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« Simon says...? | Main | Baghdad Fi »

Steig's method massacred

Ryan O'Donnell has posted a splendid pictorial guide to the oddities of Eric Steig's method for creating trends in the Antarctic. If you have been one of the people not following the story too well so far, here's a little layman's version of the posting, which assumes no prior knowledge. I hope this helps.

There's a lot of talk of the Antarctic peninsula. This is fairly obvious at the left hand side of each map below. The name refers only to the narrow bit of land though. The slightly fatter bit that joins the Peninsula to the main part of the Antarctic continent is West Antarctica.

Now Steig's method purported to show that he whole continent was warming, and particularly West Antarctica. Previously it had been thought that only the peninsula was warming.

Here's Steig's original result with the warming showing up as the dark colour in West Antarctica.

O'Donnell has now shown what happens when you artificially add warming or cooling trends to some of the weather stations included in the dataset. Firstly see what happens when you add some warming to stations in the Peninsula. As you go from left to right in the map below, more and more warming is being added, but only to the peninsula stations. However, mangled by Steig's algorithm, this extra warmth turns up as warming, not in the Peninsula, but in West Antarctica.

Now what happens when you cool those same Peninsula stations down? As you can see, the effect is to cool down the south Pole and, erm, to make West Antarctica warmer...

Now see what happens when you add warmth to stations that are actually in West Antarctica. Not much actually...

And what about cooling them down? No, that has no effect either.

So what the Steig method does is to take any warmth in the Peninsula and spread it out over West Antarctica. In other words, Steig's result is an artefact of his methodology and not something that is inherent in his data.

Game, set and match.

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Reader Comments (81)

Ha - bizarre. Just got back from reading that...

Feb 8, 2011 at 7:16 PM | Unregistered CommenterBBD

It's also at WUWT. Ridiculing Eric Steig and RC is the best tactic I'm sure.

Feb 8, 2011 at 7:19 PM | Unregistered CommenterPhillip Bratby

If this is all true - and I have no reason to doubt O'Donnell - then Steig deserves a thorough and public lambasting. Too often things are disproportionate in the blogosphere, but on this occasion, I think the anger (and mockery) are justified.

Feb 8, 2011 at 7:22 PM | Unregistered CommenterBBD

Did you see the Nature cover, alarmism generated by the original Steig Paper

Antartica Warming

Michael Mann was also one of the co-authors of that paper. I wonder what he has to say about Steig's behaviour as a reviewer and co-moderator at RealClimate

Oh, and James Delingpole has an article now, good timing for him, further evidence of peer review duplicity, just 2 weeks after that Horizon program. Lots of tips this morning, ;)

Feb 8, 2011 at 7:25 PM | Unregistered CommenterBarry Woods

Thanks Bish,
Just what was needed
a concise explanation of a complex issue

Feb 8, 2011 at 7:26 PM | Unregistered CommenterNeil Hampshire

Brilliant! Isn't there supposed to be a benefit to cooking the books?

Feb 8, 2011 at 7:31 PM | Unregistered CommenterKevin

Much better explained here than at WUWT or CA. Thanks Bish.

Feb 8, 2011 at 7:35 PM | Unregistered CommenterStu

Dellers has named it.


That is a really clear explanation of the Steig method, Bish.

Feb 8, 2011 at 7:36 PM | Unregistered CommenterShub

I think "RealClimate Douche-baggery" is a more appropriate moniker.

Feb 8, 2011 at 7:43 PM | Unregistered CommenterAL Clark

at the end of the pier.....

Feb 8, 2011 at 7:45 PM | Unregistered CommenterFenbeagle

Statistics is like sausage -- particularly with regard to how some of each is made.

Eric should have gone into Black Pudding making. He appears well suited for it. He could sell Steig Pudding to a number of people we know.

Feb 8, 2011 at 7:46 PM | Unregistered CommenterDon Pablo de la Sierra

Thank you, Bishop!
I have just completed reading The Hockey Stick Illusion (for the second time) and although much of the science is still beyond my comprehension I can now more easily understand the malfeasance which you have explained so clearly. Your explanation here will be particularly useful for thickos like me who know there is something rotten in the science but have difficulty in persuading others of the problems behind the 'concensus'. Thanks again for translating the science into a form which I can understand!

Feb 8, 2011 at 7:46 PM | Unregistered CommenterTony Windsor

Although it's on Climate Audit - it's not a Steve Mc posting. It's another blast from Ryan O'Donnell

[BH adds: Thanks Fixed now]

Feb 8, 2011 at 7:49 PM | Unregistered CommenterNick Moon

Excellent explanation, Bish.

Feb 8, 2011 at 7:53 PM | Unregistered CommenterViv Evans

What Nick Moon said. Nonetheless, a description of what he did. He should include your explanation together with his figures.

