALP's objectionable policies on election day, because the Greens are far more worthy of protest.