Friday, December 7, 2012

Only a hammer in your toolbox

Talk about climate change, and be sure that your analyses are rock solid, because you will get some serious backlash. What interests me most is the danger of "if the only tool in your toolbox is a hammer, everything will look like a nail" thinking.

http://www.statisticsblog.com/2012/12/the-surprisingly-weak-case-for-global-warming/ is a blog post written by a graduate statistics student, with this summary:
"TL;DR (scientific version): Based solely on year-over-year changes in surface temperatures, the net increase since 1881 is fully explainable as a non-independent random walk with no trend. 
TL;DR (simple version): Statistician does a test, fails to find evidence of global warming."
The correcting nature of the connected scientific community quickly came to the rescue (?) in the form of Dr. Fellows http://blog.fellstat.com/?p=304:
"What we have shown is that the model proposed by Mr. Asher to "disprove" the theory of global warming is likely misspecified. It fails to to detect the highly significant trend that was present in our simulated data. Furthermore, if he is to call himself a statistician, he should have known exactly what was going on because regression to the mean is a fundamental 100 year old concept." 
I  find it really brave that a grad student puts himself out there, blogwise (see Commandment 6); especially with a subheading that reads:
"In Monte Carlo we trust"
Mr. Asher put a lot of effort into writing that post, given the length and thought that went into it. And he clearly feels very strongly about this issue (see Commandments 1-3). Too bad he put too much trust into his hammer, as pointed out by Dr. Fellows. I do think that Dr. Fellows also plays the man in his final comment, which was not necessary, given his rebuttal; but I can see where his frustration is coming from.

I was going to write that "Hopefully, I will not make the same mistake as Mr. Asher when writing for this blog", but then there is always Commandment 8 ("Thou Shalt Not Simply Trot Out thy Usual Shtick."), so luckily I can then always fall back on Commandment 5 ("Thou Shalt Not Flaunt thine Ego. Be Thou Vulnerable. Speak of thy Failure as well as thy Success.").