Bad Astronomer Does Bad Statistics: That Wall Street Journal Editorial

Remember when I said how you shouldn’t draw straight lines in time series and then speak of the line as if the line was the data itself? About how the starting point made a big difference in the slope of the line, and how not accounting for uncertainty in the starting date translates into over-certainty in the results?

If you can’t recall, refresh your memory: How To Cheat, Or Fool Yourself, With Time Series: Climate Example.

Well, not everybody read those warnings. As an example of somebody who didn’t do his homework, I give you Phil Plait, a fellow who prides himself on exposing bad astronomy and blogs at Discover magazine. Well, Phil, old boy, I am the Statistician to the Stars—get it? get it?1—and I’m here to set you right.

The Wall Street Journal on 27 January 2012 published a letter from sixteen scientists entitled, No Need to Panic About Global Warming, the punchline of which was:

Every candidate should support rational measures to protect and improve our environment, but it makes no sense at all to back expensive programs that divert resources from real needs and are based on alarming but untenable claims of “incontrovertible” evidence.

Plait in response to these seemingly ho-hum words took the approach apoplectic, and fretted that “denialists” were reaching lower. Reaching where he never said. He never did say what a “denialist” was, either; but we can guess it is defined as “Whoever disagrees with Phil Plait.”

The WSJ‘s crew said, “Perhaps the most inconvenient fact is the lack of global warming for well over 10 years now.” This allowed Plait to break out the italics and respond, “What the what?” I would’ve guessed that the scientists’ statement was fairly clear and even true. But Plait said, “That statement, to put it bluntly, is dead wrong.” Was it?

Plait then slipped in a picture, one which he thought was a devastating touché. He was so exercised by his effort that he broke out into triumphal clichés like “crushed to dust” and “scraping the bottom of the barrel.” You know what they say about astronomers. Anyway, here’s the picture:

Global warming

See that red line? It’s drawn on a time series—wait! No it isn’t. Those dots are not what Plait thinks they are. They are not—they most certainly are not—global temperatures. Each dot instead is an estimate of global temperature: worse, most dots are also different kinds of estimates from each other. That is, the first dot was estimated using data X and method A, and the second dot was estimated using data Y and method B, and so forth. Well, maybe the first and second dot were the same, but older dots are different than the newer ones.

With me so far? All you have to remember is these dots are estimates, results from statistical models. The dots are not raw data. That means the dots are uncertain. At the least, Plait should have shown us some “error bars” around those dots; some kind of measure of uncertainty.

Now—here’s the real tricky part—we do not want the error bars from the estimates, but from the predictions. Remember, the models that gave these dots tried to predict what the global temperature was. When we do see error bars, researchers often make the mistake of showing us the uncertainty of the model parameters, about which we do not care, we cannot see, and are not verifiable. Since the models were supposed to predict temperature, show us the error of the predictions.

I’ve done this (on different but similar data) and I find that the parameter uncertainty is plus or minus a tenth of degree or less. But the prediction uncertainty is (in data like this) anywhere from 0.1 to 0.5 degrees, plus or minus. That is, prediction uncertainty is about five times larger.

I don’t know what the prediction uncertainty is for Plait’s picture. Neither does he. I’d be willing to bet it’s large enough so that we can’t tell with certainty greater than 90% whether temperatures in the 1940s were cooler than in the 2000s. And also such that, just as the WSJ‘s scientists claim, we can’t say with any certainty that the temperatures have been increasing this past decade.

In other words, the scientists were right and Plait was wrong. Or, as he might phrase it, he blatantly misinterpreted long term trends. Notice old Phil (his source, actually) starts, quite arbitrarily, with 1973, a point which is lower than the years preceding this date. If he would have read the post linked above, he would have known this is a common way that cheaters cheat. Not saying you cheated, Phil, old thing. But you didn’t do yourself any favors.

Somewhat amusingly, Plait ends his semi-random venting by telling us that Michael Mann has been “tweeting furiously” about this. Good grief! This isn’t helping his case. Mann’s understanding of statistics may be likened to an overly enthusiastic undergraduate who left the lecture early.

———————————————————————————

1I’m here all week.

P.S. Hey, Phil. Since you brought it up: the total consideration I’ve received for my work in global warming from Big Oil (or anybody) is number so small that dividing by it is forbidden. How much do you get for your blog or other environmental work, including government funds?

P.P.S. I didn’t forget about that “warmest years on record” stuff. Those “warmest years” are still estimates and have to be compared to the old data, which itself must be accompanied by uncertainty measures. And anyway, it has been much hotter in the past than it is now. Jurassic anybody?

Update Thanks for all the comments, everybody! 100+ and no signs of slowing. I will read them in all, in time, but for now, since many of them repeat odd claims and misunderstanding of statistical methods, let me point you to the BEST project posts (here and here). BEST had parameter-based error bars, but not predictive ones. But some acknowledgment of uncertainty is better than none! Also look under the Start Here tab and pay attention to the smoothing time series posts, the homogenization of temperature series posts, and read this weeks’ All of Statistics series. You may also read, inter alia, the Probability Leakage post which describes the Bayesian predictive approach I am using. A lot of confusion and frank unfamiliarity for some of you.

Update to the Update See this brand-spanking new post that clarifies some of the statistics some of you couldn’t be troubled to look up.

Update See this cartoon which shows that the IPCC has been known to employ the technique of variable start dates.

Update It is imperative that all read this series, where I describe just how so many people make mistakes. Those below who have been shouting the loudest are most in need.

Comments

Bad Astronomer Does Bad Statistics: That Wall Street Journal Editorial — 150 Comments

  1. OOH you wascally wabbit, there you have gone and done it. Pieces like these will attract rants bested only by your posts on free will
    Thanks Doc.

  2. Matt,
    [1]The bad astronomer is displaying this graph of land temperature anomaly reconstruction as a source of something to said about global warming.

    [2] It is obvious that the post is written in haste. BA has fallen out the climate groove and then jumps right in to write this post. He should be excused

    [3] BA makes a prediction that ‘deniers’ would flood his comment section. Reality diverged. The comments section is filled with consensus supporters.

  3. Shub,

    About [3] His blog’s comments are moderated and every comment needs explicit approval, so I don’t think it’s significant that the comments are supportive. I’ve posted to request that he addresses the criticism in this blog post. Somehow I don’t think my comment will be approved.

    Best Regards

  4. Richard Lafoie,

    Good point. I’ve also emailed Plait and offered him space for a rebuttal (as is my usual practice).

