Steig et al – falsified

Smearing around data or paint - the results are similar

Smearing around data or paint - the results are similar

Jeff Id of The Air Vent emailed me today inviting me to repost Ryan O’s latest work on statistical evaluation of the Steig et al “Antarctica is warming” paper ( Nature, Jan 22, 2009) I thought long and hard about the title, especially after reviewing the previous work from Ryan O we posted on WUWT where the paper was dealt a serious blow to “robustness”. After reading this latest statistical analysis, I think it is fair to conclude that the paper’s premise has been falsified.

Ryan O, in his conclusion, is a bit more gracious:

I am perfectly comfortable saying that Steig’s reconstruction is not a faithful representation of Antarctic temperatures over the past 50 years and that ours is closer to the mark.

Not only that, Ryan O did a more complete job of the reconstruction than Steig et al did, he mentions this in comments at The Air Vent:

Steig only used 42 stations to perform his reconstruction. I used 98, since I included AWS stations.

The AWS stations have their problems, such as periods of warmer temperatures due to being buried in snow, but even when using this data, Ryan O’s analysis still comes out with less warming than the original Steig et al paper

Antarctica as a whole is not warming, the Antarctic peninsula is, which is signficantly removed climatically from the main continent.

Click for a larger image

Click for a larger image

It is my view that all Steig and Michael Mann have done with their application of RegEm to the station data is to smear the temperature around much like an artist would smear red and white paint on a pallete board to get a new color “pink” and then paint the entire continent with it.

It is a lot like “spin art” you see at the county fair. For example, look (at left) at the different tiles of colored temperature results for Antarctica you can get using Steig’s and Mann’s methodology. The only thing that changes are the starting parameters, the data remains the same, while the RegEm program smears it around based on those starting parameters. In the Steig et al case, PC and regpar were chosen by the authors to be a value of 3. Chosing any different numbers yields an entirely different result.

So the premise of the Steig et al paper paper boils down to an arbitrary choice of values that “looked good”.

I hope that Ryan O will write a rebuttal letter to Nature, and/or publish a paper. It is the only way the Team will back down on this. – Anthony

UPDATE: To further clarify, Ryan O writes in comments:

“Overall, Antarctica has warmed from 1957-2006. There is no debating that point. (However, other than the Peninsula, the warming is not statistically significant. )

The important difference is the location of the warming and the magnitude of the warming. Steig’s paper has the warming concentrated on the Ross Ice Shelf – which would lead you to entirely different conclusions than having a minimum on the ice shelf. As far as magnitude goes, the warming for the continent is half of what was reported by Steig (0.12 vs. 0.06 Deg C/Decade).

Additionally, Steig shows whole-continent warming from 1967-2006; this analysis shows that most of the continent has cooled from 1967-2006. Given that the 1940’s were significantly warmer in the Antarctic than 1957 (the 1957-1960 period was unusually cold in the Antarctic), focusing on 1957 can give a somewhat slanted picture of the temperature trends in the continent.”

Ryan O  adds later:  “I should have said that all reconstructions yield a positive trend, though in most cases the trend for the continent is not statistically significant.


Verification of the Improved High PC Reconstruction

Posted by Jeff Id on May 28, 2009

There is always something going on around here.

Up until now all the work which has been done on the antarctic reconstruction has been done without statistical verification. We believed that they are better from correlation vs distance plots, the visual comparison to station trends and of course the better approximation of simple area weighted reconstructions using surface station data.

The authors of Steig et al. have not been queried by myself or anyone else that I’m aware of regarding the quality of the higher PC reconstructions. And the team has largely ignored what has been going on over on the Air Vent. This post however demonstrates strongly improved verification statistics which should send chills down their collective backs.

Ryan was generous in giving credit to others with his wording, he has put together this amazing piece of work himself using bits of code and knowledge gained from the numerous other posts by himself and others on the subject. He’s done a top notch job again, through a Herculean effort in code and debugging.

If you didn’t read Ryan’s other post which led to this work the link is:

Antarctic Coup de Grace

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Fig_1

Fig. 1: 1957-2006 trends; our reconstruction (left); Steig reconstruction (right)

HOW DO WE CHOOSE?

