More on the Marcott et al “hockey stick”. All of the ‘Marcott 9’ had altered dates.
![marcott-A-1000[1]](http://wattsupwiththat.files.wordpress.com/2013/03/marcott-a-10001.jpg)
While it took me a while to get the time together to write an article about the Marcott paper, that does not mean I have not been looking at it and discussing it from nearly the day it was released. There has been volumes of discussion within The Right Climate Stuff group that I have been involved with. The ones that lean towards CO2 as something to be concerned about were initially rather excited about this paper, but that has taken a course correction as it has become clear how poor the science is in the Marcott paper.
Many skeptics are calling this the newest hockey stick and there is certainly some accuracy to that, but what I initially found interesting was the Holocene cooling that he shows. In one respect his paper is different because it shows the cooling that has been taking place for thousands of years. That also makes the stick at the end more extreme, but it is something most will not show.
For those who missed the details of the Marcott paper I will provide a brief summary. The paper was published on March 8th in the ultimate of peer-reviewed journals, Science Magazine. The paper was loudly broadcast by the media as further proof of global warming. The paper basically says that the most modern period of the Holocene (the current interglacial which the Marcott paper states as 11,300 years) has been warmer than ~75% of the Holocene. The paper states that this is especially significant as the Holocene has shown steady cooling for the past few thousand years, but that has now completely reversed. The conclusion is that mankind has drastically altered the natural climate of the Earth.
The paper itself is a composite of 73 different temperature proxies. These proxies were used to reconstruct the Earth’s climate over the past 11,300 years. The 73 proxies were not uniformly distributed around the world. The following is a summary of the spatial distribution.
Tropics: 33 proxies
NH Polar: 12 proxies
NH Mid: 20 proxies
NH Tropics: 16 proxies
SH Polar: 4 proxies
SH Mid: 9 proxies
SH Tropics: 12 proxies
NH Total: 48 proxies
SH Total: 25 proxies
The NH is over represented by 3x in the polar region and 2x in the mid-latitudes. This of course can be dealt with easily enough, but the real resolution in the NH is better than the SH. None of this is directly critical to the paper, but it is something worth noting.
Far more troublesome to the conclusion of the paper is the dating of the proxies. Other sites have some excellent write-ups on the re-dating in the paper itself and I will touch on it, but my more immediate concern is how recent most of the proxies are based on the published data of the proxies.
Here is the breakdown of the last date in the proxies he used.
1950+ 9 proxies (1960, 1970, 1991, 3x 1995, 1998, 1999, 2000)
1900-1950: 16 proxies
1800-1899: 11 proxies
1600-1799: 7 proxies
1000-1599: 14 proxies
< 1000: 15 proxies
This leaves one proxy (GeoB 3313-1) with the last known data of ~1750 AD. There are 3 data points for temp after that, but no dates associated.
Since the modern period by almost everyone is considered to be post 1950, only 9 of the 73 proxies contain any data that can be relevant to the global warming issue. Right away that concerned me, but when I looked at the data for those 9 proxies something very interesting became apparent.
I will be referring to those 9 proxies as the Marcott 9. They are perhaps the most interesting proxies that he used and those proxies disprove the conclusion of his paper. In order of the most modern data, the Marcott 9 are:
Lake 850, most recent data is from 2000.
Flarken Lake, most recent data is from 1999.
Lake Nujulla, most recent data is from 1998.
Tsuolbmajavri Lake, most recent data is from 1995.
Homestead Scarp, most recent data is from 1995
Mount Honey, most recent data is from 1995
Composite MD01-2421…, most recent data is from 1991
Moose Lake, most recent data is from 1970
Agassiz & Renland, most recent data is from 1960
What is most interesting about all of these proxies is that none of them show the warming result the paper ended up with. Not a single one.
Without further ado, here are charts for the Marcott 9.
These nine proxies are the only ones of the 73 that Marcott used that have data past 1950. The only one that shows any kind of warming is the last one which is the Agassiz-Renland ice core and the warm point was not the most recent, but the proxy from 1940. The last point which is 1960 shows as cooler than the data from 1940. The ice core certainly does indicate that the warming in the 1930-1940 period was impressive, but few claim that mankind caused that warming.
There is far more to discuss about this paper. I have an idea where I am going to go with my research, but others may beat me to it which will alter the path I take. Based on what information is being found by others, primarily by Steve McIntyre over at Climate Audit is that Marcott re-dated data that didn’t fit into the hockey-stick result.
This agrees with what I have found as well. All of the Marcott 9 had altered dates associated with the last date with the Moose Lake data changing the least at 20 years. Flarken and Tsuolbmajarvi Lake were moved back into the 1800’s and the MD01 Composite removed the last 3 data points. The end-point strategy for this paper was full of shenanigans. Since it is only the end-point data that matters to the conclusion of the paper, well, let the Marcott 9 speak for themselves.
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John Kehr is a Chemical Engineer by schooling and Research and Development Process Engineer by profession. He has more than a decade of experience at the cutting edge of technology for a large semiconductor company. That experience was critical for him while wading through the often contradictory information that exists about global warming. He was generally neutral about the subject of global warming until he met and married a wonderful woman who challenged him to make a choice.
There are few things more dangerous than challenging an engineer to make a choice like that on a scientific topic. While occasionally taking a break from research to breathe and go on getaways with his beautiful wife, he spent many months deeply involved in his research. When he finally reached his conclusion, the only logical thing was to put all that research into a book, The Inconvenient Skeptic
Related articles
- McIntyre finds the Marcott ‘trick’ – How long before Science has to retract Marcott et al? (wattsupwiththat.com)
- How Marcottian Upticks Arise (climateaudit.org)
- Hiding the Decline: MD01-2421 (climateaudit.org)
- The Marcott-Shakun Dating Service (climateaudit.org)
- Marcott’s hockey stick uptick mystery – it didn’t used to be there (wattsupwiththat.com)
Of course the Marcott study doesn’t tell you about warming past 1950. It was a study of the Holocene period. It used very long term proxies which do not have fine dating resolution.
For warming of the last century plus we have an extensive thermometer record. No need to look to proxies.
Any sign of the Marcott FAQ yet?
This post strongly suggests the FAQs are breeding at a rate faster than the authors can respond to.
Another decline that must be hidden?
No wonder Mann Ipulate was touting this as more evidence of hockey stick global warming, it was simply made to measure.
It’s bad enough when somebody cries “Wolf!” and none appears, but instead, a herd of Ice-Age Mastodons proceeds to trample your world. Marcott should be labeled as an empty wolf-crier.
Marcott’s “perturbations” are the 2nd key to his final output. After the final data were prepared, the last step was to permutate each datum 1000 times, using the age-uncertainty of that datum as bounds. Thus a datum dated 1700AD with an age-uncertainty of 100 years would be permutated into the range 1600AD-1800AD — thus its temperature value is distributed into those years. However, for the final 1940AD bin, Marcott set its age-uncertainty to zero. Therefore all those data were permutated only within the 1940AD bin. The result is that the 1940AD bin did not share its temperature values with its neighbors, and so was not flattened as were all other bins. It is just a mathematical trick which Marcotte used to guarantee that the 1940AD bin would preserve the same value after the perturbations, that it had before.
