GHCN's Dodgy Adjustments In Iceland

Guest post by Paul Homewood


Take a look at the two graphs above. They are both mean temperature plots for Stykkisholmur, a small town in the west of Iceland.

Now take another look!

The top one is the official Icelandic Met Office (IMO) plot, and it clearly shows a gradual upward trend since the early 19thC, interrupted by cold periods between 1860 and 1880, and again in the 1960’s and 70’s. (The latter are famed in Iceland as the “Sea Ice Years”, when agriculture and fishing suffered so heavily that unemployment soared and the currency devalued by 50% for a full history, check here.) Current temperatures are about the same as they were in the 1930’s and 40’s. (The graph only runs to 2007, but temperatures have dropped since then).

The IMO’s narrative that appears with the graph states.

The time from 1925 onwards is dominated by a very large cycle that does not show an overall significant warming, although the temperature rise of the last 20 years is considerable.

The 20th century warm period that started in the 1920s ended very abruptly in 1965. It can be divided into three sub-periods, a very warm one to 1942, a colder interval during 1943 to 1952, but it was decisively warm during 1953 to 1964.

The cold period 1965 to 1995 also included a few sub-periods. The so called “sea ice years” 1965 to 1971, a slightly warmer period 1972 till 1978, a very cold interval during 1979 to 1986, but thereafter it became gradually warmer, the last cold year in the sequence being 1995. Since then it has been warm, the warmth culminating in 2002 to 2003. Generally the description above refers to the whole country, but there are slightly diverging details, depending on the source of the cold air.

Now take a look at the second graph. This is from GHCN. Ignore the bits on the left and check the graphs on the right. The top, red, plot is the actual temperature record, which follows the IMO trend. The second, yellow plot, however, is the adjusted GHCN record, which is the one actually used for global temperature calculation by both GHCN and also GISS. The bottom graph shows the value of the adjustment, with blue indicating adjusting down up to 1964 and red being upwards adjustment since. The scale is a bit unclear, but the overall effect of the adjustment is to add a warming adjustment of 0.74C.

You might ask “where did the Sea Ice Years go?”, and you would be right. GHCN have pretty much adjusted these out of existence. The GHCN algorithm has obviously mistaken the sharp fall in temperatures in 1965 as some sort of aberration caused by a change of location or equipment, and therefore wiped it from the record. However it has not made the same assumption about subsequent and equally sharp rises. The result is that temperatures since 1990 appear to be consistently higher than the 1930’s and 40’s, which, according to the IMO, simply is not the case.

Let’s stop for a moment, and review what GHCN have to say about why they adjust.

Surface weather stations are frequently subject to minor relocations throughout their history of operation. Observing stations may also undergo changes in instrumentation as measurement technology evolves. Furthermore, observing practices may vary through time, and the land use/land cover in the vicinity of an observing site can be altered by either natural or man-made causes. Any such modifications to the circumstances behind temperature measurements have the potential to alter a thermometer’s microclimate exposure characteristics or otherwise change the bias of measurements relative to those taken under previous circumstances. The manifestation of such changes is often an abrupt shift in the mean level of temperature readings that is unrelated to true climate variations and trends. Ultimately, these artifacts (also known as inhomogeneities) confound attempts to quantify climate variability and change because the magnitude of the artifact can be as large as or larger than the true background climate signal. The process of removing the impact of non-climatic changes in climate series is called homogenization, an essential but sometimes overlooked component of climate analysis.

So have there been any such changes in Stykkisholmur in 1965? Well, not according to Trausti Jonsson, a Senior Climatologist with the IMO, who tells me

“There were minor relocations at Stykkishólmur in May 1964, May 1966 and April 1968. None has been found important at the 0.2°C level. “

Furthermore, as Trausti makes clear on his blog Iceland Weather, the IMO has calculated series with some appropriate adjustments for each individual station. In other words, if there have been changes in location or recording methods, they have adjusted for these on a specific basis already. There is no need for GHCN to make further adjustments.

So, back to GHCN. To isolate the inhomogeneities they talk about, they compare a station with other stations, via a “Pairwise Homogeneity Algorithm”. Put simply, if Stykkisholmur shows a sudden drop in temperature while other nearby stations don’t, it suggests that the “drop” is due to local, non-climatic factors, and is therefore adjusted back to the trend of other stations. But is there any evidence that this is the case in Iceland?