In order to choose which version of Antarctica is more likely to represent the real 50-year history, we need to calculate statistics with which to compare the reconstructions. For this post, we will examine r, r^2, R^2, RE, and CE for various conditions, including an analysis of the accuracy of the RegEM imputation. While Steig’s paper did provide verification statistics against the satellite data, the only verification statistics that related to ground data were provided by the restricted 15-predictor reconstruction, where the withheld ground stations were the verification target. We will perform a more comprehensive analysis of performance with respect to both RegEM and the ground data. Additionally, we will compare how our reconstruction performs against Steig’s reconstruction using the same methods used by Steig in his paper, along with a few more comprehensive tests.

To calculate what I would consider a healthy battery of verification statistics, we need to perform several reconstructions. The reason for this is to evaluate how well the method reproduces known data. Unless we know how well we can reproduce things we know, we cannot determine how likely the method is to estimate things we do not know. This requires that we perform a set of reconstructions by withholding certain information. The reconstructions we will perform are:

1. A 13-PC reconstruction using all manned and AWS stations, with ocean stations and Adelaide excluded. This is the main reconstruction.

2. An early calibration reconstruction using AVHRR data from 1982-1994.5. This will allow us to assess how well the method reproduces the withheld AVHRR data.

3. A late calibration reconstruction using AVHRR data from 1994.5-2006. Coupled with the early calibration, this provides comprehensive coverage of the entire satellite period.

4. A 13-PC reconstruction with the AWS stations withheld. The purpose of this reconstruction is to use the AWS stations as a verification target (i.e., see how well the reconstruction estimates the AWS data, and then compare the estimation against the real AWS data).

5. The same set of four reconstructions as above, but using 21 PCs in order to assess the stability of the reconstruction to included PCs.

6. A 3-PC reconstruction using Steig’s station complement to demonstrate replication of his process.

7. A 3-PC reconstruction using the 13-PC reconstruction model frame as input to demonstrate the inability of Steig’s process to properly resolve the geographical locations of the trends and trend magnitudes.

Using the above set of reconstructions, we will then calculate the following sets of verification statistics:

1. Performance vs. the AVHRR data (early and late calibration reconstructions)

2. Performance vs. the AVHRR data (full reconstruction model frame)

3. Comparison of the spliced and model reconstruction vs. the actual ground station data.

4. Comparison of the restricted (AWS data withheld) reconstruction vs. the actual AWS data.

5. Comparison of the RegEM imputation model frame for the ground stations vs. the actual ground station data.

The provided script performs all of the required reconstructions and makes all of the required verification calculations. I will not present them all here (because there are a lot of them). I will present the ones that I feel are the most telling and important. In fact, I have not yet plotted all the different results myself. So for those of you with R, there are plenty of things to plot.

Without further ado, let’s take a look at a few of those things.

Fig_2Fig. 2: Split reconstruction verification for Steig reconstruction

You may remember the figure above; it represents the split reconstruction verification statistics for Steig’s reconstruction. Note the significant regions of negative CE values (which indicate that a simple average of observed temperatures explains more variance than the reconstruction). Of particular note, the region where Steig reports the highest trend – West Antarctica and the Ross Ice Shelf – shows the worst performance.

Let’s compare to our reconstruction:

Fig_3Fig. 3: Split reconstruction verification for 13-PC reconstruction

There still are a few areas of negative RE (too small to see in this panel) and some areas of negative CE. However, unlike the Steig reconstruction, ours performs well in most of West Antarctica, the Peninsula, and the Ross Ice Shelf. All values are significantly higher than the Steig reconstruction, and we show much smaller regions with negative values.

As an aside, the r^2 plots are not corrected by the Monte Carlo analysis yet. However, as shown in the previous post concerning Steig’s verification statistics, the maximum r^2 values using AR(8) noise were only 0.019, which produces an indistinguishable change from Fig. 3.

Now that we know that our method provides a more faithful reproduction of the satellite data, it is time to see how faithfully our method reproduces the ground data. A simple way to compare ours against Steig’s is to look at scatterplots of reconstructed anomalies vs. ground station anomalies:

Your browser may not support display of this image.

