Bishop Hill Spiking the Marcott hockey stick
Apr 3, 2013 Climate: MWP Spiked magazine has taken a look at the Marcott hockey stick and is singularly unimpressed:
On Easter Sunday, Marcott and his colleagues published a response on the Real Climate blog. Most notable was this comment: ‘Our global paleotemperature reconstruction includes a so-called “uptick” in temperatures during the twentieth century. However, in the paper we make the point that this particular feature is of shorter duration than the inherent smoothing in our statistical averaging procedure, and that it is based on only a few available paleo-reconstructions of the type we used. Thus, the twentieth-century portion of our paleotemperature stack is not statistically robust, cannot be considered representative of global temperature changes, and therefore is not the basis of any of our conclusions.’
Wow.
In other words, all that stuff about having the highest temperatures for millennia and about eye-popping warming over the past 100 years appears to have no basis in the paper’s actual temperature reconstruction.
I get a mention too.
Reader Comments (108)
Thanks Curt
As already noted - I think first on ClimateAudit, Marcott's PhD thesis has an almost identical proxy graph, but without the uptick.
Its interesting to consider what would have happened if the Marcott et al paper had been submitted without the uptick (which they acknowledge even in the original paper is not 'robust'). Would Science have accepted it? And if they had, what would the pro-AGW community have said about it? Probably nothing. No big press releases or triumphant reporting. We almost certainly would not be talking about it now.
We can feel angry at 'yet another piece of shoddy misinformation', but on the other hand, it says: 'is this the best they can come up with'? It rings of desperation.
EM,
And you claim to be have been a teacher? All I can say is I hope to God you never taught any of my children. Do you really, really not understand why you cannot “plug” the high resolution instrumental temperature record into the end of a 300yr smoothed proxy reconstruction? Honestly? This is basic 101 stuff. You should be damned well ashamed of yourself. I don’t normally lose my temper these days, but I find it absolutely disgraceful that a teacher, a teacher ffs, would promote such a disingenuous and dishonest act. Let me make this absolutely clear to you once and for all. This 11500 yr reconstruction tells us nothing about the modern day warming. Nothing. It does not tell us that the current warming is in any way anomalous simply because the multi-centennial smoothing that this reconstruction employs, wipes out any evidence of any such similar slopes (up or down) that may have occurred (and likely did occur) in the past. That a teacher (and a science teacher at that) should need this pointing out beggars belief. I repeat, you should be damned well ashamed of yourself.
MikeC and chris y,
I have applied some Climate Science™ to your problem.
In climate science we see something happening then we extrapolate linearly to make our 'projections'. I have hindcast using this technique and I believe that the correct answer for the global mean temperature in 1198 is 29.0°F.
2012 - 1198 = 814 years
using the 0.2°C/decade from Mike Jackson's post:
81.4 * 0.2 = 16.28°C = 29.30°F
1198 mean temp = 58.3 - 29.3 = 29.0°F
This is a robust™ statistic.
Do you really, really not understand why you cannot “plug” the high resolution instrumental temperature record into the end of a 300yr smoothed proxy reconstruction?"
Apr 3, 2013 at 11:00 PM | Laurie Childs
No' I dont understand.. Several people have said this, without explaination. Assume I've gone senile and use simple words.
Billy Liar--
Awesome!
Apr 4, 2013 at 12:16 AM | Entropic man
I sometimes think you are committed to making people waste their time on your ignorance.
You find out and tell us.
Entropic Man, I'll try and present a simplified and condensed version as I understand it.
Look at the two graphs that Roger Pielke Jr re-posts on his blog on this matter at the link I also gave earlier:
http://rogerpielkejr.blogspot.co.uk/2013/03/fixing-marcott-mess-in-climate-science.html
The first plot shows that the older proxy data is much smoother ('less noisy', though I use the term advisedly) than the more recent data. This is inescapable because the physical environment irretrievably mixes the core samples as they form over time, quite apart from other dating and sampling issues. There is no nice year-on-year sequence of layers that can be counted like tree rings (as if they were always that simple). This is low-resolution data. As Curt pointed out earlier, there are few fancy tricks that can reproduce what actually happened once that information is lost. (By analogy, I can give you the arithmetic mean of 10 integers and you can know nothing about the individual 10 numbers I used to calculate that mean).
