Saturday, February 9, 2008

Accuracy, Precision, Description

Today you'll hear a lot of talk about the predictive (or descriptive) power of models -- mathematical models, physical models, usually run by powerful computers. A model is a simulation that describes what a part of the world is like, or can predict what one part of the world will be like in the future (or what it was like in the past). Of course, the description can't be so detailed that it describes the world perfectly -- with no stone left unturned. But this "imperfection" is probably the very reason they are talked about so much. It's generally assumed that if the model can't describe the world in great detail, it mustn't be a good model at all.

But what counts as "great detail"? And what good would models be if they mimicked the world in such great detail that they'd...become the world?

In his book, On Exactitude in Science, the author Jorge Luis Borges quotes a fictional author who tells of an empire that "perfected" their maps (their model making) to the point of absurdity.

"In that Empire, the craft of Cartography attained such Perfection that the Map of a Single province covered the space of an entire City, and the Map of the Empire itself an entire Province. In the course of Time, these Extensive maps were found somehow wanting, and so the College of Cartographers evolved a Map of the Empire that was of the same Scale as the Empire and that coincided with it point for point. Less attentive to the Study of Cartography, succeeding Generations came to judge a map of such Magnitude cumbersome, and, not without Irreverence, they abandoned it to the Rigours of sun and Rain. In the western Deserts, tattered Fragments of the Map are still to be found, Sheltering an occasional Beast or beggar; in the whole Nation, no other relic is left of the Discipline of Geography." (*)

This echoes an exhange in one of Lewis Carroll's books, Sylvie and Bruno Concluded.

"That's another thing we've learned from your Nation,' said Mein Herr, `map-making. But we've carried it much further than you. What do you consider the largest map that would be really useful?'
`About six inches to the mile.'
`Only six inches!' exclaimed Mein Herr. `We very soon got to six yards to the mile. Then we tried a hundred yards to the mile. And then came the grandest idea of all! We actually made a map of the country, on the scale of a mile to the mile!'
`Have you used it much?' I enquired.
`It has never been spread out, yet,' said Mein Herr: `the farmers objected: they said it would cover the whole country, and shut out the sunlight! So we now use the country itself, as its own map, and I assure you it does nearly as well. Now let me ask you another question. What is the smallest world you would care to inhabit?' (*)


Ultimately, the issue is whether the information conveyed by any description is enough for whatever purpose seems to be at hand. But what some critics of models seem to forget is that when they demand an incredibly high standard of description, they border on asking the absurd. Of course, there are the ones that conclude that the description isn't accurate because it's not absolutely precise. (So 2 + 2 doesn't equal some number between 3 and 6?). But a lack of precision doesn't translate into a lack of accuracy, although admittedly we want to have some kind of precision in our descriptions of the world. The statement, "it's 12 o'clock give or take 12 hours" is accurate, but so imprecise that it's not a valuable description at all.

Even in a complex world, a relatively simple description can be useful. It can give you the broad picture, and very rarely do small and seemingly insignificant details matter much. Anyone who muses that you need to be more specific or detailed in order to "get the picture" is asking too much. Creationists do it all the time: "show me precisely how and when humans evolved from their ancestors, or else you can't really claim at all that we're the products of evolution". Or, better yet, "until we can pinpoint exactly how much humans are contributing to global warming, how can we say humans are contributing at all?".

There are times, though, when such small details matter. Modelling the future is a difficult business, and in a world where small things can lead to big changes, it often helps to be thoroughly detailed even about purportedly insignicant things. But there comes a point when the model must, by definition, fall just short of reality (or the reality of what is to come). To abandon the model on that account, though, is foolish -- it still can tell you a lot. There really isn't "only one way to find out". You can find out, more or less; get an good idea, but not the clearest picture.

On that note, time to add my own allegory. I used to debate whether I'd be a good enough visual artist to be an architect. Will I be able to draw my ideas quickly and in the proper detail? Over time I learned that a not-so-perfect drawing is actually the most elegant of all. There is something of character in a representation that doesn't give too much away -- but enough to appreciate what is to be built.

Of course, there are those computer programs that strive to make a design seem exactly as if it's been built. I suppose this was a solution to the problem of the skeptical client who might say, "I won't agree to this design unless I see what it would really look like -- none of these fancy drawings and models work for me". To which the architect then replies, "I can build bigger ones".