There are altogether six Icelandic stations listed by GHCN that are still current: Reykjavik,Vestmanneyja, Akureyri, Keflavik, Hofn and Stykkisholmur. The IMO have produced the following plot for Reykjavik, Akureyri and Sykkisholmur.


Figure 2. 7-year running means of temperature at three locations in Iceland, Reykjavík (red trace)), Stykkishólmur (blue trace) og Akureyri (green trace). Kuldakast = cold period. The first of the marked periods was the coldest one in the north (Akureyri), the second one was the coldest in Reykjavík

So not only are the cold periods seen at Stykkisholmur repeated at Reykjavik and Akureyri, they were actually more pronounced at the latter. And what do GHCN say?



Just as with Stykkisholmur, the temperature has been adjusted down prior to 1965 and/or up since. And not only in Reykjavik and Akureyri. Every single site in Iceland has been adjusted in the same fashion. (You might also notice that in some cases the very warm period around 1940, that the IMO refers to above, has been adjusted down).




The “Pairwise Algorithm” is claimed to isolate non-climatic changes by comparison with other stations. But in Iceland this clearly has not happened. Every single station exhibits the same trend and at every one the algorithm has adjusted it out. There are no stations that the algorithm could possibly have used to have come to the conclusions that it did.

It is impossible to come to any other conclusion than that the software is hopelessly flawed.

How significant is all this? GHCN state that the latest set of adjustments have added 0.13C/century to global land temperatures, and of course this is on top of adjustments arising from earlier versions. This is a quarter of the reported warming across the globe since 1980.

But if the adjustments made in Iceland are patently false, can there be any confidence that adjustments made elsewhere are not also fatally flawed?

BTW – check out Reykjavik. Not only has GHCN added a massive adjustment, but GISS have actually made matters worse by adding to it when supposedly adjusting for UHI – see here.


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The Invisible Thumb at work.


Paul Homewood:
Why all the fuss? If you don’t like data GHCN provide today then wait a week or two and GHCN will change it. And if you don’t like what you then get then just be patient. /sarc off


Another case of manipulating the data to fit the hypothesis. It is sickening when incompetents are paid millions to do this, and rate their efforts as being scientifically accurate. Cheers all around for one more incorrect data project shown up? I bet Al Gore is red faced, eh?


Do they take into account that they are a land of the midnight sun, and in winter they are dark, bar for the fact the main source of energy and lighting is generated geo-thermally. And in summer the sun never sets, but is not as warm as at midday? No wonder they suffer from Vit D
depletion. Like all the Arctic circle countries.

Lawrie Ayres

It is obvious that no government instrumentality can be trusted. They all use taxpayer funds to hoodwink the taxpayer. True in the US, true in the UK and true here in Australia. It was also true in NZ but since they now don’t have an official temperature record it’s hard to tell. Our BoM did such an atrocious job redoing their record after Jo Nova and her team of volunteers convinced the auditor general to take a look at their adjustments that they made some thousands of mistakes where min temps were greater than max temps. We are surrounded by untrustworthy people whose data cannot be relied on for future research.

Ole Olson

So how do you take perfectly good data and turn it into an “Inconvenient Truth”? You use an Al-Gore-ithm of course.

Some time ago I compared Stykkisholmur atmospheric pressure and temperatures
On bases of which a long term forecast can be made with a good degree of confidence .


If Paul’s calculations are correct the true data have been distorted – one could say corrupted – by GHCN’s homogenisation. Whether this distortion was the result of conscious fabrication on the part of GHCN or simply cavalier incompetence (and I suspect a fair slice of the latter) is beside the point – Paul’s results need to be published in the mainstream literature.

I have done some digging similar to Paul’s and found the same data fiddling. For Siberia and Iceland GISS has revised downwards older temperature records, raised more recent ones and – hey presto! – a warming trend of approx 1C per century is conjured out of nothing.
My view is that publicly-owned data is being fraudulently manipulated in order to generate a spurious warming trend and further the interests of a Global Warming Industry funded by the taxes of honest citizens. The sooner this wickedness is tested in the courts the better.