Now look at the second plot which has been extended into the modern era. As we approach the present day the resolution becomes sharper. (The nature of the proxies also change but I put that aside): The peaks and the troughs in the data become more visible and pronounced. Marcott et al have chosen a form of data processing, and an unsubstantiated selection of data-points from the most recent past that produces the very large modern up-tick. They could have chosen to ignore other recent data-points to produce a down-tick. The justification is still awaited.
In either event, you need to look at the older data and imagine what it would look like if you superimposed the modern 'noise' on top of it: You would see much higher (and lower) peaks which would put the modern up-tick into a thoroughly unremarkable context. They have carved the blade of their hockey-stick out of the natural variability that can be measured in more recent times. 'Cherry-picking' the data is a great way to produce any trend you want, once you have enough data points to select or discard.
Asserting that the unmeasurable variability in the past was not as great as it is today is baseless. If they had evidence to that effect, I'm sure they would have presented it.
EM - you are correct. You can plug anything you want since 1950 onto the end of this reconstruction. Infant mortality, grain yields, average "global" temperature, anything at all that is not related to the proxies used for the reconstruction. Just don't expect to be taken seriously.
Apart from that, you might also care to reread curt's post on Nyquist and chris y's on proxy resolution.
As the official host for the Marcott et al. FAQ document, Real Climate bears a major responsibility (I would argue), voluntarily assumed, to ensure the document is responsive to criticism. The authors avoided responding to Revkin (Dot Earth/NY Times blog) or any other critical questions for three weeks by promising an impending FAQ that would address issues fairly comprehensively.
It seems, in reality, that the "Real Climate wall" has been erected to ensure that the authors don't need to engage critics at all, even very indirectly, while pretending to have addressed all reasonable "FAQ".... in fact, we know that the FAQ document entirely omitted or evaded the questions that had given rise to the need for such a public document in the first place.
Related to this, I have noticed that RC is tending to "Borehole" or even disappear inconvenient comments and commentators. Also, Brandon Shollenberger reports that he noticed long ago he had been pre-emptively banned from posting at Real Climate, presumably because of his critical review of the Mann (2012) book. Following up on the issue of whether people could be pre-emptively banned at Real Climate, it appears that I am in the category, to my great surprise. I have never tried to post there and am certainly a minnow (or a bit of plankton) in the blog climate world, yet it appears I may be unable to post at RC simply based upon my "Skiphil" handle. Interesting....
Brandon Shollenberger was pre-emptively banned from commenting at Real Climate??
Reading "boreholed" comments at RC is a real hoot
Apr 3, 2013 at 5:25 PM | thinkingscientist -
Apr 3, 2013 at 5:41 PM | Entropic man -
Nothing, it will most likely on balance be a positive outcome.
Skiphil:
"Following up on the issue of whether people could be pre-emptively banned at Real Climate, it appears that I am in the category, to my great surprise. I have never tried to post there and am certainly a minnow (or a bit of plankton) in the blog climate world..."
--------------------------------
I think most of us would be classified as pond-scum at Real Climate.
Ok, my 3rd comment did appear with an explanation, although I still don't know what happened with the first two (nothing in the Borehole). But obviously there is no reason to think I was "pre-emptively" banned at all.
While Lewandowsky types may pretend this was an example of "conspiracy ideation" I'd say it was an ordinary suspicion (why couldn't I post at a site which I did not know to have prior moderation of all comments). I rapidly disposed of the suspicious conjecture once one of my comments appeared with an explanation (still don't know why the other two would not appear, but that can be chalked up to web mysteries I suppose).
This simple enough for ya?
EM? Really?
This actually is at the heart of the "I am a Climate Scientist, you are not, and cannot comment on Climate." Something that you promote at length.
I did an engineering degree with some statistics. Thirty years ago. Cannot remember any of the specific terms or processes. I moved away from engineering. Yet...
After it was discovered what those graphs contained, I took one look at them graphs, and just thought: "what a load of b*******!'. Really it is that simple and basic. it is so bleedin' obvious I am surprised someone like you, who tries to show some element of technical intellect, does not get it (unless your ignorance is feigned.)