Fig_4Fig. 4: 13-PC scatterplot (left); Steig reconstruction (right)

The 13-PC reconstruction shows significantly improved performance in predicting ground temperatures as compared to the Steig reconstruction. This improved performance is also reflected in plots of correlation coefficient:

Fig_5Fig. 5: Correlation coefficient by geographical location

As noted earlier, the performance in the Peninsula , West Antarctica, and the Ross Ice Shelf are noticeably better for our reconstruction. Examining the plots this way provides a good indication of the geographical performance of the two reconstructions. Another way to look at this – one that allows a bit more precision – is to plot the results as bar plots, sorted by location:

Fig_6Fig. 6: Correlation coefficients for the 13-PC reconstruction

Fig_7Fig. 7: Correlation coefficients for the Steig reconstruction

The difference is quite striking.

While a good performance with respect to correlation is nice, this alone does not mean we have a “good” reconstruction. One common problem is over-fitting during the calibration period (where the calibration period is defined as the periods over which actual data is present). This leads to fantastic verification statistics during calibration, but results in poor performance outside of that period.

This is the purpose of the restricted reconstruction, where we withhold all AWS data. We then compare the reconstruction values against the actual AWS data. If our method resulted in overfitting (or is simply a poor method), our verification performance will be correspondingly poor.

Since Steig did not use AWS stations for performing his TIR reconstruction, this allows us to do an apples-to-apples comparison between the two methods. We can use the AWS stations as a verification target for both reconstructions. We can then compare which reconstruction results in better performance from the standpoint of being able to predict the actual AWS data. This is nice because it prevents us from later being accused of holding the reconstructions to different standards.

Note that since all of the AWS data was withheld, RE is undefined. RE uses the calibration period mean, and there is no calibration period for the AWS stations because we did the reconstruction without including any AWS data. We could run a split test like we did with the satellite data, but that would require additional calculations and is an easier test to pass regardless. Besides, the reason we have to run a split test with the satellite data is that we cannot withhold all of the satellite data and still be able to do the reconstruction. With the AWS stations, however, we are not subject to the same restriction.

Fig_8Fig. 8: Correlation coefficient, verification period, AWS stations withheld

With that, I think we can safely put to bed the possibility that our calibration performance was due to overfitting. The verification performance is quite good, with the exception of one station in West Antarctica (Siple). Some of you may be curious about Siple, so I decided to plot both the original data and the reconstructed data. The problem with Siple is clearly the short record length and strange temperature swings (in excess of 10 degrees), which may indicate problems with the measurements:

Fig_9Fig. 9: Siple station data

While we should still be curious about Siple, we also would not be unjustified in considering it an outlier given the performance of our reconstruction at the remainder of the station locations.

Leaving Siple for the moment, let’s take a look at how Steig’s reconstruction performs.

Fig_10Fig. 10: Correlation coefficient, verification period, AWS stations withheld, Steig reconstruction

Not too bad – but not as good as ours. Curiously, Siple does not look like an outlier in Steig’s reconstruction. In its place, however, seems to be the entire Peninsula. Overall, the correlation coefficients for the Steig reconstruction are poorer than ours. This allows us to conclude that our reconstruction more accurately calculated the temperature in the locations where we withheld real data.

Along with correlation coefficient, the other statistic we need to look at is CE. Of the three statistics used by Steig – r, RE, and CE – CE is the most difficult statistic to pass. This is another reason why we are not concerned about lack of RE in this case: RE is an easier test to pass.

Fig_11Fig. 11: CE, verification period, AWS stations withheld

Your browser may not support display of this image.

Fig_12Fig. 12: CE, verification period, AWS stations withheld, Steig reconstruction

The difference in performance between the two reconstructions is more apparent in the CE statistic. Steig’s reconstruction demonstrates negligible skill in the Peninsula, while our skill in the Peninsula is much higher. With the exception of Siple, our West Antarctic stations perform comparably. For the rest of the continent, our CE statistics are significantly higher than Steig’s – and we have no negative CE values.

So in a test of which method best reproduces withheld ground station data, our reconstruction shows significantly more skill than Steig’s.

The final set of statistics we will look at is the performance of RegEM. This is important because it will show us how faithful RegEM was to the original data. Steig did not perform any verification similar to this because PTTLS does not return the model frame. Unlike PTTLS, however, our version of RegEM (IPCA) does return the model frame. Since the model frame is accessible, it is incumbent upon us to look at it.

Note: In order to have a comparison, we will run a Steig-type reconstruction using RegEM IPCA.

