Repeat After Me: Correlation Does Not Necessarily Imply Causation (Katrina and Global Warming)

More people need to read this.

"In the wake of Hurricane Katrina, some commentators are jumping to the conclusion that global warming is responsible for its destructiveness. While there is a theoretical possibility that higher ocean temperatures could lead to more powerful hurricanes, no individual hurricane can be shown to be so affected. Moreover, most scientists who study hurricanes believe that we are moving from a period of low hurricane activity to one of greater activity – change not caused by global warming. So, arguing that Katrina’s ravages are the result of climate change commits a causal fallacy."


"1. There is no way of telling how much, if any, of Katrina’s destructiveness was caused by global warming. There were equally, and even more, destructive hurricanes prior to global warming, and it is impossible to differentiate between a hurricane that is destructive due to global warming and one that is just plain destructive."

"2. Most scientists who study hurricanes believe that they are becoming more severe due to cyclical changes which have nothing to do with global warming, so it may be that all of Katrina’s destructiveness was due to these other causes. If this were not the case, there would be a plausible argument that global warming was responsible for Katrina’s excessive destructiveness for lack of an alternative explanation. However, there is an alternative. Now, I am not a scientist who studies hurricanes myself, so I’m relying upon press reports for the expert opinions of those who do (see the Resources below). Of course, press reports are not always reliable, so caveat lector."

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About Funky Dung

Who is Funky Dung? 29-year-old grad student in Intelligent Systems (A.I.) at the University of Pittsburgh. I consider myself to be politically moderate and independent and somewhere between a traditional and neo-traditional Catholic. I was raised Lutheran, spent a number of years as an agnostic, and joined the Catholic Church at the 2000 Easter Vigil. Why Funky Dung? I haven't been asked this question nearly as many times as you or I might expect. Funky Dung is a reference to an obscure Pink Floyd song. On the album Atom Heart Mother, there is a track called Atom Heart Mother Suite. It's broken up into movements, like a symphony, and one of the movements is called Funky Dung. I picked that nickname a long time ago (while I was still in high school I think), shortly after getting an internet connection for the first time. To me it means "cool/neat/groovy/spiffy stuff/crap/shiznit", as in "That's some cool stuff, dude!" Whence Ales Rarus? I used to enjoy making people guess what this means, but I've decided to relent and make it known to all. Ales Rarus is a Latin play on words. "Avis rarus" means "a rare bird" and carries similar meaning to "an odd fellow". "Ales" is another Latin word for bird that carries connotations of omens, signs of the times, and/or augery. If you want to get technical, both "avis" and "ales" are feminine (requiring "rara", but they can be made masculine in poetry (which tends to breaks lots of rules). I decided I'd rather have a masculine name in Latin. ;) Yeah, I'm a nerd. So what? :-P Wherefore blog? It is my intention to "teach in order to lead others to faith" by being always "on the lookout for occasions of announcing Christ by word, either to unbelievers . . . or to the faithful" through the "use of the communications media". I also act knowing that I "have the right and even at times a duty to manifest to the sacred pastors [my] opinion on matters which pertain to the good of the Church, and [I] have a right to make [my] opinion known to the other Christian faithful, with due regard to the integrity of faith and morals and reverence toward [my and their] pastors, and with consideration for the common good and the dignity of persons." (adapted from CCC 904-907) Statement of Faith I have been baptized and confirmed in the name of the Father, Son and Holy Spirit. I, therefore, renounce Satan; I renounce all his works; I renounce all his allurements. I hold and profess all that is contained in the Apostles' Creed, the Niceno- Constantinopolitan Creed, and the Athanasian Creed. Having been buried with Christ unto death and raised up with him unto a new life, I promise to live no longer for myself or for that world which is the enemy of God but for him who died for me and rose again, serving God, my heavenly Father, faithfully and unto death in the holy Catholic Church. I am obedient to the Magisterium of the Catholic Church. That is, I promote and defend authentic Catholic Teaching and Faith in union with Christ and His Church and in union with the Holy Father, the Bishop of Rome, the Successor of St. Peter. Thanks be unto Thee, O my God, for all Thy infinite goodness, and, especially, for the love Thou hast shown unto me at my Confirmation. I Give Thee thanks that Thou didst then send down Thy Holy Spirit unto my soul with all His gifts and graces. May He take full possession of me for ever. May His divine unction cause my face to shine. May His heavenly wisdom reign in my heart. May His understanding enlighten my darkness. May His counsel guide me. May His knowledge instruct me. May His piety make me fervent. May His divine fear keep me from all evil. Drive from my soul, O Lord, all that may defile it. Give me grace to be Thy faithful soldier, that having fought the good fight of faith, I may be brought to the crown of everlasting life, through the merits of Thy dearly beloved Son, our Savior, Jesus Christ. Amen. Behind the Curtain: an Interview With Funky Dung (Thursday, March 03, 2005) I try to avoid most memes that make their way 'round the blogosphere (We really do need a better name, don't we?), but some are worth participating in. Take for instance the "interview game" that's the talk o' the 'sphere. I think it's a great way to get to know the people in neighborhood. Who are the people in your neighborhood? In your neighborhod? In your neigh-bor-hoo-ood...*smack* Sorry, Sesame Street flashback. Anyhow, I saw Jeff "Curt Jester" Miller's answers and figured since he's a regular reader of mine he'd be a good interviewer. Without further ado, here are my answers to his questions. 1. Being that your pseudonym Funky Dung was chosen from a Pink Floyd track on Atom Heart Mother, what is you favorite Pink Floyd song and why? Wow. That's a tuffy. It's hard to pick out a single favorite. Pink Floyd isn't really a band known for singles. They mostly did album rock and my appreciation of them is mostly of a gestalt nature. If I had to pick one, though, it'd be "Comfortably Numb". I get chills up my spine every time I hear it and if it's been long enough since the last time, I get midty-eyed. I really don't know why. That's a rather unsatisfying answer for an interview, so here are the lyrics to a Rush song. It's not their best piece of music, but the lyrics describe me pretty well.

