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1934 and all that

Filed under: — gavin @ 10 August 2007

Another week, another ado over nothing.

Last Saturday, Steve McIntyre wrote an email to NASA GISS pointing out that for some North American stations in the GISTEMP analysis, there was an odd jump in going from 1999 to 2000. On Monday, the people who work on the temperature analysis (not me), looked into it and found that this coincided with the switch between two sources of US temperature data. There had been a faulty assumption that these two sources matched, but that turned out not to be the case. There were in fact a number of small offsets (of both sign) between the same stations in the two different data sets. The obvious fix was to make an adjustment based on a period of overlap so that these offsets disappear.

This was duly done by Tuesday, an email thanking McIntyre was sent and the data analysis (which had been due in any case for the processing of the July numbers) was updated accordingly along with an acknowledgment to McIntyre and update of the methodology.

The net effect of the change was to reduce mean US anomalies by about 0.15 ºC for the years 2000-2006. There were some very minor knock on effects in earlier years due to the GISTEMP adjustments for rural vs. urban trends. In the global or hemispheric mean, the differences were imperceptible (since the US is only a small fraction of the global area).

There were however some very minor re-arrangements in the various rankings (see data [As it existed in Sep 2007]). Specifically, where 1998 (1.24 ºC anomaly compared to 1951-1980) had previously just beaten out 1934 (1.23 ºC) for the top US year, it now just misses: 1934 1.25ºC vs. 1998 1.23ºC. None of these differences are statistically significant. Indeed in the 2001 paper describing the GISTEMP methodology (which was prior to this particularly error being introduced), it says:

The U.S. annual (January-December) mean temperature is slightly warmer in 1934 than in 1998 in the GISS analysis (Plate 6). This contrasts with the USHCN data, which has 1998 as the warmest year in the century. In both cases the difference between 1934 and 1998 mean temperatures is a few hundredths of a degree. The main reason that 1998 is relatively cooler in the GISS analysis is its larger adjustment for urban warming. In comparing temperatures of years separated by 60 or 70 years the uncertainties in various adjustments (urban warming, station history adjustments, etc.) lead to an uncertainty of at least 0.1°C. Thus it is not possible to declare a record U.S. temperature with confidence until a result is obtained that exceeds the temperature of 1934 by more than 0.1°C.

More importantly for climate purposes, the longer term US averages have not changed rank. 2002-2006 (at 0.66 ºC) is still warmer than 1930-1934 (0.63 ºC – the largest value in the early part of the century) (though both are below 1998-2002 at 0.79 ºC). (The previous version – up to 2005 – can be seen here).

In the global mean, 2005 remains the warmest (as in the NCDC analysis). CRU has 1998 as the warmest year but there are differences in methodology, particularly concerning the Arctic (extrapolated in GISTEMP, not included in CRU) which is a big part of recent global warmth. No recent IPCC statements or conclusions are affected in the slightest.

Sum total of this change? A couple of hundredths of degrees in the US rankings and no change in anything that could be considered climatically important (specifically long term trends).

However, there is clearly a latent and deeply felt wish in some sectors for the whole problem of global warming to be reduced to a statistical quirk or a mistake. This led to some truly death-defying leaping to conclusions when this issue hit the blogosphere. One of the worst examples (but there are others) was the ‘Opinionator’ at the New York Times (oh dear). He managed to confuse the global means with the continental US numbers, he made up a story about McIntyre having ‘always puzzled about some gaps’ (what?) , declared the the error had ‘played havoc’ with the numbers, and quoted another blogger saying that the ‘astounding’ numbers had been ‘silently released’. None of these statements are true. Among other incorrect stories going around are that the mistake was due to a Y2K bug or that this had something to do with photographing weather stations. Again, simply false.

But hey, maybe the Arctic will get the memo.


620 Responses to “1934 and all that”

  1. 1
    John Cook says:

    I’ve been perusing some of the skeptic blogs where there is much air-punching and back-slapping. The predominant theme, particularly in the reader comments, is that this new adjustment means global warming hasn’t actually been happening these last 30 years, it was all a NASA glitch. Or to loosely paraphrase Bob Carter, “global warming stopped in 1934″.

