While we are on the subject of the book of Revelation (see previous post), here are some different versions of 'John the Revelator'. The one from the Blues Brothers film has a nice gospelly feel to it, but my favourite is the delta bluesy version by Blind Willie Johnson. I also like this energetic version by the White Stripes.

The Seven Seals is a phrase used in the Book of Revelation to refer to the symbolic seals that seal the "book" or "scroll" that John of Patmos saw in his vision.

Who is Antichrist?

In medieval logic 'Antichrist' was a proper name frequently used as an example of reference to an individual who does not exist now, but will exist, just as 'Caesar' was the stock example of reference to an individual who does not exist now, but used to exist. This may help to illuminate the curious discussion going on at Vallicella's place. For all the following statements are (almost uncontroversially) true, in my opinion.

(1) At least some of the biblical texts (including Daniel 7, 8 and 11, Revelation 13 and 17) claim to make identifying reference to a man or creature who would rise up against God and the 'Son of Man', and who would wage war on the saints. For example, Daniel (7:8) claims to have seen the person in a dream, a direct revelation of the future ("and behold eyes like the eyes of a man were in this horn, and a mouth speaking great things"). Thus, even if the prophets weren't making an identifying reference, they thought they were.

(2) When the medieval scholars used the term 'Antichrist', they were aiming to refer to the same individual that prophets thought they were referring to. Thus the name 'Antichrist' was used, and is used, with the aim of making an identifying reference.

(3) Various descriptions of Antichrist are given in the biblical texts, in order that we might recognise him. Hence the question arises, even now, if whether certain individuals who exist now should be identified as Antichrist. Eg. Ian Paisley denounced Pope John Paul II as the Antichrist in 1988, and many people in America think that Obama is Antichrist.

(4) But the significance of the name should not be confused with any description by means of which we are told to recognise Antichrist. If the name signified the description, the identity would have the status of a logical truth, and we could not reasonably question whether anyone satisfying that description was Antichrist.

In summary, the name 'Antichrist' is a singular term used to make an identifying reference, or with the aim of doing that. Thus it makes an identifying reference to an individual who probably does not exist yet, or aims to make such a reference (in the case that Antichrist never exists). It is not a description, for there are individuals satisfying the description of whom one could reasonably deny they are Antichrist. E.g. when I say that Obama is not Antichrist, I am not denying a logical truth.

Debt and equity

I continue to fret about what the world would look like if all finance were 'Islamic'.  What would equity look like?  The liabilities of a normal company are typically split between about 10% of 'equity' and 90% of 'debt'.  The debt is a deterministic liability that involves the repayment of principal at a determined maturity, and an agreed and fixed coupon payable at agreed intervals.  The equity is merely the difference between the current value of the assets and the debt.  This gives two advantages to the person who owns the equity.  (1) Any of the asset income stream that remains after the coupon has been paid belongs to the equity holder, as does any capital gain resulting from the increase in asset value.  And (2) if the asset value falls below the debt, the equity holder can walk away from the company, which will fall into the hands of the creditors, the owners of the debt (at least, assuming the company is limited liability).  The first advantage gives a strong incentive to the equity holder to reduce costs of the assets, and maximise the income. The second means that the losses of the equity holder are limited to the equity.  This gives a chance for those with limited capital to set up in business, without the risk of materially large losses.

Under an Islamic system, no deterministic liabilities (i.e. 'debt') are allowed. All investors in the company must share the risk of a fall in the value of the assets, and all must share the rewards.  In effect, it makes every investor an equity holder, and dilutes the possibility of extraordinary profits available under the debt-equity system. Could a modern capitalistic economy thrive under such a system? 

Future identifying reference

Vallicella is agonising here (see also here) about the problem of how (or whether) it is possible to identify individuals who do not exist, but will exist in the future. This requires that there must be a way to individuate all possible individuals that in no way depends upon their actual existence. But that in turn means that 'haecceities' must exist - supposed non-descriptive properties that have no other function than to belong to the very individual they belong to. Or as Vallicella puts it:

A haecceity is a property H of x such that: (i) H is essential to x; (ii) nothing distinct from x exemplifies H in the actual world; (iii) nothing distinct from x exemplifies H in any metaphysically possible world.