New World Man He's a rebel and a runner He's a signal turning green He's a restless young romantic Wants to run the big machine He's got a problem with his poisons But you know he'll find a cure He's cleaning up his systems To keep his nature pure Learning to match the beat of the old world man Learning to catch the heat of the third world man He's got to make his own mistakes And learn to mend the mess he makes He's old enough to know what's right But young enough not to choose it He's noble enough to win the world But weak enough to lose it --- He's a new world man... He's a radio receiver Tuned to factories and farms He's a writer and arranger And a young boy bearing arms He's got a problem with his power With weapons on patrol He's got to walk a fine line And keep his self-control Trying to save the day for the old world man Trying to pave the way for the third world man He's not concerned with yesterday He knows constant change is here today He's noble enough to know what's right But weak enough not to choose it He's wise enough to win the world But fool enough to lose it --- He's a new world man...
2. What do you consider your most important turning point from agnosticism to the Catholic Church. At some point in '99, I started attending RCIA at the Pittsburgh Oratory. I mostly went to ask a lot of obnoxious Protestant questions. Or at least that's what I told myself. I think deep down I wanted desperately to have faith again. At that point I think I'd decided that if any variety of Christianity had the Truth, the Catholic Church did. Protestantism's wholesale rejection of 1500 years of tradition didn't sit well with me, even as a former Lutheran. During class one week, Sister Bernadette Young (who runs the program) passed out thin booklet called "Handbook for Today's Catholic". One paragraph in that book spoke to me and I nearly cried as I read it.
"A person who is seeking deeper insight into reality may sometimes have doubts, even about God himself. Such doubts do not necessarily indicate lack of faith. They may be just the opposite - a sign of growing faith. Faith is alive and dynamic. It seeks, through grace, to penetrate into the very mystery of God. If a particular doctrine of faith no longer 'makes sense' to a person, the person should go right on seeking. To know what a doctrine says is one thing. To gain insight into its meaning through the gift of understanding is something else. When in doubt, 'Seek and you will find.' The person who seeks y reading, discussing, thinking, or praying eventually sees the light. The person who talks to God even when God is 'not there' is alive with faith."
At the end of class I told Sr. Bernadette that I wanted to enter the Church at the next Easter vigil. 3. If you were a tree what kind of, oh sorry about that .. what is the PODest thing you have ever done? I set up WikiIndex, a clearinghouse for reviews of theological books, good, bad, and ugly. It has a long way to go, but it'll be cool when it's finished. :) 4. What is your favorite quote from Venerable John Henry Newman? "Ten thousand difficulties do not make one doubt." 5. If you could ban one hymn from existence, what would it be? That's a tough one. As a member of the Society for a Moratorium on the Music of Marty Haugen and David Haas, there are obviously a lot of songs that grate on my nerves. If I had to pick one, though, I'd probably pick "Sing of the Lord's Goodness" by Ernie Sands.

8 thoughts on “Repeat After Me: Correlation Does Not Necessarily Imply Causation (Katrina and Global Warming)

  1. Rob

    Did you read the report analyzing the change in hurricane strength since the 1960s?

    The trend exactly parallels ocean temperature, which has been rising. Ocean temperature supplies energy to hurricanes.

    This holds true no matter where in the world. If it were simply a cycle, you’d see other areas at opposite ends of the cycle. Hurricane cycles throughout the world are either uncorrelated or anti-correlated. So it’s not like we’ve been in one huge cycle since the ’60s.

    We can’t say what percentage of Katrina was due to global warming, but we can say that the overall trend of fiercer hurricanes as global temperatures increase can only be attributed to global warming.