  5. One does not need error bars to show that there has been no warming no significant warming in the past decade. This article shows two graphs from the Berkley Earth Surface Temperature (BEST) series. http://www.dailymail.co.uk/sciencetech/article-2055191/Scientists-said-climate-change-sceptics-proved-wrong-accused-hiding-truth-colleague.html The first graph, just as the graph to which BA links, shows the long-term trend, which is rising, but obscures the flat temperatures for the past ten years. The second graph show the trend for the last ten years only, which is flat.

    What about the other global temperature time series? This link shows the global temperature trends for various periods using various indexes– http://www.climate4you.com/GlobalTemperatures.htm (when you get to the page, click on hyperlink for global temperature trends). From these charts, one can see the following ten year trends for the period ending December of 2011: UAH- barely positive; RSS-barely negative; GISS—no trend; NCDC—barely negative; Hardcrut 3—barely negative. Accordingly, the factual assertion that there has been a “lack of warming” for more than a decade is correct.

    What of the claim that the decade starting in 2000 is the warmest on record. This could also be true, leaving aside error bars. Temperatures rose throughout the 1980′s and 1990′s and then the trend went flat for the decade ending in December of 2011. Imagine walking up the stairs of a building (the positive trend for the 1980′s and1990′s) and then getting off and walking around on the top floor (the flat trend for the 2000′s). Even though you are no longer going up, you are walking around on a floor that is higher than the stairs you were climbing.

  6. Pingback: Briggs schools the “Bad Astronomer” on statistics | Watts Up With That?

  7. Posted an excerpt on WUWT.

    Still waiting for some feedback from you on that other project.

  8. Bad Astronomer uses “global LAND temperature”, so his purported refutation of “global temperature” is at best invalid, at worse a rhetorical strawman.

  9. “What of the claim that the decade starting in 2000 is the warmest on record. ”

    Such claim can be put in the category “CAGW talking point” but it is moot. Even if the next 50 years’ temperature doesn’t change which is a clear refutation of the AGW theory, they can still claim “warmest on record” and “the trend is a warming” by drawing a linear regression starting at 1850.

  10. As you discussed in your earlier posting and above the secret to Phil’s point is picking the starting point. He uses a 40 year trend line to address the authors contention that there has been a lack of global warming for the last 10 years. As I pointed out over there, here are the Met’s temperatures for the last 10 years:
    2001 – 14.41,
    2002 – 14.47,
    2003 – 14.47,
    2004 – 14.45,
    2005 – 14.51,
    2006 – 14.45,
    2007 – 14.43,
    2008- Not on table,
    2009 – 14.47,
    2010 – 14.47 and
    2011 – 14.44.
    As for 2012 the Met predicts 14.48.

    You don’t even need to run the stats to demonstrate a lack of significant warming in this set. Did the WSJ authors misrepresent the data? No they stated at the outset that they were looking at the last 10 years. Maybe Phil is right over the longer term and maybe he is wrong, but over the 10 year period covered by the authors of the WSJ piece are clearly correct in their assertion.

  11. William,

    How is it that you can dismiss the most recent 40 years data discussed as “estimates” but you seem to know precisely what temperatures were in the Jurassic some 200-145million years ago “has been much hotter in the past”?

    Since you’re demanding precision, can we please see any Jurassic temperature data that has greater than 90% certainty.

  12. I thought post-modern science meant that you didn’t have to worry about statistical rigour if your argument was for a good cause? Consensus trumps reality every time, what?

  13. Peter H,

    Forget the Jurassic and think instead about 4 billion years ago. Hotter then?

    What did you think of the main points of the article, and not the joke about the Jurassic?

  14. Did you know that in the GHCN data base we have world-wide at the end of 1969 on duty 9644 stations? In the epoch 1970-99 a number of 9434 dropped out. Included were 2918 new stations. Therefore, at the end of 1999 we had 3128 stations on duty in this base. Do you think that inclusion and drop-out were random? Just compute for each station its correlation over time with its regional time series. You will find that the drop-outs had the lowest correlations. Therefore, those points in the long term series come from all kinds of seriously biased sets.

  15. ” Notice old Phil (his source, actually) starts, quite arbitrarily, with 1973, a point which is lower than the years preceding this date.”

    Uhhhhh. Quite arbitrarily??

    Wasn’t 1973 about the nadir of ‘global temperature’ that was inciting the climate experts to insist that ‘The government MUST do something RIGHT NOW to stave off the onslaught of the imminent and all but inevitable ice age.’? And weren’t those climate experts from the same organizations and in many cases the same individuals who have now been incited (by the data only of course) to insist that ‘The government (optimally a world wide government with infinite power and a Marxist frame of mind) MUST do something RIGHT NOW to stave off the onslaught of the imminent and all but inevitable melting of the polar and Greenland ice caps.’ sometime in the next few hundred years, flooding all the unfortunates who stand near the ocean in anticipation and who live long enough to enjoy it, as they go under with a hugely satisfactory ‘I told you so!’?

  16. Pingback: A quote worth remembering and using « gottadobetterthanthis

  17. For Blair at 1:35 PM:

    You are right of course about the lack of trend, but am I the only one who is skeptical that we have had in place during the 20th and 21st centuries, never mind hundreds or thousands of years ago, an instrumentation system capable of measuring the Temperature of the Earth, however defined (if it ever has been) with a precision OR resolution of +/- .01 degrees C?

    The Met is clearly confident, as their TOE’s for the last ten years vary only in the hundredths of a degree Centigrade range.

    Frankly I would be astonished if the climate experts could instrument my house, collect data for a year, and announce the ‘annual temperature of Bob’s House’ with an accuracy and resolution of +/- .01 degree Centigrade with any degree of conviction.

  18. I’ve been reading Phil’s blog for years and it communicates about astronomy pretty well with a good mix of technical and just plain interesting information. However, even though he fancies himself a skeptic, Phil refuses to question the climate science data. Everybody has blinders, but if you claim to see you’d better be right or ever eager to challenge your own positions. Sadly, Phil would rather get into the political arena by labeling people who disagree on this issue as “deniers.” The degree of disagreement doesn’t matter, only that they aren’t totally bought into AGW claims.

    Btw, his blog commentary is not moderated for content that disagrees with the post, although the fanboys and girls can be set to howling pretty easily. Expect the temperature around here to go up if Phil engages in debate.

