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Doug Hutcheson at 12:42 PM on 4 February 2012Monckton Myth #17: Debate vs. Denniss, Part 2
MangoChutney @ 18 You just spoiled my morning. I followed your link, partly to see what all the fuss is about concerning WUWT. I read Christopher Monckton's article and the thread of comments following it. The comments thread had very few entries challenging the article, or even asking for clarification, contrary to the case at SkS where challenging and questioning is actively encouraged. My conclusion is that following WUWT results in diminished ability to critically assess the scientific evidence. As a true sceptic, seeking evidence-based conclusions, I have found SkS to be an excellent learning resource. Several comments on the WUWT thread claimed that John Cook would not post Christopher's article on SkS, because John's arguments had been 'eviscerated' by Chris's calm and 'scientific' deconstruction. Some urged that he take John to court for slander. I am hoping that John can find the time to respond to Chris in an appropriate manner. -
Stephen Baines at 12:41 PM on 4 February 2012Still Going Down the Up Escalator
mc @ 47 I agree that more uncertainty in observations leads to more uncertainty in estimates. But I don't see how Brigg's can use this basic observation to critique analyses (like Dana's) showing increasing temp as naïve and misleading. In fact, I think taking account of observational uncertainty it would cut the other way. Let me explain. First, the prediction of individual points is really not of interest to us, so that's a red herring. No one in their right mind would use a simple linear extrapolation to predict temperature for other than heuristic reasons- that's what physics is for. What is of interest in this case is the slope parameter that allows us to make the best predictions of the data in hand. If we have confidence that the slope parameter is positive, we can say confidently that temperature has increased. Second, the error in estimation of yearly means is already implicit in the spread of the data. That error was not removed when the means were calculated. In the simplest model one can imagine, the variance around the predicted line should be equal to the sum of the variance associated with the central tendency (intercept and slope) and the variance in the yearly means associated with observational uncertainty. Suggesting that the existence of variance about the yearly means adds to variance already observed in the data is a form of double-counting, as far as I can see. Now often one does not often have the wherewithal to decompose the variance about a trend line into separate components related to the line parameters themselves, and the observation error. But in this case, the information to do so exists...and in spades. A fully Bayesian model would use the observed errors around individual yearly means to estimate a probability density function (pdf) for the measurement error...and would use this information and the residual errors to estimate pdfs for the slope and intercept parameters. Those parameters pdfs would be constrained to have less variance than would be inferred simply from the total variance of the residuals. The only way that wouldn't be true is if there were some strange positive correlation between the parameter and the observation error pdfs. -
Composer99 at 12:37 PM on 4 February 2012Still Going Down the Up Escalator
Eric (skeptic): On what evidentiary basis do you make this claim?the periods that IPCC are showing in the graphic you posted in #68 imply acceleration which has now ended. The chart should be updated to reflect the fact that the acceleration has ended or it should be withdrawn.