There are two key statistics for this: r and R^2. R^2 is called “average explained variance”. It is a similar statistic to RE and CE with the difference being that the original data comes from the calibration period instead of the verification period. In the case of RegEM, all of the original data is technically “calibration period”, which is why we do not calculate RE and CE. Those are verification period statistics.

Let’s look at how RegEM IPCA performed for our reconstruction vs. Steig’s.

Fig_13Fig. 13: Correlation coefficient between RegEM model frame and actual ground data

As you can see, RegEM performed quite faithfully with respect to the original data. This is a double-edged sword; if RegEM performs too faithfully, you end up with overfitting problems. However, we already checked for overfitting using our restricted reconstruction (with the AWS stations as the verification target).

While we had used regpar settings of 9 (main reconstruction) and 6 (restricted reconstruction), Steig only used a regpar setting of 3. This leads us to question whether that setting was sufficient for RegEM to be able to faithfully represent the original data. The only way to tell is to look, and the next frame shows us that Steig’s performance was significantly less than ours.

 Fig. 14: Correlation coefficient between RegEM model frame and actual ground data, Steig reconstructionFig. 14: Correlation coefficient between RegEM model frame and actual ground data, Steig reconstruction

The performance using a regpar setting of 3 is noticeably worse, especially in East Antarctica. This would indicate that a setting of 3 does not provide enough degrees of freedom for the imputation to accurately represent the existing data. And if the imputation cannot accurately represent the existing data, then its representation of missing data is correspondingly suspect.

Another point I would like to note is the heavy weighting of Peninsula and open-ocean stations. Steig’s reconstruction relied on a total of 5 stations in West Antarctica, 4 of which are located on the eastern and southern edges of the continent at the Ross Ice Shelf. The resolution of West Antarctic trends based on the ground stations alone is rather poor.

Now that we’ve looked at correlation coefficients, let’s look at a more stringent statistic: average explained variance, or R^2.

Fig. 15: R2 between RegEM model frame and actual ground dataFig. 15: R^2 between RegEM model frame and actual ground data

Using a regpar setting of 9 also provides good R^2 statistics. The Peninsula is still a bit wanting. I checked the R^2 for the 21-PC reconstruction and the numbers were nearly identical. Without increasing the regpar setting and running the risk of overfitting, this seems to be about the limit of the imputation accuracy.

Fig_16Fig. 16: R^2 between RegEM model frame and actual ground data, Steig reconstruction

Steig’s reconstruction, on the other hand, shows some fairly low values for R^2. The Peninsula is an odd mix of high and low values, West Antarctica and Ross are middling, while East Antarctica is poor overall. This fits with the qualitative observation that the Steig method seemed to spread the Peninsula warming all over the continent, including into East Antarctica – which by most other accounts is cooling slightly, not warming.

CONCLUSION

With the exception of the RegEM verification, all of the verification statistics listed above were performed exactly (split reconstruction) or analogously (restricted 15 predictor reconstruction) by Steig in the Nature paper. In all cases, our reconstruction shows significantly more skill than the Steig reconstruction. So if these are the metrics by which we are to judge this type of reconstruction, ours is objectively superior.

As before, I would qualify this by saying that not all of the errors and uncertainties have been quantified yet, so I’m not comfortable putting a ton of stock into any of these reconstructions. However, I am perfectly comfortable saying that Steig’s reconstruction is not a faithful representation of Antarctic temperatures over the past 50 years and that ours is closer to the mark.

NOTE ON THE SCRIPT

If you want to duplicate all of the figures above, I would recommend letting the entire script run. Be patient; it takes about 20 minutes. While this may seem long, remember that it is performing 11 different reconstructions and calculating a metric butt-ton of verification statistics.

There is a plotting section at the end that has examples of all of the above plots (to make it easier for you to understand how the custom plotting functions work) and it also contains indices and explanations for the reconstructions, variables, and statistics. As always, though, if you have any questions or find a feature that doesn’t work, let me know and I’ll do my best to help.

Lastly, once you get comfortable with the script, you can probably avoid running all the reconstructions. They take up a lot of memory, and if you let all of them run, you’ll have enough room for maybe 2 or 3 more before R refuses to comply. So if you want to play around with the different RegEM variants, numbers of included PCs, and regpar settings, I would recommend getting comfortable with the script and then loading up just the functions. That will give you plenty of memory for 15 or so reconstructions.

