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The Marcott Hockey-stick: smoothing the past and getting a spike from almost no data?

The message to the world is unequivocal:

“We are heading for somewhere that is far off from anything we have seen in the past 10,000 years – it’s through the roof. In my mind, we are heading for a different planet to the one that we have been used to,” said Jeremy Shakun of Harvard University, a co-author of the study.

Source: The-world-is-hottest-it-has-been-since-the-end-of-the-ice-age–and-the-temperatures-still-rising.

There are two factors in the new Marcott paper that are major red flags. For one, there is hardly any data in the modern end of the graph. Ponder how researchers can find 5,000 year old Foraminifera deposits, but not ones from 1940? Two: they’ve smoothed the heck out of longer periods. Marcott et al clearly say there is “…essentially no variability preserved at periods shorter than 300 years…” So if there were, say, occurrences of a warming rise exactly like the last century, this graph won’t show them.

Some of the data has a resolution as poor as “500 years” and the median is 120 years. If current temperatures were averaged over 120 years (that would be 1890 to now), the last alarming spike would blend right in with the other data. Where would the average dot be for the “last 500 years”. It would be low, cold, and there would be no hockeystick at all in a “500 year” averaged graph. But if there was a period of rapid warming sometime in the last 10,000 years, one which occurred over say, 50 years, it would disappear amongst the uncertainties.

Robert Rohde (of the BEST Project) points out that so much of the variance is lost that it is equivalent to smoothing the series with a 400 year running average, saying “it will completely obscure any rapid fluctuations having durations less than a few hundred years.”

It may be necessary to sacrifice the variance, and blend and blur those past peaks (given the uncertainties) but after doing so, how can Marcott et al say anything at all, even a squeak, about the rate of warming in the last 100 years?

In the end the hockey stick seems to come from a 20 year “reconstruction” of data that has a median of 120 year resolution. Would that have the effect of heavily weighting some proxies while smoothing out the others? It’s all very well to trumpet that there are 73 proxies, but some of them obviously count for a lot more than others.

Repeat of the old hockey-stick: The last 2,000 years.

The new hockey-stick blends high and low resolution data from many proxies in the past with mixed resolution data (but few proxies) in recent times. It’s a complex method which produces something not seemingly reflected in the actual proxy data. Where are the hockey-stick-proxies? It also doesn’t help that ten percent of all 73 proxies fail their own criteria for inclusion. (Thanks to Willis for all those spectacular spaghetti graphs, and thanks to both Craig Loehle, and Roberto Soria for advice).

There appear to be hardly any records from the time of the spike?

Am I reading this incorrectly? Note fig a and fig e here. See that dive to zero on the right hand edge — just at the point that the “hockey-stick” appears in lower graphs? Are there virtually no proxy records during the time of the spike? Note that the lines in the other graphs here come from “temperature reconstructions” which are area weighted and “Monte Carlo” based graphs.

.Fig. S10: Temperature reconstructions separated by latitude. (a) Number of records used to construct the temperature stack through time for the 5×5 degree weighted 90-60°N sites (black line), 60-30°N sites (blue line), 30-0°N sites (green line), 0-30°S sites (pink line), 30-60°S sites (purple line), and 60-90°S  sites (brown line). (b-d) 5×5 degree weighted temperature envelope (1-σ) of the global temperature anomaly (blue fill) plotted against the 5×5 degree weighted latitudinal sites. Uncertainty bars in upper left corner reflect the average Monte Carlo based 1σ uncertainty for each reconstruction, and were not overlain on line for clarity. e-h same as a for the last 11,300 years. Temperature anomaly is from the CE 1961-1990 average. Note that b and f have larger y-axes, but are scaled the same as the axes in c,d,g,h. (Click to enlarge)

 

See also the next figure. Note in a and d, the ragged edges as the proxies run out of data on the right? See how the number of records plummets to zero? Note how this correlates with the spike (c and f). Steve McIntyre writes that the Alkenone proxies are the largest group of proxies (31 of 73) yet the uptick is mysteriously absent from the data. McIntyre does not believe that the uptick is due to splicing in of the instrumental data, but cannot explain it yet. Can Marcott explain it? You would think so, but his response left McIntyre baffled.