  19. Josh,

    Thanks! I posted this comment on his site (could you check later and see if it makes it through?):

    Oh dear and oh my. You, too, have forgotten the error bars. If it’s any consolation, it’s a common mistake. You add to it by making the second frequent error: confusing the fitted line for the data itself.

    You’ll note (if you do your homework) that I’ve extensively critiqued the Berkeley results.

    Everything is not an estimate, as you claim: a silly thing to say.

    And I don’t own any wool, so I can’t pull it over anybody’s eyes.

  20. To add to Blair’s contribution here are the anamolies from the NCDC global temperature time-series from the National Climate Data Center, U.S. Department of Commerce
    2001 0.54
    2002 0.6
    2003 0.61
    2004 0.56
    2005 0.64
    2006 0.59
    2007 0.58
    2008 0.5
    2009 0.58
    2010 0.64
    2011 0.51
    http://www.ncdc.noaa.gov/sotc/global/

    There is no discernable warming trend is this data from the past 10 years.

  21. I am unclear on the distinction being made here between an estimate and a prediction. I understand that what matters for the takeaway is not the error bars on the parameters of the statistical model but the error bars on the output of the model, but isn’t the output of the model called an estimate?

    Is Mr. Briggs calling the station data the parameters and calling the global temperature they are used to estimate a prediction?

    In any case, there is a more obvious criticism of Plait: that to rebut a claim about “the lack of global warming for well over 10 years now,” he draws a trend line through temperatures from 1973! The only thing he has to say about the period in question is that “nine of the ten hottest years on record all occurred since the year 2000.” (True enough if he is referring to the instrumental record, and we ignore “the 1940′s problem”). But the claim he is calling “dead wrong” is a claim about the TREND over this period, and Plait never even looks at it. Apparently the guy doesn’t have the IQ to distinguish level and trend, even when this is the exact subject in question.

    Unfortunately, the one thing Mr. Briggs says about this part of the issue is not quite accurate. “Just as the WSJ’s scientists claim,” he writes, “we can’t say with any certainty that the temperatures have been increasing this past decade.” But that isn’t what they said. They simply referred without qualification to “the lack of global warming for well over 10 years now.”

    That CAN be interpreted to mean that there is a lack of certainty that it has warmed, but if one is going to interpret the statement at all, the more natural interpretation is a claim that there has been a lack of significant warming over this period (not “statistically significant,” just significant). Interpreting the statement in terms of uncertainty actually cuts against it in absolute terms. As Briggs so ably points out, for all we know actual temperatures could have warmed significantly in the last decade, once the uncertainty of our measurements is taken into account.

    We expect the alarmists to be sloppy. Briggs, not so much.

  22. As soon as I saw “Skeptical Science” on the chart I knew it was bogus. If BA wants credibility he needs to use a credible source, not one funded by George Soros and run by a cartoonist.

  23. Pingback: Transterrestrial Musings - Temperature Statistics

  24. Based on years of working with linear regressions, I would crudely estimate the uncertainty of the inputs (GLT Anomaly estimates) to be on the order of 0.5 degree – the mean width of the ‘envelope’ confining 2/3 of the inputs around the regression line. This corresponds roughly to the square root of the variance.
    The standard Least-Square Linear Regression also permits estimates of the uncertainty of the regression parameters, notably the slope of the regression line. This is an important detail almost universally ignored.
    Unfortunately ASCII does not permit reporting the equations used for making these estimates (slope, intercept, variance, etc.) but they are covered in my old Statistics text – “Applied Statistics for Engineers”, Wm. Volk, 1958 – in Chapter 8.
    For the graph provided my ‘wild guess’ is that the regression line has a slope of 0.025 deg/yr and a +/- of 0.025 deg/yr.
    In other words, a *flat* line at an average ‘anomaly’ of 0.5 deg, with a zero slope, would still fall within the uncertainty range of the inputs throughout the entire domain.
    If I could get my hands on a table of the data pairs used to generate this chart, I could easily improve the reliability of my guesswork using the Least-Square Regression statistics available through an Excel Spreadsheet.

  25. For Peter H.:

    http://earth.usc.edu/~stott/Catalina/Mesozoic.html

    is a nice introduction to the Mesozoic (that spans the Jurasic). See the nice chart near the bottom on evaporative deposits. Note that warm blooded mammals start to evolve (keeping warm being less needed prior to then). Note the lack of any indications of ice caps or glaciation. Note reefs found at greater range N and S (so waters warmer). Note ferns found at high latitudes. etc. etc. etc.

    I’ll take biological “facts in the ground” over fudged, adjusted, homogenized, statistically abused, and hypothetical “global average temperatures” any day. Plants don’t lie and don’t have ‘statistical error’ in where they can survive. They live or they die.

    Now, can you get back to the author’s point and let go of the trollish distraction? Or do you really want to argue that the world of ferns, giant reptilians, tropical forests, and no ice was colder? …

    @William Brigs:

    Thanks for the article. Nicely done. I would likely have added a comparison graph that started in, oh, 1930, with segments going downhill into the ’70s then uphill out and flat over the whole range, but I tend to overkill ;-)

    FWIW, one ‘beef’ I have with the whole “Global Average Temperature” thing is that temperatures are INTRINSIC variables. What is the average temperature of a pot of water made by dumping in one jug of water at 0 C and one bucket at 20 C?

    We simply can not know.

    What were the sizes of the two starting lumps of water? Was that 0 C melted or frozen? What were the salinities? It is simply ASSUMED that mass and phase changes average out.

    Given multiple hundreds to thousands of years residency time for water to flow through the bottom currents of the ocean, the mass involved in surface temperatures is a constantly changing set. The amount of frozen water changes; by year, by decade, by century, by geography. The amount of water VAPOR too. Recently the sun quieted and the height of the atmosphere shrank. Winds changed (and with it compressive forces).

    That is why it is simply forbidden to average intrinsic properties vs extrinsic ones.

    http://plato.stanford.edu/entries/intrinsic-extrinsic/

    has an interesting discussion of the ‘problem’, if a bit deep…

    So I would ask: How do you put an error bar on a forbidden operation?

    What is the error bar on 12 / 0 = 12 infinities?

  26. “I’ve done this (on different but similar data) and I find that the parameter uncertainty is plus or minus a tenth of degree or less. But the prediction uncertainty is (in data like this) anywhere from 0.1 to 0.5 degrees, plus or minus. That is, prediction uncertainty is about five times larger.”

