sabato 19 dicembre 2009

Global Warming 2 (the revenge)

Il commento oggetto del mio post precedente ha suscitato vivaci reazioni, tanto che James Randi si è sentito in dovere di pubblicare alcune precisazioni.

Buona lettura.

I Am Not "Denying" Anything

Written by James Randi  
Thursday, 17 December 2009 11:01
Well, my piece on AGW -- Anthropogenic Global Warming -- has elicited a huge response, both positive and negative. The subject, dealing with the influence of our species on the observed increase in overall temperatures around the globe -- said to be about 0.7º Celsius -- is apparently a matter of great contention, and I almost regret having entered into it. Almost...
I must say that much of the commentary I see refers to "about one degree" without specifying Celsius or Fahrenheit scales. I'm so old-fashioned and fuddy-duddy that I sometimes refer to the Celsius scale as Centigrade, though it was Swedish astronomer Anders Celsius -- almost two centuries ago -- who came up with the plan to divide the span between the temperature at which water ice melted, and water boiled, into 100 parts. Only at -40º do the Fahrenheit and Celsius thermometers agree, but life is complicated, and we have to deal with such facts. Since about 1980, Celsius has become fashionable. For some perverse reason, and at risk of another storm of comments, I rather think that the USA should drop Fahrenheit -- a German/Dutch scientist even more dead than Celsius -- along with inches, pounds, quarts, miles, yards, furlongs, and other cute but incompatible units we inherited from the UK. But then, I'm a confirmed fuddy-duddy, as you know.
Back to business. Somehow, my AGW commentary was seriously misunderstood by some. Part of the reason for that is probably due to the fact that I took a much longer, 5,000-word piece, and cut it down to about 1,400 words to better fit Swift's needs. Along the way, some clarity was lost. For that, I apologize. But here are a couple of the typical negative comments I received, which are unfounded:
"Randi just came out against the science that indicates that Global Warming is happening, that it is man made, and that it will harm our biosphere (and is currently doing so)."
"I was also saddened by Randi siding with the GW denialists. He seems to have fallen for a number of logical fallacies, and apparently prefers self-deception and ignorance when it comes to this issue. Very, very sad."
Sad? Yes, if it were true. But it's not. There were a good number of other, similar comments, all quite wrong. I do not, and did not, deny the established fact -- arrived at by extensive scientific research -- that average global temperatures have increased by a bit less than one Celsius degree. My commentary was concerned with my amateur confusion about the myriad of natural phenomena that obviously bring about worldwide climate changes and whether we can properly assign the cause to anthropogenic influences. Yes, I'm aware of the massive release of energy -- mostly heat -- that we've produced by exhuming and burning oil, natural gas, and coal. We've also attacked forests and turned them into fuel by converting them into paper at further energy expense, paper that is also burned, in turn. My remarks, again, are directed at the complexity of determining whether this GW is anthropogenic or not. I do not deny that possibility. In fact, I accept it as quite probable. I remain respectful of science and its participants. I stand outside the walls of academe, in awe.
Here are a few of the comments that are kinder and much closer to the truth:
"Whether Randi is correct or not, he is honest enough to say that he does not know enough or does not have the expertise to make a fully informed decision. Right there he is 100% more honest than any denier (or religionista for that matter). When in the future he is given the requisite climate change information, if he changes his mind, he will change his mind (again, unlike deniers and religionistas). For that, my respect for him remains intact."
"I find it kind of strange to admonish James Randi here. He's a skeptic like most of us, and he disagrees with the common scientific opinion right now, with qualifications. He's not even trying to be convincing. He's reserved, repeatedly showing that he has doubts of the conclusion he's indicating. He even states that his opinion is uninformed."
"This kind of response, that he should be ashamed for expressing his opinion (especially in such a humble manner) is unnecessary. I'd be surprised if most of the people (climatologists excluded) who have concluded that AGW is occurring have looked at any more data than Mr. Randi here; the venom is a knee jerk reaction to someone disagreeing with them. Let's face it, we're (mostly) all armchair experts here. That said; I also disagree with James Randi here, but I'm more confused that he came to his conclusion than saddened or upset."
"For what it's worth, I think PZ [Paul Zachary Myers, a biology professor and the author of the science blog Pharyngula] is wrong to say Randi has joined the denialists. Randi simply said he doesn't know."
I must quickly add that PZ and I are friends and allies, and that we're not at odds. However, I perceive that he often tends to rush to publication without first checking with the author of some provocative item. This provides PZ with lots of controversy and attention, but at the expense of the author in question.
I'll close this matter with very appropriate comments from Dr. Phil Plait, who serves as President of the JREF for another two weeks, after which his position will be taken by D. J. Grothe, who I'm sure is known to all my readers. Phil effectively clarified a few points for me:
"Like many others, I was surprised when I read your Swift entry on global warming. I agree with much of what you said, but as I'm sure some have pointed out to you, there were two key issues I think you may have not considered.
"One is the Petition Project; while it has a veneer of respectability, it is only that: a thin veneer. It's not a scientific document, and many of the signatories are not climate scientists. It's been dissected pretty well on the net, for example, on e-skeptic."
In consulting this source, I suggest that you go directly to "Case Study: The Oregon Petition" to see just how this "project" was created and distributed. I admit that I was unaware of the true nature of the Petition, and I thank Dr. Plait -- and several others -- who pointed me to this reference and a much better grasp of the situation. Phil continues:
"That's an excellent deconstruction of why this project is not valid. Note also that only about 10% of the signers at best are actually educated in the field of climatology, and it's unclear what 'educated' means, exactly, in this context. Do they perform current research in climatology, and are they up-to-date with current thinking in the field? There's no indication of this in the petition.
"Also, you had mentioned how complex GW is and how difficult it is to model. That too is true, but the observations of the climate are very clear and indeed overwhelming: the Earth is warming, and the effects are entirely consistent with CO2 increase. The Sun has been shown clearly not to be the cause of this (there is no increase in solar output, for example), and the climate change we observe is too rapid to be due to vagaries in the Earth's orbit. It must be something local. The lack of a simple model doesn't prevent climatologists from understanding many of the key issues underlying global warming."
As I've indicated, I do not deny the finding of GW. AGW, to me, is less clear, though I accept that it is likely true. Phil again:
"Your claim that 'we're aware that lunar tides, solar wind, galactic space dust and geomagnetic storms have cooled the planet by about one centigrade degree in the past 150 years' is at odds with the instrumental records of NASA, NOAA, the University of East Anglia and the Japan Meteorological Agency, all of which show a warming of approximately 0.7 degrees C since 1850."
I'm still trying to find where I discovered this gem of text. I suspect that "cooled" should have been "warmed," but my currently chemo-altered encephalon stumbled... Both my enecephalon and I stand corrected. Phil again:
"While we are both amateurs, I think it behooves us to give in to those who have devoted their professional lives to understanding this complex subject. And what they have to say can be boiled down to this: the world is warming and humankind is responsible for at least half of that rise in global average temperatures."
Accepted. Again, the importance and the impact of this phenomenon is well beyond my grasp. I merely expressed my thoughts about the controversy, and I received a storm (no pun intended) of comments, many of which showed a lack of careful reading that led to unfair presumptions and interpretations. Will I do it again with other subjects? Without fail, I promise you. This is what human interaction is all about, what makes it important. I've shown that I can make observations on subjects barely within my understanding, while admitting my shortcomings, and provoke reactions that are interesting, constructive, and sometimes furious. That's okay. Language is a means of expressing one's thoughts and opinions without resorting to fisticuffs or worse. This encounter was bloodless, gentlemanly, and civilized.
And I thank you all for the use of the hall, as I used to say in simpler times...