Vallicella takes it for granted there cannot be haecceities. They are 'creatures of darkness'. But assuming there aren't, the problem is that if God is omniscient (i.e. knows everything that is, has been and will be) then he must have known which individuals he was going to create when he created the world. (For example, he must have known he was going to create Socrates). This cannot be explained without presuming haecceities (per Vallicella). Since there are no such things, God is not omniscient.

I reply: if we can make an identifying reference for items that exist now ('this baby here'), and items that existed in the past ('Isaiah'), why can't we make identifying references in the future? Isn't the 'he' below such a future identifying reference? Does it require a haecceity existing when Isaiah made the prophesy? Why? Why can't the reference reach over the future centuries in order to identify the yet-to-be-born Jesus?

For to us a child is born,
to us a son is given,
and the government will be on his shoulders.
And he will be called
Wonderful Counselor, 
Mighty God,
Everlasting Father,
Prince of Peace. [Isaiah 9:6]

A matter of numbers

I have been having a fairly ‘vigorous’ discussion with Brandon Watson here, about fair pricing of financial contracts in general and, more specifically, the practice of making such contracts ‘Sharia compliant’, which, as far as I can see, consists in taking products which have a built-in and unavoidable interest rate cost, and disguising that cost by calling it something else, such as a fee or planning cost or whatever. Brandon has replied with the fairly astonishing claim that “you seem to have the odd idea that fairness in contract is a matter of numbers.”

Fairness is about being is transparent as possible the source of the product costs, and hence the amount of profit. That’s why companies have accountants, and is why, indeed, accountants are called ‘accountants’. Many of the recent problems in the financial area stem precisely from a lack of transparency. 

Most retail banking and investment products are simply cobbled together from products freely available in the wholesale markets, traded at market rates, or are internal products whose risk and price can easily be computed by a financial model of some kind. An annuity, for example. The simplest form of annuity is a product that pays you a fixed and agreed sum of money on a monthly basis from a certain age until you die, in return for a lump sum paid in advance by you. Annuities are the building block of all pensions, of which probably every person in any developed country has at least one. They are a basic, as well as very important financial product. The price of an annuity is also very simple to calculate. You begin with a set of long term government bond rates, which pay a fixed sum far into the future. Then you apply a set of mortality rates which work out the probability of you being alive in any of the years in which you hold the annuity. These allow the provider to work out the fair value ‘spread’ over the government bond yield which it can afford to pay, before the annuitant dies. A fair value annuity is thus one where the mortality-adjusted value of the excess spread exactly balances the profit the provider will receive by owning the bond after the annuitant dies. This fair value can be objectively calculated by using government bond rates – objectively verifiable – and statistical tables, also available from the government. Thus, in this case and most others - pace Brandon - fairness in contract is entirely a matter of numbers.

Of course, the product provider will rarely explain this to you, and will almost certainly hide the fact that standard products like annuities are available almost at cost, if you know where to look. There is little profit in providing such standard pension products. You are more likely to be sold a ‘wrapper’ or pension plan of some kind which combines a standard annuity with other wrinkles such as other forms of insurance, investment plans and early redemption options, all of which are also individually available at a fair cost, plus a whacking great hidden charge, of course. The salesman’s main job will be to emphasise the (geniune) attractiveness of the product, while minimising any hidden risks and hidden charges – one of which will be a handsome fee for ‘advising’ you.

Reform of the financial system involves changing the law to force providers to disclose hidden charges, and to be explicit about the true costs. ‘Sharia-compliant’ products seem like a retrograde step, in my view. They tend to make the raw costs of the product completely opaque to the customer, for the reason that making them explicit would make them immoral, from the customer’s standpoint. How would you construct a Sharia compliant annuity? Impossible, in my view, and the experts seem to agree. Attempts to provide a different product that is not a genuine annuity may lead to risk or harm for the customer – for a sad example see here.