    Not five times LARGER, but five times AS large: i.e. four times LARGER. The number 5 is not five times LARGER than the number 1. It’s four times larger (1 the original number + 1 + 1 + 1 + 1 = 5), or five times AS large.

  27. None of this matters anyway. We all know the world is going to end in December 2012. The Mayans proved it!

    /sarc

  28. “tadchem, Richmond, VA says:
    1 February 2012 at 3:35 pm

    Based on years of working with linear regressions”

    tadchem – my thoughts too – maybe GATA is going up (a little) or down (a little) or staying the same (sort of…) and now suppose GATA is doing any of that because of the tiny margin of man-made CO2? Really? I’m just not sold.

    The so-called data just looks like some noisy static to me – but hey; it’s the fashion these days doncha know mankind destroying the planet and all.

    It is fascinating watching grown up adults with actual technical / science credentials gaze at GATA noise and draw conclusions therefrom. Count me in. This is big fun.

  29. Jean Demesure says:
    1 February 2012 at 1:03 pm

    Bad Astronomer uses “global LAND temperature”, so his purported refutation of “global temperature” is at best invalid, at worse a rhetorical strawman.

    Not forgetting that usually Northern Hemisphere data is taken to be Global. The Southern Hemisphere tells a different story. Example here:

    http://notrickszone.com/wp-content/uploads/2011/12/Caryl2.72.gif

    But then I may just be being parochial ;-)

  30. Briggs,
    Do you disagree with the demonstrated physics showing CO2 trapping heat and that measurements have confirmed that the rise is CO2 is entirely due to the burning of fossil fuels? If you do, on what basis and data do you do so?

  31. Of course, your interpretation of what the scientists (scientists, really? By what definition is Burt Rutan a scientist? … but I digress) claimed when you contend they were correct and what the WSJ quoted them as saying are different. And they are different in a way that, I think, you would agree is significant.

    WSJ: “Perhaps the most inconvenient fact is the lack of global warming for well over 10 years now.”

    Briggs paraphrasing them: “just as the WSJ‘s scientists claim, we can’t say with any certainty that the temperatures have been increasing this past decade.”

    I think that the reason you paraphrased them in this way is that you agree with their point of view and, had you quoted them as they stated it rather than as you paraphrased, you’d need to acknowledge that they engaged in the same sort of analysis for which you’re criticizing Plait.

  32. 10 years is too short a period to assert with reasonable confidence what the global temperature trend is, so first off, the 16 scientist are wrong to make such a claim, Plait, in his eagerness to argue that temperatures are still rising went on to wrongly argue that extrapolation of the historic trend was enough to argue that this proved the trend was continuing.

    Briggs was wrong to claim that because of Plait’s error, the 16 must be right, which is BS logic.

  33. Even assuming that temperatures stayed exactly the same for the next 50 years, a linear regression starting in 1973 would still show a warming trend.

    If it didn’t warm for 50 years would it still be warming? Apparently Mr. Plait thinks so.

    I have some charts to illustrate this that can be downloaded as a pdf file here:

    http://www.mediafire.com/?zu53lj75477oa4g

  34. The actual Skeptical Science (sic) graph as originally presented with it’s animation shows the exact opposite of what Plait used it to prove, to wit that the trend over the past decade has been level (slightly negative actually in their graph). It’s impossible to stick to facts and argue that the temperature has risen significantly over the past decade, anyone who has been following the science knows this, all one can argue is what significance to attach to the temperature plateau. Plait could have used it as Skeptical Science (sic) did to show that it is an artifact of start point chosen and that the trend since 1973 has been upward despite periods of cooling (which raises the question of why choose 1973 as a start point when 1973 was the bottom of a 30 year decline in temperature), and argued that short term cooling or stable trends are not significant to the general long term trend. Plait’s piece galls me since apparently Plait no only failed to read Brigg’s on the issue, but he missed that the Skeptical Science (sic) article he took the graph was about the same point and showed the 21st century temperature plateau.

  35. Speaking of the Jurassic, it might be interesting to note that the consensus among scientists who study such things is that the Wisconsin Glaciation was the coldest glacial period of the Pleistocene (commonly referred to as the Ice Ages).

    The consensus today is that the Pleistocene (the last 1.8 million years) is the coldest epoch since the Karoo Ice Age of 250 million years ago.

    In other words, the Older Dryas of a mere 20,000 years ago was the coldest point that Mother Earth has experienced in the last quarter of a billion years.

    I submit to you all that the climate of the Pleistocene is NOT the normative condition, nor is it the desirable future condition.

    WARMER IS BETTER — FIGHT THE ICE

  36. Rob Ryan said @ 1 February 2012 at 4:42 pm

    Of course, your interpretation of what the scientists (scientists, really? By what definition is Burt Rutan a scientist?

    A scientist is one who generates knowledge (what is necessarily the case) about the world. Do you have evidence that Briggs’ scientists are not generating knowledge?

  37. Luis, maybe he doesn’t usually censor his comments section but he deleted a post of mine for quoting the first sentence of a blog he linked to. Claimed it contained material inappropriate to his audience yet he pointed to it; invited his audience to view it; and made it clear he agreed with it. Richard’s comment did go through. Briggs’ comment hasn’t (perhaps there hasn’t been enough time).

    If Phil were to take a step back he would note with irony that he has been exhibiting the very attitude and posturing of those supernaturalists he derides. His defense is that the finding of CAGW a the result of Science and Science as Gospel is never wrong.

  38. @Jean Demesure

    “What of the claim that the decade starting in 2000 is the warmest on record. ”

    Such claim can be put in the category “CAGW talking point” but it is moot. Even if the next 50 years’ temperature doesn’t change which is a clear refutation of the AGW theory, they can still claim “warmest on record” and “the trend is a warming” by drawing a linear regression starting at 1850.

    Indeed, that CAGWist talking point is well-locked in for the foreseeable future. Even if the CAGW hypothesis is completely killed off and buried, that talking point will live on until the trend from 1850 start sloping downwards. By then of course we may well be on the verge of another Little Ice Age.

  39. Psychology can settle this dispute.

    The Daily Mail published some obvious lies. The header they published read “Met Office: ‘claim’”. Met office responded, said they never made such a claim, and the Daily Mail simply didn’t understand it, or misrepresented.

    Now you can actually find out, who is on which team. The people who genuinly think they are representing the honest scientific community, will say the Daily Mail lied. They can do that by saying:
    “The Daily Mail lied, and AGW is real, proven fact” or by saying:
    “The Daily Mail lied, and AGW is not at all a proven fact, however, I certainly think the Daily Mail is not representing my case well at all, by misrepresenting Met Office”.