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Still Going Down the Up Escalator
Eric (skeptic) - If you follow the links I gave here you can take a look at the 125 and 75 year trends as well. But since you didn't make that effort, here it is. The trends for 125 and 75 are closer to 150 and 100 years (respectively), but the trend increases for each shorter time period. "The chart should be updated to reflect the fact that the acceleration has ended or it should be withdrawn. Where is the 75 year trend line and why was it left out of the original chart? Same question for 125?" Eric, I hope I'm incorrect, but are you implying that there is some deception here? Note that the statistically significant 17 year trend (as per Santer 2011) is also 0.16C/decade, almost identical to the 25 year trend - and that's with the late '90's El Nino and 2000's La Nina's. There is no statistical support for claiming that acceleration has now ended - and unless you're willing to also include insignificant periods like the 2x "acceleration" in the late 90's (which I quite frankly hear very little mention of by skeptics), I think your rather accusatory tone is unwarranted.Moderator Response: [DB] Fixed link and text per request. -
Eric (skeptic) at 12:31 PM on 4 February 2012Still Going Down the Up Escalator
Dana, sorry I didn't see your last post. I basically agree that a longer term trend is not a good linear fit. But that also begs the question of why a 25 year linear fit is significant in the context of long term natural variations and cycles. -
Eric (skeptic) at 12:28 PM on 4 February 2012Still Going Down the Up Escalator
Dana, the caption says "(Top) Annual global mean observed temperatures1 (black dots) along with simple fits to the data. The left hand axis shows anomalies relative to the 1961 to 1990 average and the right hand axis shows the estimated actual temperature (°C). Linear trend fits to the last 25 (yellow), 50 (orange), 100 (purple) and 150 years (red) are shown, and correspond to 1981 to 2005, 1956 to 2005, 1906 to 2005, and 1856 to 2005, respectively. Note that for shorter recent periods, the slope is greater, indicating accelerated warming." in http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-faqs.pdf -
dana1981 at 12:26 PM on 4 February 2012Still Going Down the Up Escalator
The figure caption, among many other statements, says "Note that for shorter recent periods, the slope is greater, indicating accelerated warming." I don't particularly like fitting linear trends to the longer-term data which clearly isn't linear. Some sort of exponential fit would be preferable, but of course that would also support the 'accelerated warming' conclusion. I fail to see what the issue is with this graphic. Eric claims the acceleration has stopped - based on what? The short-term data in the 'skeptic' Escalator view? -
dana1981 at 12:14 PM on 4 February 2012Still Going Down the Up Escalator
Eric @73: what is your basis for claiming what the graphic in question "implies"? What is the context in which it's presented? I take serious issue with these assumptions (started by Monckton) about what the IPCC graphic is meant to "imply". The IPCC is not responsible for (mis)interpretations of its graphics. -
Stephen Baines at 12:07 PM on 4 February 2012Still Going Down the Up Escalator
RobertS @62 and 67 So basically, Briggs criticism rests on an obvious confusion of regression intervals (uncertainty around central tendency) and prediction intervals (uncertainty around individual point)? If so, I fail to see what relevance this point has to do with detection of temperature change. That's a first year stats mistake. To imply it is a common mistake among those doing analyses of temperature patterns is downright puzzling. -
Eric (skeptic) at 11:59 AM on 4 February 2012Still Going Down the Up Escalator
Rob Honeycutt, the periods that IPCC are showing in the graphic you posted in #68 imply acceleration which has now ended. The chart should be updated to reflect the fact that the acceleration has ended or it should be withdrawn. Where is the 75 year trend line and why was it left out of the original chart? Same question for 125? -
Bob Lacatena at 10:55 AM on 4 February 2012Still Going Down the Up Escalator
66, barry, Yeah, jeeze... I never knew being a "skeptic" was so hard! I guess I'm just not cut out for it. :) -
keithpickering at 10:52 AM on 4 February 2012Still Going Down the Up Escalator
Dana, I don't have your email address, but I have uploaded my spreadsheet to google docs: Spreadsheet -
Phila at 10:46 AM on 4 February 2012Check With Climate Scientists for Views on Climate