As a bonus, I included the reconstruction that takes the output of our reconstruction, uses it for input to the Steig method, and spits out this result:

Fig_17Fig. 17: Steig reconstruction using the 13-PC reconstruction as input.

The name for the list containing all the information and trends is “r.3.test”.

—————————————————————-

Code is here Recon.R

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Malcolm

A better title would be “Steig et all Debunked”.

VG

These people have been most careful in making any statements that Steig et al were falsified. Me thinks that Nature will now have to face the music. BTW Nature is an incredible journal and has published some brilliant work… this should not detract from its inherent quality.

Lars Kamél

The Team will of course never back down on this. The Team members will say that the errors don’t matter and soon “independent” studies by “independent” groups will verify the Antarctic warming. All these “independent” studies about the Antarctic warming will be highlighted in the next IPCC report.

VG

My father published this work in Nature in 1937
http://www.nature.com/nature/journal/v135/n3417/abs/135654a0.html
Not unrelated to Svenmark’s work.. its a great day for Science! (that why I don’t want to put Nature down LOL)

Pierre Gosselin

The Steig paper is falsified.
The entire AGW science is falsified.

Good luck getting ANY coverage of this in the mainstream media. That same media that plastered Steig at al’s flimsy and biased results all over the place earlier this year.
So there we have it, Antarctica has NOT warmed after all. Ice extent keeps increasing year on year and the mainstream media STILL carries alarmist stories about ice melting faster than ever before.
I guess we can amend that old saying, “there are lies, damn lies, statistics and mainstream media climate stories.”

VG

Ken Hall: I think in this case you may be wrong. I think the media will pick up on this because its sensational. Also the Svensmark Videos seems to have been made very professionally (the other story) and this will also be picked up by major networks. This is my guess of course (we can always hope).

Alan the Brit

A bit too technical for me but I got the gist!
In reference to the Cheesemans Safaris ad above, if memory serves, (& that’s a big if in these days), is there not a region of the Western Antarctic (no bears) where ecobunnies travel to in luxury aboard liners, & they land, dip their toes into the sea, then warm up in a geothermal pool somewhere nearby, or am I losing it? I am sure I’ve seen this activity on some holiday programme somewhere. Nobody seems to add 2 + 2 & ask a question, could this be what contributes to any apparent warming in the Peninsula? I’ll try & do a bit of research on that.

VG

Re a bit OT Svensmark: I agree that cloud nuclei do form more frequently when sun activity is less. The proviso may be that they form where they usually would form (ie not in the Sahara). I would have to say that living in East Queensland (Australia) they have formed dramatically more than over the past year especially Cumullus nimbus (low cloud) which have been responsible for extremely above average rainfall in this area this year (ie all the dams are full) and drought is over (usual in this part of the world)

timbrom

OT and maybe worthy of a separate post? World’s leading scientists warn climate change is as great a threat as nuclear warfare
Ramping the rhetoric ahead of Copenhagen. How do we Realists respond to stuff like this?

Alan the Brit

I found this extract from the Cheesemans Safaris website, so I wasn’t dreaming after all! Deception Island is on just off the Peninsula. They also mention on their site that there is evidence for global warming in the oceans around the Peninsula, but clearly can’t see the possible connection, probably because it doesn’t fit their belief system.
“Deception Island, in the South Shetlands, is one of the most exciting islands on our voyage. This horseshoe-shaped volcanic island is still active, as the hot thermal pools there demonstrate. We hope to land on both the outside wall and inside the caldera center that opens to the ocean via a narrow gap called Neptune’s Bellows. The landing at Bailey Head on the outside has close to half a million Chinstraps nesting at this time of year, but the sea can be a bit tricky with steep swells crashing on an exposed beach. Inside Deception’s huge caldera we hope to make a fascinating landing, which may include a short hike up the mountainside to the lookout among the lichen-draped cliffs. On the beach at Whaler’s Bay we may find Weddell Seals basking and we’ll go ashore if the tide is correct and the weather is favorable. Then prepare for one of the most unique experiences of this voyage – soaking in the island’s thermal pools surrounded by clouds of steam alongside the beach at Pendulum Cove. The water temperature can be fairly comfortable, although it can get so hot that it’s necessary to mix it with colder water. ”
Now that’s what I call warming! Definitely a third ice cube required for the G & T at bath time me thinks. They also add this proviso:-
“NOTE: Antarctic conditions change very rapidly and we will make every possible effort to accomplish our schedule, however local weather can’t be predicted or controlled and we must be flexible. Don’t be fooled, no tour operator can guarantee landings.”
I thought the whole raison d’être for stopping global warming was to control the weather. Presumably non-local weather can be predicted & controlled then?
AtB