Commenters above have tried to explain. An engineer would be embarrassed to present that at a project meeting. They would be ridiculed.
As an engineer you could actually be accused of professional misconduct if you promoted such a graph in a design and it led to an accident or failure or financial loss to a customer.
But of course, this is Climate Science. We, the great unwashed, are not allowed a valid opinion.
It must be my eyes but I have started reading "proxy reconstructions" as "poxy reconstructions". (Seriously!)
I think I might be onto something.
Entropic Man- I'm really trying to help here.
Look at this series of numbers;
2,2,3,2,3 mean = 2.4
4,1,1,2,4 mean = 2.4
6,1,2,1,2 mean = 2.4
1,2,2,3,4 mean = 2.4
Consider the first 3 sets to be proxy measurements that have been averaged to give, say, 200 years resolution. All the "high frequency" variability is lost.
The last set is instrumental data. If it is treated in the same way as the previous 3 sets, it gives the same mean.
However if it is plotted as its individual values, preserving the high frequency variability, it gives the appearance of a rapidly rising (temperature) signal.
This is why you cannot simply "splice" proxy and instrumental data, of greatly different resolutions and expect to get a meaningful result.
Do you finally "get it"?
RE: Entropic Man: "And if the AGW theory is correct? What harm will have been caused by doing nothing?"
Go and read Bjorn Lombergs chapter 24 on global warming in "The Skeptical Environmentalist". Remember that Lomberg is pragmatic, but essentially a warmer on the science. Also keep in mind that Lomberg was writing before newer evidence suggested a much lower climate sensitivity is likely.
Assuming high climate sensitivty and the IPCC scenarios from 2001 are right (which they are clearly not - they are far too pessimistic, as shown by the temperature plateau of the last 16 years and implied low climate sensitivity, lack of significant sea level rise etc), to fully implement the Kyoto treaty is estimated to cost around 2 - 4 per cent of the entire world GDP. That means that by 2050 that would be a cost to the world of $900 Billion per year, every year in todays money. And for all that expenditure we would delay the global warming expected under the IPCC scenario from 100 years... to 106 years. As Lomberg concludes, even if you believe the IPCC scenarios are right, the remedy is pointless: there are far better things to spend that money on that would save far more lives and improve the quality of life for far more people on the planet.
Oh, and Entropic Man if you really do not understand why you cannot compare two time series at completely different resolutions (ie Marcott et al at 300+ year resolution and modern temperature at 1 year resolution) then I suggest you need to educate yourself before posting. Until you can understand such a basic concept in sampling theory and statistical averaging then you really should restrain from posting the kind of uneducated nonsense that you have been doing on this thread. You are only making yourself look foolish in front of people who know far more about the topic than you. If you want to be educated, either do it yourself with a little self-help through reading, or show a little humility and actually listen to those posting here who do know what they are talking about on these topics.
Billy Liar
michael hart
Jiminy Cricket
thinkingscientist
Thank you for your clarifications. I bow to your superior sophistication in data analysis and recognise that it can be difficult to maintain continuity when combining datasets in different formats into a single set.
Unfortunately you have lost track of the purpose of the whole exercise. That is to produce as accurate a description of past and present climate as our techniques allow.
There is an old philosophical trap, mistaking the map for the territory. The wheelchair graph I linked is a map of global temperature change over the last 20,000 years. It is based on a variety of proxy and actual temperature measurements, with different variabilities, accuracies and resolutions. It is not itself the reality.
The planet is a thermodynamic system following the laws of physics. It responds to long term trends in energy input from orbital cycles by changing energy content and energy flows. The result is glacial and interglacial periods, with changing temperatures, sea levels, ice cover, biography and local climate. On top of that are short term changes (noise) on all scales and, more recently, human influences.
The planetary changes are an external reality. They are not dependant on the techniques used to measure them, the statistical limitations of the data, or the format after analysis.
My concern is to produce a long term description of planetary temperature change. The proxies, the summations by Shakun, Marcott, the Hadley centre etc are all means to that end.