Monday, February 4, 2008

Voodoo Logic in the Climate Change Debate

Let me start out by saying that when I write "climate change debate", I mean the popular debate -- in the media, in documentaries, and the like. While there is still scientific debate surrouding climate change (earth's climate change, mind you), most, if not all, of that debate centers around either quantifying certain forcings and their climate sentitivity or predicting future climate and its effects. The popular debate doesn't seem to know what it wants to discuss -- but rest assured, it discusses anything and everything, from whether climate change is happening, to how expensive solutions are. A fertile, but oft frustrating discussion, to be sure.

The Voodoo Logic

If there is one ultimate example of the failure of critical thinking in this issue it's the one concerning the Vostok ice core records and the supposed reverse causal relationship between temperature and rises in carbon dioxide. It has been surmised by some -- most famously Dr. Tim Ball as seen in Martin Durkin's documentary, The Great Global Warming Swindle -- the the Vostok ice core records show that it isn't C02 that causes warming, but it is in fact temperature rises that cause a rise in C02 concentrations.



The Vostok ice core record. Compiled over the last two decades by several research teams, it was used, more famously, as a centerpiece of Al Gore's slideshow presentation in An Inconvenient Truth.


The supposed problem is this. While the ice core records do show a very strong correlation between C02 and temperature, temperature rises before C02 concentrations rise, ahead by around 600-800 years. As Tim Ball asserts in Swindle:"...they say that if the C02 increases, then the temperature will go up. But the ice core record shows exactly the opposite...so the fundamental assumption of human caused climate change is shown to be wrong...". See also here.


Interestingly, the papers that documented the research on the Vostok record didn't come to the same conclusion, nor did the IPCC in its treatment of the issue in 2001.


But there is a more fundamental flaw to the conclusion that "human caused climate change is shown to be wrong". Logically, it's an invalid argument. How does one go from claiming a reverse relationship to claiming a contradictory one? Well, you can't, because reverse relationships aren't neccessarily contradictory.


For example, how is Ball's argument no different than saying that since there are times when you've seen fire causing heat to spread, heat must not be able to cause fire, or cause fire to spread. Another more devious (and definitely not as effective or clear) analogy is if someone were to say that since in fact we can say that the sunrise follows moon rise, moon rise cannot follow sunrise. Thus, even though it's probably true that C02 rises after temperature, that doesn't automatically refute the idea that C02 causes temperature to rise! In fact, both relationships can exist without creating a contradiction.


Yet, we have supposed scientists -- great heretics, they like to call themselves -- that can't even get their logic straight. I can see how someone not trained to think critically might fall into the trap. But Ball? No wonder he hasn't published anything serious for a long time. If you find more examples of this flawed and overly tired argument, please post!


And what exactly was going on in the ice core record? While it's not entirely clear, temperature rises during those periods were likely due to changed in the earth's orbit around the sun -- Milankovtich cycles -- that are surmised to play a role in the onset and end of glacial periods. C02 is also thought to have amplified the effects of these cycles -- effectively creating the kind of glacial and interglacial periods seen in the ice core records. A lay summary of the issue can be found on NewScientist.

Sunday, August 12, 2007

Straw

Tonight I took a break from editing and decided to watch a little TV. I don't do this often, and I thought it was time for a little change of view. I don't really find TV that interesting, save for the odd science show; for the most part, however, science shows are far too general and flashy for my taste. I want to know why they are saying what they are saying.

While flipping the channels I came across Richard Attenborough's Planet Earth, and of course I watched what was left of it, as the visuals themselves tell you a lot of about the subject matter. After that, I came across another show that, in my opinion, couldn't hope to be called a serious scientific program. It took a look at the phenomena, but tried increasingly to tie such phenomena to impending disaster. The show was about natural disasters: one about hurricanes and one about volcanoes and earthquakes. There was a lot of "scientists are saying", "scientists are urgently trying to piece together", "...are coastal cities living on borrowed time?" - otherwise leading statements that gave the impression that the science supported the view that we are on the edge of impending doom. In fact, none of the interview segments connected to the narration in any obvious way.