    It also doesn’t matter that some of the global warming is not caused by man. That we are partially responsible is sufficient. It’s also worth noting that, since we’re partially responsible, we have the ability to moderate the cycle as well. Not only can we undo the damage done by humans, but it’s within human grasp to reduce the natural global warming.

    We’re humans. We modify our environment to improve our lives on small scales. Why not large?

  2. Funky Dung

    On the whole, I believe that human-induced global warming is a real phenomenon. However, I don’t buy a lot of the Chicken Little hype that I hear. My scientific training won’t let me make the leap from statistics to blame so quickly.

    From the page I quoted:

    To clarify the above post, this is what I am and what I am not criticizing: I am criticizing the “jumping to a conclusion” that Gelbspan and others do in claiming that the severity of Katrina was due to global warming. I do not mean to criticize the premiss that the globe is warming, nor do I claim that the conclusion that Katrina’s severity was due to global warming is false. Rather, my point is that it is impossible to know whether climate change contributed to Katrina’s destructiveness.


    People frequently assume that if one criticizes an argument one is thereby claiming that the argument’s conclusion is false. This is presumably because one reason to criticize an argument is believing that its conclusion is false. However, logicians such as myself are trained to analyze arguments whether or not they believe the conclusion. Moreover, it is quite possible to argue badly for something that is true; it happens all the time! So, when I criticize an argument in this weblog, or in the examples throughout the files, I am not taking a position on the truth-value of the conclusion.

  3. dlw

    I think that due to the non-experimental nature of the data, and our limited records going back in time that there are ambiguities in its interpretation.

    I think the real question is what should be our risk-function.

    I haven’t seen anything that explains why the fact we are entering a season of increased hurricane activity in and of itself would make the hurricanes stronger. As I understand it, global warming, via the higher temperatures in the gulf of mexico, is making the hurricanes stronger not more numerous and it really doesn’t matter if there have been just as strong hurricanes in the past. Such hurricanes would be the most powerful of many, many hurricanes and the issue at hand is whether recent hurricanes are tending to be more powerful/destructive, so the comparison is not a very good one.


  4. dlw

    I think I meant to use the word loss-function, not risk function. The risk-function is derived from the loss-function or was it the other way around. Does FunkyDung believe in Bayesian Statistics?


  5. Funky Dung

    Define “believe in”.

    You might be good and politics and economics, but you’d make a poor scientist. There’s far too little historical data to comfortably say that the rising intensity of storms is *caused* by anything but normal cyclic changes. The best we can say with the data at hand is that there is a strong correlation between warming oceans and storm strength. That’s a no-brainer because tropical storms feed off warm water. What’s not so obvious is why the water is warmer. It’s no trivial matter to deduce whether or not humans have contributed appreciably to global warming. My gut says we have, but I don’t have an appropriate theory of the phenomena and stats to back it up.

    To paraphrase the author I linked to, just because I pick aprat a bad argument, doesn’t mean that the conclusion of the argument is wrong. It only means that the means of reaching that conclusion, the logical methodology, is flawed.

    “There’s nothing I like less than bad arguments for a view that I
    hold dear.” – Daniel Dennett

  6. dlw

    I define Bayesian Statistics as a non-positivistic approach to statistics that seek to clarify the a priori assumptions made in the interpretation of data with the end of improving decision-making using all the relevant information available.

    And my point is that we may have to make decisions now based on less than ideal situations and less information than we would prefer.

    I.e., the p-value may be high, but the more important question is how we should weigh the making of a type-one vs type-two error.


  7. Funky Dung

    “I.e., the p-value may be high, but the more important question is how we should weigh the making of a type-one vs type-two error.”

    From a response policy standpoint, I can agree with you. However, I draw the line at throwing blame around. For instance, some have blamed the destructiveness of Katrina on Bush not signing the Kyoto Protocol (and other mus-slinging nonsense).

  8. dlw

    I will agree that causally I doubt signing the Kyoto Protocol and making the changes would have prevented Katrina from being destructive.

    But from a political spin perspective, Katrina-style destructiveness is the reason the sorts of measures proposed in Kyoto were made.

    In politics, a lot of hay is made by the manipulation of associations in people’s minds. Hence, you see conservatives repeating the news that Mars is having its own global warming. I don’t see this as mud-slinging, I see it as a somewhat opportunistic manipulation of the images/insecurities in the minds of a people who generally won’t take the time to do a more careful study of the matter.

    Ideally, we should call on people to deliberate, to read up on the facts of the matter, not to flush most of what they learned about science in high-school down the toilets of their minds upon graduation. But inasmuch as such exertion is not pleasant for most people, it’s going to take some serious changes in our hyper-individualized culture for people to become better informed voters, more skeptical of the spin we are fed daily in our news.


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