Carbon500: According to the internet IPCC Chairman Dr. Rajendra Pachauri has a Ph.D. in industrial engineering. I believe he also has a Ph.D in economics with a focus on energy and resources. Of course, this hardly matters since the IPCC doesn't conduct climate research and as DrTsk notes, Dr. Pachauri is basically an administrator. Beyond that, the CVs of "skeptics" tend to deserve heightened scrutiny for the simple reason that they're the ones making extraordinary claims. When an industrial engineer accepts the expert consensus on climate, things are pretty much as they should be. When a weatherman or a petroleum geologist compares the experts to Lysenko, it's quite reasonable to take a closer look at his credentials. (Especially if he's making arguments that are demonstrably wrong.) -
iceshelves at 10:43 AM on 4 February 2012Still Going Down the Up Escalator
Re the IPCC graph above, it's worth noting that the IPCC gives error bars on the figure showing that each of these trends is statistically positive. Maybe the "escalator" graph could come with error envelopes on the "cooling" trends? -
michael sweet at 10:31 AM on 4 February 2012Check With Climate Scientists for Views on Climate
John at 84, I love the tiger graphic. Skeptical Science should develop a similar graphic or ask permission to use it. -
Still Going Down the Up Escalator
A trend over 25 years is statistically significant, and 50, 100, and 150 years are likewise. Here's the same 150, 100, 50, and 25 year trends display for: HadCRUT3: 0.049, 0.076, 0.13, 0.16C/decade BEST: 0.071, 0.097, 0.22, 0.30 C/decade GISTEMP: (from 1880) 0.06, 0.073, 0.14, 0.18C/decade So: steadily increasing trends as time goes on when looking at sufficient data for statistical significance. As opposed, of course, to 'selected' 10 year time periods, where variability is such that you can find almost any slope you want to... -
Rob Honeycutt at 09:56 AM on 4 February 2012Still Going Down the Up Escalator
Okay... This is really silly. Skepticsville is claiming the IPCC is doing the same as Dana's escalator graph. Only every trend picked by the IPCC is a statistically significant trend and the shortest is 25 years. Fake skeptics create the escalator effect by choosing short trends that are NOT statistically significant. Trends that are rarely more than 10-12 years long. If they can't see the difference I would suggest it's due to willful blindness.
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RobertS at 09:55 AM on 4 February 2012Still Going Down the Up Escalator
Let me rephrase the first paragraph of my post @62 since Briggs did use confusing terminology here. When he used the term "classical parametric prediction interval" he means the confidence interval for the regression. He chose to use the former because this interval often (improperly) conflated with the predictive interval, and views the confidence interval as far less informative of the actual error in "predicting" unobservables. -
barry1487 at 09:29 AM on 4 February 2012Still Going Down the Up Escalator
Sphaerica, 1987 to 1997 is a positive slope in your RSS Escalator graph. You can get a negative slope to December 2011 starting from 1998 and 2001, too. Here's my bash at getting a clean looking Escalator.Moderator Response: [RH] Fixed image width. -
Steve L at 09:22 AM on 4 February 2012Public talk: Global Warming - The Full Picture
Hi John, I watched the whole thing and really liked how you kept bringing things back to "Let's look at the full picture." I'm going to try that more generally in more discussions of my own. I think it worked really well. I don't think you went into too much detail in your answers. But regarding word choice (groan), I think you could have been more incisive! I'm hoping next time somebody asks about "Global Warming" versus "Climate Change", the presenter will ask the questioner when/where he thinks those terms were thought up. If they have an interesting answer, so much the better, but in general I think they're just trying to make a glib comment to make them seem smart, and I think it is useful for them to have it dumped back in their lap to let them struggle with it for a short while. Then the presenter comes in and saves them: "Do you know when the first IPCC report was published? Do you know what IPCC stands for?" Back to your approach regarding the full picture, though, "carbon" versus "carbon dioxide" was a new one for me. It would be difficult to come back with this on the spot, but I believe Arrhenius used the term "carbonic acid". Would the questioner prefer that scientists stick to the original in that case? -