    They don’t seem to realise the global trend over the last 30 years still shows dramatic warming, both in the US and especially globally. In fact, the trend seems to me a more important statistic than the “top ten warmest years”. What I would be interested in seeing is the change in the global warming trend since 1975. It was around .17C per decade – does anyone have exact figures from before and after?

  2. 2
    DaveS says:

    It isn’t “much ado about nothing”, it’s an embarrassment. I don’t usually agree with you, but I have always considered you to be a credible and honestly contrary opinion until you made that statement.

    Do you think we can now be “99% certain” that 1938 was the warmest year in the last 1000 years, or are we still 99% certain that it was 1998. How certain are we of ANYTHING that Hansen says, now?

    The problem with most skeptics isn’t that we don’t have open minds… we do. I know I do at least. The problem is the grotesque hubris we associate with scientists who are championing scientific conclusions that we intuitively know to be MUCH shakier than they are letting on. This only reinforces that.

    [Response: Sure it's embarrassing, but only the end result determines whether it matters or not. This doesn't for anything important. Would you characterise the blogosphere reaction as proportionate to the 0.03 deg C shift between 1934 and 1998 in the US temps? Perhaps you'd like to point me to any statements that said anything about being 99% that 1998 was the warmest year in the US? Read the Hansen quote above - written in 2001! -gavin]

  3. 3
    Nick says:

    They don’t seem to realise the global trend over the last 30 years still shows dramatic warming, both in the US and especially globally. In fact, the trend seems to me a more important statistic than the “top ten warmest years”. What I would be interested in seeing is the change in the global warming trend since 1975. It was around .17C per decade – does anyone have exact figures from before and after?

    Yes. 1940-1975 the temperature was falling whilst CO2 was increasing.

    Apparently its due to pollution, however, now the evidence is that pollution causes the temperature to rise.

    Its been a bad week for AGW.

  4. 4
    Tex says:

    Actually to be fair, your statement that “the people who work on the temperature analysis (not me), looked into it and found that this coincided with the switch between two sources of US temperature data.” is incorrect. Steve M pointed out where the error came from in his blog posts and his email notifying GISS of the problem. The GISS people simply confirmed that he was correct.

    [Response: Not so. He saw the jump but did not speculate as to the cause. - gavin]

  5. 5
    bjc says:

    John:
    I have been monitoring the same blogs. Clearly the magnitude of the correction is of no great significance to the overall trend. Some on those sites have become inappropriately elated. But I seriously dispute your assertion that this means the majority of regular contributors believe that this proves global warming isn’t happening. Certainly that was not Steve McIntyre’s position. Where it is dramatically important is in the arguments over access to data and the ability to replicate methods. In this instance, GISS’s error provided Steve McIntyre with a proverbial “smoking gun”.

    Frankly, my hope is that this “ado” does in fact lead to a dramatic increase in openness and access to data and statistical techniques and code used to analyze climate data.

  6. 6
    Lee says:

    Here is a back-of-envelope calculation of the effect of this on world temp analysis. I’ve posted this a few places now.

    It is an 0.3% change to world temp anomaly results after 2000.

    0.003C.

    The error was only in data for the lower 48 states, and was 0.15C for that data. The lower 48 is about 2% of the earth’s surface. 0.15 x .02 = 0.003C

    Global temp change over the last century is 0.8 – 1.1C depending on method. .003C out of 1C (in the range and easy to calculate) is 0.3%

  7. 7
    bjc says:

    Gavin: It would be helpful if both graphs used the same Y-axis scale.

  8. 8
    DaveS says:

    Perhaps you’d like to point me to any statements that said anything about being 99% that 1998 was the warmest year in the US?

    I apologize. I appear to have mixed-up my climatologists. I think it was one of your co-bloggers who made that statement.

    It should also be noted that most people fully understand that this is US-only data. The manner in which that is pointed out, however, is characteristic of the same sort of “hubris” I mentioned earlier… it’s somewhat dismissive and something along the lines of “This is US only, though. The rest of the world’s data is still almost as good as we thought the US data was a couple of days ago.