MattN

I knew they made it up….

timbrom

Still OT, but having poked the Daily Telegraph in the eye, thought I should balance with another of today’s articles: Rachel Carson, environmentalism’s answer to Pol Pot . Note the comments immediately descend into ad hom. Delingpole is clearly a Realist. That makes two on the Telegraph’s roster.

Espen

Alan the Brit: On the official deception island site (http://www.deceptionisland.aq/volcanic.php) I find the following: “In 1992, enhanced seismic activity on Deception Island was accompanied by ground deformation and increased water temperatures.”. There are also several undersea volcanos near the Antarctic Peninsula, I think. Could some of the warming of the peninsula simply be caused by increased volcanic activity?

par5

Robustness! Great job.

hunter

Steig’s work = Junk science = AGW

Steve D

I notice Real Climate is “temporarily down for maintenance”. I can’t wait for them to re-emerge & comment on this one; they seem to be have been comprehensively debunked.

Thanx timbrom for that link. It also references a short article by Steve Milloy, who runs the excellent JunkScience site: click

Ryan O

Haha. 🙂 Thanks, Anthony for carrying this – nice surprise to wake up this morning and see this as a new post.
REPLY: It is my honor to do so, you sir are to be commended for this work. – Anthony

Jimmy Haigh

And isn’t ‘Deception Island’ a wonderfully appropriate name for a bunch of AGW proponents to visit/holiday?

Chris S

I await the publication of this after peer review with baited breath – perhaps it would be an interesting exercise for Ryan O to take us through the submission & review process step-by-step as it happens?
One thing I notice from ‘fig. 1’ above – There’s still a lot of red on the map is there not?

Ryan O

Chris: Yes. Overall, Antarctica has warmed from 1957-2006. There is no debating that point. (However, other than the Peninsula, the warming is not statistically significant. )
The important difference is the location of the warming and the magnitude of the warming. Steig’s paper has the warming concentrated on the Ross Ice Shelf – which would lead you to entirely different conclusions than having a minimum on the ice shelf. As far as magnitude goes, the warming for the continent is half of what was reported by Steig (0.12 vs. 0.06 Deg C/Decade).
Additionally, Steig shows whole-continent warming from 1967-2006; this analysis shows that most of the continent has cooled from 1967-2006. Given that the 1940’s were significantly warmer in the Antarctic than 1957 (the 1957-1960 period was unusually cold in the Antarctic), focusing on 1957 can give a somewhat slanted picture of the temperature trends in the continent.

blcjr

Chris S (04:50:12) :
I await the publication of this after peer review with baited breath – perhaps it would be an interesting exercise for Ryan O to take us through the submission & review process step-by-step as it happens?
One thing I notice from ‘fig. 1′ above – There’s still a lot of red on the map is there not?

I encourage Ryan to compose this as a comment on the original and submit it to Nature. If they reject it, it will be interesting to see why. It can always be published elsewhere. While the bias for peer review in established journals will continue for some time, if they keep publishing bad science, and then not acknowledging it, they will eventually lose stature. In time, they may go the way of the MSM. I think “open access journals” will eventually rival, and maybe even surpass, the traditional print journals. There is also arxiv.org.
On Fig. 1, I think if one starts a few years in the future, their will be more blue. But since Steig started in 1957, it is best to challenge it without distractions over cherry picking. It is the method, not the time period, that needs to be debunked.

Andy Y

Chris,
If you follow the two Jeffs’ work, they do show some warming at about 1/2 the rate quoted in Steig. One of the Jeffs (I forget which) also showed that most of the actual warming occurred in the first 5-10 years. Take those years out and the trend flips towards cooling for the last 40 years. (You’d have to backtrack through AirVent and Climate Audit but the work is there.)