    However, the person who wrote this article, mr. Briggs, decided to attack the DM critics. They are called ‘apologists’. Although they do not necessarily agree with the DM, they clearly show they are more interested in attacking one side of the argument, rather then attacking the biggest liar (clearly, the biggest liar is the exposed DM), and then representing what they think is the truth.

    Ctrl + F type “daily mail”, only hits are the few times i’ve mentioned it. Mr. Briggs, open your eyes, you are an apologist. Take a clear stance against lies, or you lose all credibility on first glance. Note that you also never mentioned many ‘facts’ from the original Wall street journal. A child could see you’re lying. Whether AGW is true or not, I don’t even discuss that, it’s pretty obvious you know you are misrepresenting facts right here, even if you do believe you are correct, deep down you know you’re lobbying here, rather then discussing facts. Ken Ham would be proud.

  40. @Mark Schaffer
    > Do you disagree with the demonstrated physics showing CO2 trapping heat and that measurements have confirmed that the rise is CO2 is entirely due to the burning of fossil fuels?

    What demonstration?? Good grief. CO2 has been demonstrated absorbing heat in a narrow IR range, but we knew that long ago. A sealed container has been shown to get warmer if there is air with CO2 in it and it is irradiated. The radiation warms the air and the pressure rises and it further heats adiabatically. If it is not pressurised it does not increase in temperature. Double the CO2 inside; makes no difference. This was convincingly demonstrated last year. It will not take you long to find it in a search of the web.

    Measurements show that less than 1/2 the rise in CO2 is even possibly attributable to human burning of anything, let alone fossil fuels. And the methods are both suspect and fraught with other possible interpretations. Yes I have read about isotopes. There is not even agreement on how many years CO2 remains in the atmosphere to within 2 orders of magnitude.

    I personally would be very interested to see any experiment that showed the CO2 in the atmosphere causes more warming than the off-setting cooling influence of increased storm height. The CO2 attribution question is a difficult one to resolve.

    Were you aware that there is not enough accessible carbon based fuels to double the atmospheric CO2 level? Ever? Most catastrophists blithely ignore this and talk about CO2 as if there was an infinite supply of oil and coal available. You may have heard of ‘peak oil’. When the CO2 was 7000 ppm a great deal was locked up in limestone and reefs. Oh, and it was not warmer then. That may interest you.

    Perhaps the ultimate empirical observation will be convincing: when the CO2 level starts to stall, then drop as the oceans cool in the coming 30 years. There will be a lot of ‘splainin’ to do.

  41. “A scientist is one who generates knowledge (what is necessarily the case) about the world. Do you have evidence that Briggs’ scientists are not generating knowledge?”

    A definition that includes Rutan (an aircraft designer and, with perhaps Kelly Johnson and a couple of others, one of the most brilliant of the last 100 years) is pretty broad. He characterizes himself as a designer and engineer. Smart guy? Yes. Scientist? No.

  42. Hi
    yes, William, your comment at Greg’s made it thru and he responded… as did Phil. It looks like a lot of points being scored on different pitches, using different rules and different games.

  43. Rob Ryan said @ 1 February 2012 at 5:45 pm

    “A scientist is one who generates knowledge (what is necessarily the case) about the world. Do you have evidence that Briggs’ scientists are not generating knowledge?”

    A definition that includes Rutan (an aircraft designer and, with perhaps Kelly Johnson and a couple of others, one of the most brilliant of the last 100 years) is pretty broad. He characterizes himself as a designer and engineer. Smart guy? Yes. Scientist? No.

    The Git’s Dictionary of Science & Technology defines an engineer as “One engaged in the science and art of engineering practice”. Yes, the definition of science is necessarily broad. All attempts to narrow it in order to exclude pseudo-science have had the unfortunate effect of eliminating science that we wish to include.

    Now, you have not answered the Git’s question: “Do you have evidence that Briggs’ scientists are not generating knowledge?” You have only asserted that Rutan is an engineer as if that automagically excluded him from being a scientist. Does that mean if one is a scientist, that one cannot be an engineer? I’d ask my brother who appeared to be a scientist, a mathematician, an engineer, a parent, a cricket coach and many other things, but he died recently.

  44. Git, be happy with your broad definition of “scientist”, I’ll stick with one that reserves the term “scientist” for those that have proven to have generated knowledge with a PhD thesis in science or have shown to have made other contributions to science.

    Have you got evidence that Rutan himself claims to be a scientist, rather than an engineer?

  45. Rob Ryan,

    Would you agree Burt Rutan is an engineer? Would you agree engineers are good with numbers? Engineering is applied science. Statistics is applied math. It seems the evidence for CAGW relies heavily on statistical techniques yet it seems hardly any of the climate scientists are experts in statistics. Some certainly seem to have gone out of their way to prove that statement. One even quite vocally so and proudly proclaimed that he wasn’t a statistician. I hear he has been recently tweeting madly. So if you’re worried about someone stepping outside of their profession, why aren’t climate scientists using statistics included?

  46. So what exactly are you doing Mr Briggs? You take an ANIMATED GIF that is meant highlight how climate skeptics tend cherry pick short periods vs climate realists preferring to look at the big picture then try to make some point about the statistics of an illustrative diagram! You even went to the trouble converting the GIF file into a JPG, just to make sure no-one would be able to see the real image. Then remove the caption at the top to change what it appears to be so you can misrepresent it to people.

    There are names for that sort of behaviour and most of them have legal conotations.

    For those who are interested in the real graph try this

    Or if embedding it didn’t work, go here
    http://www.skepticalscience.com/pics/SkepticsvRealistsv3.gif

  47. The quest to educate people that the temperature “data” is not data is an impossible one IMO. You can make all the arguments you like but there is a lack of basic statistical understanding out there (and a lack of common sense, i mean how can a measurement taken 100 years ago be data after it has been adjusted by a model?!), as you can see from some of the responses to this blog post.

    Then you add in the use of linear trend lines, its enough to make one cry!!

    As for Phil Plait, certainly one of the most close-minded folk in the blogosphere. He belongs in the dark ages punishing ‘heretical’ thoughts…

  48. Nick

    Thats why I posted a message for the monkey. Have a look at the real graph Nick to see what Briggs did. That is if you are interested in accurate representation of things, not plagiarism & distortion.