    A more healthily skeptical reply would note that it is, indeed, US only, and only affects global temperatures slightly, but, given the fact that the US has the most reliable and well-maintained network, it raises concerns about the quality of data we have been using across the board.

    On a related note… is it true that the “margin of error” for the “global surface temperature” is actually larger than the net warming in the 20th century? I’ve seen that claim thrown around and figured it wouldn’t hurt to ask.

  9. 9
    tamino says:

    Re: #3 (Nick)

    When you say

    Yes. 1940-1975 the temperature was falling whilst CO2 was increasing.

    you are mistaken. As I have pointed out before on this blog, there is no justification for such a claim.

    The most revealing aspect of the AGW debate is this: when the “warmers” make a claim, it’s based on serious research and considerable effort, and if an error is found, it’s admitted and corrected ASAP. When “deniers” make a claim (like yours), it’s based on the lack of serious research or considerable effort, and if an error is pointed out, it’s excused away or triggers a scrambling attempt to change the subject.

  10. 10
    DaveS says:

    As I have pointed out before on this blog, there is no justification for such a claim.

    Perhaps he would justify it with the 2 charts in this post.

  11. 11
    John Cook says:

    Gavin, a query re your link to the global mean (http://data.giss.nasa.gov/gistemp/graphs/Fig.A2.txt). I downloaded that data a few months ago and comparing it to now, the values after 2000 are exactly the same. Is this because the change to global T is smaller than two decimal places? Or has that data not been updated yet?

    Bjc, you’re right that most of the blogs themselves aren’t saying global warming isn’t happening, it’s more happening in the readers’ comments. Overall, I found the emphasis is on comparing 1934 to other top ten’s – very little to no mention of the change to the global trend.

    [Response: Changes are too small to show. - gavin]

  12. 12
    Justin says:

    I think it’s also worth considering that many people have taken this to indicate that any future corrections will, like this one, indicate a lesser trend in 20th century warming (at any locale or globally). But this is clear gambler’s fallacy: You can’t point to the roller and extrapolate what they’ll roll based on what they have rolled.

    Worth considering also the seeming desperation of some to associate “audits” with showing that warming is less than we thought. “Audits” can easily show that warming has been more than we thought.

  13. 13
    steven mosher says:

    Run for the ICE. I find this a common meme on the AGW side. When the land record gets a little quake the instinct is to run for the ICE. Actually, it’s pictures of ice, and as we have been told pictures have no value. unless, that is, they are pictures of “nighlights” used by hansen or pictures of Ice, preferably with polar bears, used by Gore.

    Consider this. If one makes an error about data input files ( the first thing you check in IV&V) it is not advisable to run to a slippery surface. The artic ice record prbably needs a good audit as well.

  14. 14
    spilgard says:

    The positive result of this brouhaha: an army of people who up until this week dismissed the temperature graphs, now not only embrace them but embtace them to a point-to-point accuracy on the scale of 1/100th of a degree.

  15. 15
    Justin says:

    Just to expand on my last point at 12, (somehow) many see this as indicating that we can’t trust anyone (especially Hansen) to handle the data properly. In fact, if a slight error – the possibility of which already indicated by Hansen 6 years ago – causes us to become Cartesian skeptics about him, then why didn’t the small detections and corrections in the computer code used in models, which are publicly indicated by NASA?

    My mother slightly overcooked the garlic bread in the oven tonight; I guess I can never be sure whether she will make the best prepared food for my friends when they come over. How can I know what will happen????!!!

    J

  16. 16
    Justin says:

    spilgard,

    I concur. This whole debacle reminds me of a chess game I had last night with my significant other (gotta love him). We’re both pretty good players, and at first he was winning (took my knight AND bishop; I had no hits), but eventually the tables turned. Near the end he took one of my pieces and declared: “Aha! I’ve got your piece!” to which I replied, “Honey, you used one of your last pieces to knock one of my many; I’m winning” ;)

    S. Mosher (comment 13) says AGW’s (I hate polarization) run to the ICE, but no – we simply remind, everyone, and with a little alarm, that the trend is clear.

  17. 17
    zac says:

    The argument from “denialists” has been: We’re not sure about the data because there may be abnormal heating do to the artificial environments close to the temperature stations.