Watching the program about hurricanes, it is easy why some people feel often that global warming is simply alarmist hype. Many of the expositions of the subject that you find on TV, or even in some books, don't seem like they are out to convince anyone but are instead out to scare. And it is easy to see why all the misinformation spreads as easily as it does, and why it often targets the more alarmist claims: not only is it easier to refute such alarmism, but it is also easy to dismiss it if its supporting science isn't made easily accessable. "They are alarmists with no basis" cry some (while neglecting the fact that they haven't looked hard enough). The one question I have is: why aren't many people rational enough to see that they are sitting in a field with a straw man?

Friday, July 27, 2007

Skepticism: It's all about the method

Tony Jones of ABC Australia recently hosted and directed a dicussion panel that focused on the flaws of the highly controversial (and if the US and British media is any indication - highly popular) documentary The Great Global Warming Swindle, written and directed by Martin Durkin.

Watching the documentary, I felt sick. While the movie was obviously intended to "refute" the basic science behind anthropogenic global warming, and as such was obviously intended to be a "skeptical" attack of the "dogmatic" establishment, it missed the fundamental point of skepticism: skepticism is not simply a position, but is a method. And the method, like any method concerned with interrogation, should be robust and should aim at getting at the truth.

Many of the flaws (yes, there were many flaws) of the documentary stemmed from the fact that it simply did not interrogate the other side well, and it certainly was not aimed at getting at the truth of the matter (as a foray into Jones' interview with Durkin will show). That is, it's method was flawed. In this way, it's skepticism was not good at all. And in this way, the position that Durkin took was not very skeptical (despite that fact that it was trying to raise doubt). Yet, many viewers of this documentary see it as skeptical simply because it raises its fist and goes against mainstream scientific thought. But so do many aspects of religion and junk science, but we wouldn't call them skeptical, would we?

Just because a position seems to be the result of skeptical inquiry doesn't make it skeptical.

Even Tony Jones fell into the skepticism as position trap when he seemed baffled by Dr. David Karoly's (IPCC contributing scientist) assertion that he was "still" a global warming skeptic. The apparent contradiction is solved when you see that, as a scientist, Karoly can adhere to the mainstream view but still approach it with caution. And indeed, he can be skeptical of other global warming theories - like the solar-forcing hypothesis that Durkin, amongst others, have put forth. The apparent contradiction further disintegrates when you consider that Krowley (and many other proponents of the mainstream view) approach the issue with the correct method, which includes getting the facts correct and interpreting competing arguments charitably, something that Durkin - the so called "skeptic" - in many cases didn't even bother to do.

No, a skeptical position is built upon a logically robust and reasonably robust method. Nor are skeptical positions reserved only for those that are outside the mainstream; indeed, skepticiam has usually been associated with the refutation of pet theories or pseudo-scientific views, most of which are usually in the minority.

Wednesday, July 25, 2007

Peering Into the Puddle of Gore’s Melted Scientific Claims (Part 2)

In his Chicago Sun-Times article, James Taylor makes the case against Gore's claims in An Inconvenient Truth by drawing upon some credible sources, but also by drawing on outright fabrications (see last post).

There are, however, some interesting points worth taking seriously. Taylor makes the point that Gore's implied linkage between tornadoes and global warming is faulty. Whether or not these is indeed any research which shows a link between tornado activity and global warming, Gore's point on this matter was intrinsically weak: he showed no evidence for his argument anyway.

Actually, the lack of supporting argument was one of my main problems with the film: it showed a lot of scientific conclusions, but never showed why things work the way they do, or why certain data counts as evidence for this and nor for that, and so on. When I first viewed the film, I remarked that while the message was delivered powerfully, the film's influence as a simple summary of the main issues was never properly clarified. In any summary, the references are left for later, the digging left as an addendum. In my opinion, some people aren't smart enough to realize that a documentary cannot hope to convey all of the information and nuance of its issue of choice; however, the movie's promotion tended to give to viewer the impression that it was the last word, and that it is time to act - not to do more research on your own. While this does not, in principle, invalidate the main conclusions of the film, it does speak to weakness of the film as a presentation and summary. Or, maybe, it speaks to the idea of a science-based documentary filmmaking in general.

Deserts Retreating?