I have made this point repeatedly on other forums, but it seems to be outside of peoples’ understanding. In my field we work with large data all the time, and this method of perturbing is a substitute for doing excruciating statistical analysis. It smooths nicely, but to assign a governing zero-uncertainty to the end point of the distribution is an absolute abuse of the method. And this is the last time that I am posting on this topic.
Is it fraud to alter the dates to obtain a different conclusion to that which would be obtained had the dates not been ordered? Can a legal prosecution arise from this? It might be interesting to get a FOIA email dump from these guys to see what was discussed.
I think Marcott and Mann had orthogonal approaches to the hockey stick development.
Marcott adjusted the ‘x’ axis.
Mann adjusted the ‘y’ axis.
Well somebody had to say it!
Two suggestions: plot all proxies with the same Y-scale: Lake 850 only has a range of 2.5 deg C.
Lake Nujella squeezes 6 deg into the same space.
Create another set that zooms into the most recent 2063 years (YBP 2000 to today) and again uses a common Y-axis scale (cm per degree) would also expose the “shenanigans” (no more polite word for it).
Frankly, this “Years Before Present” while scientifically defensible, is an obfuscation to camouflage his shenanigans. If Marcott had shown the hockey stick at a year labeled “1940” instead of YBP 10, he would have been laughed out of the room. Instead, using YBP he attempts to fly under the radar to deliver his payload to the IPCC.
While I find the analysis of this paper by Steve McIntyre, John Kerr and others enlightening and instructional, I can’t help but note an amusing similarity between such analyses and a crash investigation of a kamikaze flight.
“All of the Marcott 9 had altered dates associated with the last date”
What are the odds of that being accidental and getting past the authors?
OT, Delingpole’s best ever. (See the last 3 paragraphs).
http://blogs.telegraph.co.uk/news/jamesdelingpole/100208918/global-warming-if-only-wed-listened-to-the-experts-eh/
Changing the data like this is either sloppiness, or deliberate fraud. Either way, it’s GIGO.
“Since it is only the end-point data that matters to the conclusion of the paper”
The end point is irrelevant to the conclusions of the paper.
REPLY: OK then, write to the journal, tell them to retract the paper, have Marcott remove the end point spike that has all the idiot journos in a tizzy, then republish it. Simple. – Anthony
Why would anyone use proxies in favour of actual temperature measurements when available?
There are numerous, supposedly rigorously adjusted & homogenised, temperature series from thermometers since the 1950s – why not use them, provided it is explained that this has been done (rather than hide any decline)?
Thanks for the summary. I’d like to see the same 9 after the re-dating. Do they show the kind of spike that shows in the final report? I wager there’s more to it, i.e. they also did something when setting up the parameters for the Monte-Carlo runs, or they re-dated some of the others to add data to the modern era.
the link to the book The Inconvenient Skeptic is broken
REPLY: Fixed thanks, wordpress can’t handle a missing http: – Anthony
“All of the Marcott 9 had altered dates associated with the last date with the Moose Lake data changing the least at 20 years.”
Does anyone have a plausible reason to offer for why the Marcott paper might legitimately do such wholesale altering of dates on the most recent data? Or did they think they could fool the world?
Given the controversial nature of the paper, and that others like it (Mann) have had – um – a chequered history, while others (Gergis) have had to be retracted, how come good folks like Steve McIntyre and John Kehr still have to spend time with these forensic dissections rather than it being the job of thesis advisors, peer reviewers or magazine editors?
Kudos to Steve, John et al; megaFAIL for the latter lot.
John Trigge (in Oz) says:
March 26, 2013 at 5:19 pm
Why would anyone use proxies in favour of actual temperature measurements when available?
There are numerous, supposedly rigorously adjusted & homogenised, temperature series from thermometers since the 1950s – why not use them, provided it is explained that this has been done (rather than hide any decline)
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Because we don’t have thermometer readings from 11,000 years ago and you should not splice thermometer records on to proxy records.
Not one dating error in favor of a non- AGW scenario? I’m sure the SI has a detailed justification an methodology for those date changes, when will Science release that information.
NZ Willy says:
March 26, 2013 at 4:42 pm
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Thanks, I’ve played around with many different smoothing methods to replicate Marcott’s end point and smoothed Holocene lines and couldn’t even come close so gave up.
Your explanation is the only thing that makes sense now, so thanks a bunch.
“John Trigge (in Oz) says:
Why would anyone use proxies in favour of actual temperature measurements when available?
There are numerous, supposedly rigorously adjusted & homogenised, temperature series from thermometers since the 1950s – why not use them, provided it is explained that this has been done (rather than hide any decline)?”
The instrumental record should be shown alongside the proxy data. However this may show that the proxy data does not align with the instrumental record and therefore indicate that one or more of these records is incorrect.
Stephen Rasey says: March 26, 2013 at 4:45 pm
“Create another set that zooms into the most recent 2063 years (YBP 2000 to today) and again uses a common Y-axis scale (cm per degree)”
Clay Marley says: March 26, 2013 at 5:25 pm
“Thanks for the summary. I’d like to see the same 9 after the re-dating. Do they show the kind of spike that shows in the final report?”
You can see them with re-dating here. You can set up a blink test to show the dating effect. There’s an option for last 2000 years, with common Y-axis.
Louis says: March 26, 2013 at 5:35 pm
‘“All of the Marcott 9 had altered dates associated with the last date with the Moose Lake data changing the least at 20 years.”
Does anyone have a plausible reason to offer for why the Marcott paper might legitimately do such wholesale altering of dates on the most recent data?’
Yes. All dates are inferred, by authors or others, usually from carbon dating. Marcott et al used the most recent programs to do this, systematically. The program they used (eg Marine09) won’t date beyond about 1954, because of atomic tests.
I found this article simply written, not too long and very useful. I was wondering what the fuss was about, and now I can see clearly. Thank you
Are some people really having trouble understanding that a low resolution proxy cannot have thermometer data spliced onto the end of it? For those who keep posting about it, the proxies are average temperature spanning decades but sometimes much longer on the scale of centuries. They will tend to smooth out more extreme temperature fluctuations over shorter periods that instrumental data can detect.
Nick Stokes in the grand tradition of the black knight, fights on….
Nick
Are you saying none of the underlying works calibrated dates correctly. And since you note the atomic tests, which show up as a hard and definitive marker in the cores – that you do not need any dating calibration for, how do you address Steve McIntyre’s noting finding a bomb spike in one of the cores Marcott substantially re-dated?
Have you been able to reproduce the hockey stick portion of the Marcott graph, and if so can you tell us how they managed to get that large hockey stick when none of their reconstructions contained anything close to that amount of warming?
The authors admitted at least the appearance of issues, and that they would issue a FAQ to address them. It would seem this should be a pretty simple task, yet weeks are passing and nothing has been forthcoming. How long is fair in you opinion to wait for this ‘clarification’ from the authors.