You are using a mismatch between the properties of different datasets to forbid the linking of the temperatures derived from them into a longer sequence. I do not want to plug the
datasets together. I want to plug the temperature sequences together.
It is not the dataset properties we are interested in, but what the temperature sequences they produce can tell us about past and present climate.
Entropic Man- I assume from your response to
Billy Liar
michael hart
Jiminy Cricket
thinkingscientist
"You are using a mismatch between the properties of different datasets to forbid the linking of the temperatures derived from them into a longer sequence. I do not want to plug the
datasets together. I want to plug the temperature sequences together."
But this is the point we have been trying to hammer into your thick skull- You can't.
One is a temperatures series (the instrumental) and one is an averaged proxy data sequence which does not contain any actual temperature data.
I also suggest you read my previous post. Even if the two spliced sequences contained actual temperature data, they still could not be linked in the way you suggest. See below.
Look at this series of numbers;
2,2,3,2,3 mean = 2.4
4,1,1,2,4 mean = 2.4
6,1,2,1,2 mean = 2.4
1,2,2,3,4 mean = 2.4
Consider the first 3 sets to be proxy measurements that have been averaged to give, say, 200 years resolution. All the "high frequency" variability is lost.
The last set is instrumental data. If it is treated in the same way as the previous 3 sets, it gives the same mean.
However if it is plotted as its individual values, preserving the high frequency variability, it gives the appearance of a rapidly rising (temperature) signal.
This is why you cannot simply "splice" proxy and instrumental data, of greatly different resolutions and expect to get a meaningful result.
This is my last communication with you on this topic.
You are either thick, or being deliberately obtuse.
Entropic Man: As you go back in time, estimating temperature, the estimates are either high resolution temporally but no resolution geographically (eg ice cores) or they are very low resolution/highly uncertain temporally and low resolution geographically (eg proxies such as tree rings).
In analyses like this you cannot have your cake and eat it. Its called uncertainty for a reason: because there are things you cannot know because you have no means of measuring them directly. When you measure them indirectly and with great uncertainty then you can no longer see details. In a 300 year resolution measurement of the holocene background temperature trend (the "scythe" from Marcott for example) you could hide the modern day temperature record in just half a sample. In other words, you simply cannot see variations like the modern annual temperature as they are simply lost in the smoothing of results such as Marcott et al. Splicing the modern temperature record onto the end is then a visual trick, nothing more, to try and pretend something happens now, when in fact the same type of changes would be expected to be happening throughout the Holocene. You cannot see them in the reconstruction because they have all been smoothed out. If you want to see true (but local variability) over long timescales go and look at high resolution ice core measurements. There is a great picture in Ian Plimer's book Heaven and Earth taken from the GISP2 ice core, page 38 in the book. You want to see natural variability, and how terrible the BIG and SUDDEN temperatures drops to cold could be, take a look at that picture, and be thankful you live in the warm and benign Holocene of the last 10,000 years or so, with a variation of only +/- 2.5 degC or so.
Try a spreadsheet example. Download the longest continual temperature measurement data set in the world, the Central England Temperature data set from:
http://www.metoffice.gov.uk/hadobs/hadcet/cetml1659on.dat
In a spreadsheet, using the last column which is the annual average CET since 1659 plot a graph of temperature versus time without smoothing and then plot it at 300 year resolution. Just to help you, using a centred average the last point on the 300 year smoothed graph would be plotted as the year 1862 with a value of 9.3 degC and a 95% confidence interval of +/- 1.3 degC. There wouldn't be another point on the 300 year average graph because you would have run out of data. Meanwhile have a closer look at the CET annual data, which shows variations greater than 7.5 to 10.5 degC. You also get a nice sense of the gentle, steady warming since the Little Ice Age, a warming that has been steady for the entire length of this record. You can also see that the warming spurt over the period 1700 - 1736 was far more continuous and for a longer period than the warming at the end of the Twentieth Century, and with a bigger temperature change. Which is why Phil jones is on record as saying that the late C20th warming is not statistically different to 3 other periods of warming in the CET record.
The regulars who post on The Bishop's blog are polite and helpful. Occasionally, their politeness and helpfulness enables (psychobabble) a troll. Trolls exist to create noise that side tracks discussions taking place on the blog. In my humble opinion, EM is a troll.