In summary, while other factors must be considered in assessing fairness, correct accounting and transparency about underlying costs are crucial.

Meanwhile, some gospel music

Richard mentioned Mahalia Jackson (who I like a lot).  But here is something just as good, possibly even better.  Sweet Honey in the Rock.

Global warming - thanks for the links

Thanks to everyone who posted on my global warming questions.  It confirmed my view that the science of global warming is somewhat more complicated than the simple explanations suggest.  At some point I will collect together the links to resources, but I don't think that there is (yet) any resource on the web which takes the reader through every logical step of the argument but without being needlessly complex or difficult. The resources which go into detail have massively more than is logically required, and those which are aimed at a less 'technical' audience tend to skip over important logical steps - particularly the move involving the logarithm of CO2 concentration, which is not properly explained in any of the non-technical sources.

Wikipedia would be the ideal place for such a resource, but that has problems of its own (it seems to have a policy that the basic science should not be explained).

Reply to Aquinas on usury

Before discussing Aquinas’ argument against usury, a brief recapitulation. My main thesis is that the scholastic complaint against ‘usury’ was unreasonable, and at best uninformed. This requires understanding what they did mean by ‘usury’, on which Aquinas’ argument in the previous post is very clear. Aquinas did not mean that usury was a form of unreasonable charge against a loan, such as administration costs, or simply very high charges over and above a ‘natural’ interest rate. He was not talking about any form of overcharging. He was talking about any form of charge for the use of money itself. Charging for the use of money is to sell the use of a thing whose use consists in its consumption, and is therefore like selling the same thing twice. It is rather like selling wine separately from the use of wine. It is a form of fraud, and is therefore wrong, he argues.

His argument rests on a mistake. Clearly the use of money is like the use of wine. We consume money by spending it. As Aristotle says “the proper and principal use of money is its consumption or alienation whereby it is sunk in exchange". Money is not like a house, which you can live in, nor a car, which you can drive. Its use consists in destroying it.

But the charge for a loan (meaning the ‘risk free charge’) is not a charge for the use. Rather, it is the difference between the value now of a sum of money to be used in the future, and its value then. Giving £95 to you now, in return of a payment of £100 in a year’s time is simply my purchasing something from you, namely the future £100. The £95 is a payment, not a loan. The loan is the two things together: the present payment, and the contract for a future payment. And the ‘charge’ of £5 is not a charge for the use of the £95, but rather the difference between the future value of the future £100, and its present value, which is exactly £95. Thus it is not a charge for use, and thus we are not selling the same thing twice. Rather, the borrower is selling something to me (the future £100) and I am purchasing it from him at its present value (which is £95). One sale, one purchase, which is how things should be.

Aquinas on usury

Thomas Aquinas discusses usury in a very clear argument in the Summa Theologiae (IIª-IIae q. 78 a. 1). I summarise his argument as follows. He says that it is unjust to sell the same thing twice, but usury is selling the same thing twice, therefore usury is unjust. The minor premiss is proved as follows. Usury is selling the use of money, and demanding the same money back. Now the use of money consists in its consumption - according to Aristotle (Ethic. v, 5; Polit. i, 3), money was invented chiefly for the purpose of exchange: "and consequently the proper and principal use of money is its consumption or alienation whereby it is sunk in exchange". But to sell the use of a thing whose use consists in its consumption, and to demand the same thing back, is selling the same thing twice, therefore etc.

Thomas compares usury to selling wine separately from the use of the wine. This is to be distinguished from renting a house, where the use consists in dwelling it, not in destroying it. To rent out a house is not selling the same thing twice, and therefore not unjust.

The argument seems clear and forceful. But it seems to contradict the conclusion I came to in a previous post, namely that money does have an intrinsic 'time value'. What has gone wrong? More tomorrow.

Are we entitled to the risk-free rate of interest?

Yesterday I asked why there is a risk-free rate at all. Today I shall ask whether we have a moral entitlement to it. You might say that we don't, arguing syllogistically as follows.

1. Getting a risk-free profit is consistently getting something for nothing.
2. You are not morally entitled to consistently get something for nothing.
3. Therefore, you are not morally entitled to a risk-free profit.