    Here we have had literally billions of dollars put into research of climate data, and the only person who catches a glaring error is an outsider.

    What if the change do to asphalt or AC units had been more gradual? Should we have any confidence that anyone will be able to, much less want to, find the error?

    If we can only detect the anomalies when there is an obvious spike in the data, and the only people that make corrections are “denialist”, doesn’t that shed ANY doubt in your mind on the integrity of the process?

    Any at all?

    even like . . . one Iota?

    [Response: First lesson: don't believe your own propaganda. - gavin]

  18. 18
    steven mosher says:

    RE 14. we never dismissed the temperature graphs.

    1. Believers: accepted them without question.
    2. Deniers: ignored them without cause.
    3. Doubters: put questions to them.

    The doubters were right.
    The deniers, like a stopped clock, got lucky.
    The believers, ran for the ice.

    It strikes me that the belief that Ice melts only because it gets warm is somewhat simplistic. So gavin,
    perhaps we could benefit from a lesson in arctic ice formation and decay and the various causes– wind stress, temperature, albedo, soot, salinity, wave roughness, leads, pressure ridges, etc etc etc.

    Now I know that shrinking ice has the same propaganda impact as Air conditioners by weather stations, but a little more depth on the Ice issue might be a good idea,
    thin ice metaphors and all that.

    Oh, Which stations do you use to measure arctic temp?

    [Response: Leave the 'believers' and 'doubter' rhetoric at home. No scientist believes anything in the sense you claim. Nor as I made abundantly plain two weeks ago is anyone who works with real data blind to the problems there are. The ice isn't just good propagand a, it's a hard nosed fact that makes fooling around with AC theories of climate change moot. Arctic temperatures are directly measured by the Arctic Buoy program, but in the GISS analysis, the temperatures are extrapolated from nearby land stations. That works quite well, but it would be better to assimilate the buoy data directly - there's been some discussion I think, but I don't know what the status is. - gavin]

  19. 19
    Timothy Chase says:

    steven mosher (#13) wrote:

    Run for the ICE. I find this a common meme on the AGW side. When the land record gets a little quake the instinct is to run for the ICE. Actually, it’s pictures of ice, and as we have been told pictures have no value. unless, that is, they are pictures of “nighlights” used by hansen or pictures of Ice, preferably with polar bears, used by Gore.

    Well, I think it makes a little more sense for supporters of science to point at the arctic ice as this is something people are likely to understand than it does for climate “skeptics” to point at the Dust Bowl and Great Depression of the 1930s. Do skeptics really want the American public thinking in those terms….?

    Consider this. If one makes an error about data input files ( the first thing you check in IV&V) it is not advisable to run to a slippery surface. The artic ice record prbably needs a good audit as well.

    Don’t worry – I suspect you will be getting a fair amount of data in the next month and a half. Pictures, charts, commentary… the whole nine yards.

    As for the global climate, expect a little breather until 2009….

    Earth will feel the heat from 2009: climate boffins
    By Lucy Sherriff
    10th August 2007 15:31 GMT
    http://www.theregister.co.uk/2007/08/10/climate_model/

    It appears that climatologists are in the process of improving their short-range forecasting.

  20. 20
    niiler says:

    There was a bunch of chatter on Slashdot regarding this. I felt the need to point out that there were so many other disparate sources of evidence for global warming that there was really no question, even if said glitch actually was significant:

    1) Scientists are witnessing ice shelves in Antarctica falling into the sea.

    2) The North Pole is melting so that there will soon be a North-West Passage to which Canada is laying claims.

    3) Much of the global warming data does not come from NASA.

    4) Ski areas in the Alps are soon to be going out of business.

    5) There is glacial melting everywhere.

    .

    6) Indonesia’s islands are being submerged by rising sea level

    I’m sure this group can come up with many more proofs that are independent of the problematic data.

  21. 21
    steven mosher says:

    RE 16. remind me the trend is clear? Clear?
    Clear +- a little fuzzy. How clear? Crystal clear?
    foggy windshield clear? Tinted glass clear? Leaden glass clear? clear? Trends are Positive or Negative.
    Trends have slopes. Those slopes have errors.