  49. Glenn Tamblyn –
    My goodness, man, what a rant! After you get down from that high horse, please trot over to Phil Plait’s website — that is the subject of this post, after all — and see just who turned that .gif into a .jpg.

  50. Glenn Tamblyn, I’ve seen it, just happened to read an article about it. I was just quoting it because it showed exactly what you just said. I also posted a comment on this article earlier, emphasizing the same problem we’re seeing here.

    The thing is, this was never about any graph, or moving .gif, this was about a couple of reporters clearly misrepresenting facts, misquoting met office, falsely claiming 16 scientists were relevant in the field of climatology, etc.

    Then, what Briggs is doing, is simply drawing our attention to what he thinks is a mistake in an article written by a critic of those blatant lies, which is a clear sign that Briggs knows the articles are full of lies (otherwise, if he was genuinely upset by colleagues making mistakes, he would’ve written a furious article about tDM and tWSJ as well). That ‘mistake’, which is not actually a mistake, obviously, is the monkey, the data is the mountain of evidence suggesting the earth is warming because of human behavior. I was drawing your attention to the monkey in an attempt to be sarcastic about the slow and steady destruction of the earth.

  51. What I am doing, Glenny, is marveling at your accusations. I took the graph exactly as the Bad Astronomy guy had it on his site.

    Legal connotations forsooth!

  52. Anyone else notice that Skeptical Science GIF that I have seen at numerous locations including comments about this article seems to cut off the last couple years in the long-term trend while showing them in the short-term trends. Is that an accident or what Dr. Briggs would call the work of a “very clever magician”.

  53. Andrew W, I’ll stick with one that reserves the term “scientist” for those that have proven to have generated knowledge with a PhD thesis in science or have shown to have made other contributions to science.

    I’m sure you’ll correct me if I’m wrong but a PhD only means that possessor once did independent research and was able to keep it from being trashed by a committee. It doesn’t convey nor indicate special abilities. It’s on par with an engineer’s first project.

    Burt has made same very remarkable advances in aerospace technology using much of the same math he mentions in the WSJ. If anything, engineers know their reputation stands on whether their work “works”. They constantly check themselves. They don’t hide behind “trust me, I’m an expert” and don’t lose the data upon which their works are based. An engineer knows his (or her) work must stand the test of time. It has to be reliable.

    So, I put more reliance on someone who expects their work to withstand scrutiny, like Burt, than I would place on a certain State College, PA denizen (as an example).

  54. Dav:

    Non-sequitur. I’m addressing the article, its authors, and Dr. Briggs’ commentary. My understanding of whether engineers (of whom I employ 6, all registered in CA) are good with numbers, whether climate scientists are or should be statisticians, etc. is not germane to the topic.

    My worry isn’t about someone stepping outside of their profession, particularly if the have expertise in the field into which they step (which Rutan clearly does not, as demonstrated by his lengthy pdf, his acknowledged brilliance as an aircraft designer and the sycophantic cheering on WUWT notwithstanding). My worry is about the misrepresentation of the article. Rutan stands out in particular but few of the others (there are exceptions) have the background to characterize themselves as having expertise on the subject at hand.

  55. Speak of the devil and who should appear?….my apologies Glenn I realize you are not the devil but your timing was quite impressive. Anyways as discussed, the GIF (called the escalator) I was asking about is now linked courtesy of Glenn Tamblyn.

  56. Also Harold, if you go to the SkS post it clearly says that the data is from BEST. ANd Briggs coiuld have found this out just as easily by following the link from Plait’s post.

    So Brigg’s comment “See that red line? It’s drawn on a time series—wait! No it isn’t. Those dots are not what Plait thinks they are. They are not—they most certainly are not—global temperatures. Each dot instead is an estimate of global temperature: worse, most dots are also different kinds of estimates from each other. That is, the first dot was estimated using data X and method A, and the second dot was estimated using data Y and method B, and so forth. Well, maybe the first and second dot were the same, but older dots are different than the newer ones.”

    Is simply wrong. All done using the same method that BEST apply to all their temperature series. But Brigg’s says otherwise. Says it very definitely. So how does he have this certainty when he is in fact wrong. Is that how a Statistician to The Stars operates. Does the stats but doesn’t check the sources of the data they analysing?

    ‘The Stars’ may like that sort of Statistics, but to most other folks its more like Numerology.

  57. Dav:

    Many (far from all, far even from a majority imho) engineers carry the belief that “because I design things upon which lives depend, I have to be correct. Therefore, my intuition about the way things are enables me to determine the accuracy of things presented in unrelated fields without doing the requisite study and hard work to develop subject matter expertise in that field.” Rutan is an archetypical example.

  58. Glenn Tamblyn –
    Yes, Plait’s .jpg image was hot-linked to the same SkS article which was hot-linked just above it. Please look back at your post at 6:18 — see anything wrong with it?

  59. Blair

    Its because the last year or so of the BEST data aren’t reliable enough, including the fact that the big down spike at the end exists because it is only sampling part of the year. So the SkS graph is showing two ways in how one should treat the data.

    Yet you had formed a contrary view. See how easy it is to be misled by people who aren’t very honest in how they present things.

  60. Hi William,

    I don’t really understand your point on predictions. The estimate of the global temp. comes from whatever averaging method of the local temperature anomalies. Since we’re interested in the temperature change of the global average, we should want the uncertainty of the average itself (the ‘error bars of the estimate’). Prediction uncertainty would provide the intervals for a new hypothetical local temperature (I’m ignoring location effects here). Figure 9 of the BEST analysis (http://berkeleyearth.org/pdf/berkeley-earth-averaging-process.pdf) shows 95% data uncertainty using different methods (results incomplete, but illustrative), and they’re not as bad as you state them to be.

    I think the presence of data uncertainty is a great point that’s not made enough in these discussions, but at the same time averaging is a tried and true way of reducing that uncertainty. I’m pretty sure the significance of the difference between 1940s temps and 2000s temps (another average!) will pass in flying colors.

  61. Interesting comment by Tamino as well here http://tamino.wordpress.com/2012/02/01/william-m-briggs-numerologist-to-the-stars/ He’s no slouch as a statistician either. And he picked up something I missed

    “Now—here’s the real tricky part—we do not want the error bars from the estimates, but from the predictions. Remember, the models that gave these dots tried to predict what the global temperature was. When we do see error bars, researchers often make the mistake of showing us the uncertainty of the model parameters, about which we do not care, we cannot see, and are not verifiable. Since the models were supposed to predict temperature, show us the error of the predictions. ”

    Doh! Briggs doesn’t actually understand what he is talking about. These aren’t models, they aren’t predictions. They are measurement. An area weighted average of measured temperatures. Not a prediction in sight.