The author himself noted the recent reconstructions and conclusions therefrom were “not robust” and that the majority of the hockey stick came from a single record – Agassiz-Renland. Yet the authors and their institution have promoted the hockey stick as the featured and most important finding, when in reality they admit it is not “robust” and really shouldn’t be relied upon..
Seems we’ve heard that recently – where Lewandowsky pimped and promoted the sensationalized by minor finding of the paper, which like here was supported by the thinnest threads of data, which vanished altogether once the clearly scammed handful of responses were removed.
I wonder if we’ll see a similar ‘Recursive Fury in the Blogoshere over Marcott” follow on paper.;-)
Oh … and to all readers here – make sure you visit Nick’s site and try out his truly EXCELLENT Marcott visualization app.
You can look at a graph of all, and any, of the Marcott proxy’s data in a absolutely cool interactive app.
With the way this is shaping up, can these people be charged with fraud? I don’t understand why we allow such behaviour. This deserves much more than a slap on the wrist. If we don’t start making these “climate scientists” responsible, we give no incentive for the rest of them to “honest-up”.
NZ Willy says:
I am glad you posted–I am one of those that don’t understand the details, but i get the intent and I am very grateful for folks like you who bother to break it down and give it to us in more understandable terms.
Nick Stokes says: March 26, 2013 at 4:19 pm
For warming of the last century plus we have an extensive thermometer record. No need to look to proxies.
Niiiiick….yes, and the proxies are smoothed, by their nature (each point covering many years/decades) and by statistics ….. and the temperature record is not … (let’s call it spiky!)
So the appearance of an ‘end spike’ is simply an ‘illusion’ … if the rest of the record was equally spiky it would not even be noticeable.
Anthony Watts, I have sent via your ‘contact section’ a message on 25 March 2013 and 27 March 2013 … an urgent request of your permission to use some of your site content in a book I have written. I know this is not the place for this but it is important. Please contact me urgently. Thanks. Other readers, please excuse me for this.
[Reply: Suggest posting this comment under Tips & Notes, where Anthony is much more likely to read it. — mod.]
Nick’s hoping that no one can see the elephant in his room, which is that Marcott et al. is either a pile of shit, or scientific fraud – or both of course, since they’re not mutually exclusive.
A 12-year old could see that from the get-go. Fight on Black Knight. Bite someone’s legs off. Wanker.
A. Scott says: March 26, 2013 at 6:56 pm
“Have you been able to reproduce the hockey stick portion of the Marcott graph, and if so can you tell us how they managed to get that large hockey stick when none of their reconstructions contained anything close to that amount of warming?”
Yes, I described the process here. I get much the same spike with Marcott re-dating, and nothing much without. I think it’s pretty much as Steve Mc (and Tamino) says – the end result is very dependent on which proxies drop out when, and so very affected by re-dating. Personally, I think they just shouldn’t plot their proxy recons in the modern period. There’s too much room for end artefacts, and not enough data. And it’s not needed – the thermometer record is much more reliable.
On the bomb spike etc, I think what Marcott et al have done is to simply use the established programs (eg INTCAL09, MARINE09, based ob Calib 6) systematically. I think that’s advisable. There’s a separate issue of inferring a coretop condition, and a bomb spike might help there, if it can be precisely located.
I’ve noticed Mann seems to be avoiding any talk of Marcott et al on Twitter timeline since the flaws have been pointed out.
I’ve been using his favorite hashtags #extendedhockeystick & HSCW to attract attention to his audience.
Good article. Thanks.
Nick Stokes says:
March 26, 2013 at 4:19 pm
Of course the Marcott study doesn’t tell you about warming past 1950.
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You are splitting hairs in a less than honest fashion. Marcott adjusted the end dates of the proxies to 1950. Your spagetti graph of the proxies shows no pattern of modern warming, thus either debunking the modern thermometer record or Marcott. Time to call it like it is.
What the data shows is the temperatures have been falling of thousands of years and no significant modern warming within the resolution of the proxies. It is the adjusted the data post thesis that created the hockey stick.
It is hard to see how this is an error. Rather it appears to be a purposeful distortion with the earmarks of scientific fraud.
Anthony,
I apologize since this is slightly off topic, but it would be “cute” to capture the current humorous Weather Channel guy explaining why this cold March is actually caused by Global Warming.
I laughed out loud when he explained that since the US is only 2% of the area of the earth, the fact that March has been so cold in the US has no bearing on the fact that the globe is warming. Of course this is not the consistent with the story of last year when they repeatedly mentioned that the contiguous US set warm records as being due to global warming without mention of the 2% figure.
Then he went on to explain how the cold March was likely due to global warming being caused by ice melting and blocking highs causing the cold jet stream to dip further South.
Then finally he went on the point out that the warmest 10 out of 12 years (?) have occurred in recent years without mentioning that there has been no warming in the last 15+ years.
The Weather Channel has no integrity what so ever.
I laughed out loud, this would be great to capture, but I don’t have the technology to do so.
Delete if you feel appropriate.
Was this post supposed to contribute something that wasn’t said in the other dozen or so already done on the same subject?
Perhaps all can agree that
(a) Marcott said the final decades of the reconstruction are “not robust”, so maybe that means they are not robust.
(b) Thermometers have measured the warming in this century, which is generally what people are referring to when they talk about the recent increase in temperatures.
(c) The authors understand that their conclusions are limited by the lower resolution of the proxies: “Strategies to better resolve the full range of global temperature variability during the Holocene, particularly with regard to decadal to centennial time scales, will require better chronologic constraints…”
If the data from the proxies since 1950 do not match the observed temperature record, how useful can these proxies really be??? Isn’t this good reason to throw them out?
Nick: “For warming of the last century plus we have an extensive thermometer record. No need to look to proxies.”
Oh, good lord Nick, not you again!
A. The thermometer record disagrees with the proxy record.
B. If it disagrees now, then why would it not also disagree in the past.
C. How can we say that the current climate situation is different from the past climate situation when we don’t have thermometers in the past and when the proxy data shows that the current climate situation is not different from the past.
In the science community, do they really thing we’re going to buy the racial divide and conker strategy? I’ve been seeing a lot of this kind of news lately. The TV MSM doesn’t seem to want to touch it though.
Within Mainstream Environmentalist Groups, Diversity is Lacking
““We essentially have a racially segregated environmental movement,” said Van Jones, co-founder of the nonprofit Rebuild the Dream and a former adviser on green jobs to the Obama administration. “We’re too polite to say that. Instead, we say we have an environmental justice movement and a mainstream movement.””
http://www.washingtonpost.com/national/health-science/within-mainstream-environmentalist-groups-diversity-is-lacking/2013/03/24/c42664dc-9235-11e2-9cfd-36d6c9b5d7ad_story_1.html
Nick: “I get much the same spike with Marcott re-dating, and nothing much without.”
Good boy Nick. You are half way there.
“Personally, I think they just shouldn’t plot their proxy recons in the modern period. There’s too much room for end artefacts, and not enough data.”
And it’s particularly embarassing that the “end artefacts” for all the different kinds of proxies seem to all disagree with the highly “adjusted” temperature records. There seem to be no proxies at all that show the same kind of temperature spike as the instrumentation record. As far as “not enough data” goes, I assume that all of the physical processes that were producing proxies 11,000 years ago are still doing so today.