Theo Goodwin - I agree.
Don Keiller
Still you miss my point. You present different samples of data which have different degrees of variability, but give the same mean. That is why you need standard deviation or 95% confidence information along with the means.
I also recognise that when you sample along a time series your choice of sample size affects your time resolution. A small sample size will pick up short term changes but with larger confidence limits. A larger sample size gives a more reliable description of long term trends but at the expense of an insensitivity to short term variation. Marcott et al and Hadcrut4 are at different ends of this spectrum.
Lets reverse the problem. To all of you discussing this data analysis problem, let me use your expertise.
We both have an interest in comparing the most recent 120 years of instrument measurements with the Holocene temperatures. I would contend that the temperature rise observed in the instrument record is unusual and probably anthropogenic. You would contend that it is a normal part of the Holocene variability and not anthropogenic.
Available as data are proxy and direct measurement temperature information from a variety of sources, of widely different variabilities, confidence and time sensitivities. How would you derive a global average temperature sequence for the last 20,000 years which is as close as possible to what actually happened and which could be used as evidence to distinguish clearly between our two viewpoints?
Theo: I think Don and my comments (among many others) are helpful and informative to anyone with a passing interest who happens across this discussion and is not familiar with these issues. They are relevent to the discussion of Marcott and why you cannot simply splice on different types and resolutions of data and then draw conclusions. EM is probably a troll, but the rebuttal to EM is therefore more valuable to be left for others to see. It takes little effort on my part to help people who maybe do not have a good (or any) understanding of these technical issues.
I suspect Don Keiller's statements of "thick" or "deliberately obtuse" probably cover all the available options with regards to Entropic Man.
Entropic Man: "How would you derive a global average temperature sequence for the last 20,000 years which is as close as possible to what actually happened and which could be used as evidence to distinguish clearly between our two viewpoints?"
If you mean to say a 20,000 year record with annual variation to the accuracy of modern temperature records, you cannot and never will be able to achieve this. And therefore because you cannot demonstrate that the modern warming hypothesis of AGW is different from (unmeasurable) natural variations that could fit inside the error bars of a low resolution/smooth 20,000 year temperature reconstruction, the theory of AGW therefore falls foul of the null hypothesis. Hence it is an unproven hypothesis, not a theory.
Have you done your homework and plotted up those CET values in a spreadsheet yet?
Oh - Entropic Man, you appear to be conflating the terms sample rate, sample size and resolution in your post at 2.41 pm.
Sample size refers to the number of measurements, sample rate to the frequency of the measurements and resolution refers to the temporal or spatial averaging of the measured sample (sometimes known as the "support" of the measurement).
Thank you for your compliments. :-)
Those of mainstream opinion such as Bitbucket and I serve a useful function here. Most of those posting on Bishop Hill are present because you are sceptics. You post comments agreeing with each other's viewpoints.
We give you the opportunity to debate with others holding different views. The rudeness we often encounter is probably best viewed as a territorial response. If you wish to retain an atmosphere of reassuring agreement among yourselves we are an unwelcome distraction. If you genuinely want your views more widely accepted, you should encourage more of us onto your site so that we can be persuaded.
Entropic Man, I have no problem with yourself and BitBucket.
But I have mentioned it before, you are by nature both "tail pullers", so just expect to get bitten a few times ;-)
I give up.
Not because I am wrong, but because I am tired.
There is a very apt saying that I believe epitomises the "debate" with Entrollic Mann.
"You can lead a horse to water, but you cannot make it drink".
Over and out.
Thanks for the clarification of sample size, sample rate and resolution. I'm 12 years retired from teaching and not as taut on the details as I once was. Some of the ice core and dendrochronology data has near-annual resolution, so you might be surprised how good the Holocene data can be.
I'm quite happy to think of AGW as a hypothesis, since the long term consequences can only be demonstrated to be correct in retrospect. This does not mean it false, just unproven. A good Popperian would not jump automatically to that conclusion, without direct falsifying evidence. We'll come back to that in a century or so, perhaps. :-)
The short term temperature behaviour of the atmosphere and oceans, energy budgets, OLR spectra etc. are consistent with AWG and have not been falsified.