    So he has tried to create a storm in a teacup but forgot the teacup!

  62. Passingby,

    Thanks. I did. I wrote this (let me know if it shows):

    Actually, of course, an average is a model—at least if you want to attach any meaning to it. It at least assumes the data that went into the model is measured without error.

    I’ve also pointed out that the points represent different models (i.e. averages), and that the uncertainty in these are not accounted for. This is true. On my site (under the Start Here tab in the relevant climate posts) I go into great detail about how to treat temperature and time series, particularly how to speak of uncertainty. If you can trouble yourself to read these, you’ll understand why I use the word “prediction” (and the other terms: see my All of Statistics thread from this week). It’s just too much for me to re-type everything here.

    Now, I’ve been asked by others to examine some of your other statistical work. It’s quite poor, so I suggest you spend some of your time boning up on the meaning behind the terms you use?

    And my dear Tamino, condescending?

    Rattus—she hasn’t, but boy the stuff she’d learn!

    Deep Climate–try this from the 1940s.

    Glenn—now, now. You know better. The graph is exactly the same as Plait presented.

    Glenn,

    Tamino no slouch? More like slouching towards Bethlehem. (Hit the link in the notes of this post.)

  63. Briggs said: “What I am doing, Glenny, is marveling at your accusations. I took the graph exactly as the Bad Astronomy guy had it on his site.”

    The Bad Astronomy graph is linked to the original Skeptical Science article and graph.
    Maybe in future you will think before you click the publish button. If you wanted a balanced view, you would allow visitors to your site to see the source in a similar manor.

  64. Briggs said: “Glenn—now, now. You know better. The graph is exactly the same as Plait presented. ”

    NO it is not.

  65. Paul D,

    I guess Plait didn’t want a balanced view as he presented the same graph I am. And, anyway, because other people made different errors does forgive Plait of his.

  66. Andrew W said @ 1 February 2012 at 6:18 pm

    Git, be happy with your broad definition of “scientist”, I’ll stick with one that reserves the term “scientist” for those that have proven to have generated knowledge with a PhD thesis in science or have shown to have made other contributions to science.

    Have you got evidence that Rutan himself claims to be a scientist, rather than an engineer?

    No, I have no evidence that Rutan “claims to be a scientist rather than an engineer”. I’m not sure why you see these as mutually exclusive. Rutan’s main expertise, it seems agreed, is innovative aeronautics, the science involved with the study, design, and manufacturing of flying machines.

    If, as seems likely, you are claiming that aeronautics has nothing to do with science, it behooves you to explicate what it is: magic, alchemy, legerdemain, voodoo, witchcraft?

  67. Glenn,

    If the data is unreliable, should it not then have been omitted from both graphs?

    As for my view, I had not formed one at that point. I provided two possible alternatives and waited with an open mind to be informed. Funny thing is…some of us actually do come to these debates without set positions.

  68. Briggs said “I guess Plait didn’t want a balanced view as he presented the same graph I am.”

    Presentation is not purely visual. You do bot know why he displayed it as a jpg and created a link. There may have been technical difficulties. Given you know the facts. You can easily link yours to the Skeptical Science article and put that right.

  69. Glen. “An area weighted average of measured temperatures” is still a model and not a measurement as you claim. Obviously you have no clue about spatial science matters.

  70. Dav:

    You’ve got an interesting view of achieving a Ph.D. in a scientific field. Considering that dissertations take many months at best, must be original research, and must be defended; that one must sit for so-called “comprehensives,” that one must successfully undertake significant coursework at the graduate level and perform to high standards, to compare it to “an engineer’s first project” is both insulting and ludicrous. Don’t think I’m taking personal offense – I have no Ph.D.

    That aside, most engineering is done by getting data with respect to design criteria and plugging it into a computer program. I employ engineers and work with many others – structural, civil, mechanical, geotechnical – and none of them do a lot of math and what they do isn’t difficult, rarely if ever extending beyond high-school algebra. They’ll typically have taken mathematics in college through a semester of differential equations and a semester of linear algebra. They’ll have solved a non-homogeneous second order differential equation or two; they’ll have determined eigenvalues and eigenvectors for some linear systems, they’ll take several courses in their preferred area of engineering, they’ll take a semester of materials, they’ll take a semester of engineering thermodynamics and, likely, they’ll have taken an introductory statistics course. They will graduate with a B.S. degree (typically).

    For a working engineer (who is registered) these courses will have been taken years in the past (since they must typically become an EIT – Engineer in Training – and then work under the direction of a registered engineer for several years). During this time, they do not solve differential equations, they do not determine eigenvectors and eigenvalues, they do not perform statistical analyses. They draft using Autocad, Catia, Solidworks, etc. and they plug design criteria and material properties into FEA programs that are either general (ANSYS, Nastran) or one written more specifically for their field (ABAQUS for example for Structural Engineers).

    None of this gives an engineer specific subject matter expertise beyond their field. Some develop such expertise and good for them. Rutan may have done so in other fields but clearly has not in climatology or geophysics.

  71. By the way, I meant to mention that what engineers do all day is, quite correctly, called “modeling.” The software they use produces finite element “models.”

    Hmmmm……

  72. Blair

    The point of the graphis was to show how data should and should not be used. Contrasting the appropriate way of handling that data vs the common inappropriate method often used by skeptics.

    It was to demonstrate the flaws in an approach

  73. The accusations about the graph seem the silliest of the year (so far). Plait names it “skepticalscience_globalwarming” and SkS presents it as the way “realists” (=the SkS authors) view global warming. The escalator has nothing to do with Briggs’ point.

  74. I think the problem here is a lack of understand about what education is about.
    As Glenn has stated, the graph is intended to be used in the context of understanding specific point. eg. it is wrong to cherry pick a short section of data that shows one thing, when YOU KNOW the complete data shows something else. Such principles apply to the production of cars as it does to temperatures or the statistics of pink elephants.

  75. Maurizio if the graph is not relevant to Briggs point. Then it shouldn’t have been used.

  76. Pompous Git:

    EXCELLENT strawman, congratulations! No one said, and I expect no one would say, that “aeronautics has nothing to do with science.” The argument is over whether an aircraft designer, no matter how brilliant is, BASED ON HIS BEING AN AIRCRAFT DESIGNER, a scientist. It’s not about whether aerodynamics is a branch of science, it’s not about whether one who designs aircraft might possibly also be a scientist, etc.

