Guest post by Nancy Green
Tamino claims he has added 3 spikes to the Marcott et al proxy data and the Marcott et al process detects them.
Source: http://tamino.files.wordpress.com/2013/04/many_vs_unpert.jpg
This, he then proposes, is proof that there are no 20th century spikes in the Holocene. This claim appears to run counter to a prediction I made recently in a WUWT post; that as you increase the proxy resolution you are more likely to find spikes.
See:
http://wattsupwiththat.com/2013/04/03/proxy-spikes-the-missed-message-in-marcott-et-al/
Having had my reply disappeared at Tamino’s site, I thought readers at WUWT might be interested. I don’t believe Tamino’s conclusion follows from his results. Rather, I believe he has demonstrated the truth of my original prediction. What needs to be understood is that adding a spike to the proxy data is not the same as adding a spike to the proxies. This is where people get confused.
The proxies are ocean cores or similar sitting in some repository. They are real, physical objects. To truly add a spike to the proxies you would need to travel back in time and change the temperature of the earth. This would then affect the proxies in some fashion, depending on the resolution of the proxies, how they respond regionally, including lags, gain or damping. The proxy response might also be affected by other unknown factors at the time that are not visible in the proxies. In other words, the spikes that you add to the proxies would have all the resolution problems that the proxies themselves have.
However, adding spikes to the proxy data is an entirely different animal. The proxy data is an abstract representation of the proxy. It is numbers drawn on a sheet of paper or electronic equivalent. Now you are adding (drawing) high resolution spikes onto low resolution proxy data, with no accounting for regional affects, lag, gain, damping or confounding factors. It should be no surprise at all that these high resolution spikes jump out. If they didn’t, it would point to a serious flaw in Marcott et al.
An analogy might help better understand the problem. Imagine for a moment that we are not dealing with temperature, but rather trying to detect planets around stars. We have before us a photograph of a star taken by a telescope on Earth. We look at this under the microscope. However, we find no planets because the telescope lacks the angular resolution to distinguish them from the star itself.
Now let’s go out to the star in question and add planets around the star and take more photos with our telescope. These planets are real objects. We know they exists. However, it will make no difference; we still can’t see the planets with our telescope. In this example we have added a spike to the actual proxy and it has made no difference.
Now let’s add a spike to the proxy data. Instead of placing planets around the star, take the photo from the telescope and draw a picture of a planet on it. This is an example of adding a spike to the proxy data. The photo is an abstract representation of the star and its planets, equivalent to the proxy data. Now examine the photo under a microscope and voila, the planet (spike) will now be visible.
What we are seeing in action is actually a form or misdirection used in stage magic. It fools us on the stage just as it does in science. It is our minds that create the confusion (illusion) between what the proxies actually are and what the proxy data actually is. The proxies are ocean cores – they are real objects. The proxy data is an abstract representation of the real object. However in our minds we are so used to dealing with real objects as abstract representations that we are fooled into thinking they are one and the same.
If anything, what Tamino has actually done is to prove the point of my original article. He has added high resolution spikes to the low resolution data and as predicted they are detectable. To conclude however that this somehow proves there are no 20th century type spikes in the Holocene makes no sense. As we have seen in this example, no matter how many planets you physically add around a star it makes no difference if you lack the resolution to detect them. This is no proof that they don’t exist. It is only after you examine them at sufficiently high resolution that they become visible.
What Nancy says is correct.
Tamino has not properly taken into account the variable time sampling resolution of individual proxies. The average resolution is 120 years, with while some are as high as 500 years. When you add even a modest sampling jitter of 20% of the resolution the peaks disappear see graph here. Marcott’s paper even says: “The result suggests that at longer periods, more variability is preserved, with essentially no variability observed at periods shorter than 300 years.”
The original narrative implicit in the Marcott paper was that the Hockey Stick had been vindicated by Marcott’s uptick and that today’s temperature increases are unprecedented since the last Ice Age. Perhaps this may even be true, but you still need hard scientific evidence to support it.
The Marcott uptick has now essentially disappeared. This means that the narrative now relies on the instrument data. This is also fine by me provided we can be sure the two “anomalies” actually line up properly? This then depends on re-normalizing average temperature from 5000 years ago to the instrument anomalies normalized to 1961-1990. In my case I just simply added 0.3 C to the proxies to normalise them to Hadcrut4, but I have seen no convincing evidence to support why this should be the case. I interpreted the paper this way but perhaps someone can enlighten me on the evidence for this.
The second key assumption of the proposal that today’s temperature rise is unprecedented, is the necessity to demonstrate that something similar didn’t happen in the past. Hence the importance to provide evidence that Marcott would have detected such changes had they happened. Therefore you need to determine the sensitivity of the proxies to short to medium term climate excursions. I think it is important to show that the raw measurements would be able to detect such changes, rather than some Monte-Carlo interpolations based on those measurements.
The conclusion is that there is insufficient resolution in the proxies to see any past temperature excursions up to 1C which lasted less than ~400 years.