Taylor notes that, contrary to what Gore claims (and I can't remember what Gore claimed) about drying regions of Africa, certain regions of the southern Sahara and the Sahel have seen a retreat in the extent of the desert, and that the area has been wetter than previous years, according to research reported on in NewScientist. Setting aside the fact that the article is not up to date (it's from 2002), and setting aside the fact that the article did not attribute African desert retreat to, say, a global cooling, NewScientist recently published a piece claiming just the opposite of what Taylor cites: African semi-arid regions are becoming much drier. It is clear that there is too much nuance in this issue to relegate discussion to generalizations about what the climate is doing or will do, although pure and unfiltered research can give us a glimpse of what trends are clear and what this means in regards to global warming.

Kilimanjaro

This is yet another aspect of Gore's film that probably could have been better explained, and the dynamics between glacial trends and climate trends elucidated. (Then again, consider the difficulty in keeping the film nuanced.) The melting of Kilimanjaro and its attribution to global warming is indeed controversial - the paper that Taylor cites is valid, but there is other research and argument in favour for the global warming-Mt. Kilimanjaro link. I wonder, however, if Taylor sees this as evidence that the globe is not warming, which is most certainly is, assuming the data is correct.

Wednesday, July 11, 2007

Addendum to Part 1

As it turns out upon closer investigation and a little digging, the purported quote drawn from the Journal of Climate paper was indeed made up (deliberately or not) - as I had feared.

In his article, James M. Taylor quotes a paper from the esteemed Journal of Climate, which is intended to be shown as evidence that Gore is incorrect in his claims regarding Himalayan glaciers. However, foraging through the actual paper, the purported quote is not a quote at all - none of its words and phrases, nor the entire text itself, can be found amongst its content.

You can view the actual paper here, and then compare notes with Taylor's article. On a related note, the language used within the 'quote' was itself suggestive that it was made up. There is simply no way that a paper describing the dynamics and processes involved in Himalayan glacier retreat and advance - a paper that did not take any substantive view on alarmism or hysteria - would use language with the words "alarmists" or 'confounded alarmists'. The business of the paper is to present real and serious scientific work, and not to foray into the political or the psychological attributes of certain locuters. In other words, the language of the quote was fishy, and it needed to be put under the skeptical glasses.

Friday, July 6, 2007

Peering Into the Puddle of Gore’s Melted Scientific Claims (Part 1)

The Chicago Sun-Times recently published a piece scathing some of the claims made by proponents of the view that climate change is happening, is man-made, and is dangerous. Namely, it was Al Gore to which the attack was directed, and its targets were Gore's main theses set out, respectively, in his books The Assault on Reason and An Inconvenient Truth (AIT).

On Reason (a book which I have not yet found time to read), the article author draws attention to Gore's argument that genuine intellectual and reasoned debate and discussion has declined - and is even under attack - in the US (hopefully this blog can help with that), but uses AIT, and Gore's scientifically-based arguments therein, as a way to essentially make a tu quo que argument against Gore: that because Gore apparently does not engage in reasoned and intelligent discussion via AIT, Gore is a hypocrite (and therefore wrong in Reason?)

Whether or not climate change is happening, is man-made, and is dangerous, is not the main issue in this post. To address that question, I direct you to the summary provided by NewScientist's article entitled Climate Change: A Guide for the Perplexed, which isn't so much the final word on the issue as it is a good start for any curious observer of this issue who is, well, looking for a credible and reliable place to start. What is at issue is whether the article's author makes a strong case against Gore's claims, and whether or not the piece is worthy of being referred to as "skepticism".

There are a number of claims in this article that I would like to address. When reading any article written about scientific conclusions, it is important to double-check the papers from which they cite and see whether or not they really support the conclusions drawn from them. I think that we can agree that any respectable skeptic, if he or she is out to find the truth, should check to see if a game of Chinese Whispers has not occurred and to make sure that everyone has interpreted everyone else correctly. Otherwise, there is no point in being a skeptic.
The Article's Discussion
James M. Taylor, the author of the Sun-Times article, presents several strings of argument and research that are meant to discredit the claims that Gore makes in the slideshow presented in AIT. On the one hand, some of them are strong, and make for some startling and persuasive (but probably unfair) criticisms of Gore’s presentation. (However, it’s unclear how some of these are supposed to support the notion that Gore has distorted the discussion in the way he refers to in Reason.) On the other hand, Taylor draws some quite unjustified conclusions from the research he cites. I will go through both hands in their turn, and in no particular order.
Wind Shear?
Gore's claim about hurricanes is probably the most familiar and relevant to Americans who have seen (and who have heard about) AIT. The author touts that research done in 2007 argues that hurricane activity (i.e. either the amount of storms or the strength of storms) will not increase this century due to increased “wind shear”. This seems to directly contravene Gore’s points. Yet, the article states only that this may be the case, and that more research needs to be done on the subject. Indeed, they state:

