Home > Environment > Lindzen and “No statistically significant warming since 1995″

Lindzen and “No statistically significant warming since 1995″

March 3rd, 2010

I discussed the ‘no statistically significant warming since 1995′ talking point in this post. For those who came in late, this talking point has been around the delusionist blogosphere for some time, though with a lower profile than ‘global warming stopped in 1998′, and was put as question to Phil Jones of UEA in a BBC interview. Jones answered honestly, if a bit clumsily, that the data period since 1995 is marginally too short to derive a statistically significant trend, a response which was headlined by the Daily Mail as “Climategate U-turn as scientist at centre of row admits: There has been no global warming since 1995?” and became the talking point of the day. As has been widely noted, confusing not statistically significant’ with ‘not significant; in the ordinary sense indicates either deliberate dishonesty or ignorance of a point covered in excruciating detail in every introductory stats course.

But where did this silliness come from? I’d seen Janet Albrechtsen quote Lord Monckton on the point, and it seemed about right for him, an innumerate debating point that would take a fair while to refute, during which time he could move on to the next one.

Imagine my surprise, then, when I discovered the point being made (and apparently originated) by Richard Lindzen of MIT who is (or ought to be) by far the most credible figure on the delusionist side. In a piece published on “Watts Up With That” Lindzen says ‘There has been no warming since 1997 and no statistically significant warming since 1995′ and in this piece for Quadrant he gives a variation, saying “has been no statistically significant net global warming for the last fourteen years” and “the fact that warming has ceased for the past fourteen years is acknowledged” . Note the slide from “has been no statistically significant net global warming for the last fourteen years ” to “warming has ceased”, committing the basic newbie error against which all budding stats students are warned.

Lindzen has published a couple of hundred papers in climatology, so I think we can assume he knows that the statement “there has been no statistically significant warming since 1995″ means nothing more than “given the variability in the data, we need at least 15 observations to reject the null hypothesis at 95 per cent confidence”, a fact so trite as not to be worth mentioning.

It is sad to see a respected scientist reduced to this kind of thing. And as far as I can tell, all this is simply to avoid admitting that he backed the wrong horse back in 1990, when he bet that he was smarter than the majority of climate scientists who thought humans were (probably) causing global warming. The data since then has supported the majority view, but instead of revising his position, Lindzen has resorted to dishonest statistical trickery.

To quote The Economist, with respect to the Daily Mail

Since I’ve advocated a more explicit use of the word “lie”, I’ll go ahead and follow my own advice: that Daily Mail headline is a lie.

But at least the Daily Mail headline writer could plead ignorance. Lindzen has no such excuse.

Update: More on this from Deep Climate

Categories: Environment Tags:
  1. zoot
    March 3rd, 2010 at 13:42 | #1

    As a layman, I cannot understand how the “no warming since insert year here” can coexist with the fact that we have just completed the hottest decade on record, containing a substantial number of the hottest years on record. What happened to the much vaunted “common sense”.

  2. Graeme Bird
    March 3rd, 2010 at 14:16 | #2

    If you look at the graph he’s working off its a perfectly fair statement. No warming since 1997. No statistically significant warming since 1995.

  3. Pterosaur
    March 3rd, 2010 at 14:32 | #3

    If you are willing to “cherry pick” your starting and end points, by for instance selecting a hotter than usual “start” year, then it is quite possible to make such a statement.

    Of course, by doing so, your honesty and credibility as a researcher/commenter will take a significant hit, especially if you attempt to use such methodology to make, or argue any point apart from the fact that it is possible to use data dishonestly.

  4. Nick R
    March 3rd, 2010 at 14:43 | #4

    Everybody here is wrong. The earth was molten goop 4 billion years age and has cooled significantly since then. Oh… wait… Wasn’t there an ice age 10,000 years ago? Sorry, clearly the planet is warming… You can claim whatever you like if you cherry pick the data.