Feb 8, 2011 at 7:55 PM | Unregistered CommenterCarrick

Make that "a great description".

Feb 8, 2011 at 7:56 PM | Unregistered CommenterCarrick

Stygate anyone? A gate to keep the pigs' snouts in the trough.

Feb 8, 2011 at 7:58 PM | Unregistered CommenterPhillip Bratby


Thanks for the link. Weirdly (it's probably me), I couldn't find you when I went looking the other day.

Feb 8, 2011 at 8:01 PM | Unregistered CommenterBBD

bravo. i needed that narrative. you've nailed it again, bish.

Feb 8, 2011 at 8:05 PM | Unregistered Commentermark

...They seek him here.... They seek him there

Feb 8, 2011 at 8:06 PM | Unregistered CommenterFenbeagle

Thanks for an excellent exposition. Now excuse me while I do my Bad Fairy at the christening impersonation...
Remember Yamal? “One tree to rule them all and in the darkness blind them”? Remember our joy, and the media response? Zero, except for the Guardian, who sent a photographer to the Yamal peninsula to photograph reindeer dying of heat stroke.
You need proper science journalists to get this story out to the general public. Someone with a reputation for exposing Bad Science for example. Are there any?

Feb 8, 2011 at 8:09 PM | Unregistered Commentergeoffchambers

Under normal circumstances a chap would be over the moon to be the subject of both a Josh and a Fenbeagle on the same day. I rather think though that Dr Steig may have some reservations about this particular piece of notoriety...

Feb 8, 2011 at 8:10 PM | Unregistered CommenterCumbrian Lad

I could not understand Ryan's hurried explanation of the series of maps on WUWT but the Bish made perfectly clear in just a few words what the brouhaha was about - cut straight to the heart of the matter.

What a talent for presenting complex data clearly to non-scientists! I bet Steig learned something from the Bish's explanation, too, not to mention Gavin and Mann!

Feb 8, 2011 at 8:11 PM | Unregistered Commentermarchesarosa

See, this is exactly why climate scientists should not be forced to release their data and methods. Numpties like Ryan will find things wrong with it and as a result create confusion with the general public. /sarc

Feb 8, 2011 at 8:15 PM | Unregistered Commentermpaul


I'm laughing my a*** off! I do like your work. Thanks.

Feb 8, 2011 at 8:16 PM | Unregistered CommenterBBD

Climate wars indeed. Who would have thought that the "good guys" are, indeed, the bad ones? It's like seeing a movie where Luke Skywalker killing innocent bystanders, Obi Wan goes around drunk stealing money from the bank with his mental powers, Rambo decides to become an assassin, and Neo is working for the machines against mankind...

Feb 8, 2011 at 8:18 PM | Unregistered CommenterLuis Dias

Yes, a really good explanation - the man's got talent!

Feb 8, 2011 at 8:20 PM | Unregistered CommenterPeter Czerna

As first pointed out by Jeff Id, the map in figure 1 of the post at:
shows the locations of the only two weather stations in West Antartica that Steig used in his reconstruction, Byrd and Russkaya. Byrd is the upper red dot on the map, Russkaya is the lower red dot. These are the two West Antartica stations to which Ryan added or subtracted a trend varying between 0.1 and 0.4 degrees C per decade in the final two rows of the graphics shown above.
These trends are for the full 50 year reconstruction period (1957-2006) and are sizeable: Steig's reconstruction showed a West Antartica trend of 0.20 degrees C per decade, ours a West Antartica trend of 0.10.

Feb 8, 2011 at 8:27 PM | Unregistered CommenterNic Lewis

It took me 2-3 reads of Ryan's original post ; Your explanation is spectacularly simple. Well done.
Will this get out of the blogs? No, sadly.

Feb 8, 2011 at 8:32 PM | Unregistered CommenterG.Watkins

mpaul has it exactly right. If the numpties are able to embarass the august and distinguished personages and their exquisite credentials, the public will not be so easily led. Can't have that.

Feb 8, 2011 at 8:35 PM | Unregistered Commenterstan

Let me echo the plaudits of others. The above is a superbly clear explanation of Ryan's diagrams. I still believe a comparison with Ryan et al's approach would put the proverbial nail in the proverbial coffin.
Outstanding stuff in any event.

Feb 8, 2011 at 8:36 PM | Unregistered Commenterbernie

At WUWT, O'Donnell asked that we refrain from criticizing the editor of the journal. However, I would like to say that for an editor to assign the task of reviewing an article to the scientist criticized in the article is so far beyond the pale that one can only wonder if Steig was assigned the task because it was thought that he would be especially effective in blunting the main point of the article. In my mind, knowing the review process well from the inside, the fact that Steig was assigned the review confirms in spades our worst fears about corruption in the peer review process, fears that were raised by Climategate.