DSL at 09:16 AM on 4 February 2012Check With Climate Scientists for Views on Climate
And Tarcisio, Estoy casi seguro de que Google Translate ha destruido mi respuesta a usted. -
DSL at 09:15 AM on 4 February 2012Check With Climate Scientists for Views on Climate
Tarcisio: "To explain the global warming we see the physical as meteorologists study the atmosphere of up to two meters and global warming is linked to the lack of soil water to evaporate and take heat beyond 500mb." ¿Su teoría de la humedad del suelo explicar el enfriamiento estratosférico observado? "This proves that the atmosphere is opaque to long wave emissions, and therefore does not help reduce CO2 emissions." Traductor Google ha destruido todo lo que estábamos tratando de decir. Supongo que no quería decir que debido a que la atmósfera es opaca a ciertas frecuencias ampliado a la presión de la radiación infrarroja, las emisiones de CO2 se reducen. Eso sería un non sequitur. -
Robert Murphy at 09:07 AM on 4 February 2012Still Going Down the Up Escalator
@64 Oops. My apologies. I completely misread what he was saying. And I can't even use lack of caffeine as an excuse. <<< smacks head. -
Composer99 at 08:49 AM on 4 February 2012Check With Climate Scientists for Views on Climate
Carbon500: Dr Pachauri's PhD does not "make or break" the IPCC AR4. The great quantity of scientific literature to which the AR4 refers, and which no critic or contrarian has yet satsifactorily deconstructed, is what gives the IPCC its authority as a reference for policymakers and the public on the subject of climate change. With regards to the two Wall Street Journal letters, what is important is that the letter written by Trenberth et al is in line with the overwhelming body of empirical evidence, and it is this conformance to the evidence which grants Trenberth and company their authority. By contrast, the letter/editorial written by Lindzen et al consists mainly of a series of rehashed, long-refuted contrarian claims which are out of line with what the evidence shows. This lack of evidentiary support negates the implicit claim to authority that Lindzen et al appeal to through highlighting their credentials. -
muoncounter at 08:44 AM on 4 February 2012Check With Climate Scientists for Views on Climate
Carbon500: That would be interesting if Dr. Pachauri was a sole author. As the IPCC is an agency that reviews current research, it makes no difference whatsoever what Dr. Pachauri does for a living. -
DrTsk at 08:44 AM on 4 February 2012Check With Climate Scientists for Views on Climate
The chairman is an administrator dude!!! They only thing he needs is good management, people, and negotiation skills...nothing else....move your strawman elsewhere!!! -
Carbon500 at 08:29 AM on 4 February 2012Check With Climate Scientists for Views on Climate
Do you consult your dentist about your heart condition? According to the internet IPCC Chairman Dr. Rajendra Pachauri has a Ph.D. in industrial engineering. -
Composer99 at 08:15 AM on 4 February 2012Still Going Down the Up Escalator
Robert: keithpickering was creating a verion of the "Down the Up Escalator" using the UAH data. He is most definitely not accusing anyone at SkS of cherry-picking. -
RobertS at 08:10 AM on 4 February 2012Still Going Down the Up Escalator
Sorry - "uncertainy interval" should read "predictive interval". -
Tarcisio José D at 08:08 AM on 4 February 2012Check With Climate Scientists for Views on Climate
Elsa. To post a chart in your comments, you need to put it on a server and indicate the link with the "patch" full. Example: "<" img src = "http://www.scam.com.br/tjdavila/solo/clima/trenberth07.jpg"">" Loock:
I take this opportunity to tell Dr. Trenberth as for matters of the heart I'd rather see a counselor sentimental and I agree with Dr. Alegre "No need to panic about global warming." For deduction of your chart above, for a radiation of 390 watt square meters, only 40 escaped from the atmosphere into space. This proves that the atmosphere is opaque to long wave emissions, and therefore does not help reduce CO2 emissions. To explain the global warming we see the physical as meteorologists study the atmosphere of up to two meters and global warming is linked to the lack of soil water to evaporate and take heat beyond 500mb.
The_Greenhouse_ effect_completely_natural
Moderator Response:Your claim is addressed in the post here. Per the comments policy for this site, please keep your comments on-topic, and post future discussion of this point on the appropriate thread.