    Now, I never denied the trend. I question the trend. As I have pointed out on CA I am a confirmational Holist.

    Simply, all theory is underdetermined by data. All observation is theory laden. Falsification can always be avoided by appealing to other data ( sea ice, SST, species migration, etc etc etc).

    Acceptance of theory has an epistemic component (“fits” the “data”) a pragmatic component ( makes useful predictions) and a social component ( the dreaded consensus)

    What I noted is a meme. When the land record is attacked, believers tend to run for the ice. Primarily because it serves as a common sense reference point.
    Folk wisdom. Ice melts when it gets warm. It’s rooted in common experience, but I suspect it’s more complicated that the cubes in my G&T.

  22. 22
    steven mosher says:

    RE 18 gavin.

    I will gladly leave the believer /denier rhetoric at home. Funny, I have never seen you inline a similar chastisment to people who throw the denier label around.
    I think it is an instructive distinction relative to the issue of confirmation bias. Be that as it may. I count you therefore in the doubter crowd:neither as a believer in AGW or a disbeliever. A true skeptic.

    Shrugs. ( that is the skeptic handshake)

    Which artic land stations?

  23. 23
    SCP says:

    12: Worth considering also the seeming desperation of some to associate “audits” with showing that warming is less than we thought. “Audits” can easily show that warming has been more than we thought.

    So let’s do them and find out. Is it too hot, too cold or is my poridge just right? This has passed the point of being scientific data. It has become financial data. If someone wants to start taxing me and interfering with my economy based on these data and models, it’s time for full disclosure and accurate accounting.

    http://www.giss.nasa.gov/research/briefs/hansen_07/
    “…Figures 1 and 2, makes clear that climate trends have been fundamentally different in the U.S. than in the world as a whole…”

    Maybe. Or maybe they make it clear that there’s even more of a problem with the data in the rest of the world. Perhaps if we had quality data for the rest of the world, the trends wouldn’t be so fundamentally different?

    If you want me to believe in catastrophic global warming, you’ve got to convince me it’s not just a case of Garbage In Garbage Out. So far, I’m not convinced. I’m less convinced today than I was last week.

    We need to be confident in the data to believe the trends you show us in the nice pretty pictures. Between this error and photos at surfacestations.org, I’m not confident in the US data, let alone those from the rest of the world. Peer review is for science. The IPCC can do all the peer review they want. That doesn’t cut it for economies. Economies use accounting and audits. Failure to do so leads to situations like Enron and WorldComm. If we just want to do science, stick with peer review. If someone wants to influence economies, it’s long past time for auditors to start poking around.

    If NASA doesn’t want to publish source code and all data, at a minimum maybe they should hire an accounting firm to audit climate related data, methods and processes and to issue a public report on the quality they find (and that firm should hire Steve McIntyre ; -). I’m not saying I’d trust that report as much as full and open disclosure, but it would be a start. Both a formal audit and full disclosure would be fantastic!

    Oh. And changes to published data should be version controlled, with something akin to release notes.

    Opaque or unaudited data should not find its way into the policy debates. Ever.

  24. 24
    papertiger says:

    Just to expand on my last point at 12, (somehow) many see this as indicating that we can’t trust anyone (especially Hansen) to handle the data properly.
    I think the point is that we shouldn’t have to trust someone as in a single person or entity such as Nasa GISS to develope what is in effect policy for our country.
    It’s un democratic and un scientific.
    A person could make a mistake. Ahem.

    Imagine if we were to use only one thermometer to measure the global temp, say Houston.

    [Response: Presumably in that case you're happy that other people are producing global temperature records, for example CRU - William]

  25. 25
    papertiger says:

    It’s interesting that bit about the Arctic ice retreating to it’s furthest extent already.
    We better get some ice cores from that unmelted portion before that record is lost forever. Who knows what revelations it will add to Antactic, Greenland, and assorted glacial ice series. – oh wait we are talking about Arctic ice. Sneaky bit of misdirection by you guys.

  26. 26
    papertiger says:

    I am wondering if the ocean is rising and flooding out Indonesia, why isn’t it flooding Cape Cod? are they not all at sea level?