Fig. S11: Temperature reconstructions separated by ocean vs land. (a) Latitudinal distribution of the  records used to construct the terrestrial (brown bars), and ocean records (blue bars). (b) Number of  records used to construct the temperature stacks through time (terrestrial – brown line; ocean–blue  line). (c) Global temperature anomaly 1-σ envelope (5×5 degree weighted) (blue fill) and terrestrial (brown), and ocean records (blue). Uncertainty bars in upper left corner reflect the average Monte  Carlo based 1σ uncertainty for each reconstruction, and were not overlain in plot for clarity. d-f same as  a-c for the last 11,300 years. Temperature anomaly is from the CE 1961-1990 average. (Click to enlarge)

Notice in c, the hockey-stick spike is coming mostly from the “ocean”? Hmm.

Even the author admits the spike is not robust?

Even Marcott admits the reconstruction of the modern spike is not robust in either the Northern or the Southern Hemisphere, and where else is there? (Thanks to Steve McIntyre for asking him).

Regarding the NH reconstructions, using the same reasoning as above, we do not think this increase in temperature in our Monte-Carlo analysis of the paleo proxies between 1920 − 1940 is robust given the resolution and number of datasets. In this particular case, the Agassiz-Renland reconstruction does in fact contribute the majority of the apparent increase.

Regarding the SH reconstruction: It is the same situation, and again we do not think the last 60 years of our Monte Carlo reconstruction are robust given the small number and resolution of the data in that interval.

So why all the newspaper headlines? The non-robust result turns into a PR message.

Did they mention this is the paper in paragraph four as Marcott says? Well, kind of — not really.  Here’s a “hint”:

Without filling data gaps, our Standard5×5 reconstruction (Fig. 1A) exhibits 0.6°C greater warming over the past ~60 yr B.P. (1890 to 1950 CE) than our equivalent infilled 5° × 5° area-weighted mean stack (Fig. 1, C and D). However, considering the temporal resolution  of our data set and the small number of records that cover this interval (Fig. 1G), this difference is probably not robust. Before this interval, the gap filled and unfilled methods of calculating the stacks are nearly identical (Fig. 1D).

He’s saying the “difference” between the two versions is not robust, but not that the main feature of the graph is fickle, flakey, or may disappear under analysis. (Thanks to McIntyre and Eschenbach for spotting that.)

Me, I wonder why Science published the paper in the first place?

The proxies, the proxies

Now look at the graphs of the actual proxies offered in the supplementary material. Note how the proxy data – in red and blue lines shows no hockey-stick. But this is the tropics, so that’s not unexpected.

Fig. S5: Upper. Map showing location of sites. Lower. Temperature reconstructions at select sites where  different proxy-based reconstructions were used. In each of these comparisons, the blue lines represent  temperature reconstructions derived from alkenones (UK’37) and the red lines represent temperatures  from planktonic foraminifera (Mg/Ca).

Same with these northern hemisphere proxies. No hockey stick in this data either?

A lot of the data is from the ocean, which shouldn’t rise and fall nearly as much as land based data, yet apparently caused the spike?

Fig. S6: Left. Temperature reconstructions at select sites where different proxy-based reconstructions 157 were used. (a) Pollen temperature reconstruction (blue) compared with chironomid records (red). (b) 158 Alkenone (UK’37) record (blue) compared with radiolaria record (red). (c,d) Alkenone records (UK’37) (blue) 159 compared with TEX86 records (red). (e) Alkenone record (UK’37) (blue) compared with branched 160 tetraether membrane lipid (MBT) record (red). Right. Map showing location of sites. (Click to enlarge)

 

The spike below certainly looks spectacular on the 11,000 year scale. Great “visual”, nice “optics” but we struggle to point to many actual proxy data points from individual sites that shows this shape, let alone many widespread proxies which we ought to expect if this is a global temperature representation? Marcott averaged many non-spikes and got a spike … tricky eh?

 

Fig 1 B — The last 12,000 years

 

So where does the spike come from?

The supplementary material is extensive, which is commendable. It describes, at length, how they use simulations to reconstruct the global temperature. On top of that is a 20 year sampling done on the data in the last 1500 years. The hockey stick does not show in 100 year or 200 year samplings. (The blue line below is the 20 year sampling). It also did not show in the Marcott PhD thesis of 2011. The plot thickens?