Now, Nick, I guess that you will have to go to work to find rationalizations for why every one of those proxies has an “end artefact” that is always less than the instrument record.
Catcracking: He said “ice melting?” Where? Certainly not in the arctic. Does this guy at TWC feel his audience is that stupid?
Leo: (a) Marcott said the final decades of the reconstruction are “not robust”, so maybe that means they are not robust.
Without a good explanation, maybe it means that they were never robust.
You could claim that they were robust in the past because they agree with the other proxies of the past and that they are not robust today because they disagree with the instrument record today; but the problem is that the other proxies that you are comparing them to in the past also don’t agree with the instrument records today. So obviously you can’t say anything about robustness in the past. Or, alternately, you could claim that all the proxies support each other and are, therefore, robust while the instrument record is not.
ferd berple says:March 26, 2013 at 8:07 pm
“You are splitting hairs in a less than honest fashion. Marcott adjusted the end dates of the proxies to 1950. Your spagetti graph of the proxies shows no pattern of modern warming, thus either debunking the modern thermometer record or Marcott.”
Well, they are certainly not debunking the thermometer record. Nor are they debunking Marcott – the proxies aren’t his.
The fact is, they are low resolution. That generally means they are not perfectly layered. There has been mixing between layers – apart from the issue of determining the date, at the same layer there is a mixture of date material. And as this post says, on author dating only 9 proxies extend beyond 1950 (on Marcott dating, none). On that basis they just couldn’t detect modern warming.
Marcott was doing a study of the Holocene. He chose proxies that were stable over long periods and could be independently calibrated (ie did not require overlap with historic thermometer measurements). He could not have that plus the resolution needed to detect modern warming.
@cbk: If the proxies don’t match the observe temperaure record then, there is a) noise in the proxies, b) noise in the observed anomally temperature record, or c) noise in both.
Stick a 50 year moving average filter on the observed temperature record to make it appear closer to the resolution of the highest resolution proxy. Then debate how much of that smoothed signal is microsite and UHI increase over the past 100 years – from Watts et al 2012 it might be 1.5 deg C / century. Take what’s left and extend by slope only the Marcott trend from the time period where he is down to 20 proxies. It will be less a hockey stick and more of a spoon.
“Of course the Marcott study doesn’t tell you about warming past 1950. It was a study of the Holocene period. It used very long term proxies which do not have fine dating resolution.
For warming of the last century plus we have an extensive thermometer record. No need to look to proxies.”
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yes we have a good thermometer record. So, lets see how good the proxies are?
after all if they cant get the present correct, what good are they for the past
“For warming of the last century plus we have an extensive thermometer record.”
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Hahaha! what a joke. Moving thermometers,More 2/3 world without moving thermometers. in case you didn’t noticed it is called sea. Maybe you can tell me the temperature of last 200 years outside cities of Europe and some in Asia and US… I am not even going into cloud cover, wind changes and temperature variations in altitude. You know there is a third dimension.
All of this to claim 0.x degrees of change. It is a social construct and you Nick Stokes only have that opinion because you value your social life more. Because many professions are increasingly more social and less scientific.
Karl says:
March 26, 2013 at 8:56 pm … Catcracking: He said “ice melting?” Where? Certainly not in the arctic. Does this guy at TWC feel his audience is that stupid?
Answer YES. The smart man on the TV said black was white (or was it vice-versa?) so to non inquiring minds it must be true. Mission accomplished.
Tilo Reber says: March 26, 2013 at 8:52 pm
“There seem to be no proxies at all that show the same kind of temperature spike as the instrumentation record.”
Let me give you an idea of what low resolution means. Of the proxies here:
Lake 850 has its most recent readings at
2000, 1950 then 1800. They are 9.43, 9.47 a,d 9.96°C respectively
Flaren Lake has most recent readings at
2000, 1770 and 1543 (5.74, 6.15 and 5.6°C)
Lake Nujulla
1998,1794, 1691 (7.31,8.19,8.28°C)
Tsuolbmarjavri Lake
1995, 1920, 1822 (11.42, 11.56, 11.40°C)
etc
How could they ever pick up the warming of the last 40 years?
My TV report on this paper is here:
http://www.kusi.com/videoclipId?=86191808autostart=true
Not deep science, but a challenge to the process and conclusions of the paper.
Change that http to
http://www.kusi.com/videoclpId?=8619808autostart=true
I re-iterate what Steven Mosher said. “[A]fter all if they cant get the present correct, what good are they for the past.”
There really isn’t enough focus given to that glaring issue.
Nick Stokes, you mean Marcott was only interested in the Holocene so we could discover again that there was still a Holocene Climatic Optimum despite heavy smoothing… and trying to make it smaller than the 20th century warming? Woaw. All this for that?
Funny you show up here after being sent packing on climateaudit…
hide the decline
Steven Mosher says: March 26, 2013 at 9:22 pm
“after all if they cant get the present correct, what good are they for the past”
Expecting them to determine modern warming is like expecting a telescope to find bacteria. A telescope is a fine optical instrument that can see a long way. But if it can’t see the bacteria do you:
say they don’t exist?
throw the telescope away?
reach for a microscope?
I bet you could get a better hockey stick out of Jackson Pollock’s work.
10th rate scientists trying to pretend they’re not 10th rate scientists, in public even, is getting kinda embarrassing.
[snip]
Tilo Reber says:
You mean an explanation like the one they gave in the paper in the sentence that included the words “not robust”?
There’s no shortage of people demonstrating the effect of the small number of records (such as McIntyre in some of those dozen posts here), although I think this one does it best:
http://tamino.wordpress.com/2013/03/22/the-tick/
Obviously you can’t use an uptick that is exaggerated because of a small number of records to imply a problem with robustness where there are a large number of records…
The better question to ask is whether a temperature increase like the one clearly measured by the instrument record in this century could go undetected back in the past because of the low temporal resolution. Co-author Shakun has commented on this elsewhere:
http://blogs.discovermagazine.com/imageo/2013/03/13/art-of-the-anthropocene-the-scythe
Catcracking says:
March 26, 2013 at 8:11 pm
Anthony,
I apologize since this is slightly off topic, but it would be “cute” to capture the current humorous Weather Channel guy explaining why this cold March is actually caused by Global Warming.
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Cat, I don’t know if Anthony will, but some pinhead in Guardian was spewing similar stuff.. You might be interested in this post….. http://suyts.wordpress.com/2013/03/26/warmcold-strikes-again-lack-of-ice-blamed-for-snow-and-cold-climate-math-on-display-15-is-20-of-16/
“Modern warming” is what they trumpeted in media. In a very “newspeak” Orwellian way you now say what they trumpeted has no relevance.
Comment was for Nick Stokes March 26, 2013 at 10:12 pm
@NZ Willy March 26, 2013 at 4:42 pm:
I’ve made a similar point about multiproxy reconstructions.