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RobertS at 08:07 AM on 4 February 2012Still Going Down the Up Escalator
Tom @23, I think Briggs' point in the temp proxy link is that the dark tan band (confidence interval for the regression line) is often conflates for the 'uncertainty interval' given for the unobservables. And I wasn't attempting to defend Briggs by arguing that he was too precise, nor do I think that precision in terminology necessarily makes one's argument any good. I think Briggs could be far more clear with his writings. My point was that many of his critics simply did not understand what he was getting at, primarily because Bayesian predictive statistics and it's associated terminology isn't common to climate science, or the physical sciences in general. So folks assumed his word choice was some form of "novice sophistry." -
Robert Murphy at 07:39 AM on 4 February 2012Still Going Down the Up Escalator
@59 "Those numbers end in December 2010, not December 2011" The slopes ending in December 2010 are a bit larger than those ending in December 2011 (2010 was warmer). Want to try that again? -
Robert Murphy at 07:36 AM on 4 February 2012Still Going Down the Up Escalator
"But take heart, cherry pickers!..." You cherry pick some start dates, calculate incorrectly and claim a negative slope when there is none, but have the nerve to call us cherry-pickers? Now that's chutzpah. -
dana1981 at 07:31 AM on 4 February 2012Still Going Down the Up Escalator
rust @57 - yes, that's the graph Monckton cried foul over, though for no good reason. As I recall, Monckton's criticism was not of the graph itself, but rather his interpretation of what the IPCC was using the graph to try and argue. It was very convoluted. Coincidentally we may have a post in the works addressing that very subject. On second thought, it's probably not coincidental. Josh probably got the idea from Monckton. The cartoon still makes no sense whatsoever though. -
keithpickering at 07:30 AM on 4 February 2012Still Going Down the Up Escalator
Well, I guess there are three types of people in the world: those that can count, and those that can't. Those numbers end in December 2010, not December 2011. Sphaerica is right: there is no negative slope ending in December 2011 in the UAH data from any point. But take heart, cherry pickers! Dr. Roy is promising a version 6 of the UAH data, which is cooler during the past few years. -
Robert Murphy at 07:17 AM on 4 February 2012Still Going Down the Up Escalator
"My cherry-picker spreadsheet for UAH shows slight negative slopes ending in 2011 December, for the following begin dates: ...1997 January, 168 months" WoodforTrees gives a warming of about .14C for that time period. "1997 February, 167 months" .13C of warming "1997 March, 166 months" about .12C of warming "1997 April, 165 months" About .11C of warming "1997 May, 164 months **" .09C of warming "1997 June, 163 months" .09C of warming "1997 July, 162 months" about .09C again of warming. None of the starting dates you picked shows a negative slope. -
rustneversleeps at 07:14 AM on 4 February 2012Still Going Down the Up Escalator
@ Trent, dana - for some reason, in the context of the "escalator", they are recently fixated on pointing to that 3rd graph. I saw it on twitter and elsewhere in the last few days. I don't see the point either. But is that the IPCC and/or Pauchuri graph that Monckton cried "fraud" over? He made some arcane argument about how "you must never do this", but I recall that was nonsense... -
dana1981 at 07:05 AM on 4 February 2012Still Going Down the Up Escalator
Trent - Josh is apparently trying to argue that looking at trends over 25, 50, 100, and 150 years is exactly the same as looking at trends over 10 years. He has apparently entirely missed the point, which was about short-term cherrypicking, not about looking at different trends. There's nothing wrong with looking at trends over various timeframes, as long as those trends are statistically significant, which all the trends in the IPCC figure are. -
Trent1492 at 07:04 AM on 4 February 2012Still Going Down the Up Escalator
Oh, sorry! I did not give the link. Here it is: Cartoon by Josh. -
keithpickering at 07:03 AM on 4 February 2012Still Going Down the Up Escalator
Sphaerica, My cherry-picker spreadsheet for UAH shows slight negative slopes ending in 2011 December, for the following begin dates: 1997 July, 162 months 1997 June, 163 months 1997 May, 164 months ** 1997 April, 165 months 1997 March, 166 months 1997 February, 167 months 1997 January, 168 months The May (**) has the most negative slope. There are probably longer ranges out there too, but my program only goes 14 years max. -
Trent1492 at 07:01 AM on 4 February 2012Still Going Down the Up Escalator
I was just sent this cartoon by Josh. What is he going on about? I see the SKS graphic of the the skeptic and realist view of the temperature from 1973 with his snarky, text got that. So what is he on about with the third graphic? I see the trend for 25, 50, 100 and 150 years. I see the individual years. Where is the scandal? -