Homework not done, alas. I did a quick inpection scan, but no longer have spreadsheet software handy.
Regarding our discussion of short term Holocene temperature variations, I am surprised that noone has mentioned the paleoclimate data from El’gygytgyn Crater Lake in Russia. I vaguely remember a paper on a spike in temperature about 8200BP, which might support your position.
Entropic Man:
"Those of mainstream opinion such as Bitbucket and I serve a useful function here."
Court jester springs to mind.
"Most of those posting on Bishop Hill are present because you are sceptics. You post comments agreeing with each other's viewpoints."
Actually, no. I prefer to post here because (a) comment is almost totally uncensored (providing you are generally polite) and (b) because people posting here (with notable exceptions, for example yourself and bitbucket) listen to and engage in reasoned argument and are well educated and well informed, with a wealth of experience in physics, earth sciences, mathematics, engineering and many other important disciplines.
I would happily post at RealClimate if they actually wanted rational debate rather than being a propaganda mouthpiece for AGW and didn't simply delete comments that disagree with the party line of "The Climate Mafia".
Entropic Man: "The short term temperature behaviour of the atmosphere and oceans, energy budgets, OLR spectra etc. are consistent with AWG and have not been falsified."
Or sorry, not the case. Just a few examples: no tropospheric hot spot as predicted by AGW models, missing heat problem and of course the issue of a plateau in temperatures for 16+ years, which cannot be replicated by models using AGW theory as they are unable to generate more than about 10 years of no temperature increase. Just one fail is to enough to cast serious doubt upon the hypothesis. That's three in a row, and there are many others.
The period of warming attributed to AGW in the late twentieth century is only just statistically significant and the temperature plateau is on the brink of falling out of the bottom of the 95% confidence interval for the temperature predcitions for the GCM models. Robust theory? Hardly.
thinkingscientist
If we get into the generality of AGW we'll spend the rest of the day playing reference tennis and neither is likely to convert the other.
A pleasant game to play, if you wish, but not what this particular post is about.
Did you have any luck with El’gygytgyn? There were several expeditions coring the lake sediments and a conference with, I think, 14 papers, as a result.
I've found one paper so far.
https://gsa.confex.com/gsa/2013NE/webprogram/Paper216677.html
Entropic Man:
"I vaguely remember a paper on a spike in temperature about 8200BP, which might support your position."
------------------------------
If you hadn't got yourself banned at WUWT you could still go there are discuss it. Today someone also pointed out at WUWT that there are huge recorded volcanic explosions in the same period, 10x the size of anything recorded, with ejecta detectable in the ice cores at both poles, which would be expected to cool the planet very significantly-by the "mainstream" of opinion. They do not show up in the temperature proxies of Marcott et al.
The proxies just aren't up to the job of reporting past temperatures in sufficient detail. It's like trying to read with poor eyesight, but without glasses and in the dark. Amongst many other things, proponents of AGW need to show there is something exceptional about the present temperatures compared to previous climatic regimes in the Holocene. This paper is another failed attempt (and it also says nothing about carbon dioxide either, as you well know).
It would be a bit boring if we had to agree with each other all the time on this blog without you and BitBucket.
Entropic simple Question Have you got confidence in your own believe in Global Warming?
Don't think you have .Otherwise why do you get so hysterically aggressive and defensive when your believe in AGW is questioned casually.
Its not like believing in Ghosts or the Lock Ness Monster or UFOs is it. What do you have to lose if your proved wrong.the world just carries on as before as it always has done.
re: models
James Annan's latest discusses models running warm:
James Annan's latest on model projections
Its not like believing in Ghosts or the Lock Ness Monster or UFOs is it. What do you have to lose if your proved wrong.the world just carries on as before as it always has done.
Apr 4, 2013 at 7:17 PM | jamspid
I'm more concerned with what will happen if I'm proved right. I keep prodding you here in hope that you'll provide persuasive evidence that I'm wrong.
