Guest Post by David Middleton
The Gorebots are all atwitter about this new paper…
Science 8 March 2013:
Vol. 339 no. 6124 pp. 1198-1201
DOI: 10.1126/science.1228026
A Reconstruction of Regional and Global Temperature for the Past 11,300 Years
Shaun A. Marcott, Jeremy D. Shakun, Peter U. Clark, Alan C. Mix
Surface temperature reconstructions of the past 1500 years suggest that recent warming is unprecedented in that time. Here we provide a broader perspective by reconstructing regional and global temperature anomalies for the past 11,300 years from 73 globally distributed records. Early Holocene (10,000 to 5000 years ago) warmth is followed by ~0.7°C cooling through the middle to late Holocene (<5000 years ago), culminating in the coolest temperatures of the Holocene during the Little Ice Age, about 200 years ago. This cooling is largely associated with ~2°C change in the North Atlantic. 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. Intergovernmental Panel on Climate Change model projections for 2100 exceed the full distribution of Holocene temperature under all plausible greenhouse gas emission scenarios.
Marcott et al., 2012 is behind a paywall; however the supplementary materials include a link to their proxy data.
This paper appears to be a text book example of creating a Hockey Stick by using a low resolution time series for the handle and a high resolution time series for the blade…
Let’s test one of the 73 proxies.
I picked ODP-1019D, a marine sediment core from just offshore of the California-Oregon border because it has a long time series, is a an annual reconstruction and has a nearby long time series instrumental record (Grants Pass OR).
ODP-1019D has a resolution of 140 years. Grants Pass is annually resolved…
Let’s filter Grants Pass down to the resolution of the Marcott et al. reconstruction…
Grants Pass sure looks very anomalous relative to the rest of the Holocene… Right?
Well, not so fast. ODP1019D only has a 140-yr resolution. The record length at Grants Pass is less than 140 years. So, the entire Grants Pass record would be a single data point in the ODP-1019D record…
While, the most recent ~140 years might be warmer than most of the rest of the Holocene in this particular area, does anyone else notice what I did?
The Grants Pass/ODP-1019D area has been warming at a fairly steady rate for 6,500 years…
I don’t know how many of these proxies I will have time to analyze… Probably not very many. Maybe this could become a WUWT crowd-sourcing project.
Title revised per notes below, 03-11-2013. Mod]
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David, James and Hank have been all over it…..have a look
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/
…and here
http://suyts.wordpress.com/2013/03/10/the-hockey-stick-resurrected-by-marcott-et-al-2012/
astonishing… climate science really has nothing to do with science anymore. how on earth can this pass any review when the error in this new hockeystick is this bad.
thanks for exposing this infantile attempt to fraud. i hope they will get excommunicated from their universities asap.
Best explanation for hockey-sticking I have seen. Thank you. Book-marked and saved.
Unless bandwidth is reasonably constant across the entire time period, the claims on rates mean nothing. Grafting a low bandwidth recontruction on to a high bandwidth time series makes for garbage.
I look forward to the crowd-sourcing.
So far this looks like the equivalent of the “one tree in Yamal” phenomenon 🙂
“This paper appears to be a text book example of creating a Hockey Stick by using a low resolution time series for the handle and a high resolution time series for the blade…”
You established your point beautifully. No, Marcott and friends did not use exactly Mikey’s “Nature trick” but they showed imagination and invented another trick that has the same effect as Mikey’s “Nature trick.” It is a “trick” in the bad sense of the word. It misrepresents data. It gives an illusion of something not only important but ominous where the truth is altogether mundane.
You have to wonder if some of these climate scientists, so-called, are ex-announcers for the NBA. You know, “He shoots from downtown! and puts it in!!!”
Elegant work!!!
Title and text should all say “2013” not “2012” for Marcott et al. (2013)
So this paper is yet another example of the trick of attaching (adjusted, of course) temperature data to the end of a proxy record. Not surprising that we get another hockey stick, though this one seems a little bent — perhaps it’s been used as a weapon since we last saw it?
Era of the Pharaohs: Climate was HOTTER THAN NOW, without CO2 And yet … Alexandria was NOT a flooded island. Weird
http://www.theregister.co.uk/2013/03/11/holocene_was_warmer/
That was my initial citation. For some reason, I changed it to 2012. However, it does appear that the correct citation should be 2013. Hell, some days I can’t even remember what day it is… 😉
Can we see the “peer reviewers comments” that passed this crazy paper ?