Say one is including 30 proxies. If the dating of each proxy’s peak or ‘valley’ varies by a few years, back 200+ years ago, then each proixy HAS a peak or valley. But when blended/averaged/homogenized, even with the correct temp values, the peaks being spread out on the time line, over decades or even centuries, the peaks will be flattened out, by being aligned in time with other proxies’ non-peaks. Thus the process artificially flattens peaks and valleys.
I am 100% certain that Mann’s super-flat slow decline (before the hockey stick blade upturn) was due to this, in major part. He didn’t even HAVE to try to flatten them – the process did it automatically. Peaks were erased by averaging and uncertain dates not aligning in time.
But similar to what you say, the instrument record doesn’t have this uncertainty, so recent peaks exist where older ones don’t. Even when the peaks are in all the individual proxies.
Don’t feel bad – I’ve had my comments on this end up in the void, too. Some day someone will wake up to both our points.
Steve Garcia
For those of you that are saying that reconstructions are not needed for the modern period because we have accurate temperature data, the obvious reason is that you are comparing apples to oranges. The other reason is that reconstructions have a tendency to smooth the yearly/decadal spikes that occur in the temperature record.
I’ll bet when the modern temp record gets smoothed on a century scale that the modern spike disappears.
Re dated? … So if the data doesn’t fit, alter it so that it fits and claim it as proof of something?
Some would consider that as outright fraud.
Why does “Marcott 9 from outer space” come to mind?
The thing that intrigues me about farcical papers like this is what makes the authors think they can get away with it. I can only assume that having seen an earlier generation of alarmists achieve success via far more outrageous activities, they have a sense of entitlement: ‘they did it, why can’t we?’
So I wrote a song about it. Those of you fortunate enough to have forgotten the original can find it here:
There’s a little group sending in a paper to the journal Science.
It’s been torn to shreds by wiser heads, but they’re still shouting out in defiance.
“Other people publish series that are equally crap and they end up with fortune and fame…
What about us? It isn’t fair!
When Michael Mann did it no-one seemed to care!
PhD’s! That’s all we want!
And a stonking great big grant!”
Now there’s a commentator writing in support of the paper to the climate blog Watts Up With That.
He admits there’s mistakes, but hey, that’s the breaks; he’s got all of his excuses down pat.
“So what if it’s wrong? Can’t we all get along? Can’t we give the poor fellow a break?
Don’t be rude! It isn’t kind!
When Phil Jones did it no-one seemed to mind.
Misconduct in science is such a little charge
When Peter Gleick is still at large!”
@NZ Willy March 26, 2013 at 4:42 pm
So basically Marcott et al. were sticking the end of the spaghetti to the wall and then forming the hockey stick out of the rest of the spaghetti? Maybe we should call this “the Marcott sticky trick”?
Perhaps then, since the authors clearly and publicly ADMIT the KNEW the recent proxy value was not robust – and their hockey stick was essentially an artifact unsupported by the data – they should NOT have made the hockey stick and the recent warning the focus of the paper and their claims.
One might paraphrase:
‘Yeah, we know we have little data to support it and we admit our work with that scant data is admittedly not robust, but HEY LOOK AT THAT! ITS UNPRECEDENTED – A HOCKEY STICK! We gotta so something or we’re all gonna die …’
Expecting [very low resolution proxies] to determine modern warming is like expecting a telescope to find bacteria. A telescope is a fine optical instrument that can see a long way. But if it can’t see the bacteria do you:say they don’t exist? throw the telescope away? reach for a microscope?
But apparently it’s useful to look through the telescopes in order to compare bacteria on another planet to that visible in the microscopes. Thanks for the analogy.
Take away the splicing that should never be done and what are you left with?
The end of the Holocene is nigh!
Be afraid, be very afraid.
Pethefin (March 27, 2013 at 12:07 am) says: So basically Marcott et al. were sticking the end of the spaghetti to the wall and then forming the hockey stick out of the rest of the spaghetti? Maybe we should call this “the Marcott sticky trick”?
That’s a fair analogy and monicker. Indeed they did affix the 1940-bin temperature (because they knew that their perturbation algorithm would not change that temperature), and then the rest of the Holocene got flattened. Before the 1000x perturbations, 0.8C rises & falls are common in the trendline — but afterwards, only the 1940-bin 0.8C rise was left — because the perturbations, by design, didn’t touch the final (1940) bin, as I explained above. As the old poem says,
There once was a group called The Team
Who invented the climate change meme
But the data didn’t work
So they made it all up
And flatlined the whole Holocene
I can recommend John Kehr’s book for the aspiring layman. He does belabour the point at times but I guess that is me becoming more knowledgeable. 🙂
Nick Stokes, to compare the instrumental record to these proxies, one should use a 300 year (or so) moving average. Which means that NONE of the the headlines about the current temperature or rate of warming that this paper has generated make any sense at all. And anyone with a minimum of statistics understanding should know that.
NZ Willy makes a good point. The Monte-Carlo procedure they use essentially smooths out the central part but acts like a skipping rope fixing the end point at a 1940 high. Marcott then interpolates all proxies to a 20 year time-base. I think it is always wrong to interpolate proxy data because any scheme that increases the time resolution over that of the actual measurements is bound to introduce biases. In other words Marcott generates pseudo-data instead of using the measured data directly.
The best you can do is to make a time histogram of the measured data with fixed time binning. I did that for a 50 year binning and there is no uptick in the data. see : http://clivebest.com/blog/?p=4790 !
Steve Mosher says, “yes we have a good thermometer record. So, lets see how good the proxies are? after all if they cant get the present correct, what good are they for the past”
Surprised that you got into that issue. By my understanding a) these proxies can be independently calibrated and b) their resolution in most cases is greater than the length of the modern era. Accordingly overlap is unnecessary and inappropriate.
I fear that Nick Stokes finds himself on the correct side of this portion of the Mrcott debate and I do hope you’ll set me straight.
Espen says: March 27, 2013 at 12:53 am
“Nick Stokes, to compare the instrumental record to these proxies, one should use a 300 year (or so) moving average.”
We know the temperature history of the last century plus. There’s no reason to pretend we don’t because of the low resolution of some proxies.
It’s true that the Holocene story has to be interpreted carefully in the light of that low resolution. Marcott et al in their abstract said:
“Current global temperatures of the past decade have not yet exceeded peak interglacial values but are warmer than during ~75% of the Holocene temperature history.”
And the press release, reflecting that, was headed:
“Earth Is Warmer Today Than During 70 to 80 Percent of the Past 11,300 Years”
Neither of those statements would be negated by high frequency fluctuations.
Give them the modern temperature data. Tack it on to the proxies. But then smooth working backwards from the present day. Do it for three hundred year intervals. So the average temperature between 1713 to 2013 would be one data point. 1413 to 1713 another. 1113 to 1413 another etc. In that way all data periods would be smoothed equally.
Of course, doing it that way would make it all too obvious that even if we have had a minor uptick in temperature for fifty years or so — that it has really been nothing but “weather”. All those other 300 year periods probably had just as much internal variance that averaging also eliminated.
It seems to me if the intent of that paper was to study the long term temperature record over many thousands of years that would be how you would do it. You would go out of your way to avoid getting into the hockey stick controversy.
