Hide the Incline with the “Rank Trick”

or, Hey David Whitehouse — why is the sky orange?

It seems that David Whitehouse still doesn’t understand basic statistics. I mean the really basic stuff.

But he sure understands how to mislead people! This time Whitehouse is all about how this year will *not* be a record hot year. If you use data from NASA GISS for the whole globe then this year almost surely will be a the hottest on record — but Whitehouse doesn’t mention that. He does glibly quote numbers, not mentioning until the end that he’s using the CRUTEM3gl data set, which is for land areas only. That’s not what most people use when talking about global temperature — we regard the ocean as part of the globe — but it really doesn’t matter. Except as an indicator that David Whitehouse is kinda new to this whole “global temperature” thing, but nonetheless feels qualified to pontificate from his position of ignorance.

But hey — let the baby have his bottle! Let’s take a look at CRUTEM3 data (land-only average temperature from HadCRU). What should we have expected all along from 2010? Here’s the CRUTEM3 data (annual averages) from 1975 through 2009:

I’ve plotted the trend over this time period (which is approximately linear), and extrapolated the trend to 2010, in order to determine what the “upward trend” theory (a.k.a. “global warming”) would have predicted for this year (indicated by the red “x”). It should be about the 3rd-hottest on record (for CRUTEM3gl). Although we only have 2010 data for 10 months (the year not yet being over), here’s the average thus far:

Well gosh! It looks like this year is set to come in right on target — in fact, it’s set to come in a wee bit hotter than prediction — if you use that “upward trend” theory of global temperature. The one called “global warming.”

Once again, the observed data follow the existing global warming trend almost exactly. And once again, spinmeisters find a way to make that seem to “falsify” global warming.

And how, pray tell, does Whitehouse “spin away” the fact that this year’s temperature will be right on target according to global warming? He uses the “rank trick” — pointing out that this year will not rank #1 hottest year (if you use land-only data from HadCRU).

If the media headlines are to be believed 2010 is heading to be either the warmest or in the top three warmest years since the instrumental global temperature records began 150 years ago, and proof that the world is getting ever warmer. But looking more closely at the data reveals a different picture.

2010 will be remembered for just two warm months, attributable to the El Nino effect, with the rest of the year being nothing but average, or less than average temperature.

Here’s the month-by-month temperature anomaly from CRUTEM3gl, for the years 1998 to 2010. I’ve plotted 1998 in blue, 2005 in green, and this year (as yet unfinished) in red:

No single year is ranked #1 hottest for every month, but most months this year have been pretty hot compared to years 1998-2009. But is it accurate, is it fair, is it honest, for Whitehouse to characterize most of 2010 as “the rest of the year being nothing but average, or less than average temperature”?

Only if you cheat. Whitehouse begins his missive talking about “since the instrumental global temperature records began 150 years ago,” then conveniently ignores everything before 1998. Here’s the month-by-month temperature anomaly from CRUTEM3gl, for the years 1850 to 2010. As before, I’ve plotted 1998 in blue, 2005 in green, and this year (as yet unfinished) in red:

If you say that any month in 2010 can be called “average, or less than average,” then I say that your statement is inaccurate, unfair, and dishonest.

It’s a very common trick used by those who deny the reality of global warming, to focus only on the “#1 hottest record” so they can draw attention away from what really counts. It’s the trend, stupid.