  5. Ernestine Gross
    March 3rd, 2010 at 15:15 | #5

    JQ refers to an article by a Janet Albrechtsen in the Australian. Albrechtsen talks about ‘alarmists’. I don’t know about ‘alarmists’. As far as I am concerned, we are witnessing one of these obfuscation exercises which gives some people, like Albrechtsen, an opportunity to write ‘something’. It seems to be pretty obvious that if anybody would have had some sincere concerns about any paragraph in the IPCC report they would have written to the organisaton. Only if they would have been ignored after several attempts would these people have a reason to go public, preferably via a reputable journalist rather than an opinion author. Further, I agree with those who say that having a ‘debate’ – like a school debate on some philosophical question – is already enough evidence for the silliness of the said exercise.

    The other day I read an article and saw pictures of people with banners, according to which there are some people in the US want to have legislation against the second law of thermodynamics because it doesn’t correspond to their religious beliefs. It wasn’t part of a carneval parade, so it wasn’t meant to be funny. How much dumbing down has taken place during the last 20 years in some places in this so-called globalised economy? ‘Too much’ is probably a sufficiently precise answer.

  6. John Mashey
    March 3rd, 2010 at 15:34 | #6

    Actually, Lindzen goes way further back on this than 1990; read Stephen Schneider’s “Science as a Contact Sport.”

  7. Tony G
    March 3rd, 2010 at 15:39 | #7

    Maybe Jones meant there was no statistically significant warming trend, because there was a statistically significant cooling trend according to the satellite data;

    Analysis of the satellite data shows a statistically significant cooling trend for the past 12 to 13 years, with it not being possible to reject a flat trend (0 slope) for between 16 and 22 years.

    Absract;

    “Global satellite data is analyzed for temperature trends for the period January 1979 through June 2009. Beginning and ending segments show a cooling trend, while the middle segment evinces a warming trend. The past 12 to 13 years show cooling using both satellite data sets, with lower confidence limits that do not exclude a negative trend until 16 to 22 years. It is shown that several published studies have predicted cooling in this time frame. One of these models is extrapolated from its 2000 calibration end date and shows a good match to the satellite data, with a projection of continued cooling for several more decades.”

    From here pdf;

    http://www.ncasi.org/publications/Detail.aspx?id=3230

  8. wilful
    March 3rd, 2010 at 16:08 | #8

    Tony G, that study was published in Energy & Environment. ’nuff said.

  9. Fran Barlow
    March 3rd, 2010 at 16:12 | #9

    @Ernestine Gross

    The other day I read an article and saw pictures of people with banners, according to which there are some people in the US want to have legislation against the second law of thermodynamics because it doesn’t correspond to their religious beliefs. It wasn’t part of a carneval parade, so it wasn’t meant to be funny.

    It was an article in The Onion to which I posted a link. The Onion is a satirical magazine. It’s funny because it is not so nuts that you couldn’t imagine it, although as far as I know, no such protest happened.

  10. Andrew c
    March 3rd, 2010 at 18:08 | #10

    A reviewer in the ALR today magisterially decided that since there are two extremes in this debate, ergo the truth is the middle. Also it is better that we irreperably damage the capacity of the Earth to support 8 billion people than Clive Hamilton hurt the feelings of climate denialists – oops – sceptics.
    Well not exactly the second bit, but I think it a reasonable inference from his argument.

  11. Andrew c
    March 3rd, 2010 at 18:12 | #11

    Re the repeal of the 2nd Law, there is also a funny Onion article about replacing gravity with the Theory of intelligent Falling. Of course the controversy MUST be taught.

  12. Fran Barlow
    March 3rd, 2010 at 18:34 | #12

    @Andrew c

    Interestingly on PM tonight Richard Dawkins explicitly rejected the truth lies in the middle meme and spoke of the misuse of “balance” in the media

  13. Mark
    March 3rd, 2010 at 18:41 | #13

    @Graeme Bird

    A MIT professor walks into a bar around dusk.

    A punter enjoying a cold beer remarks that the weather has not warmed since midday.

    The professor congratulates him on making a “perfectly fair statement”

    They keep drinking and talk about if there will ever be an hour as hot as the one at midday.