I have been telling people it will become colder through 2035. I have also blogged that it will be a colder century ahead.
These numbers tend to make me think that the present solar minimum will have longer effects on our climate in terms of cooling way past 2035. It may impact us out to 2050.
Here in Florida, we had two major cold snaps after the rather flat sunspot cycle from 1964 to about 1965. They two cold snaps happened in the 1990s, much as the numbers show for Ireland.
The sunspot minimum has already effected our drought and crop export. It would be interesting to see what the crop and meat exports looked like through the late 70s to mid 90s to see the overall impact of reduced sunspot activity or a rather flat cycle such as 1964 to 1976.


”But if the adjustments made in Iceland are patently false, can there be any confidence that adjustments made elsewhere are not also fatally flawed?”
Of course there can’t! The whole process is fraught with errors and differences of data treatment, etc, etc. What really, really ‘pi$$es me off the most though, is that if the individual stations were reviewed in just this manner, they would (have been?) seen. Just showing before and after comparisons, and undertaking HUMAN eyeball review would show the flaws in a split second. But do they ever show the before and after? do they ever tell us how the adjustments are derived? Do they actually KNOW what the flipping computer adjustments are anymore?
The temp data is FUBAR of the highest level and quality!


Bushbunny writes:
“Do they take into account that they are a land of the midnight sun, and in winter they are dark, bar for the fact the main source of energy and lighting is generated geo-thermally. And in summer the sun never sets, but is not as warm as at midday? No wonder they suffer from Vit D
depletion. Like all the Arctic circle countries.”
However, only a tiny bit of iceland is above the Arctic Circle. So this dramatic description is a bit over the top. Go to Norway if you want to experience the real north.

Brian H

richardscourtney says:
October 15, 2012 at 12:34 am
Paul Homewood:
Why all the fuss? If you don’t like data GHCN provide today then wait a week or two and GHCN will change it. And if you don’t like what you then get then just be patient. /sarc off

Won’t work. All the adjustments go in the same (bigger warming trend) direction, so the data you’ve got now is the least distorted you’re ever going to get.

Paul Homewood: Nice work old chap! Paul is typical of the hardworking realists which occupy WUWT blog.


UHI in Iceland! The mind boggles.

This will set them up to make more ludicrous claims in the future. They have in the past operated in the same fashion. Leftists and their questionable causes that is. With Biofuel, which they now finally admit “may” have been a mistake but was responsible for millions of deaths. The starvation that caused and of course do not forget the DDT erasure, which has been responsible for killing millions which reintroduced Malaria by removing that product under the false guise that it was unsafe for humans. Then we have the World Bank’s denials on dam building for water and hydro dams to supply power to millions of people in Africa and Asia, including India. Condemning millions to an early grave as they inhale smoke from their kitchen fires on a daily basis.They are prepared to lie, cheat and steal, encourage dishonesty and anything else it takes so they can further their various questionable and population reducing causes. This is just sadly another example of how they work and it truly is a disgrace. They continue to demonstrate that honour, dignity and principals are irrelevant where they are concerned.

Bloke down the pub

If the consequences of this were not so serious, it would be funny.


meanwhile, back in the real world:
15 Oct: Vancouver Sun: Matthew Fisher: There may be more to the Arctic thaw than global warming
At the same time Russia, with Finnish help, has been slowly building a fleet of ice-strengthened cargo vessels capable of travelling across the north in tandem with its icebreakers.
All this is necessary because some Russians believe that global warming will not proceed as quickly in the Far North as some western experts have predicted. Whatever the speed of the retreat of the polar ice cap every summer, ice will still cover the entire circumpolar world for at least six months a year for decades to come…


Brian H:
re. your post addressed to me at October 15, 2012 at 2:04 am.
Yes, I know. That is why my post had a sarc tag.
If you doubt that I know then read this
If I did not laugh then I would have to cry so I chose to make a joke.