In a comment on the previous post, Brandon questioned 2*.  Perhaps there are circumstances when you are morally entitled to receive something for nothing, on a consistent basis?  I shall not discuss this here. I shall simply assume that premiss 2 is correct.  It is the first premiss I am concerned with today.

In defence of the first premiss, it might be argued that investing money at the risk free rate, so that you are guaranteed to get your money back after a period of time, plus an extra component corresponding to the risk-free return, seems like a consistent way of getting something for nothing.  You haven't done anything to get the return, and you ran no risk in doing so.  The only thing that got you the return was the ownership of the principal amount. Thus you have earned something for nothing.

I reply: premiss (1) is trivially false. In the previous post, I argued that the root cause of the risk-free rate is mere time preference.  A farmer wants to sell £100 worth of crop in a year's time.  He sells that future crop to someone now for £95.  Time preference explains the discounting, and the discounting explains the risk-free rate.  And so you are not getting something for nothing. In earning the discounted amount (i.e. the £5) you have to wait for one year.  Thus, the £5 pays you for the waiting.  In lending at the risk-free rate, you are getting something (the risk-free return) for something (waiting until the loan matures). 

As to whether there is a non-trivial sense in which the first premiss is true (perhaps by qualifying 'nothing' in some way - perhaps mere waiting is not a genuine 'something'), I will leave that for Brandon to comment, and I may say something about it later.

Note that modern financial theory only allows two kinds of interest rate, namely the risk-free and the risky rate.  The other kinds that Brandon mentions in his original post (administration charges, social value) are not interest rates at all, at least not in the modern sense.  We should not confuse the various charges and costs built into a loan, with an interest charge itself.

* Or rather, he questioned something like 2.  I'll leave him to comment here if he disagrees.

Usury and the risk-free rate

Yesterday I discussed the efficient market theory and excess risk-adjusted returns.  The theory says you cannot consistently achieve such returns.  However, an 'excess return' means an excess over the risk-free rate.  The risk-free rate is a return that is absolutely guaranteed (because it is risk-free!) and which you can get by lending money over a period of time.  Today I shall examine why there is a risk-free rate at all.  Tomorrow I shall examine whether, given its root cause, we have a moral entitlement to receiving it.

The root cause of the risk-free rate is time preference for money or goods. Would you prefer to have something now, or in a year's time? No one is indifferent to waiting, and everyone would prefer to have something now, rather than later. However, many physical goods we have to wait for, such as a crop. Time preference suggests that the value now of a crop that will be harvested in a year's time will be less than its value in a year's time. Thus if I wish to sell you that crop for future delivery, even if we are agreed that its value then will be £100, its value now will be less than that - say £95.  Banking originally grew out of the practice of selling grain-sale rights at such a 'discounted' price against future harvest, in Lombardy in the Middle Ages.

Note that discounting does not of itself involve lending as such.  We are buying future goods from the farmer with hard cash, who can walk away with the money as his own, with nothing to return. But its implication for lending is obvious.  The 'law of one price' ensures that the risk-free rate and the discount rate converge.  If the discount rate is higher, then I can borrow at the risk-free rate, buy future goods at the discount rate, and make a guaranteed profit.  If it is lower, then I can sell future goods, and invest at the risk-free rate, with guaranteed profit.  If everyone understands this - as the efficient market thesis says they will - the two rates will converge.

In summary, time preference - the preference for value now rather than the same value in the future - leads to discounting.  Discounting in turn (via the law of one price) leads to money having a sort of intrinsic value.  None of this involves any ethical judgment, merely observations or facts about human behaviour.  Tomorrow I will ask whether we are morally entitled to receive this time-value from money.

On usury

Brandon Watson has two fascinating posts here (July 2011) and here (July 2009) about the morality of lending money (‘usury’) and scholastic theories thereof. I raised the question of whether modern financial theory can inform us about this subject, without any satisfactory answer – partly because of the problems of thread formatting, partly because of confusion about the meaning of the terms involved.