  14. Peter T
    March 3rd, 2010 at 20:02 | #14

    Tony G

    30 seconds on the net brought up this summary of satellite trends and match to the surface records:

    http://www.realclimate.org/index.php/archives/2005/08/et-tu-lt/

    It’s an easy read. I recommend it.

  15. Alice
    March 3rd, 2010 at 20:33 | #15

    @Fran Barlow
    Well Fran

    according to this link such a protest did in fact happen (against the second law of thermodynamics by religious protesters…?) A quick google proves Ernestine may be right.

    http://www.theonion.com/content/node/28308/print/

  16. Alice
    March 3rd, 2010 at 20:35 | #16

    Mind you Fran – I will grant that there are only four lonely souls and one sign photographed as evidence of a protest (and it looks bad from a numbers point of view)…

  17. Tony G
    March 3rd, 2010 at 20:36 | #17

    “Tony G, that study was published in Energy & Environment. ’nuff said.”

    Wilful, they are qualified in the field, and independent of government; but I suppose you do not like them because they are not co conspirators.

    Peter T

    Thanks for that link;

    This quote from your link seems to sum it up;

    “as long as weather satellites show that the atmosphere is not warming, I cannot put much faith into theoretical computer models that claim to represent the atmosphere but contradict what the atmosphere tells us. “

  18. jquiggin
    March 3rd, 2010 at 20:45 | #18

    “as long as weather satellites show that the atmosphere is not warming, I cannot put much faith into theoretical computer models that claim to represent the atmosphere but contradict what the atmosphere tells us. “

    That’s great news, Tony. Visiting arch ‘sceptic’ Roy Spencer of UAH, we find

    “The global-average lower tropospheric temperature anomaly soared to +0.72 deg. C in January, 2010. This is the warmest January in the 32-year satellite-based data record.”

    http://www.drroyspencer.com/2010/02/january-2010-uah-global-temperature-update-0-72-deg-c/

    So, I guess your next comment will be a statement that, given the success of the models, you now accept them, recognise the reality of AGW and support action to stabilise the climate before it’s too late.

    Just joking! For a moment I imagined you were one of those reality-based lefty types. Please continue with your alternate universe talking points.

  19. Alice
    March 3rd, 2010 at 20:50 | #19

    @jquiggin
    Be kind JQ – Tony has finally……. found a single friend in here to support him…Peter T. (Tony G and Peter T? Strange they compose their names smimilarly).

    And he will continue with his alternative universe talking points – and he might have to find one to live in as well.

  20. Fran Barlow
    March 3rd, 2010 at 21:05 | #20

    @Alice

    It’s The Onion Elise. They do satire. Read their other stories. I posted the original link, though I think Merc over at LP deserves the Hat-tip. There’s another on a home chemist who proves gold is a gas …

    At least I hope it’s satire …

  21. sdfc
    March 3rd, 2010 at 21:06 | #21

    Alice maybe you should read the link Peter T posted before lumping him in with Tony G.

  22. charles
    March 3rd, 2010 at 21:12 | #22

    Well if this is true you can stop calling people names and just point to the data.

    http://krugman.blogs.nytimes.com/2010/03/02/freakout-nomics/

  23. Chris Warren
    March 3rd, 2010 at 21:21 | #23

    @Graeme Bird

    You are not thinking properly. You are not looking at the graph properly.

    The graph is of temperature anomaly.

    It has been positive ever since 1995 and has increased to just under 0.5 degrees since 2001.

    This anomaly may fall, but still represent more heat in the earths system.

    If you do not know what an anomaly is why are you even reading this?

    Earlier threads have crawled over this issue, and it is amazing that slow learners are still reading anomaly graphs as temperature graphs.

    Decades of positive positive anomalies cooks the planet – even though the anomalies may decline themselves (if so).

    There is nothing more that needs to be said about this graph, except to have a good laugh at those who claim it does not show a significant warming trend.

    It precisely demonstrates a very surprising solid continuing warming trend.

  24. jquiggin
    March 3rd, 2010 at 21:26 | #24

    I’d draw the opposite conclusion, Charles. No amount of data will convince these guys. Test case is Tony G above, who set out a specific test on which the data clearly goes in the opposite direction to that he expected. I’ll give dollars to donuts that he doesn’t change sides as a result.