Blakemore is, as usual, alarmed:
14 Oct: ABC America: Bill Blakemore: Sea Level Rising Toward Washington and Other Cities
Recently, the world’s climate experts have reported that global sea level rise is speeding up much faster than they expected only a few years ago.
They now calculate there could well be a rise of another one to two meters before the end of the century.
This would mean serious flooding in many sea level cities before mid century — within 40 years…
Russia’s St. Petersburg Already Ringed By Extensive New Sea Wall…
Russian history set this solution in motion more than 300 years ago…
There are three general ways for city planners to think about dealing with this accelerating sea level rise, according to a comprehensive climate impacts report from the U.S Global Change Research Program, published by Cambridge University Press and entitled “Global Climate Change Impacts in the U.S.” — GCCIUS — available online…
The above online GCCIUS report is notable for its illuminating, solidly sourced explanations and its clear and user-friendly color graphics on many aspects of how manmade global warming is impacting the United States.
Illuminating and bracing as this report is, it should be noted that it was published in 2009. The next edition will incorporate the more worrisome news about the acceleration of the warming’s impacts that has come from the world’s climate scientists since then. It is due out by the end of 2013…
“Once again, we’re ahead of schedule,” says widely respected climate scientist Michael Mann of Pennsylvania State University.
Mann tells ABC News that satellite measurements also show that the land may be absorbing at least some of the excess water newly lost from the ice-sheets, but that even if that is true, with the temperature only expected to rise steadily for the coming decades, such absorption by the land would at best only be masking an inevitable jump in sea level rise.
Mann points out that some of the world’s low lying countries, including island nations in the great oceans, are already experiencing the rise of salt water in their groundwater and in the center of some of their fields and a rapidly advancing coastal erosion…


not just “ahead of schedule”, but “decades ahead of schedule” says Mann. lots on the “forces of denial”/koch bros and the intimidation of scientists which is to warn off other scientists from speaking up!
4 Oct: Guardian: Jo Confino: Climate change may force evacuation of vulnerable island states within a decadeLeading climate scientist warns that vulnerable island nations may need to be evacuated within a decade as evidence shows polar ice is shrinking at greater speeds than models predicted
Michael Mann, director of the Earth System Science Center at Pennsylvania State University, said the latest evidence shows that models have underestimated the speed at which the Greenland and west Antarctic ice sheets will start to shrink…
“We know Arctic sea ice is declining faster than the models predict,” Mann told the Guardian at the SXSW Eco conference in Austin, Texas. ..
“The models have typically predicted that will not happen for decades but the measurements that are coming in tell us it is already happening so once again we are decades ahead of schedule…


Being charitable I’m inclined to view this as cock-up rather than conspiracy, but it still reveals a chronic lack of QA on the part of those responsible. I’ve had some painful experience of trying to automate data processing tasks, in my case trying to infer certain events in historic process control data where the actual triggers for those events hadn’t been recorded. Even though we were looking for a distinctive pattern, it proved necessary to expend considerable effort to avoid a relatively small number of false results; in the end we still had to rely on a certain amount of manual checking despite adding layers of checking to the number-crunching routines. I spoke to others who’d had similar experience. However smart you think your routines are, the chances are you won’t have thought of everything, and some proportion of your output is going to be wrong; unless you do proper QA and sense checks, this won’t be picked up.


As there are few reporting stations in Iceland, it wouldn’t surprise me if the pairwise homogenization algorithm chose neighboring stations which are far away, perhaps Scotland or Norway. The Icelandic climatic phases which you describe may not have occurred there, but there may be regional, long-term correlation which satisfies the criteria to be a significantly-correlated neighbor to be in homogenization. In which case, the adjustments, aiming to produce a temperature anomaly field which is spatially smooth, will act to suppress the Icelandic variation.
I understand that there’s an open-source version of the code. It would be worthwhile to use that to determine which neighboring stations were used to homogenize the Icelandic stations. The Menne algorithm may need modification, to allow for local climatic variation in some instances.

Ian W

Using a software algorithm that generically modifies accurately reported temperatures may be simple but it is also flawed. I think many will get the feeling that had these software algorithms made the world look cooler, they would have been rejected. Therefore, it is difficult to avoid the suspicion of malfeasance or at least an unwillingness to dig when the answers are what is wanted in the knowledge that they are incorrect.
The entire weather reporting network as run by NOAA/NASA the Met Office and UEA is an object lesson in failed quality control and laziness. There are not that many observation sites in the world all of them have qualified meteorologists who know the sites. Each site should have its own control log and any adjustments made should be on a site by site basis by meteorologists who know and understand the local area.
The IMO has developed an ISO standard for climate observations – it is time a similar ISO standard was set for management of the collation and software processing of the meteorological observations into climate reports.