Some of the concepts used by the scholastics have a direct counterpart in modern financial theory. For example, damnum emergens, an entitlement to a charge for the administrative costs involved, and periculum sortis, entitlement to a charge covering the risk of the loan defaulting. Two others are much more difficult: lucrum cessans – entitlement to compensation for losing profit that the lender would have certainly had if he had not done the lending, and the view that money on its own never carries an intrinsic title to interest – “money does not breed. It carries no intrinsic potential for profit, and it is immoral and unnatural to treat it as if it did -- 'unnatural', indeed, is the word they often used for it”.

In the following series of posts I will try and make sense of these ideas in terms of modern financial theory. The best place to start would be the efficient market hypothesis. This is the hypothesis that financial markets are "informationally efficient", and that an investor cannot consistently achieve returns in excess of the risk free rate on a risk-adjusted basis, given the information available at the time the investment is made.

Like all theories, it has a theoretical and an empirical aspect. The theory is that because excess returns are so desirable, people will soon find out about them (that’s the ‘informationally efficient’ part), and so competition for them will drive the return down (usually by driving up the price of the investment that yields the returns). Thus, though some investors may find excess returns, they cannot consistently do so. The ‘risk-adjusted’ part involves stripping expected losses from risks to the investment. Some investments may apparent yield excess returns. But once the return is adjusted for the expected or probable loss, it will disappear.

The empirical part is driven by statistical analysis. Louis Bachelier was the first person to propose (in 1900) that stock markets follow a random process. Though his theory was rejected at the time, subsequent investigation seemed to confirm that, if market prices are random, it follows at least that the ‘weak’ form of the hypothesis is true*. One cannot earn excess returns by analysis of past investment prices. The theory is not uncontroversial, particularly after the recent ‘credit bubble’ and subsequent collapse.

The efficient market hypothesis has no ethical component, and involves no moral judgment. It simply posits that there is, in fact, no ‘free lunch’. But there is an associated moral judgment. Our natural view – apparently shared by the medievals – is that a genuine free lunch is somehow wrong or immoral. Unearned income is wrong: everything we get, we should earn, etc. What the efficient market hypothesis suggests is that there is a kind of natural justice. There shouldn’t be excess returns, and in fact – as suggested by the theory and the science –there aren’t.

However, the modern theory diverges from the scholastic one on at least three key points. First, the theory defines excess returns as the risk-adjusted returns over the ‘risk free rate’. The risk-free rate underpins all modern financial theory, and acceptance of it is essentially accepting that money has an intrinsic potential for return, which the scholastics did not accept. Second, the idea that one is only entitled to compensation for losing profit if there was a legitimate profit to be had is somewhat alien to modern financial theory. Third, if the theory is true, then we can reject the notion that lending and investment has to be legislated. The best way of promoting fair lending would be to abolish anti-usury laws.

I will examine these problems in the next post.
*For the semi-strong and strong forms, see the Wikipedia article Efficient-market hypothesis.

Global warming in logical form

I just found this draft paper. I hadn’t heard of Professor Bill Johns before, but his credentials seem respectable, and the paper is fascinating. It summarises the evidence and science behind each of the arguments that carbon dioxide is the main cause of the current global warming. In each case, it finds that the evidence is weaker than appears at first sight. The main arguments are as follows.

1. The Vostok argument. This is named from the Vostok ice core drilled by the Russians through Antarctic ice, and a subsequent study finding a strong correlation between the concentration of carbon dioxide and temperature over a period of 450,000 years. The data is available here. Johns notes that the correlation is striking but does not prove that increasing carbon dioxide causes increasing temperatures (medieval logicians called this the ‘fallacy of false cause’ - fallacia secundum non-causam ut causam). It is possible that the correlation simply results from the fact that when the global temperatures are low, carbon dioxide dissolves in the oceans and its concentration in the atmosphere is correspondingly reduced.

2. The exceptional rise argument. The argument is that the current rate of temperature rise is higher than any rise experienced on Earth for at least 10,000 years. This suggests that industrialisation is responsible for climate change. He concludes, using statistical analysis of earlier changes in temperature over long periods, that there may be something unusual in the current rate of global warming. “However, the statistics give only weak support to the hypothesis that there is something climatically unusual”.