    At this point, there’s no prospect of converting the political right, so the only thing to do is call them out for the purveyors of ignorance and delusion they are. It will take a long time, but the message will sink in gradually. Already the phrase “pro-science Republican” is seen as an oxymoron, and the same is coming to be true of the right throughout the English-speaking world.

  25. Tony G
    March 4th, 2010 at 00:16 | #25

    JQ said;

    “So, I guess your next comment will be a statement that, given the success of the models, you now accept them, recognise the reality of AGW and support action to stabilise the climate before it’s too late.”

    After RR & LOL i think not quite, but, yes, it is the warmest January on that 32 year data set and further reading on Spencer’s site indicate the ocean temperatures tally with it…. I will wait to I see a bit more data before I change my mind.

    Anyway, thanks John for the link to Spencer’s site, it is of interest to me as I am VERY sceptical of the AGW temperature data. I must say his site was an eye opener, you should have a good look around there.

    Spencer is also sceptical of the temperature data and to that end he is working on a new satellite data set;

    “TOWARD A NEW SATELLITE-BASED SURFACE TEMPERATURE DATASET”;

    ‘We have started working on a new land surface temperature retrieval method based upon the Aqua satellite AMSU window channels”

    Unfortunately the best (Aqua) satellite data have been available only since mid-2002; so am I correct in saying we will have to wait until 2017 before we can get something ‘statistically significant’ one way or the other out of it?

    Better get this thread back on topic, so back to Jones;

    Spencer on Jones;

    “In fact, the results for the U.S. I have presented above almost seem to suggest that the Jones CRUTem3 dataset has a UHI adjustment that is in the wrong direction.”…….It is increasingly apparent that we do not even know how much the world has warmed in recent decades, let alone the reason(s) why. It seems to me we are back to square one.”

    http://www.drroyspencer.com/2010/02/spurious-warming-in-the-jones-u-s-temperatures-since-1973/

  26. Chris O’Neill
    March 4th, 2010 at 05:13 | #26

    Graeme Bird:

    If you look at the graph he’s working off its a perfectly fair statement. No warming since 1997.

    If by since 1997 you mean including 1997 then you’re wrong. The wikipedia HadCrut3 graph shows warming if you include 1997.

    No statistically significant warming since 1995.

    Making a true but insignificant statement as if it is significant is being dishonest. Dishonest statements are hardly perfectly fair.

    BTW charles, in case you missed it, my comment about clowns was about those who still say it’s been cooling for the past decade, not about claims it’s been cooling since 1998.

  27. Alice
    March 4th, 2010 at 06:53 | #27

    @sdfc
    Oops Sdfc…I see what you mean.

    Apologies to Peter T.
    Nothing like the inimitable Tony G after all.

  28. Chris Warren
    March 4th, 2010 at 08:14 | #28

    Graeme Bird :
    If you look at the graph he’s working off its a perfectly fair statement. No warming since 1997. No statistically significant warming since 1995.

    You are not thinking properly. You (and Lindzen) are not looking at the graph properly.

    The graph is of temperature anomaly.

  29. wilful
    March 4th, 2010 at 09:28 | #29

    Tony G :
    I will wait to I see a bit more data before I change my mind.

    Hands up everybody that believes this statement.

  30. March 4th, 2010 at 10:15 | #30

    Not to excuse Lindzen but statistics is hard/subtle. I’d bet the majority of economists don’t really understand hypothesis testing. The same could be true in other disciplines. Among those who’ve never studied statistics or only at the most basic level there will be no clue about these ideas and what they mean.

  31. Jim Birch
    March 4th, 2010 at 14:31 | #31

    This link from the New republic article JQ quoted presents the statistics clearly:

    http://tamino.wordpress.com/2009/12/15/how-long/

    The quote on the Lindzen Quadrant article was probably the most naked summary of the denialist position I’ve read to date:

    “Today’s debate about global warming is essentially a debate about freedom. The environmentalists would like to mastermind each and every possible (and impossible) aspect of our lives.”