  27. 27
    steven mosher says:

    RE 18. one last thing. Gavin, the “Ice” is not a hard nosed fact. The “ice” is observed with an instrument.
    Records are collected and processed by code written by humans, subject to error and audit. Not facts. Not raw sensory input. Not facts, interpretations of data collected by instruments, processed by code. This is different from the stuff in my Gin & Tonic. I have not looked at the chain of custody for that “data”. I reserve judgement. The present record of managing data and the lack of outside audit does not inspire confidence. It deepens the need for systematic doubt.

    There are issues with the land instrument record, even though the summer heat is a hard nosed fact. And the SST record has instrument issues ( buckets, buoys, didnt you write up something on a booboo made in a recent paper that thought the sea was cooling)

    Anyway, as you know from spending a considerable time futzing with data and anomalies and adjustments and renormalizations…

    All observations are theory laden.

    [Response: Of course. But just like (I think) Tuzo Wilson said "Nothing in geology makes sense except in terms of plate tectonics", nothing makes sense in current climate change without anthropogenic factors. That's not one dataset here or one anecdote there. The body of work that demonstrates consistency with the mainstream understanding is huge. And these little hiccups don't come anywhere close to affecting it. To deny that.... well.... - gavin]

  28. 28
    Justin says:

    There is a term in accounting called “immaterial”.

    I think we could learn to use it again.

    J

  29. 29
    papertiger says:

    Earth will feel the heat from 2009: climate boffins
    By Lucy Sherriff
    10th August 2007 15:31 GMT
    http://www.theregister.co.uk/2007/08/10/climate_model/

    It appears that climatologists are in the process of improving their short-range forecasting.

    Interesting. It seems to be inproved just enough to cover the time period right after the next election.
    You sure this is a non political website?

  30. 30
    steven mosher says:

    re 25. here tiger. from wiki.

    There are two aspects of confirmation holism. The first is that observations are dependent on theory (sometimes called theory-laden). Before accepting the telescopic observations one must look into the optics of the telescope, the way the mount is constructed in order to ensure that the telescope is pointing in the right direction, and that light travels through space in a straight line (which itself is sometimes not so, as Einstein demonstrated). The second is that evidence alone is insufficient to determine which theory is correct. Each of the alternatives above might have been correct, but only one was in the end accepted.

    That theories can only be tested as they relate to other theories implies that one can always claim that test results that seem to refute a favoured scientific theory have not refuted that theory at all. Rather, one can claim that the test results conflict with predictions because some other theory is false or unrecognised. Maybe the test equipment was out of alignment because the cleaning lady bumped into it the previous night. Or, maybe, there is dark matter in the universe that accounts for the strange motions of some galaxies.

    That one cannot unambiguously determine which theory is refuted by unexpected data means that scientists must use judgments about which theories to accept and which to reject. Logic alone does not guide such decisions.

  31. 31
    Justin says:

    29.

    It would probably be best to stay out of that discussion. The same thing could easily be said about many other locuters in this discussion, even the “auditors” themselves.

    If you do nothing else, interpret the arguments in their bets light.

    J

  32. 32
    Justin says:

    24.

    I agree that we shouldn’t uncritically agree with just one source of scientific analysis. Yet even if we relied solely on NASA, NASA GISS already agreed with McIntyre even before McIntyre decided to audit climate (i.e. before his blog) – in 2001.

    Of course, there are other issues where they obviously disagree, but Gavin was quite clear and open about this – certainly not the tactics of a dogmatist that invites you to rely on NASA’s word alone. I think we ought to appreciate that.

    J

  33. 33
    steven mosher says:

    Re 27.

    Nothing comes close, YET. The point is science is always contigent. Wilson is merely stating this. If we gave up plate tectonics, we would have to redo a bunch of work. It is pragmatically valorized not epistemically more secure. As Quine noted no theory faces facts in isolation. This is why no single fact overturns accepted theory. There is always a balancing act. Facts can be ignored, epicycles created, results questioned. It is a huge undertaking to overturn a theory, and with no viable replacement, highly unlikely.

    All the more reason to free the code

    No ne denies the consistency of the body of evidence. That is the whole point of theory laden observation and confirmation bias. Surely you have encounter some folks who never saw a negative feedback they liked? Shrugs

  34. 34
    MrPete says:

    #20, etc on Indonesia. Please don’t just quote lead sentences — too often, as in this case, they are attention getters with zero substance.