Nancy Green, that was a really instructive post well presented.
Andor says:
April 7, 2013 at 11:55 pm
“It’s like to be on a ship that’s sinking or running aground. A group of scientists and egineers are on the ship trying to figure out why it is sinking. They have trends and formulas. They argue day and night about facts left out,history charts, computer programs with wrong data, why it’s sinking and on and on it goes…
Then you have the ones on board that always denied the fact that it can sink and they are caught with their pants down.
You also have a smaller group that is prepared, acknowledge the fact, acts fast and survives.
(-:”
No, what you are referring to is those people who jump in the life boats the first time a storm splashes water onto the deck, crying ‘we’ve never seen a storm like this, we’re all gonna die!’. Or even worse, they just dive into the shark-infested sea.
@Stephen Fisher Rasey:
The sediments were derived from plankton in the euphotic zone which sank upon death to the depths. It’s not a problem that such great depths don’t in themselves record temperature changes to any extent.
There are issues with some of the plankton-based proxies though – the plankton bloom in spring (and to a lesser degree in autumn) and probably therefore record the temperature of the bloom phase if anything – and the bloom is in consequence of increasing availability of light acting on well-mixed surface ocean layers, not increasing temperatures.
Not sure might be going on in the tropical plankton cores – without seasonality and big blooms, the layers can’t be very thick – would be an interesting exercise to examine these.
Not sure *what* might be going on…
It is getting more evident as time passes on, that Tamino is not very good at basic stats.
This is reflected in his published literature as well, so should come as no surprise.
Skeptical Science Snydrome is a contagious disease, and he has a very bad case of it.
Andor says:
April 7, 2013 at 11:55 pm
Not at all correct. Let me help you a bit:
It is like being on a ship that is rocking slightly in the waves.
The honest engineers and true scientists (more than 31,000 of them!) have signed their names to a document that says “The ship has been rocking in the past, it is rocking now , and it will continue rocking in the future. Keep as many passengers as healthy as possible by using energy wisely by heating the ship, cooking their food, cleaning their clothes, and keeping the lights on.”
The government-funded CAGW alarmists and theocratic so-called “climate scientists” are screaming “The ship is rocking and so it might turn over and so we must turn off the engines and turn out the lights and flood the bilges to prevent the exhaust fumes from coming back into the engines when it turns over.”
The government-funded enviro extremists hear that warning – that they paid for! – and are creaming ” The ship is rocking violently and it will turn over and kill everybody therefore we must take everybody’s money and clothing and food and then throw everyone overboard into the icy water because otherwise a few of them might get cold if we don’t do anything. (But first I must go back to the first class lounge for my next environmental meeting and lobster dinner.) “
We’re arguing about the placement of the deck chairs on the Titanic. As has been pointed out early on with the Marcott release, that “scythe” graph is sobering.
Nancy Green’s analogy is very appropriate. If you put the 20th century spike into one of the marine sediment cores, it would be resolved as a single data point.
I demonstrated this here…
http://wattsupwiththat.com/2013/03/11/a-simple-test-of-marcott-et-al-2013/
The same principle also applies to the CO2 resolution in most of the Antarctic ice cores.
“However, adding spikes to the proxy data is an entirely different animal. The proxy data is an abstract representation of the proxy. It is numbers drawn on a sheet of paper or electronic equivalent.”
By adding an artificial signal to the time series gained from the proxies that does not have the same spectral characteristics as the original time series (one could as well say, not the same statistical properties), Tamino has created an entirely artificial time series that serves no scientific purpose at all; only a propagandistic purpose.
He must know that.
DonK31 says:
April 8, 2013 at 12:14 am
“For the sake of argument, let’s accept that Tamino found 3 other spikes in the temperature record. What that proves is that what he is calling the present spike is not unusual. It’s happened at least 3 times before in the past 10K years, and with even higher amplitudes. Just means that the present spike, if there is one, is not unprecedented.”
What? Tamino has created an artificial time series. He hasn’t “found” ANYTHING. Pay attention.
To the left of centre says:
April 7, 2013 at 11:51 pm
“…”
Are you sure?
http://www.politicalcompass.org
I found Tamino’s analysis breathtaking.. Triangular pulses 200 years long in a system with a maximum frequency response of 300year-1? No attentuation? Using proxies in environments with different temperature time constants? This seems to be completely wrong.
One thing that I find baffling is that it takes 20 minutes to compute 100 iterations of his “model”. Is he using an abacus?
The problem is that Tamino’s most delusionally devout and adoring acolyte is Grant Foster.
perhaps this has already been said but I believe a good way to summarize this is to say that Tamino has demonstrated that the *data reduction process* would not in and of itself eliminate high frequency spikes; however, the *proxy formation process* does.
A well-reasoned argument.