    Vaclav Klaus
    Blue Planet in Green Shackles

    According to Klaus, Lidzen and presumable the Quadrant editors AGW is not even a scientific question at all. We don’t have to try to resolve it empirically: It’s a lifestyle choice!

    Thanks, guys.

  32. Chris O’Neill
    March 4th, 2010 at 14:44 | #32

    Roy Spencer:

    “It is increasingly apparent that we do not even know how much the world has warmed in recent decades, let alone the reason(s) why. It seems to me we are back to square one.”

    This is Spencer’s fallback position, i.e. when it becomes obvious even with his own derivation how much the world is warming, he will attempt to cast doubt on even that and conclude “we know nothing”, thus achieving his pre-determined objective that we don’t know enough to do anything.

  33. John Quiggin
    March 4th, 2010 at 15:02 | #33

    @David Stern
    I don’t think anyone really understands the classical/frequentist theory of hypothesis testing because it is fundamentally incoherent. The Bayesian framework is much more satisfactory, though it relies on assumptions of unbounded rationality. I’ll try a post on this sometime.

    None of this helps Lindzen and the rest of the delusionist crew, any more than Godel’s theorem is a justification for making mistakes in elementary math.

  34. Freelander
    March 4th, 2010 at 15:25 | #34

    @John Quiggin

    A problem with the classical approach is that it presents the results of a statistical test as providing an unconditional piece of information, although, even within its own framework the validity of the information may have been destroyed by pre-testing, or, ex post, by a selection process that results in wider publication and dissemination of a novel or confirmatory result.

    As you state: “it is fundamentally incoherent”.

  35. Freelander
    March 4th, 2010 at 15:40 | #35

    The problem with the Bayesian approach is that it is much more difficult to do, and even more difficult to do well. This is in contrast to classical statistics where pretty well any fool, even without more than modest training, can grab a software package (like MS Excel) and be up and away producing ‘results’ in an hour or two.

  36. John Quiggin
    March 4th, 2010 at 15:46 | #36

    @Freelander
    I agree. Maybe I should get you to write the post for me. In fact, feel free.

  37. Michael of Summer Hill
    March 4th, 2010 at 16:33 | #37

    Freelander, maybe you should explain why Lindzen’s LC09 is so gravely flawed.

  38. Freelander
    March 4th, 2010 at 17:09 | #38

    @Michael of Summer Hill

    Sorry, I haven’t looked at it, but from the little I have read about Lindzen, that he seems to be a contrarian for the sake of notoriety, my prior would be that someone should put a boot up his posterior.

  39. Michael of Summer Hill
    March 4th, 2010 at 17:28 | #39

    Freelander, JQ certainly knows how to put the boot into contrarians. Thumbs up JQ. Gotta go.

  40. charles
    March 4th, 2010 at 19:08 | #40

    If you want to do a serious job of using linear methods to predict next years temperature use best linear unbiased prediction. It’s the bridge between classical and Bayesian methods.

    The paper:

    Best linear unbiased prediction in the Generalized linear regression model by Arthur S. Goldberger Journal of the American Statistical Association Vol 57, No 298 (Jun 1962) gives you the background needed to apply the method to a time series.

    For an introduction from a classical and Bayesian perspective see:
    The BLUP Is a good thing: The estimation of random effects G. K. Robinson Statistical Science Vol 6 No 1 1991.

  41. Freelander
    March 4th, 2010 at 19:45 | #41

    @charles

    There is no such thing as “[as wanting to do] a serious job using linear [statistical] methods to predict next years temperature”. The serious way to do this is what climate scientists do – use a climate model. Also, unbiasedness is grossly overrated as a desirable criterion for finite sample estimation.

  42. Fran Barlow
    March 4th, 2010 at 19:48 | #42

    @Jim Birch

    As I’ve argued often enough, on the agnotological (agnosophistical?) side of the debate, it is a matter of culture war rather than a query about the science.

  43. Chris O’Neill
    March 4th, 2010 at 19:53 | #43

    @charles

    So no acknowledgement that you misunderstood who I was referring to when I said “clowns”. (Also mentioned above.)