3. The current correlation argument. The argument is that the current correlation between atmospheric carbon dioxide concentration and global warming is significant. Johns concludes that, from statistics alone, there is no reason to believe that the correlation between global warming and increased carbon dioxide concentrations is other than coincidence. “It follows that this coincidence cannot form part of the science supporting the Carbon Hypothesis”.

4. The simple science argument. Much of the support for the Carbon Hypothesis (as our commenter Belette noted) is that mathematical models of climate change predict temperatures rises with catastrophic results (i.e. 3 degrees C or more). Johns argues that mathematical models were originally designed for chemical or physical processes that are well understood, but the physics and chemistry of climate processes is not so well understood. “Modellers do not have a set of similar planets to test their models on, or to evolve their modelling tools”. His comments about the interaction between water vapour (which is the most significant greenhouse gas), and carbon dioxide, are interesting. In the presence of excess water vapour the absorptivity of carbon dioxide is strongly suppressed, and at sea level the contribution of carbon dioxide to infra-red absorption is negligible compared to the natural variability of water vapour concentration in the atmosphere. Thus the science is not so simple.

5. The consensus argument. The IPCC has a number of reliable climate models from which it concludes that there is a 90% probability that carbon dioxide is causing global warming. How can all of those scientists be wrong? Johns notes that few of these climate scientists are “main-stream scientists”, and that most come from a weather-forecasting (meteorology) background. They are not used to formulating and testing models like other scientists because they cannot go back to the laboratory to test the various elements of the model; they have to wait for the climatic conditions to arise that test the models. We should therefore read ‘scientific consensus on global warming’ as ‘meteorologists consensus on global warming’.

Please note that I am simply summarising his arguments. Note also that this is a logic blog. Arguments like ‘X doesn’t understand climate science’ or ‘Y is a global warming denier’ are logical fallacies. From a logical point of view, there are essentially only two replies to an argument of the form “p and p implies q, therefore q”. The first is that p does not imply q. The second is that p is not true.

The London plumbing crisis resolved

Summarising the gobal warming discussion so far. My ‘global warming scepticism’ is simply that the evidence for catastrophic climate change is not clear. A sceptic naturally wants evidence for p or not-p, otherwise (if necessary) he is entitled to be sceptical about both p and not-p. Excluded middle does not apply to propositions embedded in the ‘sceptical about’ operator.

Now, there is a simple ‘textbook’ or ‘idealised’ climate model that can be easily explained, and is clearly nothing to be sceptical about. But this predicts nothing catastrophic (at least not for a long time). Now there is a much more complex model, which involves ‘feedback’ effects. But the problem there, as our commenter says is that “If you want a very simple explanation of how much warming you get from increasing CO2 by Y% then you can't have one: the full theory plus modelling of the earth system is too complex.”

This is a problem for scepticism. If we drop the Fermi assumption that all complex things can be explained simply, and accept that there are some things that are simply too difficult to be explained in a short time, it follows that there will be situations where a sceptic – who is a generalist – is unable to challenge statements made by a specialist. But if unable to do that, he is no longer a sceptic.

One ray of light, however, is that at least one of my several plumbing crises may not be as serious as I feared. A clever site here tells us, for any given rise in sea level, whether our property is flooded or not. It tells me that substantial parts of West London will remain above water even with a rise of 3m. Within 500 years, London may look like Venice. That is something definitely to be welcomed.

How catastrophic is catastrophic?

As there has been no sign of a Fermi explanation so far, I had a go for myself, largely with the help of this paper. Yes, I am aware that Lindzen is widely held to be a climate change denialist and therefore an evil monster, but I admire the way he writes clearly and convincingly and without belittling or talking down to his audience.

