This is something that needs wider circulation, hence its appearance here. I’ve been mulling over how to best present this, and decided there’s nothing I could do in the way of excerpts that still told the story effectively, so I decided to present it in full. I’m pretty sure Jeff won’t mind. Readers may recall Steig et al 2009 and its cover picture on Nature saying the whole of Antarctica is warming, and the skeptic response paper O’Donnel et al 2010 response demonstrating conclusively that the peninsula is warming, but the whole of the continent is not. The reason for this is the
same flawed PCA flawed statistical methodology, similar to what was used by Mann to create the Hockey Stick. Jeff Condon, co-author of O’Donnell et al 2010 tells the story at his Air Vent blog. Andrew Montford also has a post on it where he opines about the Steig et al 2009 paper possibly being included in IPCC AR5. – Anthony
Posted by Jeff Condon
I know you guys missed me, Real Climate sure did. Eric Steig has written a letter to “The Guardian” (booming voice) in response to a Nic Lewis letter patiently explaining problems in an article written by yet-another-know-nothing with a keyboard. Unfortunately for us, the article itself has been updated in response so we can’t read the original. What is interesting about the exchange is Dr. Steig’s wild reply.
Nicholas Lewis (Letters, 28 August) complained that your report (Arctic ice melt likely to break record, 24 August) gave the impression that typical temperatures in Antarctica have risen as much as on the Antarctic peninsula.
While he is correct about this, his letter also refers to an outdated study of his, which argued that previous estimates of overall Antarctic warming were too high. In fact, the work of Lewis and co-authors has been proven wrong.
The relevant paper here is Orsi et al, Geophysical Research Letters, vol. 39, 2012, which shows that the rate of warming in west Antarctica is as great, or greater, than what we showed in our original work (Steig et al, Nature, vol. 457, 2009). Moreover, Lewis’s own paper shows there has been
significant warming in west Antarctica and that the average trend over Antarctica is of warming, not cooling as is often stated.
The reality is that the Antarctic is warming up and is contributing significantly to sea level rise; and that there is strong potential for a greater contribution to sea level rise from Antarctica in the future.
Professor Eric Steig
University of Washington, Seattle, USA
Our 2010 study is now outdated???
Seriously!! This absolutely is the doctor who never learned about matlab.
For those who have not read the history of the Antarctic wars, here is a pictorial summary.
Steig said this on the cover of Nature magazine:
We said, no you screwed up the math so using the same data it is more like this: (Ryan O’Donnel)
Because without the satellites the temperature stations alone say this:
So it absolutely cannot be the image on the right:
Steig 09 smeared the peninsula warming across the continent (see how it is missing from the peninsula on the left), but now he says O10 has been “proven” wrong. This tells me that he has apparently never understood that the result we produced is nothing more than thermometer data. That is all it is.
Temperatures as reported by thermometers. It is a skeptic plot I tell you!!
Perilously, Steig 09 was precociously printed on the previously prestigious primary page of Nature publication. Carelessly comprised of contaminated and crappy satellite data with thermometers taking a tertiary role in tolling temperature. Sorrily, Steig’s seminal segment was further stuffed by sloppy math. (alitteral too far?)
So Jeff , what did he base his conclusion that the PCA distributed thermometers of O10 are now “outdated” and “proven wrong” on?
A single borehole temperature reconstruction at a single point……
—-> o <—-
It was workmanship like that which got me labeled as a skeptic in the first place.
Notes to Real Climate and Orsi:
The PCA method S09 attempted to employ, is about redistribution of thermometer information according to covariance of AVHRR satellite data. By nature, every temperature station affects every point in the reconstruction. Kriging the temp stations, is a far more controlled and far more verifiable solution for the same thing and it would produce the same result as O10. The 3 pc’s of the Steig 09 method “smeared” the thermometer data everywhere, so no matter what is published, S09 methods will NEVER be verified. S09 can never, and will never, be correct….because it isn’t! The fact that it is to be cited in AR5 is yet another wart on the last few grains of credibility the IPCC holds.
Sorry for that.
Does the error of S09 that mean that O10 is right? No, of course not. But O10 is very close to actual thermometer results. This is because in a “skeptic” plot, we cleverly used actual thermometers. Bunch of morons I say. This is in direct contrast to S09 which preferred 3 pc’s of highly noisy Satellite AVHRR data WHEREVER available. That was not a smart plan ….. Um, if you want good results.
Even with enough pc’s as O10 used, there are points in this sort of reconstruction with noisy data, where modes of the PC are a dominant factor in creating the local trends of the plot. These methods mean that station information can be and IS copied across an entire continent. This was proven by the S09 cover of nature(Figure 1 above). The trick is to minimize the information bleeding. What this means to me is that I am quite comfortable that the O10 reconstruction will never be proven wrong, not because something as massive and complex as o10 doesn’t contain a boo-boo, but rather because it is an approximation of a field. The best anyone will ever do — is improve on it.
Apparently, this is something that Steig has never figured out. He might not ever work it out, but science is a cold sport and my guess is that those who are smarter than him ….. will.
Other notes of surprise:
What normal thinking person would take a temperature from a lousy borehole and hold that out as superior to an actual thermometer?