Russ in Houston

Maybe this is what was meant by “it’s like playing with loaded dice” comment


DaveS and HaroldW:
Your excuses at October 15, 2012 at 5:10 am and October 15, 2012 at 5:15 am, respectively, don’t wash.
The alterations to the data set from a measurement site which are reported in the article are a result of an automated system which alters each data set from each measurement station. Therefore, the observation of significant error in the adjustment of data from this measurement station very strongly suggests similar error is introduced when adjusting data from other stations. Indeed, the article reports similar erroneous adjustments of data obtained from stations near to the measurement station of the studied data set.
It cannot be known how many data sets from other measurement stations have similar large errors in their adjustments as a result of being processed by the same faulty automated system.
Importantly, it is not reasonable – and it cannot be reasonable – to adjust the station data to agree/confirm data obtained from other stations hundreds of miles away. The data is what it is. Data sets from measurement stations incorporated into a grid may need to be weighted to obtain a reasonable average for the grid, but changing the original data according to a possibly mistaken understanding is NOT acceptable as a scientific practice.
The fact that the automated system introduces so large an error into this data set indicates that the method is not fit for purpose. Therefore, the entire GHCN data should be withdrawn until the true cause of the fault in the method is identified and the fault is corrected: anything else is NOT science.


“It is impossible to come to any other conclusion than that the software is hopelessly flawed.”
This is quite possibly a great subject for a scientific paper. The consistent downward adjustment of older temperatures and upward adjustment of newer temperatures does suggest the software does have a fundamental flaw.
When you think about it, it seems obvious that homogenization will introduce spurious trends, because the adjustments will feedback on themselves. The only way to avoid this would be to ensure the algorithm only homogenizes from unadjusted numbers, never from previously adjusted numbers.
For example, say you adjust 1 station upwards by 1C to homogenize it. Then in the next run of the software you now use this homogenized value. This extra 1C will feed-back into the calculations and suggest that the surrounding stations also need an adjustment, because they will now appear too cold, in comparison to their neighbor that has warmed.
Each time the software is run, it will try and adjust the neighbors based on the adjustments to the previous run, until the data-set is ripe with spurious trends.
So, the big question is this. Does the software use raw values only for each run, or does it use the previously adjusted values? If it uses the previously adjusted values, then it seems quite likely that the software is flawed and feedback is creating spurious trends in the data.

Frank K.

richardscourtney says:
October 15, 2012 at 12:34 am
Richard – You forgot the Hansen Response ™ to such questions.
“Iceland represents only a tiny fraction of the earth’s surface area, so problems with the adjustments won’t have any impact on our conclusion that the Earth’s atmosphere and seas will boil away in ten years unless you give me climate money we do something about it.”

Leo G

Pat, excellent article out of the Vancouver Sun. Well researched and balanced. Thanx for the heads up. Wish more reality like this was the norm, not the exception.

Jeff Alberts

DaveS says:
October 15, 2012 at 5:10 am
Being charitable I’m inclined to view this as cock-up rather than conspiracy

Don’t see how that’s possible. Someone had to program the algorithm to do specific things. If it were a mistake, I think we’d see more random errors, not something totally systematic.


ferd berple:
At October 15, 2012 at 6:53 am you say

This is quite possibly a great subject for a scientific paper.

The paper cannot be published. I think you need to read

Paul Vaughan

Paul Homewood wrote:
“You might ask “where did the Sea Ice Years go?”, and you would be right. GHCN have pretty much adjusted these out of existence. The GHCN algorithm has obviously mistaken the sharp fall in temperatures in 1965 as some sort of aberration caused by a change of location or equipment, and therefore wiped it from the record. However it has not made the same assumption about subsequent and equally sharp rises.”

“It is impossible to come to any other conclusion than that the software is hopelessly flawed.”
Wow. another deep thinkerI
First thing you should do is go get the actual code from the ftp site. Its not that hard to understand. Then look at the test results from the recent double blind tests. Finally look at the range the algorithm goes before it stops looking for pairs ( it doesnt care about country borders )
Finally compare it with other approachs
hopelessly flawed? Well thats either hyperbole or a lie.
REPLY: Mosh you might want to do some deep thinking over Dr. David Stockwell’s follow up post on homgenization issues on the front page of WUWT right now. – Anthony

Jim Clarke

If the algorithm produced a consistent reduction in the warming trend, would it still be in use? Of course not! The results of such an algorithm would never even be published. The algorithm itself may not be intentionally wrong (although that is a possibility), but its continued use certainly is!