Feb 8, 2011 at 8:40 PM | Unregistered CommenterTheo Goodwin

Theo, it was appropriate of the editor to give Steig et al. an opportunity to respond to the article. What is inappropriate is the apparent undue weight that was given to his response. As I have mentioned other places, if I were an author of a paper that was being criticized, I certainly would have identified myself to the authors of the new manuscript. To not do so, in my opinion, is unethical (even if the journal standards don't require it).

Feb 8, 2011 at 8:46 PM | Unregistered CommenterCarrick

Hank Roberts, the Google Scholar is allowed to wonder:

"Another avalanche of mail and complaints?
I’m shocked ….
Wait, is there a cyclical pattern to this stuff?"

Insight seems to be finally dawning. The stuff is cyclical because The Team keeps pulling the same tricks over and over again.

I wonder how much strain these tests on the faithful can take.

Feb 8, 2011 at 8:49 PM | Unregistered CommenterShub

If you get an urge to write again, there could be a book in this Antarctica kerfuffle. It just oozes with the juice of human melodrama.

Feb 8, 2011 at 9:04 PM | Unregistered CommenterRobert Austin

Mr. Goodwin

Maybe it was on purpose.

Feb 8, 2011 at 9:14 PM | Unregistered CommenterLDLAS
Feb 8, 2011 at 9:50 PM | Unregistered CommenterShub

The strange thing about the whole episode is that the warming claimed by Steig was in reality trivial. In any event NASA are damned b y their own station measurements, if you can trust them. Here is the link for the South Pole

or the Larson Ice Shelf

Also Steig's statistical torture produces accuracy that simply cannot be got from the weather stations, especially the ones buried under the snow!


Feb 8, 2011 at 10:02 PM | Unregistered CommenterPaul Maynard

Is it difficult to switch the algorithm such that the Western Antarctic stations are treated like the peninsula stations and the peninsula stations are treated like the Western Antarctic stations? I suspect this would eliminate all the warming on peninsula using the same methodology as Steig. Now that would be a "trick".

Feb 8, 2011 at 10:08 PM | Unregistered CommenterJay

Although Bernie says (8:36 PM) "I still believe a comparison with Ryan et al's approach would put the proverbial nail in the proverbial coffin" it occurs to me that there have been many such nails. Unfortunately, Mann Made Global Warming is a zombie. Not only dead, but brainless. But it keeps raising itself up again, thanks to the science illiterates in the MSM.

I found your explanation very helpful, Bishop.

Feb 8, 2011 at 10:08 PM | Unregistered CommenterVigilantfish

The 'Antarctica warming worse than we thought' was big news on the BBC when Steig's paper was published. In the interests of the balanced reporting on AGW for which the BBC is so well known (as Fiona Fox reminds us) I'm sure there will be a lead news item soon pointing out the error in the earlier report.

Or perhaps not...

Feb 8, 2011 at 10:36 PM | Unregistered CommenterDaveS

A script writer would characterise one of the final emails from Steig to Mann and the other co-authors regards SO9 thus...

"I've just finished adding trends to the West Antarctica data to hide the lack of warming...."

But that would be a travesty no?

Feb 8, 2011 at 10:37 PM | Unregistered CommenterBaa Humbug

The trajectory of Climate Scientists is, all too often, hubris; incompetence; deceit.

Feb 8, 2011 at 10:37 PM | Unregistered Commenterdearieme

Actually for a title, I prefer "it's all gone peer-shaped", as someone commented on Delingpole's article :p.

Feb 8, 2011 at 10:40 PM | Unregistered CommenterRobinson

See what happens when you piss off an Irishman, Eric?

Ryan has his full Irish up and boiling. And like many Irish, he has the way of the words. He should go into writing. He has the talent, for sure

Feb 8, 2011 at 11:01 PM | Unregistered CommenterDon Pablo de la Sierra

Excellent description

P.S. First sentence: 'Arctic'

Feb 8, 2011 at 11:01 PM | Unregistered CommenterRobWansbeck

Yeah, I agree with others, as always, it's much much better explained here than at CA or WUWT !
Thanks so much Bishop. I wish I had you as a teacher in some tedious classes.

Feb 8, 2011 at 11:14 PM | Unregistered CommenterJean Rochefort

/smoking pipe on


There is some real talent there. Amazing! Never heard of it before. "Hello World", says the first ever entry on February 1. Good with words too.

An appreciable obsession with wind turbines (Is it going to remain as the signature item?), and Chris Huhne. The latter limits the appeal somewhat for non-Britons.

That one-eyed Grim Reaper holding a wind turbine for a scythe would make the editorial pages of any major newspaper, IMHO.

Josh would better make some room. He has a sibling coming.

/smoking pipe off

Feb 8, 2011 at 11:15 PM | Unregistered CommentersHx

Don Pablo O'Sierra

You may well have a point there ;-)

Feb 8, 2011 at 11:16 PM | Unregistered CommenterBBD

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