It also seems to me that if your real intent was to create a hockey stick you would do it like those clowns did. That paper is not about long term temperature. It is all about creating a hockey stick and grabbing headlines..
So they lie when they say this is a study of the earth’s temperature over the long run. No such thing. That is window dressing. The paper is about creating a hockey stick. The proof is that all this controversy could have been very easily avoided — and instead they went out of their way to create the controversy.
Motive is obvious here. These are corrupt people.
Eugene WR Gallun
ckb says:
March 26, 2013 at 8:20 pm
If the data from the proxies since 1950 do not match the observed temperature record, how useful can these proxies really be??? Isn’t this good reason to throw them out?
///////////////////////////////////////////////////////
Spot on. Personally, I attach next to no worth to proxies/proxy reconstructions due to uncertainties and errors. Most proxies respond to the environment in which they are living and whether that current environment is or is not favourable to them. Temperature is but one facet of environmental conditions and it is a near impossible task to isolate response solely to temperature.
This is the same point with Mann’s hockey stick where post 1960 tree ring proxies showed declining (not rising) temperatures. . It goes to proxy tuning (ie., it indicates whether the proxies have been well tuned or not to what we think that we know about temperature with a reasonable degree of certainty and it goes to proxy worth (whether the proxies validly seperate the temperature signal from their response to environmental conditions in general, ie., whether they are good temperature indicators). In teh case of Mann’s tree ring proxies which showed a decline in temperatures post 1960, Mann immediately knew from this the following:
1. If the post 1960 thermometer record was accurate, since the tree proxies were not showing a response consistent with the thermoter record, either there was a temperature tuning problem, or that his proxies were not seperating a response to temperature from a response to environmental conditions in general; or
2. If his proxies were well tuned and were validly seperating the response to temperature from the general response to environmental conditions in general, then the post 1960 temperature record was wrong (eg., possibly due to contamination from UHI or corruption from erroneous adjustments made to raw data).
If the former, the proxies should have been thrown out.
The same applies to Marcott. If his most recent proxies do not match the current thermometer record, there is either a problem with proxy tuning, or proxy worth or the current thermometer record. Given the low resolution of these proxies (and their smoothing trend) the fact that the mosts recent proxies do not show post 1950 warming tells us little about either proxy tuning or proxy worth. But is does tell us that it is wholly unacceptable to splice on the current thermometer record. It is always unacceptable to splice results from one proxy data series onto another and proxy data record and suggest that that somehow gives apicture of the whole. It does not. But it is especially inappropriate when the main proxy record is showing devivergence from the record that one wishes to splice on.
What Nick Stokes seems to overlook is that we do not know what the thermometer record would show if it went back further in time. It is quite conceivable that if it did go back further in time it would show a MWP say 1.5 to 2 degC warmer than today, Roman and Minoan warm periods say some 2.5 degrees C warmer than today and a Holocene Optimum some 5 degrees warmer than today. It might show that current temperatures are cooler than say 75% of the Holocene and that in the past there were periods with much greater and rapid warming/temperature changes. He (appears to me) to think that we can look at Marcott and accept that data as an accurate account of temperatures during the Holocene prior to about 1950. So from Marcott we now have a good temperature record of past event. We can then use the thermometer record (which ‘we’ know to be ‘good’) to put Marcott in context and to consider how today’s temperatures fit into the overall shape of the Holocene. We cannot. It is an invalid comparison. We need to come back in 300 to 500 years time and look at Marcott’s proxies for the period post 1950. When this is done, it may well be that those proxies would show no 1950 – 2020 warming, possibly even a cooling. If that is what they show then we would have a much better indication to what extent Marcott’s proxies were properly tuned and/or had worth. We might conclude from that the Holocene stick is rather depressed and that it should have showed more past warming but did not due to problems with the proxies.
Nick can’t enjoy making a fool of himself. So why does he do it?
==============================
Nick Stokes says
“Of course the Marcott study doesn’t tell you about warming past 1950. It was a study of the Holocene period. It used very long term proxies which do not have fine dating resolution”.
Nice try, Nick. You have a real gift for misdirection.
Have you ever considered a career as a magician, or perhaps even, a conman?
The bottom line here, is that without the spike at the end, this paper would never have seen the light of day.
Marcott’s rider about the spike being “unreliable”, is simply a fig-leaf to cover his embarrassment about that!
The proper names for the axes of a 2D map are ordinate and abcissa indicating the dependent and independent variables that are not necessarily ‘X’ or ‘Y’.
I still think not enough attention has been given between the glaring difference between Marcott’s original thesis and his subsequent paper.
Someone in the Global Warming Industry is responsible for the Hockey Stick being grafted on and then for the careful orchestration of the warmist section of the world’s media to trumpet the ‘proof’ that Mann was right all along.
While there is clearly a lot of statistical fraud/misinformation in Marcott’s paper, it is the grafting on of the Hockey Stick which most worries me.
I suspect Marcott is only a puppet here, we need to find the puppeteer.
@ NickStokes Isn’t the really interesting part of climate science that all the “proxies” are showing a cooling trend yet the “Temperature” data supplied by CRU and Hansen shows a warming.
Hmmmmm
Nick Stokes: How can they compare the last decade to the last 1000 decades when they don’t have the necessary resolution? If temperatures drop again over the next 50 years, 5000 years from now scientists using similar methods will only see the LIA when they look at their proxy reconstruction for the year 2012.
So the temperature goes up, the proxies go down.
So the proxies don’t reflect temperature when we can measure temperature, so why use them when we cannot?
Please do not be discouraged! There are a number of us who read your posts here and I believe at CA, and said to ourselves; ‘excellent point and great spotting of tricky methods’. I, for one, appreciate your insights.
Ann Banisher says:
March 26, 2013 at 10:43 pm
For those of you that are saying that reconstructions are not needed for the modern period because we have accurate temperature data, the obvious reason is that you are comparing apples to oranges. The other reason is that reconstructions have a tendency to smooth the yearly/decadal spikes that occur in the temperature record.
I’ll bet when the modern temp record gets smoothed on a century scale that the modern spike disappears.
=================================
Indeed it does, Ann. http://suyts.wordpress.com/2013/03/11/the-dagger-in-the-heart-maybe-a-remedial-explanation-of-marcotts-hs-blade-mikey-whats-that-about-a-dagger/
“…we can’t be sure there aren’t any abrupt global warming blips…”
Oh yes, very definitive scientific statement. A simple, “We don’t know” would’ve sufficed.
“…high resolution proxy climate records…”
“…if abrupt global warming events happened in the past, then we might expect these local records to show them…”
“…but my sense is they don’t…”
Another firm “not robust” scientific statement.
—First the smoke by referring to ‘undefined other’
—Then the diversion with ‘possible’
—Then the coup de grace, a swap to a very vague, maybe if forced to, undefined ‘wager’.
What is that a bet on? That the Holocene has global events like today? Or not?