Skiphil on April 4 at 3:02 am, above, and some other commenters mentioned a "Borehole" at RealClimate, which I at first didn't take literally, but now I see that they really meant it...and there it is on the RC masthead...and there is my own comment stuffed right down in it! I don't know whether to feel miffed or honored, but I can't help laughing. Since I love the light of day, I'll repeat it below, if it will fit,
But first I wanted to mention to the Bish' and his readers that this Marcott, et al. thing COULD--I'm really not sure--become the final straw on the CAGW camel's back, because it is uncovering yawning gaps in our understanding that apart from Marcott might not have come to light so voluminously and suddenly. I think it rivals if not surpasses "hide the decline," even though in this case it seems to have been done with PERHAPS better intent, if no less mischievous effect. I just think that you ought to give the controversy primary attention for a while longer, that's all.
Here's my boreholed RC comment, for posterity and for what it's worth:
C Reid @ #101. I hope that your well-formulated questions receive a reply, because as a relatively well-read layman who can also do my sums, I have the same questions, and I think that they are spot on.
The key issue uncovered during this whole Marcott et al. kerfluffle, whether or NOT it was an essential aspect of their paper and their research interests, is that the recent century’s (or centuries’ if one insists) uptick in global temperature has to be examined in relation to the variance inherent in the Holocene-aged proxies in order to determine if it is anomalous. The other factors like core top dating and particularities of statistical smoothing of the underlying mean temps are becoming of peripheral interest, because the key tenet of the global warming hypothesis is that the recent uptick is the result of CO2 “forcing” that PROBABLY was not present in previous eras. OK, so you need to see if there were previous upticks; it’s that simple. Only it is apparently not simple for these to be displayed, although a couple of the so-called denialist blogs are starting to display some proxies AND their variances. That should all shake out in the next few days, and then I think we will have a more clear view as to whether that aspect of the paper will survive.
Gavin, and others: You often bring up this issue as to what could possibly cause an uptick in the past, were one to be found, which is a legitimate question. But our lack of ability to understand a reason for such a fluctuation cannot really be used to deny the conclusion that something else is doing the forcing if the past data DO, reliably, show an uptick, or upticks, can it? I mean, isn’t the way that we want to see science done to be to pose a hypothesis, see if the data validates the hypothesis, and if it doesn’t, then come up with another hypothesis? Our failure to do come up with an alternative explanation or hypothesis cannot be the reason for denying the data, can it? Or is the “fact” of CO2 forcing so compelling to you that we reject any finding that is contradictory? That would be entirely circular, it seems to me.
EntropicMan:
You seem to have got this malarky the wrong way round. You and the other believers are the ones making the extraordinary claims. No-one needs to provide evidence that you are wrong. The burden of proof is on you, not us.
Entropic Man,
You are making a religious argument, not a scientific argument.
And you are not doing a very good job of the religious argument.
EM,
So you expect me to provide persuasive evidence that I am NOT hitting my wife? When you cannot provide persuasive evidence that I AM hitting my wife, except some shoddy computer models forecasting an increasing amount of bruises on her without proof I am the cause of those bruises....she's a kickboxer...
Sigh...
Entropic Man,
If you can post on this and other blogs and search for papers, you can find spreadsheet software to use. I am stunned that your internet access terminal does not come preloaded with Excel at the least. Excuse fail and detention for you laddy boy
"Homework not done, alas. I did a quick inpection scan, but no longer have spreadsheet software handy."
Echoes of Phil Jones admitting he has to get someone else to do a regression using Excel.
EM - try http://www.openoffice.org/download/
null hypothesis falsified to 95% confidence. Alternative hypothesis demonstrated.
null hypothesis demonstrated to 95% confidence . Alternative hypothesis falsified.
null hyopothesis status <95%, >5%. Alternate hypothesis not demonstrated or falsified.
Beyond clueless.
Null hypothesis always stands unless evidence otherwise. Evidence only begins by showing populations differ at 95% confidence limits. One in 20 occurrences is far from conclusive.
University stats 101 - I've taught it.
This is also peurile. No more time wasting from me on this troll.
EM:
"I'm more concerned with what will happen if I'm proved right."