littlerobbergirl at 07:01 AM on 4 February 2012Still Going Down the Up Escalator
dana, your graph is popular because it is funny :-D at a glance it shows the desparate contortions needed to produce the denier arguments. and it moves! woo! -
Phila at 06:59 AM on 4 February 2012Check With Climate Scientists for Views on Climate
What I find really a bit poor from your side is that you try to hide the fact that it has not warmed but I have found you out. Just thought this particularly unpleasant accusation of dishonesty from elsa deserved highlighting. Also, I have to add that it's always funny when people who clearly don't understand the basics of AGW become convinced not just that it's hoax, but also that the hoaxers are too incompetent to create "evidence" that can withstand casual scrutiny from an ignorant amateur. Apparently, evil geniuses aren't quite as detail-oriented as comic books led me to believe. -
dana1981 at 06:34 AM on 4 February 2012Still Going Down the Up Escalator
Mangochutney - the 'realist' view in The Escalator is basically the same as the yellow line in the IPCC AR4 figure you reference, but over a slightly longer timeframe (37 years as opposed to 25, or 42 years in the NOAA version). -
MangoChutney at 06:06 AM on 4 February 2012Still Going Down the Up Escalator
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/faq-3-1-figure-1.htmlModerator Response: [RH] Hot linked url. -
Rob Honeycutt at 05:53 AM on 4 February 2012Still Going Down the Up Escalator
MangoChutney... Could you link to the point in AR4 you're talking about? Here is a link to chaper 3 but it's not organized into page numbers... IPCC AR4 Ch.3 -
Dikran Marsupial at 05:46 AM on 4 February 2012Still Going Down the Up Escalator
Dana@44 yes, if I can find the time (better stop commenting on blogs and do something more useful!) Stephen Baines@45 The more uncertainty in the estimates, the more uncertainty there will be in the linear regression model also. I think it is likely that it will make little difference, as the uncertainties in recent anomalies are small, but there is only one way to find out! When I give a talk on Bayesianism, I often use that Rumsfeld quote about there being things we know we know, things we know we don't know, and things we don't know we don't know. The first of these is easy to deal with, the last is impossible to deal with (other than giving the caveat that the almost certainly exist). The real advantage of Bayesianism is that it gives you a sound way of using the expert knowledge that you don't know something. The main advantage is that it makes the conclusions of the anlaysis less certain, and is helpful in avoiding jumping to conclusions. The real problem is that sometimes they are too vague (e.g. a flat prior on the probability of a biased coin coming up heads - in the real world you can only make a slightly biased coin, unless it is one with a head on both sides!). -
MangoChutney at 05:41 AM on 4 February 2012Still Going Down the Up Escalator
Since most sceptics agree the world is warming and the overall trend is still warming, shouldn't the caption read "How some skeptics view global warming"? Also, how does the "escalator" compare with IPCC AR4, WG1, Ch3, p253? -
jmsully at 05:38 AM on 4 February 2012Check With Climate Scientists for Views on Climate
Elsa, even though there has not been a statistically significant increase in temperature over the last 10 years, the *must* be an increase in heat in the system because the TOA flux imbalance (about .6 Wm-2) persists. And 10 years is not "may well be" too short. It is too short. You might want to look at this "elevator" thread to see that short term flat or cooling trends are quite common in the surface temperature record, even though there is an overall warming trend clearly evident in the data. -
Stephen Baines at 05:31 AM on 4 February 2012Still Going Down the Up Escalator
DM...Correct me if I'm wrong. Considering the uncertainty in the averages should increase the credible interval for individual point observations in the time series. But wouldn't it also reducing the interval around the slope parameter, which is what we're really interested in here? I mean, adding in information regarding among-station variability is just going to help you better constrain the separate contributions of measurement variability and uncertainty/variability in the parameter to the overall variability. I guess it would depend on how you structured the error model, for sure, but this is exactly the kind of detail we are not getting from Briggs. That's beside the point that a non-informative prior in this case is basically cheating. What's the point of a Bayesian model if you're not going to include prior information?
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