Anyone who still can’t grasp the point would do well to study this painting by Magritte.
http://en.wikipedia.org/wiki/The_Treachery_of_Images
Here’s a response from a warmy friend on another blog to me:
“No wonder you and your ilk assault the Marcott study, which conclusively shows that what we are seeing in our llfetimes is indeed unprecedented during the past 11 millenia. Oh, and smoke this while you’re at it: Tamino has shown that Marcott would indeed have detected any similar past spike in temperature. As he states, “Let’s find out, shall we?” (Tamino URL)
I’m done with your nonsense.”
At that point on April 5th, I decided to waste my time and look at Tamino’s analysis. At that time he made the claim that his added signal was 1/2 of the 0.9C to account for signal “loss”. Now that silly claim seems to have been deleted. Did anyone else read his original post before editing?
In one of his responses he says “Irregular time sampling enables you to get information at frequencies much much higher than the mean sampling rate, or even the maximum sampling rate. Those who don’t understand the impact of uneven time sampling often make your faulty claim” That is followed by completely inapplicable comments about nonuniform sampling of periodic signals. Looks like Tamino’s friends (if not Tamino himself) want us to believe that the climate signal is truly periodic, something they have been denying for years!
I have contemporary climate/weather observations for Britain covering the last 1000 years from which I am reconstructing CET back 1000AD -so far I am back to 1538.They are derived from a great number of sources and through extensive prersonal desk research.
These give a resolution of 1 year. However they are considered ‘anecdotal’ and greatly inferior to so called ‘scientific’ material deriving from such things as tree rings.
I can give the temperature spikes both upwards and downwards then link them to a likely event. For example Icelandic volcanoes that caused great cold were subsequetly noted in the archives of our great cathedrals who gave poor relief, or from crop records whereby famine might ensue.
It is very difficult to see that such events were long lasting.
tonyb
Well I posted a comment on Tamino’s blog when I first saw it, I don’t usually post comments on sites where I know I’m being critical of what is being said in case it comes across as trolling. The way I read the post the artificial addition of the spikes was being used to validate the Marcott uptick that we know is not robust. I said:
“I’m confused didn’t they say the 20th century reconstruction isn’t robust? To me you could introduce any amount of data flips you like if you’re using something that isn’t robust to start with you are just going to finish up with a diminished argument not something that somehow strengthens your beliefs.”
I got the following response from someone called Bern:
“Tamino’s point is simple: the premise that the analysis wouldn’t catch a spike of the magnitude we’re seeing in the modern instrumental record is false. As usual, the denialsphere made the claim without bothering to test it analytically. Understand?”
Further responses I made didn’t show up which is probably just as well because they exposed my rather lacking understanding of what was being discussed. This post provided the necessary clarity on the issue, thank you.
Where did these spikes come from if there were no people burning fossil fuels. And doesn’t the data show that the temperature of the planet was far warmer than it is now?
Louis-
“In trying to defend press release statements about the Marcott paper, Tamino is effectively calling Marcott a liar.”
Yup. I made this point over at Dot Earth-
“So, apparently Tamino argues that Marcott’s spectral analysis of Marcott’s reconstruction is wrong, in order to defend Marcott’s initial claim that modern temperature trends are unprecedented, even though Marcott later backed off that claim. Who’s on first again…?”
Here’s an analogy of Marcott’s argument, this time using music instead of Ms. Green’s planets (keep in mind that the lowest frequency component of chimes is 500 Hz):
A very old, degraded recording of an orchestra has a frequency limit of only 300 Hz.
I do not hear chimes when I play the recording.
My ears are capable of hearing chimes.
Therefore, if chimes were played by the orchestra, I would have heard them.
This is clearly a non sequitor.
Can someone tell me if the Climate Rapid Response Team ™ has been summoned to correct Mr. Grant’s errors…oh yeah, I forgot…
What possible mechanism could produce a spike that was that thin and hard to detect in the proxies? Do we have any reason, at all, to believe that such a spike exists? If it does exist how does that make the modern manmade spike any less threatening? Couldn’t it just stack with this mythical second spike mechanism, making it even worse?
And, most importantly, how do you disprove the existence of these past temperature spikes? It looks like that bottom-dwelling undying creationist argument that until someone builds a time machine nobody can know anything about the past and all opinions are therefore equal.
Anthony, the biggest and most obvious message of the study is being overlooked by sceptics. CAGW proponents have actually pulled much different stage magic here than pointed to by Nancy, getting everyone to debate useless details of the multi-millennial temperature trace as a diversion tactic. I’ve raised this before and so far no takers:
ONE LOOK AT THE MARCOTT ET AL GRAPH and what does one see. A temperature proxy that shows (assuming proper science) A SCARY, INEXORABLE SLIDE TOWARD THE NEXT ICE AGE!! This is what the Hockey Team saw at once. This is what motivated the apparently successful attempt to divert sceptics away from it and ruined the study in the process. Someone will do another study – maybe using the same proxies, get the same type of results and get a PhD concluding an approaching end to the Holocene – the reverse of the CAGW predictions.
The fact that Marcott et al didn’t even see the obvious is a measure of the remarkable blindness of the CAGW committed. Does anyone else here see this?