You seem to support the so-called consensus, so I will assume that being "proved right" means, to first order, that the IPCC's predictions of global warming rate are correct. You might check out Lucia's "The Blackboard" site (link posted on sidebar) to find some excellent posts comparing predictions to observations. And putting things as a "AGW is right/wrong" seems to reflect a misplaced though widespread desire to over-simplify: to luke-warmers, the question is of degree, not yes/no.
Perhaps more than any other thread EM has demonstrated why CAGW is not science but a religion. And even now he can't stop digging. WOW!
EM - "No' I dont understand.. Several people have said this, without explaination. Assume I've gone senile and use simple words."
Maybe this will help. Imagine you're subscribed to the MichealMann Financial newsletter and Mann presents a study by Marcott et al showing a 2000 to 2013 200-month moving average of the SP500 with a 2013 10-day moving average tacked on the end with the headline, STOCKS HAVE NEVER GONE UP LIKE THIS!!! Would you believe him? Would you believe Michael Mann, advertised as one of the most distinquished experts in quantitative analysis, could overlook such an elementary blunder? Wouldn't you immediately suspect that he's lying to you and more importantly assume that he knows he's lying to you to sell his latest get-rich scheme to the rubes? Wouldn't you cancel his newsletter?
You obviously did not read Tamino's debunking of your spurious argument. If Dr Mann's analysis says STOCKS HAVE NEVER GONE UP LIKE THIS! that's good enough for me.
[I have invested my savings in his recommended "buy". So far, contrary to expectation, the price has remained static. But it is only a matter of time before the skyward trend resumes. The models of other investment advisors in Dr Mann's Team have confirmed it beyond doubt.]
@ I'm A Believer Apr 5, 2013 at 4:27 PM
Dear Mr Monkee (are you Dave, Mickey, Mike or Pete?),
Whilst you might say “There’s not a trace of doubt in my mind”, I am not so easily persuaded and am obviously not so stupid as to trust the viewpoint of only one company when making such far reaching financial decisions. Therefore, after reading your comment, I took it upon myself to seek other, independent perspective on the veracity of the advice you’d received from Dr Mann’s Team (DMT) Ltd.
I first emailed a company by the name of Foster, Connolley & Romm Inc and visited their website. They showed me lots of models, charts and graphs similar, no doubt, to those shown to you by DMT Ltd. They assured me that the advice given to you was, in their words, “robust” and that I too shouldn‘t hesitate in investing as much of my money as I could into this “new and exciting market“ and that they would be only too happy to handle said investments for me. Much encouraged by this, though not yet totally convinced, I decided to seek the advice of one more company before making any final decisions and told Foster, Connolley & Romm Inc of my intentions. This seemed to upset them greatly and I’m afraid our hitherto warm, friendly, and professional relationship quickly degenerated. I shan’t reveal all of the, quite frankly, shocking exchanges that followed, but if I tell you that one of them actually telephoned me to call me a “tosser”, you’ll get the general drift. I decided there and then that despite their obviously excellent business plan, I would have no further involvement with them.
So, as with Foster, Connolley & Romm Inc, I visited the website and emailed a firm by the name of Schmidt, Steig & Rahmstorf GMBH (I think they must be a German outfit - and we all know how good they are at this kind of thing). They too showed me lots of models, charts and graphs and they too said the advice you had been given was “robust” (is that a common financial term?) Although there were some differences in their models, charts and graphs compared to those shown me by Foster, Connolley & Romm Inc , they assured me that these differences didn’t matter. They too advised that I should invest as much of my money as I could and that they would be more than happy to handle all this for me. It goes without saying that by now I was totally convinced and promised to make all the necessary financial arrangements forthwith. They also suggested that I should sell my house and invest the equity too. They even put me in touch with a firm of international property developers by the name of Lewandowsky & Cook Pty, who will buy my house straight away. All they need is a quick valuation and they’ll put the cheque straight in the post. They’re sending one of their agents (a Mr Halpern) over to do the valuation this very evening. All I have to do is sign the piece of paper he’ll have with him and I’ll have the cheque on Monday. Brilliant.
So all in all Mr Monkee, I just want to say thanks for posting your comment. If it wasn’t for you, I would have missed out on this wonderful opportunity.
EM Doofus
Dunroamin
Aylesbury Road
Lower Partshitchin
Wiltshire