Bill Illis

Great work Ryan O and Jeff Id and Steve McIntyre.
The work either has to be submitted to Nature or, at least, widely spread around the temperature reconstruction community because this work also shows that the general RegEm process, itself, is not a robust in-filling procedure.
The choice of how many PCs to use radically changes the result, it almost looks random with even signs changing in between PCs. I think even relying on the PC with the highest statistical correlation only is not going to produce faithful reconstructions.
The Team and others need to abandon this process except for specialized needs, not to reconstruct important temperature series.

Mike Bryant

Chris S,
The problem is that with such limited data and ennabling algorithms, you can pick whatever color you like.
This reconstruction is somewhat like the hockey stick in that any data plugged into Steig’s program smears the data to reveal the desired result. In other words, Steig’s handiwork is wanting. By changing the PCs and regpar settings, any desired output is attainable.
Ryan also took his better reconstruction and used the Steig method, and the result is even warming over the Antarctic. It fails.
It makes you wonder if they realize that the PCs and regpar adjustments invalidate their approach, or they are hoping that no one catches on.
They are in trouble when this type of, let’s call it “inadequacy”, has been explained clearly enough that a plumber can understand it.
If Nature does not respond quickly and boldly the magazine will be a laughingstock.

stan

“I hope that Ryan O will write a rebuttal letter to Nature, and/or publish a paper. It is the only way the Team will back down on this. – Anthony”
The team will never back down. This isn’t about science. It isn’t about truth. It’s about politics.

Arthur Glass

Speaking of damned lies and half-truths, Roger Pielke Jr’s blog Prometheus is especially vital reading today. Pielke quotes what amounts to an eloquent plea for the integrity of scientific narrative.
http://sciencepolicy.colorado.edu/prometheus/purists-who-demand-that-facts-be-correct-5309
But why is their registration process so labyrinthine over at Prometheus? They scared me off.

GK

….pants on fire

Mike Bryant

“Chris S (04:50:12) :
I await the publication of this after peer review with baited breath”
What are you using for bait?

Craig W

VG (01:45:07) :
“BTW Nature is an incredible journal and has published some brilliant work… this should not detract from its inherent quality.”
That’s all fine and well. But, shouldn’t Nature do some investigation before running with a story?

WestHoustonGeo

Question:
How many kilograms in a “metric butt-ton”?

Ron de Haan

OT but important:
A Forum led by Koffee Anan will publish a report this week stating 300.000 climate casualties per year. (via Climate Depot).
The report is already under scrutany by Dr Pileke which findingd were published in the Washington Post. http://www.nytimes.com/2009/05/29/science/earth/29climate.html?_r=1&ref=earth
The latest postings at WUWT about this subject already closed the door on any alarmist findings.
When will our politicians see they are tricked by the UN and it’s corrupt sicko management? They are turning the world into a mess.

P Walker

Timbrom – thanks for the link . I enjoy Booker’s columns , but don’t go into yhe blogs . Booker is a big fan of this site . BTW , most of the ad homs are coming from a notorious troll who has found his way into a number of other sites . I hope he doesn’t show up here .

DR

@VG
I don’t share your adulation for Nature. It may have been a great journal in 1937, but for many years has transformed into a repository for all things in agreement with AGW. They seem more than willing to publish just about any article no matter how absurd, like crap through a goose as long as it passes the AGW smell test.
Look at what Steve McIntyre had to endure to debunk the hockey stick, yet Nature is still in the bag for Mann.
Although not Nature, it has been four months since Steve submitted his paper on Santer 08 with no response as of yet to the best of my knowledge.
Yet, look at the expediency given to pro-AGW papers; in like Flynn.
The rejection of Spencer’s latest work is tantamount to the political influence in many of these so-called science journals. Who wants to guess how many months will pass without acceptance should this repudiation of Steig et al be submitted for “peer review”?
That said, I would be willing to contribute financially to this effort.

John Galt

The human mind is a wonderful thing. It’s capable of detecting patterns and trends where none exist. The human ego prevents it from recognizing it’s folly.

Mark Wagner

great analysis, thanks.
how much, exactly, is a “butt ton?”

LarryD

Espan:“There are also several undersea volcanos near the Antarctic Peninsula, I think. Could some of the warming of the peninsula simply be caused by increased volcanic activity?”
Obviously yes, the real question is “How much?”

hunter

Chris S,
The ‘red’ on the map means that the ‘warmest’ places on Antarctica is cold enough to kill you, unless you are very well prepared.
As the Catlin scam discovered, believing that the world is roasting due to a human caused apocalypse is quite different from actually going out to the field.
What the ‘red’ really means is that people are easily deceived by colors and pictures, which is what Mann, Steig, Hansen, Gore, etc. etc. etc. all knew when they set out to fabricate AGW.