The concentration of carbon dioxide has increased since the beginning of the industrial age from about 280 parts per million (ppm) to about 390 ppm.  According to the simple 'textbook' model* of global warming, it is generally accepted that the warming from a doubling of carbon dioxide would only be about 1°C.  That is, the amount of carbon dioxide currently in the atmosphere (about 390 ppm) would have to double to 780 ppm in order to cause a rise in global equilibrium temperature of 1°C.  Simple arithmetic based on the rate of increase in CO2 (see the graph above) suggest that this would take almost 250 years to happen. Furthermore, because of the logarithmic effect - each doubling producing the same arithmetic increase - it would take 250+500 = 750 years to produce a 2°C rise.  This is hardly catastrophic, and gives us some time to do something.  I'll hang on to those incandescent bulbs for now.

But this is much less than current climate models suggest from the warming from a doubling of carbon dioxide.  Why is that?

*To avoid any confusion, I mean the simple textbook model described here as ‘this model’, i.e. where it says “Thus this model predicts a global warming of ΔTs = 1.2 K for a doubling of carbon dioxide.”. 

Arctic meltdown to flood London

I discussed a suitable understanding of ‘global warming’ yesterday, settling on ‘catastrophic man-made global warming’. By extraordinary chance one of the cheaper (in fact free) tabloids this morning was talking about how global warming could cause a meltdown of the Arctic, flooding London. That’s what I call catastrophic! I live close to the Thames, and hardly relish the thought of having to leave the basement for the upper floors, and travelling to Tesco’s by boat, within my lifetime or my children’s.

But let’s move on to reasons for believing in this catastrophe. Clearly the catastrophic flooding will be caused by higher temperatures. But how high do the temperatures have to get, and how will this be caused? What is the Fermi explanation?

On the Road (Carbon footprint)

I just finished 'On the Road' by Kerouac, after a space of forty years. I last read it as a sixteen year old. Had it changed? Yes. Twenty-two year old men to a sixteen year old are gods and giants, whatever they do. To a much older man, they are simply young men. Yet the book gripped me in the same way.

A recurring theme of the book is jazz, and jazz culture (as well as plenty of fast and dangerous driving). Here are two of the numbers referred to in the book. 'The Hunt' by Dexter Gordon - note the comment that says 'I came here after reading On the Road'. (Not me). And 'Congo Blues', which includes some of the giants of 1940s jazz: Dizzy Gillespie, Charlie Parker, the wonderful Teddy Wilson, and Slam Stewart.

"Woo hee!"he yelled. "I'm gonna git drunk tonight". We went back to Frankie and the kids. Suddenly Dean got mad at a record little Janet was playing and broke it over his knee: it was a  hillbilly record. There was an early Dizzy Gillespie there that he valued - 'Congo Blues', with Max West on drums. I'd given it to Janet before and I told he as she wept to take it and break it over Dean's head. She went over and did so. Dean gaped dumbly, sensing everything. We all laughed. Everything was all right.

Note the recording on YouTube is not the same as the one referred to in the book.  Note also that 'Dean Moriarty' (in real life, Neal Cassady) clearly doesn't give a monkeys about global warming, as he races across America at his usual 100 mph in various cars, and in three massive journeys.  Has anyone worked out their carbon footprint?

Definition of global warming

'Belette' commented that I hadn't been consistent in my definition of 'global warming'*.  I had asked for a 'Fermi explanation' showing why it exists, but that requires an understood and agreed definition of what it is.  OK.  There are three ideas locked up in that term, as commonly used and understood.  First, that warming is not a mere accident.  'Global warming' does not mean simply that the earth is hotter than it was some time ago. It means that there is some underlying cause or reason why it is getting warmer, and that as long as the cause exists, the warming will go on.  Second, that the underlying cause or reason is the cumulative increase in carbon dioxide in the atmosphere, caused by industrialisation.  This is properly called 'anthropogenic' global warming, but it usually has that meaning even without the qualification.  Third, that the warming will if unchecked lead to to disaster.  This should properly be called 'catastrophic anthropogenic global warming'. 

The proposition I am sceptical about is there "that increasing atmospheric concentrations of greenhouse gases, notably carbon dioxide, will have catastrophic consequences for mankind and for the planet".  Obvious I don't deny that the cumulative increase in carbon dioxide is causing long-term global temperature to rise.  But no one has explained clearly to me why this should matter.