The time resolution of individual proxy fossil data is greater than the entire period of surface temperature measurements. You cannot draw any conclusions. An analogy would be that of comparing your monthly averaged speed of car travel with one trip down a German autobahn yestreday.
Thanks for the link to Supplementary Materials. At first glance I don’t see the code.
Steven Mosher–I know you often ask for code. Would you be interested in asking for it here? I mention that because if Steve McI asks for it it will no doubt set off head explosions in the Alarmosphere.
Can you imagine if people like those are on this site (thanks) would not be here??
These guys would get away with this!!!
Oh wait,…. Al Gore,
stupid me
Isn’t there a penalty for ‘high-sticking’ in hockey?
Alfred
It looks like you placed the point for Grant’s pass at year 2000, but if it is really 124 year long record, shouldn’t you have placed the center point of that data point at T=(2013-62) or the year 1951 to maintain the correct position in time?
This highlights a question I have been asking about for some time: are all of our temp profiles comparing the past to the present a case of “Apples and Oranges”?
The Greenland core data etc. looks to me like a data set with a >70 year averaging function. All the short-term highs AND lows have been disappeared. If we were to apply such a function to the last 200 years, I betcha we will see what we see here: nada of interest.
When can we expect to see the hockey-stick team puting ‘Cows’ into their graphs, or at least, splicing thermometers onto their asses ??/sarc
http://wattsupwiththat.com/2013/03/08/a-bridge-in-the-climate-debate-how-to-green-the-worlds-deserts-and-reverse-climate-change/#more-81728
Most grateful to David Middleton for pointing out the chalk-and-cheesy technique of splicing hi-res real-world data on to lo-res proxy data. In my expert review of the next daft of the IPCC’s Fifth Assessment Report I’ll make sure proper attention is given to this point.
Just one small correction to the text: where the head post there has been fairly steady warming for 6500 years it should perhaps say 4500 years.
It may be more helpful to look at this data in terms of high frequency (or short wavelength) and low frequency (or long wavelength). The Grant’s Pass temperature record as shown appears to have no low frequency component to it, so it apparently contains no trend data on a scale (or wavelength) of one hundred years. Consequently, the Grant’s Pass temperature records would not merit even a single data point. Only the marine sediment proxy (ODP-1019D) would appear to have any low frequency (and, therefore, trend) information associated with it.
Latitude says:
March 11, 2013 at 2:31 pm
David, James and Hank have been all over it…..have a look
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/
=====================================================
Thanks Lat!
David, have a check. Feel free to use/borrow/take whatever you feel can better articulate the thought. You’re spot on! If you’re like me you had to stare at it for a while to see what the heck those pinheads did.
As Lat mentioned, if you want to see a different view, and a bit more heady for the stat nerds, Hank did a bang up job here….. http://suyts.wordpress.com/2013/03/10/the-hockey-stick-resurrected-by-marcott-et-al-2012/
Latitude says:
March 11, 2013 at 2:31 pm
“David, James and Hank have been all over it…..have a look
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/”
Everyone has to read this one. You great-grand can understand it and it is brilliant.
I saw this same technique applied a few years ago to a “hockey stick” of CO2 levels. They had grafted data from Antarctic ice cores to the modern Mauna Loa record showing an alarming increase in CO2 levels. Of course, in the desert of Antarctica snow gets blown and sifted by wind for years before it is compacted to ice so it is low-resolution compared to Mauna Loa data. Just another way to lie with statistics.
“This paper appears to be a text book example of creating a Hockey Stick by using a low resolution time series for the handle and a high resolution time series for the blade…”
That’s a reasonable criticism. And it shows a proper appreciation of what a HS is – a proxy shaft, with all its faults, and an instrumental blade. They go together.
However, the spike of the last century does have special status, apart from being well observed. It follows the insertion of 350 Gtons C into the atmosphere from fossil fuels. That hasn’t happened before. And when arguing about whether the rise has produced temperatures higher than at some point in the Holocene, and whether some past times might have been warmer, remember that there are at least 3500 more Gtons to burn.