Jim Clarke

Mosher writes:
“Finally look at the range the algorithm goes before it stops looking for pairs ( it doesnt care about country borders )”
How, exactly, is that a good thing? That would just couple uncorrupted rural sites with UHI corrupted urban sites, or distant sites with no climate significance to the site in question. Sounds like an excellent way to remove all accuracy from the temperature record!
As for comparing it to the other approaches…that is like comparing climate models. They all start with the same wrong assumptions and produce similarly wrong answers. Taking the best solution from a group of equally flawed algorithms is hardly a step in the right direction.
Here’s an idea. Examine each station individually for possible errors, changes in environment and relocation adjustments. Sure, its a big job, but we have already taken care of Iceland in this one little post. How impossible would it be to actually do proper data analysis on this all important issue of global temperature change?


And this is the truth behind the ‘hockey stick’.


And this is the truth behind the ‘hockey stick’.


I can’t help but think that this situation has arisen (at least partially) as a result of the reliance by humans on computer ‘output’. I accept that confirmation bias also plays a part!
It is not dissimilar to the problem with kids using calculators all the time, instead of being able to do mental arithmetic – they mistype in a simple calculation and simply write down the answer as being correct because they are too damn lazy to check the ‘output’ mentally (or perhaps too stupid?) but mostrly because they just assume the ;’machine’ is never wrong!
The latter is the crux of the matter – machines are indeed NEVER wrong in their calculation unless the input is wrong, or the programing is wrong – but the machine itself doesn’t make mistakes (barring obvious failure)!
Relying on Mk1 Eyeball and Mk1 brain checker is always the best way to check such things but the complexity and large numbers of calculations and results prevents obvious error spotting.
What the climate boys, and particularly those that see this data all the time, must realise is that they have a DUTY to check the data/ouput thoroughly BEFORE they use it elsewhere………
as I said earlier – its totally FUBAR – and without the completely raw data being available and the working methods being available – we simply dont know just how bad the FUBAR is.

I doubt that there is a hidden agenda in the adjustments of individual stations. I expect that the belief is that the various correction, adjustment techniques used GLOBALLY is correct, with errors on one side individually compensating for errors on the other side. Not that that is true, but that would be the belief.
GCHN is a computer-derived, “non-subjective” evaluation house. The amount of data is actually not large enough to prevent human review, but it would appear to be considered overwhelming to NOAA (Just as personally checking the placement of stations was too onerous in Hansen’s mind, but not so in Watts’). If an individual were tasked with proviing a “correct” temperature graph for Iceland, I doubt that the final result would be the same. But that low tech, old-school way is not sufficiently erudite for the doctorates involved. Field work and pencils are for post-grad assistants, not the professors.
The obvious strangeness of the New Zealand temperature corrections is similar to those of Iceland, but officially there is no problem. It must be that the top managers have been convinced, or have convinced their political masters, that once dumped into the soup of averaging, the errors cancel out. Which has been said, even though it doesn’t.
Top management is very reluctant to question the advice they receive. Boards of directors do not question the corrupt CEOs they have hired. Why? In the game, it is not facts that determine what you do, but positioning. It’s like Sun Tzu said about the best general: he is the one that wins the war without fighting a battle, because his opponent surrenders once he realizes he cannot win. The war against coal and oil is, as we all know, much more about consumerism and capitalism than it is about carbon. The best general in this war is the one who can bring about the reduction in one and put the reins on the other without having to actually bring in legislation that declares that is the objective. The directors of global warming are not going to question the “facts” when these “facts” allow them to position themselves so their opponents give up and go home. It is the victory that counts, not the rationale behind the conflict.

Wow I never ceased to be amazed at how we can model reality in a computer – forwards and backwards – better than we can observe reality itself. I mean they have got so good at it they have reincarnated Rose Mary Woods giddy deletion foot inside the AlGorerithm /sarc

D Böehm

Please stop posting that nonsense. Current temperatures are not “unprecedented”. The Medieval Warm Period, the Roman Warm Period, the Holocene Optimum, the Minoan, etc., were all considerably warmer than now. And the bright red picture of the globe at the end of your stupid video is nothing but alarmist propaganda.
Michael Mann was so thoroughly debunked by McIntyre and McKitrick that even his pals at Nature were forced to issue a rare Correction. And the fact that he hides out from any real debate shows that even Mann knows he’s peddling alarmist horse manure.
Take your silly propaganda to one of your alarmist echo chambers like SkS. They’ll eat it up. But here at the internet’s “Best Science” site, we know better.


