Saturday
Jan212012
by 
Bishop Hill
Bishop Hill Centring matters
Jan 21, 2012 Climate: MWP Readers at Climate Audit have been discussing the suggestion that a graph by Neukom et al produced a misleading rhetorical effect by centring the series - one paleoclimate reconstruction and a series of climate models - on the second half of the twentieth century. As a commenter observed, since the models run forward in time, the series should actually have been centred on a single point at the beginning. Then their divergence over time could be observed.
In response, Climate Audit regular UC has put together an animation showing how these kinds of spaghetti graphs might look centred on different periods. He has used paleoclimate rather than model data for convenience. It's rather beautiful I think.
Reader Comments (14)
That is amazing. Really elegant.
"Rather beautiful"? Blimey...and here I was thinking it was me who ought to get out more! :-)
What a difference a year makes! How to fool people with a graph.
"Rather beautiful"; yes.
Rather frightening, too. One would not even have to fudge to "prove" anything.
From the climate audit post:
Indeed!
I feel seasick.
I think Philip Bratby has hit the nail on the head with his comment.
How can they get away with such poor science.
Statistics is to science...
as
... politics is to truth
Statistics is the study of norms in terms of variation, thereby addressing not extrapolation or projections but the probability that, in context and perspective, certain iterative tendencies may cancel or reinforce.
Though "statistics" is accordingly a quantitative discipline, its odds-based, tentative conclusions, while not arbitrary are necessarily qualitative: Not objective measures subject to independent third-party verification, but subjective exercises whose significance is open to interpretation.
"Science" is a philosophy of the natural world; an empirical method for evaluating hypotheses; above all, in practice an interactive social endeavor dependent not on "peer review" as such but on adepts' replication of results by any and all means available.
Asking whether warmists' Green Gang of peculating Luddite sociopaths respects these tenets in the slightest returns the ready answer: No.
Perhaps UC should attempt to generalize his code for the graph and make it available as a "R" package. I can see where it might be very informative if applied to several past climate papers. Centering has occasionally been a rather hot topic of discussion on more that one, especially those from the "Team".
"Rather beautiful", says the Bish. As wall-art maybe it isn't beautiful but as performance art, shifting with time, it has a certain beauty.
As time progresses on the video, we see things sometimes "getting out of kilter" and sometimes just chugging along with (ho hum) variation. Isn't this the core idea behind statistics - the notion of the null hypothesis; the development of tools in order to differentiate meaningfully and wisely between different populations; the ability to pronounce, "Hah" THAT's new! Look everybody!" or, "Nah, this is business as usual. No big deal."
The fault line between us and warmists is defined by this very question. One clan sees "unique, unprecedented and dangerous change" in climate, the other reckons that climate has always oscillated and today's nowt special.
So, yep, I do find the shifting graph beautiful. It cautions the citizen against setting too much store in his perspective as opposed to the perspectives of others, or in his current view which changes over time. "Two swallows do not a summer make" is folk wisdom. "Sleep on it and see how you feel in the morning" similar. The graph's wiggling lines are a warning to gather sufficient data; not to draw too many conclusions from scanty data; not to cry wolf (very old folk wisdom!) prematurely.
If NASA's Dr. James "oceans-will-soon-be-boiling" Hansen were to go back to his undergraduate stats notes, with the stuff about significance testing, maybe he'd realise he's reading too much into the 1975-1998 temperature hike; that he's been carried away by dumb extrapolation. Maybe he'd realise that he and his AGW cronies have given the politicians a bum steer, and he should stop spouting the apocalypse nonsense.
I feel that the criticism inherent in this post is quite out of place.
Surely, an artist is allowed to hold up a (distorted) mirror to the world, to show exactly what he wants to show.
Due deference must be given to those who DO, as agaist those who merely strive to criticise.
Woops - did you say science?
I was thinking about something else entirely!
Silly me.
It is a masterpiece of art and of science criticism. Thanks so much, UC. If only we had the bucks of Big Climate then we could have such works all over network TV and in every public school in the US.
Imagine what happens if I scale them to have unit standard deviation over the anomaly period..