    The article quoted in no way claims that Indonesia has lost ANY islands due to sea rise.

    At least the substance of the article explains what has actually been happening: “The issue has become a hot topic after Indonesia upset neighbouring Singapore recently by banning sand exports to the city state, blaming sand mining for literally wiping some of its islands off the map.”

    Why wasn’t the lead about sand exports? Because that’s not an exciting topic like fear of being inundated by ever-rising sea levels.

  35. 35
    Gerald Machnee says:

    Did not Gore say that 9 of the warmest years were in the last decade? The adjustment now indicates that 4 of the warmest years were in the 1930′s and 3 of the warmest were in the last decade or so(for the USA). And you are saying much ado about nothing.

    [Response: Global means! And there nothing has changed.- gavin]

  36. 36
    Justin says:

    Re: 33,

    “It is pragmatically valorized not epistemically more secure.”

    No, Wilson said that it doesn’t MAKE SENSE without plate tectonics, not that it would be inconvenient without it. Those are two different claims. Likewise, evolution by natural selection of genes is the only thing that thus far can explain biological change in the distant past, even if we don’t quite understand the gory details of that past.

    J

  37. 37
    Robert Burns says:

    I agree with Gavin that calling people “warmers” or “deniers” is not productive. What we now know is that there was an error in the GISS record and the error was discovered by Steve McIntyre. GISS was notified and, to their credit, they investigated, found the error and corrected the reocrd. The real question is whether or not there are more errors in the record. My instint tells me that GISS is looking at the data to insure that there are no more errors. IMHO, it would be better if GISS released all their raw data, the rational and code for any and all adjustments, and any other data that is revalant to the the temprature record. This would allow everyone to inspect the data. If there are additional errors, they could be found and corrected. By releasing this data, the confidence in the record could be improved.

  38. 38
    S. Molnar says:

    Re #29: The Met Office news release says nothing about the model covering only the time after the next general election (likely to be in 2010), but perhaps there is something in the text of the article (which I haven’t read) linking the model to the British election cycle. Gavin knows more about both of these subjects than I, so perhaps he can comment.

  39. 39
    stuart says:

    Interesting. It seems to be inproved just enough to cover the time period right after the next election.
    You sure this is a non political website?

    The last election was in 2005, so the next might be in 2009, but it could be called anywhere from 2007 to 2010, whenever Gordon Brown or his government decide suits them.

    I assume you are talking about UK politics after all, as it is a UK site being linked, and the research quoted was done by the Met Office in the UK.

  40. 40
    VirgilM says:

    Does the CRU correct for the urban heat island effect as the GISS does?

    Congrats to the GISS in correcting discovered errors.

  41. 41
    steven mosher says:

    I have a related question one the web page it now states:
    “Our analysis, summarized in Figure 1 above, uses documented procedures for data over land (1), satellite measurements of sea surface temperature since 1982 (2), and a ship-based analysis for earlier years (3). Our estimated error (2σ, 95% confidence) in comparing nearby years, such as 1998 and 2005, increases from 0.05°C in recent years to 0.1°C at the beginning of the 20th century. Error sources include incomplete station coverage, quantified by sampling a model-generated data set with realistic variability at actual station locations, and partly subjective estimates of data quality problems (4).”

    I have never seen a “partly” subjective estimate of data quality issues. How does one integrate this with
    objective methods and report a Std.dev.?
    and how much of the 2sig band is objective and how much is partly subjective and how was this CI constructed and was this partly objective partly subjective method tested?

    Which individuals subjective judgement was used to assess the “data quality” issues and what repeatable methodolgy did they use? Did they employ a rating system?
    is it documented? were the individuals who did the subjective assesment instructed in the tendency of subjective assesments to regress to the mean. If more than one individual was used to subjectively asses data quality did those individuals go through a normalization process?

    Does partly subjective mean guess?

    That page is a treasure trove. Keep digging, then we get to the china station issues.

  42. 42
    Bruno says:

    Sigh.