Want to buy a car? It is a used car, maybe; but if I have to, I’ll wager not abused, if the records might not have high enough resolution…
Inferred
Assumed
Supposed
Modeled
Perturbed
on and on an on
I’d like to see/hear/read Proved! When the CAGW team says ‘Robust’, they mean it isn’t solid proof and they want us to move along and not look closely as the details are maybes mights and beliefs. When that same team says “Not robust”; just whatin’ell do they mean then? Fractured Fairy Tales comes to mind…
Here’s a direct analogy:
I bought my car in 2009. Every few months I write down the average fuel economy as recorded on the dash and reset it. This is the low resolution proxy data. It varies slightly based on whether I was driving around town or taking a trip, whether it’s winter or summer, and I can see the drop in mileage from that time the alignment was really off, but usually it’s around 22MPG.
Today, while driving on the highway, I reset the average and watched it climb to about 35MPG.
My conclusion from this cannot realistically be that my car has suddenly experienced a leap in fuel economy. Obviously, that would be a ridiculous conclusion. This is exactly the same as looking at long term low resolution temperature proxies and attaching a short term instrumental record to it. And honestly, I can’t even imagine any sane individual thinking you can do that and get any sort of meaningful result.
Correction: not a scientifically meaningful result. I could get a decent “political” result…
False analogy. Better analogy. Proxies are like using a magnifying glass to look for bacteria. Eureka says the boy, none exist! Then along come telescopes and they find them.
Both are looking for the same thing. Your analogy says the proxies are not looking for the same thing as the temperature records. I think most Climate scientists would disagree with you.
Reblogged this on Climate Daily.
I think NS represents the awful poor state of primary and secondary education science in Australia which has been extended into the higher education area and people are given virtual degrees LOL
Nick Stokes, always the optimist.
Not anything to say re: Marcott et al but I did read John Kehr’s book “An Inconvenient Skeptic” and really enjoyed it. Any body else have a positive opinion?
The paper was mostly about the Holocene?
Baloney. Run on a cubic spline fit on Marcott’s (date-adjusted) Holocene proxies that preserves all the datapoints within 200 years and you get +2.0C in the Holocene. Change it to 20 years as Marcott’s temperature stack uses and you still get close to 2.0C (as well as other known climate changes such as the 8200 BP cold spike etc).
Somehow Marcott got 0.4C in the Holocene with this ridiculous method and no MWP and no LIA and an artificial 0.9C CO2 spike at the end. A flat line pointing down with a blade at the end. I wonder what well-known shape he was trying to get.
When I click on the Nick Stokes app link (nice work Nick) I see temperature proxies with a noise level of +/- 1.0 deg C and a gentle long term drop toward the present. Who would ever consider using this data set in a PhD thesis let alone publishing it in a major rag? All it proves to me is that the temperature proxies Marcott used are worthless (not enough signal, too much noise). Oh, and no hint of a hockey stick 😉
Another treatise on the Shakun Bake paper. When seeing the actual data in this naked way, one wonders how he would set about creating the stick blade. Man, these guys sure aren’t daunted or held back by scruples.
Nick Stokes says:
March 26, 2013 at 4:19 pm
“Of course the Marcott study doesn’t tell you about warming past 1950. It was a study of the Holocene period. It used very long term proxies which do not have fine dating resolution.
For warming of the last century plus we have an extensive thermometer record. No need to look to proxies.”
I get your general point Nick Stokes but two points: 1) he did wind up with a paper on global warming since 1950 in the bargain and 2) We should be a heck of a lot more critical about the legitimacy of proxies. As with the tree rings of Mann, if their is a big decline where it is supposed to go the other way with the recent record, wouldn’t you ask yourself if the first part indeed represents what we confidently think it does?
Nick Stokes: “Of course the Marcott study doesn’t tell you about warming past 1950. It was a study of the Holocene period.” Then why is there so much ink to the right of the 1950’s in their graph as shown at the top of this article? And why did the authors, when interviewed, concentrate on the data after the 1950’s? And why have the headlines dwelt on the data after then 1950’s?
The paper obviously has a de jure and a de facto result. The official, de jure result that defenders such as yourself point to is something about the Holocene. The actual, de facto result is that things have warmed since 1950 so rapidly that it’s “unprecedented” in the last 11,000 years. When skeptics point out that the data is low-resolution data spliced with recent high-resolution data and this throws everything off, defenders say, “Hey, this paper isn’t about the present, it’s about the distant past.” That’s not the way the paper has been used or promoted by its authors, and it has nothing to do with the hockey stick graph in the top figure.
As I mentioned on CA. This paper doesn’t seem very useful for anything. The modern portion is not robust, according to the lead author, so we can ignore that. The rest of the Holocene is such low resolution and so heavily smoothed that it tells us absolutely nothing about scope and rate of climate changes during the reference period. Therefore it can’t tell us whether modern warming, such as it is, is unprecedented in any respect.
Correction, it’s useful for propaganda, that’s all.
Nick Stokes says:
March 27, 2013 at 1:46 am
True, but your very argument destroys your supposition–that today’s warmer Earth was caused by man’s influence.
During the past 11,300 years, everybody agrees we’ve had several periods of warming. They are the:
1) Medieval Warm Period
2) Roman and Minoan Warm Periods
3) Holocene Optimum.
NONE of these was caused by man’s influence–NONE! So we could just as well add the:
4) Modern Warm Period.
What’s not to like, right? Trees are growing faster, foodstuff crops are more productive–the whole biosphere is doing better overall. This current warming isn’t unprecedented at all but very much beneficial.
So your argument that we’re in another warming period similar to others destroys the very thing you want to blame it on because it’s happened several times before WITHOUT that causation!
Interesting paper by Marcott et al, Mr. Stokes–only it doesn’t necessarily prove what you think it does; it indicates just the opposite–man isn’t the problem (although in this case I suspect Mann is, sadly).
They would be negated because the current “warming” would simply be a high frequency fluctuation smoothed out by the low temporal resolution of the rest of the recon.
ferd berple says:
March 26, 2013 at 8:07 pm
Nick Stokes says:
March 26, 2013 at 4:19 pm
Of course the Marcott study doesn’t tell you about warming past 1950.
Nick,
If Marcott had simply done his work AND not added the temperature record, the paper would not have drawn arrows. He/they chose to use it to make a conclusion about CAGW issues.
Any report is just blah blah without conclusions (I’d argue recommendations, also). Truth, as James noted, has to be useful and take you somewhere to be worthy of the word. The Marcott thesis did not have the modifications and was not applicable to the conclusions. It is legitimate to jump all over the paper for what was added was targeted for the end result: CO2 is killing the planet.
Good intentions or not, the paper should be withdrawn.
Without the “spike” Marcott’s paper would have been seen as quite detrimental to the whole CAGW story, showing as it did that a significant part of the early Holocene was warmer than today.
I feel a bit sorry for poor Marcott … there appears to be some awfully naive/deceptive data adjustment in there, but it seems possible that this “spike” is perhaps not the most important part of the work he/she wanted to show, and it may have been a product of the way the work got past the ‘peer review’ process.
I’m having soooooo much fun watching Nick Stokes making a fool of himself trying to justify Marcott’s methods.