“Based on published connections between large-scale environmental parameters and hurricane activity [e.g. Emanuel and Nolan 2004], the changes shown here alone would not suggest a strong anthropogenic increase in tropical Atlantic or East Pacific hurricane activity during the 21st Century; although other regions (e.g. Indian and western/central Pacific Oceans) show consistent changes towards more hurricane-favorable conditions… Thus, it appears that – in the tropical Atlantic and East Pacific Oceans - the increase in vertical wind shear could partly mitigate the increased thermodynamic tendency towards increased storm intensity. However, it is important to note that it is only in the tropical Atlantic and East Pacific Oceans that there is a projected increase of shear during the local hurricane season. In the West Pacific and Indian Oceans, the models projected along-term decrease in vertical wind shear through the 21st Century.” (pp. 8, 23)

Besides which, Gore made his claims in 2006, before these modeling experiments were published. It is not fair to criticize Gore’s conclusions given that they were made before this paper was published. Still, as you can see, the conclusions do not necessarily refute Gore, although they comprise interesting addenda that he ought to draw attention to (perhaps in a podcast?). Gore isn’t wrong; but he is in need of an update.

A Cooling Ice Sheet in Antarctica? Which part?

It is not entirely clear where Taylor wants to go with this one. It seems as if he is claiming that Gore was wrong to be talking about melting in the Antarctic at all. He disputes Gore on three fronts: that Antarctica is melting, that it has warmed, and that it will melt much in the future. But, in fact, Gore kept most of his discussion to the West Antarctic ice sheet, and not Antarctica as a whole (which has indeed cooled somewhat). The Western ice sheet is indeed melting in certain parts. Any foray into the data will show you that, while most of Antarctica has cooled (or has not warmed), the West ice sheet has experienced warming. Taylor cites the IPCC’s statement that it does not expect Antarctica to melt much in the 21st century, in hopes (I think) of showing that Gore was wrong to say that it would melt quite a bit in the 21st century. The only point to keep in mind, of course, is that Gore did not give any predictions as to how much or when the ice would melt in Antarctica.

Growing glaciers in the Himalayas?

Onto the point about the Himalayas. Taylor simply gets wrong the main conclusions of the Journal of Climate paper he cites, and I fear (although I don’t know) he may have made up the last quote he claims to have taken from it. Whereas Taylor implies that this research shows that glacier growth in the Himalayas refutes claims that they are shrinking. The Journal of Climate paper, instead of showing that all of the Himalayan glaciers are growing - and much less than refuting global warming claims - said this:

“The observed downward trend in summer temperature and runoff is consistent with the observed thickening and expansion of Karakoram glaciers, in contrast to widespread decay and retreat in the eastern Himalayas. This suggests that the western Himalayas are showing a different response to global warming than other parts of the globe.” (Abstract)

If I remember correctly, Gore kept his discussion to the eastern glaciers located closer to China and India; it was around this point in Gore’s discussion that he turned to the potential effects of lowering glacial water runoff in these regions. It probably would have been important for him to include the western glaciers in order to illustrate that climate change is complex. But insofar Taylor is concerned, global warming claims are thrown into question by this research. My question – and indeed every skeptic’s question – should be: how?

I’ll write a little more on this article later, but what I have presented so far is, I hope, enough to show you that careful reading and fact checking are indispensable parts of any critical appraisal of an article – especially an article reporting on a very complicated and nuanced scientific issue such as climate change. However, Gore is not squeaky clean on this issue. Yet, I think that we can diagnose, with increasing confidence, that this article as just another symptom of the “decline of reason” that Gore talks about in Reason.

Look out for Part 2 of this post, which will be put up shortly.