    It was the WSJ that claimed that Rutan is a scientist (“16 scientists”). I don’t know if Rutan would, and I expect he would not, claim to be a scientist. He doesn’t do so in his pdf tome. He actually quotes one James P. Hogan as follows: “”Science doesn’t really exist. Scientific beliefs are either proved wrong or they quickly become engineering. Everything else is untested speculation.”

  77. Just to avoid confusion the person who is posting as paul d is not me–pauld– who wrote several posts above him

  78. Glen says:

    Doh! Briggs doesn’t actually understand what he is talking about. These aren’t models, they aren’t predictions. They are measurement. An area weighted average of measured temperatures. Not a prediction in sight.

    Of course since all of the temperature are all prefect measurements of a real thing without a prediction in sight and not models they we get exactly the same thing for each perfect measurement, hence HADCRUT is the same as BEST is the same as CRUTEM and they are all perfect aligned.

    Seriously, you are really going to argue this ?

  79. “Smokey says:
    1 February 2012 at 3:25 pm

    As soon as I saw “Skeptical Science” on the chart I knew it was bogus. If BA wants credibility he needs to use a credible source, not one funded by George Soros and run by a cartoonist.”

    Prove it re George Soros? You can’t just make statements that have zero proof.

  80. Glenn Tamblyn said: “An area weighted average of measured temperatures” implying that the graph slope is based solely on temperature measurements.

    Some issues with area weighted averages of temperatures: http://www.appinsys.com/globalwarming/GW_Part2_GlobalTempMeasure.htm

    The main problem with temperatures seems to be coverage bias. The other problem is the lack of an analysis of variance and summary of those results in text or on the graph. The red line is a model of a model; a primary purpose of models like that is prediction.

  81. Rob Ryan,

    Fine arts majors undoubtedly view engineers the way you depicted but the bottom line is an engineer knows that no matter how many times he’s right the only thing anyone will remember is the one (and maybe only) time he was wrong. So double-triple-quadruple checking is de rigueur. At no time does an engineer expect anyone will just take his word and expects his work will undergo (sometimes intense) scrutiny. His reputation depends on being right. Engineering results are checked against real-world facts. Compare this to some fields were pontification is the rule and scrutiny is shunned and even held in contempt. (“Don’t try this at home folks! We’re the experts”). Some of these fields don’t check their models of reality against reality. Care to guess how most of climate science measures up?

    BTW: those math things from college (linear and nonlinear analysis and calculus for example) are every day tools. How do you think the output from NASTRAN and the like gets checked? And, yes, they are indeed checked. Reputations depend on it.

    In these days of rubber stamp degrees in English and Basket Weaving Skills and Personal Relations I guess it’s easy to sneer at a BS (as if a PhD in Basket Weaving is really something). An engineer is acutely aware that while he may call himself an engineer after graduation he has only been trained to become one. That BS you sniggle at is just something to hang on the wall and makes getting that first job easier. It’s what one says and does that matters — not what degree is held.

    You make it sound like you feel you haven’t any expertise or technical skill whatever. I say this because it’s rather easy to check the facts and verify previous work — at least it is when the data aren’t hidden or destroyed and the methods are described in more than vague terms. Reliance on career trappings should only be an initial reaction. I hate to tell you this but most of the climate science stuff is quite trivial. Rocket science it ain’t. You apparently give far too much weight to a person’s early career achievements (like degrees) than to their current work. You also are a bit clueless as to what engineers actually do. But, hey! Not to worry! We can’t be all things can we? We each muddle along as best we can under the circumstances.

  82. What does the data shows about AGW?

    http://bit.ly/ADRqpM

    The above data shows, IPCC’s climate models are wrong because observed global mean temperatures are LESS than model projection for CO2 emission held constant at the 2000 level.

    AGW is not supported by the data (so far).

  83. Rob Ryan: I have both an engineering PhD and extensive engineering experience which particularly qualifies me to comment directly in reference to your statements regarding the same. With all due respect, while you certainly may know what the engineers in your employ “do,” you apparently have little understanding of what engineers do as a general rule. By definition, that alone disqualifies your comparison to a dissertation though, I must admit, my topic was quite a bit more involved than a first project. Mine was, however, a real world research project (radar), and I was specifically told I was required to advance the science if I expected to qualify for candidacy. Engineering is, after all, the practical application of science and math, not just plugging data into models (models are indeed useful, however).

    So far, a bunch of people that don’t really know how to analyze data, let alone ordered data such as time series, grasping at straws proving they know as little as dear old phil. Cmon Phil., step it up, prove you aren’t just a slave to your paycheck. Let’s see that moon hoax “brilliance” that made you famous!

    Mark

  84. Pingback: Tammy at Closed Mind is Scart of Little Ole Me? | suyts space

  85. LOL @ Rob Ryan tying himself in a knot indignantly waving the holy PhD in the face of those who actually carry out applied science on a daily basis. Both terms, “scientist” and “engineer” are broad, and appropriately so. There is a whole interesting area of study called the philosophy of science that is worth discussing in its own right. The collective wisdom reached over hundreds of years after numerous debates among thinkers more capable than all of us here is that a definitive, bright-line definition of science is not possible. Behold the Demarcation Problem.

    However, more relevant to the current discussion: It doesn’t make any difference whether Rutan or Mann or anyone else is a “scientist” by some contrived definition. The question is, who is right?

  86. “This question keeps coming back, although we know the answer very well: all of the recent CO2 increase in the atmosphere is due to human activities, in spite of the fact that both the oceans and the land biosphere respond to global warming.” (the opening line of the ‘real climate’ blog)
    the proponents know ‘all’ sources of, amounts of, and rates of CO2 emissions ? I’d like to see that !
    hat’s off to those 16 scientists brave enough to find answers to politically difficult questions, and make their voices heard.
    it does seem that computer programs make it too easy to fabricate evidence, make predictions, demonstrate bias…
    how many agw predictions have been demonstrated, with the passage of time, to be correct ?
    maybe it’s time the agw crew walked away, quit, retired. ‘DCIM’ !

  87. Mann’s understanding of physics may also be likened to an overly enthusiastic undergraduate who left the lecture early.

    In 1981 he made the huge mistake of assuming the Earth’s surface acts like a blackbody so he could attribute 33 degrees of warming to carbon dioxide and its colleagues. It doesn’t and he shouldn’t have. See http://climate-change-theory.com