    If the aforementioned skeptics had taken the time (2 minutes?) to plot both datasets in Excel, they would have found that there is little to celebrate. I guess that this speaks to the immensity of their intellectual dishonesty.

    Old CONUS Data:
    http://uploader.ws/upload/200708/OLD_CONUS.gif

    New CONUS Data:
    http://uploader.ws/upload/200708/NEW_CONUS.gif

  43. 43
    Eric says:

    The finding seems similar to “one small step for a man, one giant leap for mankind” – but instead, its “one small temperature change but one giant argument for openness and transparency” in data collection and selection methods, sites selected, algorithms and source code availability and so on. Where the goal from all parties is seeking the truth, an open source approach will be helpful in negating both pro- or con- arguments on AGW. Unfortunately, as ClimateAudit has documented, a number of climate researchers have maintained their data, methodologies, algorithms and source code are private. And hence, not tested, vetted nor reproducable by others. That NASA’s GISS had a Y2K error in its data analysis is a powerful argument that secret science is bad regardless of the field or the source.

    [Response: What is secret? The algorithms, issues and choices are outlined in excruciating detail in the relevant papers: http://data.giss.nasa.gov/gistemp/references.html - gavin]

  44. 44
    DaveS says:

    My mother slightly overcooked the garlic bread in the oven tonight; I guess I can never be sure whether she will make the best prepared food for my friends when they come over.

    Some people might argue that cooking garlic bread is more of an art than a science.

    Some people might argue that adjusting the surface record to account for UHI, etc., is more of an art than a science.

    Etc.

  45. 45
    DaveS says:

    Gavin, would you mind clearing up my question from earlier? Is it true that the margin of error in the calculation of “global surface temperature” is greater than the observed warming in the last 100 years?

    That is a point that I keep seeing. Is it true?

    [Response: No. The error on the global mean anomaly is estimated to be around 0.1 deg C now, increasing slighty before 1950 or so and a little larger in the 1880s. The global mean changes of around 0.7 deg C and significantly higher. - gavin]

  46. 46
    Bruno says:

    A minor correction to my previous post (#34): I was unaware of the blog that gavin linked to. I had in mind several blogs listed on digg.com that have been receiving the bulk of the attention today. None of those blogs had graphs of the actual CONUS data.

    But now that I know that (at least) one blog went through the trouble of plotting the data in Excel… I’m even more stunned. How desperate does one have to be in order to cling on to such trivial differences?

  47. 47
    James says:

    Perhaps this would be a good time to remind some people (and I’m sorry if I bore the rest of you by harping on this) that AGW is a prediction, not an explanation. It wasn’t derived by examining past temperature records, noting a rise, and picking on CO2 as the cause. It’s based on the measured increase in atmospheric CO2, combined with knowledge of its properties WRT infrared radiation. (Plus a lot of other factors, of course.) That some pre-industrial year, or series of years, might have been warmer than today is relevant only so far as it reminds us that CO2 is not the only possible driver for temperature.

  48. 48
    Steven says:

    Five minutes with this new data set – apply smoothing functions (at varying spans, non-causal filters), then some sinusoidal fits and analysis of residuals – brings doubt to the presence of an underlying US warming trend, let alone any room for anthropogenic effects!
    No warming trend in the US – lets hope the global data sets are better verified and validated. This is entirely embarrassing for climate science.

    We will need complete transparency in the global temperature records and any ‘adjustments’ made (techniques, methodologies), as clearly climate scientists are not up to the task. Work will need to be verified by the broader scientific community.

    regards, Steve

  49. 49

    re 30. Steve Mosher — “observations are dependent on theory”

    In the words of Albert Einstein”


    “… On principle it is quite wrong to try founding a theory on observable magnitudes alone. In reality the very opposite happens. It is theory which decides what we can observe.”

    In post #44 at http://www.kendallharmon.net/t19/index.php/t19/article/4811/
    I give an concrete example of this principle insofar as it pertains to temperature measurements by making an analogy with special relativity.

  50. 50
    Dylan says:

    One has to wonder how many other “anomalies” Mr McIntyre might have come across during his audit, but declined to inform anyone, as they happened to indicate that temperature data had been incorrectly revised too far downward.


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