Fig. S12: Temperature reconstructions using multiple time-steps. (a) Global temperature envelope (1-σ)  (light blue fill) and mean of the standard temperature anomaly using a 20 year interpolated time-step  (blue line), 100 year time-step (pink line), and 200 year time-step (green line). Mann et al.’s (2) global temperature CRU-EIV composite (darkest gray) is also plotted. Uncertainty bars in upper left corner  reflect the average Monte Carlo based 1σ uncertainty for each reconstruction, and were not overlain on  line for clarity. b same as a for the last 11,300 years. Temperature anomaly is from the 1961-1990 yr  B.P. average after mean shifting to Mann et al.(2). (Click to enlarge)

Let’s look at the “Monte Carlo” process

In their methods (below), the bolded phrase in point 3 describes how they chose to compare to “high-resolution” reconstructions of the past 1000 years, in this case to “Mann”. Their graph wouldn’t look as reliable if they compared it to Ljundqvist, or to Loehle…

3. Monte-Carlo-Based Procedure
We used a Monte-Carlo-based procedure to construct 1000 realizations of our global  temperature stack. This procedure was done in several steps:

  1. We perturbed the proxy temperatures for each of the 73 datasets 1000 times (see  Section 2) (Fig. S2a).
  2. We then perturbed the age models for each of the 73 records (see Section 2), also  1000 times (Fig. S2a).
  3. The first of the perturbed temperature records was then linearly interpolated onto  the first of the perturbed age-models at 20 year resolution, and this was continued sequentially to form 1000 realizations of each time series that incorporated both temperature and age  uncertainties (Fig. S2a). While the median resolution of the 73 datasets is 120 years, coarser time steps yield essentially identical results (see below), likely because age-model uncertainties  are generally larger than the time step, and so effectively smooth high-frequency variability in  the Monte Carlo simulations. We chose a 20-year time step in part to facilitate comparison with  the high-resolution temperature reconstructions of the past millennium.
  4. The records were then converted into anomalies from the average temperature for  4500-5500 yrs BP in each record, which is the common period of overlap for all records.
  5. The records were then stacked together by averaging the first realization of each of  the 73 records, and then the second realization of each, then the third, the fourth, and so on to  form 1000 realizations of the global temperature stack (Fig.S2 b,c and Fig. S3).
  6. The mean temperature and standard deviation were then taken from the 1000  simulations of the global temperature stack (Fig. S2d), and aligned with Mann et al. (2) over the  interval 510-1450 yr BP (i.e. 500-1440 AD/CE), adjusting the mean, but not the variance. Mann  et al. (2) reported anomalies relative to the CE 1961-1990 average; our final reconstructions are  therefore effectively anomalies relative to same reference interval.

They talk of using the instrumental record to check to see that their locations are representative of global temperature (which it may well be, but if they don’t have proxy data from recent times, they don’t have proxy data…).

To examine whether 73 locations accurately represent the average global temperature 271 through time, we used the surface air temperature from the 1×1° grid boxes in the NCEP-NCAR 272 reanalysis (83) from 1948-2008 as well as the NCDC land-ocean dataset from 1880-2010 (84). [Page 20 supplementary materials]

Then they use a simulation to reconstruct the last 11,000 years. Where is that hockey stick? Not here.

 

Fig. S16: Simulated global mean temperature for the last 11000 years (black) and the mean temperature at the 73 proxy sites (red) from the ECBilt-CLIO transient simulations (81).

The problem of the North Atlantic (Greenland) data

Look at the downward slope, and uptick in b. Note how it doesn’t mesh with the red “model”.

Fig. S25: Simulated global and regional mean temperatures for the last 12000 years (red) from the ECBilt-CLIO transient simulations (81) and the Standard 5×5° weighted temperature stack from the proxy dataset from this study (black). The temperature is an anomaly from 6,000 yrs BP (± 200 yrs).

The authors describe how the North Atlantic has the largest disagreement with the model:

Comparing the temperature  data and model simulations by region demonstrates that the largest data-model disagreement  is in the mid-high latitude Northern Hemisphere sites while the data and model in the  equatorial and mid-high latitude Southern Hemisphere sites are in agreement within the Monte Carlo based uncertainty after 9,000 yrs BP (Fig. S25b,c,d). When the North Atlantic proxy sites that show the largest temperature changes are removed, the data and model are within the Monte Carlo based uncertainty, both in the global stack and the mid-high latitude northern hemisphere stack (Fig. S26a,b). The data-model disagreement may suggest that the model could be missing a key climate component that is intrinsic to the North Atlantic basin. In particular, the AMOC may  have slowed during the Holocene, resulting in an amplified cooling in the North Atlantic basin  and a warming in the Southern Hemisphere that could have dampened any cooling effect expected from orbital tilt (87-89).