*Vallicella has just reminded me that he has some definitions here.

Where my arguments for direct reference came from

Someone posted to ask where I got the arguments for 'direct reference' from (For the purpose of this discussion, call ‘Direct Reference’ the theory that part or all of the meaning of a proper name requires the existence of a named object).

Just a question: Who gives this argument for direct reference? I haven't seen it in Kripke or any of the other big names in Phil of Lang. Just curious where you got this specific argument?

The four arguments are listed here. The argument referred to was the first of the four arguments, namely that that a proper name does not signify something that is repeatable, therefore does not signify a property. Therefore it signifies an object. Where did the argument come from? It is loosely based on Kripkean arguments against the view that proper names are non-rigid designators. I.e. I am assuming that 'non-repeatability', which Kripke does not invoke, is close enough to his notion of 'rigidity'.

The second and third arguments are closer to the early modern and medieval discussions of proper names. The fourth argument (that truth-conditional semantics rests on the assumption that the conditions for the truth of a sentence give the sentence’s meaning or significance) was taken almost verbatim from Teresa Marques' "On an argument of Segal’s against singular object-dependent thoughts" (Disputatio, volume II, no. 21, pp. 19-37) although her argument in turn owes much to John McDowell and Gareth Evans.
I haven't replied to the fourth argument yet, due to distractions about global warming and other distracting things.

Global Warming 2: “For details, read the papers”

The title is taken from a comment to my last post about global warming scepticism. That kind of remark is the source of my irritation with the global warmist lobby. They are telling us that everything is very bad, and exhorting me to throw away my stash of incandescent bulbs. But they aren’t given us sufficient reason to believe what they say, other than ‘scientific consensus’ or ‘read the papers’. Here is the comment:

The (surface of the) earth is warmer than if it was just heated by the sun, because it is heated by two sources: the sun and the atmosphere. [This is the inappropriately named ‘greenhouse effect’]. More atmosphere, more ‘greenhouse effect’. For the details, read the papers.

Commenter, this in no way wins you a £5 voucher. A ‘Fermi explanation’ has to be a complete chain of reasoning from cause (or evidence) to effect. Approximations are OK, so are gross assumptions, so long as they are reasonable assumptions, but every link of the logical chain has to be visible. Your comment is wholly useless in this respect. It doesn’t explain the relation between carbon emissions and ‘atmosphere’, nor the relation between ‘atmosphere’ and temperature, nor the relation between temperature and ‘damage’ or ‘harm to planet’. So, no prize, sorry.

On ‘read the article’, about a year ago I got tired of reading stuff about ‘scientific consensus’ and tried to work the whole thing out for myself. It was surprisingly hard. Wikipedia articles like this are a useful overview, but they remind me of those science books I read avidly at the age of 8, how telephones work, how air brakes work, how jet engines work. A useful ‘pictorial overview’, but without depth of explanation. This article is much better, but fails for two crucial reasons. First, it is mathematical. Although the mathematics is not very difficult, there are many people to whom this kind of reasoning is impenetrable. A verbal, or pictorial explanation (or a combination of those modes of explanation) is needed to explain the underlying reasoning, without the maths. The second fault is far worse, because it fails to connect the variable representing the amount of atmosphere, with the industrial process. It neatly explains in a quantitative way how increases in epsilon correspond to changes in equilibrium temperature. But it doesn’t explain how emissions in carbon dioxide are related to epsilon*. Which is what we wanted to know. How much is my stash of incandescent bulbs likely to increase the equilibrium temperature of the earth? Don’t know, and I am keeping the stash for now.

*To be fair, the article does state this implicitly, in the bit where it says “The radiative forcing for doubling carbon dioxide is 3.71 W m−2”. But it doesn’t explain where that figure comes from, nor does the article http://en.wikipedia.org/wiki/Radiative_forcing it links to. And it only gives figures for carbon dioxide emissions. As I mentioned in the previous post, carbon dioxide is not the only greenhouse gas.