Correction: The last two quotations in this piece were incorrectly attributed to Phil Plait. In fact, they come from journalist James Hrynshyn, who was kind enough to call our office yesterday to discuss the evidence for and against AGW.

6 commenti:

zanzara ha detto...

Data la mia totale ignoranza dell'inglese mi affido ai commenti del post precedente. Personalmente non sono un esperto di meteorologia, ma personalmente credo che la faccenda sia un pò pompata dai media,ovvio se mi dite che studi indipendenti e autorevoli confermano l'innalzamento della temperatura globale non posso non crederci ma empiricamente a mè non sembra almeno a mia memoria che sia cambiato molto nel clima l'inverno è freddo el'estate è calda certo capitano inverni più rigidi e estate più torride o piovose ma a mia memoria sono saltuarie. Tutto qui Saluti,

Gianni Comoretto ha detto...

In effetti questo commento rende giustizia a Randi. Qualunque sia la storia (non so e non posso sapere cosa avesse scritto nel testo piu' lungo, ed es.) riconosce le cose dove ha comunque sbagliato, ribadisce i punti che gli sono dubbi, senza pretendere di aver ragione, e molto onestamente ammette i suoi limiti.

Niente da eccepire.

@zanzara: esistono evidenze "empiriche" dell'innalzamento climatico, che so il ritiro dei ghiacciai o della banchisa polare, ma dubito che si possa riconoscere un innalzamento di un grado solo guardando il termometro, le fluttuazioni di giorno in giorni, per non parlare di quelle di anno in anno, sono molto maggiori.

Ma un grado a livello globale è tantissimo. Il minimo di Maunders, o "piccola era glaciale" del 1600, corrispose ad un abbassamento di meno di un grado.

Un innalzamento climatico di 7-8 gradi (molto maggiore di quanto si possa ipotizzare nel prossimo secolo) ha probabilmente causato l'estinzione di massa del Permiano (Vedi l'articolo su Le Scienze del Gennaio 2007).

aleks.falcone ha detto...

In effetti il primo articolo mi aveva sorpreso. Ora è tutto più chiaro e condivisibile.

zanzara ha detto...

@ gianni: Quindi empiricamente potremmo pure dire che il ritiro dei ghiacciai è una cosa naturale? Cosi come la mini era glaciale del 1600 che hai citato? Se ricordo bene mi pare che mini ere glaciali ne abbiamo registrate anche nel medioevo ma qui vado a braccio non ho consultato nessun testo.
P.S. Stasera fà un freddo cane sono le scie chimiche? :-)
Cologo l'occasione per porgerti i miei auguri di un sereno Natale a te e famiglia, nel caso non ci si legga per Natale. Auguri ovviamente pure a Claudio e famiglia.

markogts ha detto...

@ zanzara: sicuramente esistono variazioni del clima indotte "naturalmente". Il problema è che questa volta "è altamente probabile" (secondo la definizione che ne dà lo stesso IPCC) che questa variazione climatica sia causata dall'attività antropica.

La preoccupazione principale dei climatologi è il rischio di una reazione a catena. SE il riscaldamento aumenta, gli oceani assorbiranno meno CO2, mentre le calotte polari, rimpicciolite, rifletteranno meno luce solare (il ghiaccio è bianco mentre il mare è praticamente nero), due fenomeni che aumenteranno ulteriormente il riscaldamento globale. Dunque quello che si vede oggi è davvero una minima parte di quanto potrebbe accadere negli scenari peggiori.

markogts ha detto...

Ah, sì, dimenticavo lo scioglimento dei clatrati e del permafrost che potrebbero rilasciare grandi quantità di metano, gas serra ancora più potente della CO2.