Nick, I know you’re not stupid but you’re making it hard for me to justify my faith.
Nick Stokes says:
March 26, 2013 at 9:05 pm
Marcott was doing a study of the Holocene. He chose proxies that were stable over long periods and could be independently calibrated (ie did not require overlap with historic thermometer measurements). He could not have that plus the resolution needed to detect modern warming.
Nick take a deep breath and look what coalsoffire posted above:
coalsoffire says:
March 26, 2013 at 6:45 pm
Nick Stokes in the grand tradition of the black knight, fights on….
You are pretty much making exactly the same scene again and again. It has been explained to you several times, but you still come back with the same, not answering or acknowledging what people tell you.
Nick such useless stubbornness to acknowledge the reality does not help your cause, whatever that is. Of course you may continue to entertain us if you chose so, however you can do better.
NZ Willy: Marcott’s “perturbations” are the 2nd key to his final output. After the final data were prepared, the last step was to permutate each datum 1000 times, using the age-uncertainty of that datum as bounds. Thus a datum dated 1700AD with an age-uncertainty of 100 years would be permutated into the range 1600AD-1800AD — thus its temperature value is distributed into those years. However, for the final 1940AD bin, Marcott set its age-uncertainty to zero. Therefore all those data were permutated only within the 1940AD bin. The result is that the 1940AD bin did not share its temperature values with its neighbors, and so was not flattened as were all other bins. It is just a mathematical trick which Marcotte used to guarantee that the 1940AD bin would preserve the same value after the perturbations, that it had before.
Don’t we need their code to be sure of that?
Nick Stokes: Of course the Marcott study doesn’t tell you about warming past 1950. It was a study of the Holocene period. It used very long term proxies which do not have fine dating resolution.
For warming of the last century plus we have an extensive thermometer record. No need to look to proxies.
That has been said many times and many ways: what is most noteworthy in their report is not supported by their data, and what is supported by their data would (probably) not have been considered interesting enough to gain acceptance in Science.
Nick Stokes says….:
Nick, your presentation of Marcott, et al.’s proxy data at Moyhu.blogspot.com is phenomenal. You have a gift for data presentation. Everyone should check it out:
http://www.moyhu.blogspot.com/2013/03/proxy-viewer-with-choice-of-dating-and.html
However, I’m disappointed you are unable to come to terms with exactly what Marcott, et al. did:
1. They shifted the known dates of selected cores by up to 1000 years to produce a pronounced spike in 20th century temperatures. The un-shifted data shows the exact opposite: a pronounced decrease in 20th century temperatures.
2. They deleted (truncated) relevant data from selected proxies. Had this data been included, it would have dampened or cancelled out their 20th century temperature spike.
3. They held press conferences and trumpeted their results agreed with (and vinidicated) Michael Mann’s fraudulent MBH 98 paleotemperature reconstruction.
These were all done to produce a predetermined, desired outcome. This is ‘Scientific Fraud 101’. Manipulating data to produce a predetermined, desired outcome is the very definition of scientific fraud.
As for your statement:
“For warming of the last century plus we have an extensive thermometer record. No need to look to proxies.”
Thermometer readings and proxy data are apples and oranges. Nearly all the proxy data shows recent temperatures declining. Recent thermometer readings show it rising. Grafting thermometer readings onto proxy data is just another variation of Mike Mann’s ‘hide the decline’ Nature trick. It smacks of attaching an orangutan jaw to a human skull to make scientific headlines.
I did hear a rumor that a certain public climate scientist was a reviewer for this paper and i wonder what he or she advised needed to be added ammended or altered so the paper was publishable? I’m sure to make it a better paper and all.
And look at the result. Maybe someone should ask to look at the reviewers comments?
Louis,
I’m glad you liked the viewer – thanks. On Marcott, I certainly don’t think it is a perfect paper. I’ve said many times that I don’t think they should have plotted recent results (eg 29th Cen), spike or not. Too few data and too many end effects.
But I think many criticisms are misplaced, and I say so. There’s nothing intrinsically wrong with re-dating. The original observations are of depth, proxy reading and C14 ratios at date points. The actual dating is done by programs like this. Those programs get updated – they incorporate observational data which improves. It’s very reasonable to want all data using the same (modern) version.
I don’t jump to the conclusion that this was done for some conspiratorial reason. It doesn’t even work on that level. When I first saw they spike plot I thought – that looks odd, why are there two spikes? And then, but hang on, there actually wasn’t a heat spike in 1940.
The “deletion” of data is mainly consistency. The carbon dating program won’t report dates beyond 1950. Should they make them up? In one case complained of (OCE326-GGC30), the original author had eight different readings all assigned a date of 0BP. A recon only allows one temp per time, so something had to give.
The scientific world generally does not think of Mann’s results as fraudulent. But even if you do, it’s not a sin to get results that agree with them (though I think he was referring to Mann’08).
There was a time when proxies at their modern end showed a “decline” which had to be hidden with Mike’s Nature trick. Now after some modern re-calculation of dates – an uptick appears. It appears there was no need to hide Marcott’s Science trick – it went straight to press, over the heads of the scientific community straight to the hockey Moms of the MSM.
@ NZ Willy, please don’t give up, I appreciate your explanations of the arcane handwaving of these works in search of hockey sticks and warming.
Eventually we come to see what is blindingly obvious to you.
Thanks for persevering.
I appreciate the supportive comments I’ve had here, cheers.
JustAnotherPoster,
Isn’t the really interesting part of climate science that all the “proxies” are showing a cooling trend yet the “Temperature” data supplied by CRU and Hansen shows a warming.
Not all the proxies show a cooling trend, only some maximum latewood density proxies in the northern Hemisphere (the divergence problem).
Climate science is much more interesting when you get your facts straight.
On this issue, even as stated by you (incorrectly), ‘interest’ usually climaxes at the question, whereupon it is transmogrified into an argument against the entire proxy record. True ‘interest’ would follow up by testing that assumption. Steve McIntyre seems to think that one can answer these questions fuelled by a cup of Starbucks coffee. Doesn’t seem like much effort is needed. How about it?
Doug Proctor,
If Marcott had simply done his work AND not added the temperature record, the paper would not have drawn arrows. He/they chose to use it to make a conclusion about CAGW issues.
Please cite, after quantifying what ‘C’ (catastrophic) means, where Marcott et al made conclusions about ‘CAGW’.
Some proxy records show a downtick against the instrumental record after the 1960s/80s, while showing a fair match, in many cases, to instrumental temperatures prior. Marcott do not use proxy data past 1950 for various reasons, but it removes the troubled part of the proxy record that disagrees with the better-resolved instrumental record. Nothing wrong with that. Why include bad data?
The implied argument of many posts on the matter here, is that if proxy records go bad after 1960/80, why do we assume they are good prior to that date?
Answer: we don’t make that assumption. that’s the point of all these reconstructions, to test proxies against other proxies and, where appropriate, the instrumental data.
Non-sequiturs are not science. Does the divergence problem in the late 20th century mean that proxy data prior is less reliable than supposed?
Find out! Don’t just assume. Google scholar+key word search+reading is a good start.