  44. Chris O’Neill
    March 4th, 2010 at 20:00 | #44

    @charles

    If you want to do a serious job of using linear methods to predict next years temperature use best linear unbiased prediction.

    Of course next years temperature is most likely to be of very little significance with respect to climate because climate normally takes 30 years of data to sufficiently accurately measure.

  45. charles
    March 4th, 2010 at 20:10 | #45

    Freelander said:
    ”. The serious way to do this is what climate scientists do – use a climate model.”

    I agree, it’s a serious non linear system and using any linear modeling is a joke. Arguing over the start date for your linear model, or the use of “variance corrected means” (whatever that means) over raw data or the acceptance or rejection of a null hypothesis is a joke. But if you want to do the linear model properly, use best linear unbiased prediction.

    As I said when I started arguing; climate change has on it’s side an understanding of how it’s happening and a solid correlation between co2 and temperature in the ice cores. Those argue the fine points of statistical modeling have been sucker punched by those that want to hide the facts. It’s degenerated into a slanging match, a fine outcome if you don’t have facts on your side.

  46. charles
    March 4th, 2010 at 20:16 | #46

    Chris O’Neill

    I think there has been enough name calling to underline my point, even if one example can be justified.

  47. charles
    March 4th, 2010 at 20:21 | #47

    “Of course next years temperature is most likely to be of very little significance with respect to climate because climate normally takes 30 years of data to sufficiently accurately measure.”

    When you have several hundred years of records the answer is “yes”. It’s a linear prediction or if your using classical statistics a linear expectation. Nothing more.

  48. Freelander
    March 4th, 2010 at 20:44 | #48

    @charles

    If you want to do prediction right with a linear model and a finite sample you would not use an unbiased estimator. With a finite sample, better estimates, in terms of minimising the appropriate risk function, can typically be obtained with estimators that are biased.

    By the way, although I have not read the paper, “variance corrected means” probably refers to some technique to obtain more accurate estimates of the means, the averages in the series, using information on the variance of the error of estimating these averages which would have varied from year to year. [Each average for a year, would have been an estimate and would have had a distribution and variance associated with it.] Using this information and the information from other averages in the series, could improve estimation of the averages and of the series.

    But I am just taking an educated guess. (It is a long time since I learned this stuff and haven’t used it for twenty odd years, so please excuse any errors, but I think the above is correct.) If you want to read more on the decision theory approach see, for example, that ever useful source: http://en.wikipedia.org/wiki/Decision_theory

  49. charles
    March 4th, 2010 at 21:06 | #49

    Freelander

    Read Goldberger, it’s a very short and clear derivation, the example used is a time based series (which is what this is), it really is worth the read.

    My guess is Jone’s model has more than two dimensions and the variance corrected means has something to do with projecting the model back to two dimensions. I suspect we are saying the same thing but from different backgrounds. As I can’t get hold of the paper without paying I will forever remain ignorant.

  50. Chris O’Neill
    March 5th, 2010 at 13:19 | #50

    @charles

    I think there has been enough name calling to underline my point, even if one example can be justified.

    That’s the weakest mea culpa I’ve heard in a long time. After going on-and-on-and-on about how non-existent my justification was for describing some people as clowns, all you can respond with is that it’s your opinion anyway. Well, who cares about your opinion. I don’t.

  51. Peter T
    March 5th, 2010 at 19:05 | #51

    Thanks for not confusing me with Tony G. He unerringly cherry-picked a quote that was the exact opposite of the argument of the article.

    I think the denialists focus on the statistics because it offers the highest potential for hair-splitting confusion. In fact, we have multiple independent lines of evidence for warming, ranging from several different temperature records (land, sea surface, deep sea, atmosphere at different levels, several kinds of satellite, glaciers, biologic responses…), all congruent. And we have a good understanding of the mechanisms – applied for over a century in diverse fields. It would be a real surprise if, with more CO2, the earth were not warming – it would challenge a great deal of our applied physics, as well as the direct measurements.

Comments are closed.