They CAN’T back down. Kofi “Oil-for-Food” Annan tells us that “climate change” DIRECTLY is responsible for 300,000 deaths (or some such utterly unsubstantiated nonsense). It’s evidently our duty to ignore reality to save lives.
http://www.cnn.com/2009/WORLD/europe/05/29/annan.climate.change.human/index.html
😛

Benjamin P.

So, I still see warming in all your reconstructions?
REPLY: If you go back and look at what Steig did, you’ll note that he chose a start point of 1957. However from 1967 to present, there has been a cooling trend, and the amount of warming (if you can call it that, since the continent is still bitterly cold) is statistically insignificant. See Ryan O’s comments earlier. – Anthony

Benjamin P.

LarryD (06:42:07) :
Espan:“There are also several undersea volcanos near the Antarctic Peninsula, I think. Could some of the warming of the peninsula simply be caused by increased volcanic activity?”
“Obviously yes, the real question is “How much?””
Yes, but to answer the question of how much, it is mostly negligible.
REPLY: You are making an assumption without any firsthand knowledge that it is negligible. Without doing a study to determine the magnitude, you cannot be sure. Remember, we aren’t talking about much. What we do know is that water around Deception Island is warm enough to boil shrimp at times, allowing tourists there to pick up “ready to eat” shrimp on the beach. Our own moderator confirms this with direct experience. How much is the ocean warmed in the region translating to warming air temps in the Peninsula? We don’t know. What we do know for certain is that the Peninsula has a wholly different warming trend than the main continent, and that it is so far removed geographically it should probably be declared a different climate zone. – Anthony

Benjamin P.

REPLY: If you go back and look at what Steig did, you’ll note that he chose a start point of 1957. However from 1967 to present, there has been a cooling trend, and the amount of warming (if you can call it that, since the continent is still bitterly cold) is statistically insignificant. See Ryan O’s comments earlier. – Anthony
So 67+ shows cooling, and 57+ shows warming…which is the superior one to use? Where is that 67-06 reconstruction?
REPLY: Follow the trail backwards and you’ll see it. – Anthony

Chris S

Ryan O. thanks for your response. Good luck with your efforts to publish, I know from my own experience that it can be a real pain in the unmentionables. I do wonder why you feel that shortening the time period (ie throwing out data) is preferable though. Have you or (either) Jeff looked at aerosol or ozone hole effects on the temperature trend?
On a slightly different note, but interesting (to me at least) regarding Antartica – it seems a recent expedition to South Georgia recorded the first confirmed breeding by hoverflies there ( http://www.expeditionsail.com/blog.htm scroll down to Jan 14th).

John W.

P Walker (06:28:39) :
Timbrom – thanks for the link . I enjoy Booker’s columns , but don’t go into the blogs . Booker is a big fan of this site . BTW , most of the ad homs are coming from a notorious troll who has found his way into a number of other sites . I hope he doesn’t show up here .

I won’t mention his name, but I doubt the little fella will show up here. This is a science site, and he favors political journals. (He’s a regular ranter at The American Spectator.) Even if he dopes show up, the mods will snip him so much he won’t hang around.
TBH, I think he’s kind of entertaining.

John W.

dopes => does.
Freudian slip.

Ryan O

Benjamin,
A panel showing the 67-06 trend is here:
http://noconsensus.wordpress.com/2009/05/20/antarctic-coup-de-grace

dearieme

““Overall, Antarctica has warmed from 1957-2006. There is no debating that point. (However, other than the Peninsula, the warming is not statistically significant. ) ” I think that’s not an ideal way to phrase it. If it isn’t statistically significant, that means that you are not confident that extra-peninsular Antarctica has warmed. I suggest:
In Antarctica outside the peninsula, there was NO statistically significant warming in 1957-2006.

Layman Lurker

re: Bill Illis (05:43:20)
Bill, I disagree that the problem is with RegEM. It is like any other program – garbage in, garbage out. This is more an issue of understanding the problem, the data, and methods of analysis.

You can’t get more ‘Antarctic’ than this: click