Orwell: “Who controls the past controls the future. Who controls the present controls the past.”

“GHCN’s Dodgy Adjustments In Iceland”
retitle in my mind as
The Smoking Shotgun in Iceland”
“It is impossible to come to any other conclusion than that the software is hopelessly flawed.”
Yes, indeed. Iceland is a great control case.
@Steven Mosher: We don’t need to look at the code. That is not our job. We are not paid to do it. If the code does not give reasonable results within the tight confines of a small, isolated, well maintained temperature system of Iceland, GISS has some explaining to do, not us. There is NO JUSTIFICATION to homogenize an Icelandic thermometer with another on a different rock a thousand km away across a major ocean.
Iceland is THE control. It is the laboratory where the algorithm must work in isolation. If the Algorithm breaks on Iceland, the algorithm is broken. If the algorithm gives untrustworthy results because of human error, the entire process is untrustworthy.
It doesn’t matter how beautiful your theory is, it doesn’t matter how smart you are. If it doesn’t agree with experiment, it’s wrong. – Richard P. Feynman

John F. Hultquist

Steven Mosher says:
October 15, 2012 at 7:38 am

RE (I’m paraphrasing here): ‘ either another deep thinker or a liar
In the Wall Street Journal, Daniel Henninger recently posted an essay titled ‘Obama and the L-Word’ – a word you just used. Here are a couple of his statements:
This is a new low. It is amazing and depressing . . .
“Liar” is a potent and ugly word with a sleazy political pedigree.
Explicitly calling someone a “liar” is—or used to be—a serious and rare charge, in or out of politics. It’s a loaded word. It crosses a line. “Liar” suggests bad faith and conscious duplicity—a total, cynical falsity.
It dates to the sleazy world of fascist and totalitarian propaganda in the 1930s. It was part of the milieu of stooges, show trials and dupes.
. . . it is as skuzzily routine as the F-bomb has become among 15-year-old girls on the New York City subways. This is not progress.

Mr. Mosher has brought us to this level of discussion. Bless his little heart!

D Böehm

John Hultquist,
Your comment reminded me of this:

Bruce Friesen

Steven Mosher says: “Finally look at the range the algorithm goes before it stops looking for pairs ( it doesnt care about country borders )”
Steven, I understand the code is available, and documented, and that you have invested huge amounts of time satisfying yourself it does what it says it does. I for one thank you for that work, as I have not chosen to invest that time.
I understand the smoothing over 1200 km is something that has been tested, and published in the science literature, and I am willing to accept that on average over the entire globe, the algorithm you defend can be defended as a net enhancement to the outcome.
Having said all that: This post is about Iceland. A country with not one but six high quality monitoring stations, stations deployed, maintained and managed by a professional national agency. A country geographically separate and distinct; a country with a measured climate.
Why not let Iceland be Iceland? Why muck with Iceland?
Anticipating the answer “but don’t you sceptics insist on rigorous science?”, please put me down as one who all his career made time to be familiar with the raw data, and put me down as one who thinks a final, human mark-one eyeball check for reasonableness can both improve the overall product and can be defended through openness and transparency. I think a professional climatology organization such as GHCN both can and ought to invest in that next level of quality control.
I think GHCN could, station by station or region by region, say something like: “checked what the program did, decided Iceland should be Iceland, reversed the smoothing in this case”.


I assume the source, hopefully well documented, for that algorithm and its revisions is published for public review. Does anyone have a link?

Gary Pearse

bushbunny says:
October 15, 2012 at 12:43 am
“…And in summer the sun never sets, but is not as warm as at midday? No wonder they suffer from Vit D depletion. Like all the Arctic circle countries.
Just a comment out of interest as it is little known fact (outside of the Arctic countries). The wild life and fish in the Arctic areas are loaded with Vit D. In fact, polar bear livers are toxic if more than a small amount is eaten because of the ultra-high Vit D and A. Also, even lesser known, raw meat (at least from arctic animals is loaded with Vit C of all things. They don’t grow oranges up there! Probably the kangeroo is loaded with Vit C too, but you guys don’t eat them raw!!