 

Does the hockeystick come from the southern hemisphere, the Antarctic?

Here the northern Atlantic data is removed.

Fig. S26: Simulated global and regional mean temperatures for the last 12000 years (red) from the  ECBilt-CLIO transient simulations (81) and the Standard 5×5° weighted temperature stack with the North  Atlantic sites removed (black). The temperature is an anomaly from 6,000 yrs BP (± 200 yrs).

The Southern Hemisphere contains the fewest proxies. Food for thought?

Fig. S1: Location map and latitudinal distribution of proxy temperature datasets. Map of temperature datasets from this study with temperature proxy identified by color coding (dots) and datasets used in Mann et al. (2) (crosses). (Inset) Latitudinal distribution of data from this study (red) and Mann et al. (2) (gray). Note break in y-axis at 25.

There is much entertainment on skeptic blogs as this epic study gets unpacked. Tune in this weekend…

It’s just a shame that science authors are in such a rush to get their news headlines that they don’t publish online first (or ask Steve McIntyre to review it), so they could iron out the details before hundreds of thousands of people were told a story that didn’t… stack up.

 

REFERENCES

Lewis, S.E., et al., Post-glacial sea-level changes around the Australian margin: a review, Quaternary Science
Reviews (2012), http://dx.doi.org/10.1016/j.quascirev.2012.09.006 [abstract] (paywalled).

Ljungqvist, F. C., Krusic, P. J., Brattström, G., and Sundqvist, H. S (2012).: Northern Hemisphere temperature patterns in the last 12 centuries, Clim. Past, 8, 227-249, doi:10.5194/cp-8-227-2012, 2012. [abstract] [PDF] or try this [PDF] [CO2science discussion]

Svend Funder1, Hugues Goosse, Hans Jepsen, Eigil Kaas, Kurt H. Kjær, Niels J. Korsgaard, Nicolaj K. Larsen, Hans Linderson, Astrid Lyså, Per Möller, Jesper Olsen, Eske Willerslev, ‘A 10,000-Year Record of Arctic Ocean Sea-Ice Variability—View from the Beach’, Science 5 August 2011:Vol. 333 no. 6043 pp. 747-750 DOI: 10.1126/science.1202760

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The Marcott Hockey-stick: smoothing the past and getting a spike from almost no data?, 9.3 out of 10 based on 77 ratings

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179 comments to The Marcott Hockey-stick: smoothing the past and getting a spike from almost no data?

  • #
    PeterB in Indianapolis

    The articles which I have been reading show that this entire paper is a re-hash of Marcott’s PhD. Thesis. In his PhD. Thesis there WAS NO HOCKEY STICK, and in this paper, the hockey stick magically appears, but even according to the author, is “not robust”, which makes one wonder what the motivation for including it really was….


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    • #
      john robertson

      I was gobsmacked by his reply to Steve McIntyre, I think its the classic liars dilemma, but the kid is so wet, he has lost the storyline already.
      Claims they said the late era results are nor robust. Their paper says the difference (comparison) between their two methods was not robust.
      Ink is not even on paper and its breaking down.


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      • #
        cohenite

        That reply of a lack of ‘robustness’ negates the whole paper and when the confection of the modern “uptick” or hockeystick blade is removed the status quo of a warmer MWP and Holocene is confirmed.

        I can only see this paper as another example of the AGW circus getting a headline and trusting that by the time the rebuttal of it is achieved the AGW scam will have moved onto the next lie; and secondly to get it into AR5, rejuvenating the lamentable Mann hockeystick.

        Great post and overview by Jo.


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        • #

          Cohers, I’m noting how alarmists are getting polite, concessional and easy-going on the subject of the Medieval Warming. They’ll occasionally allow us “our” MWP. Sometimes they’ll localise it, sometimes they’ll cool it…in the right mood they’ll even concede us “our” MWP. If we must. But then change the subject to, say, a recent thermometer reading that set a startling record. (No, not Oymyakon, silly…Sydney!)

          The MWP, one of history’s giant facts has to go. Out the back door. Out the side door. Out the window or up the chimney. These Lysenkoists want it gone.

          The script, Mr. De Mille, always the script!


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        • #
          Lars P.

          Speaking of LIA and MWP, I saw a reconstruction Hank did at James site (suyts place) here:
          http://suyts.wordpress.com/2013/03/14/hockey-stick-found-in-marcott-data/
          Nice the see the proxies confirming MWP and LIA.
          Also not that the “not robust” part is clearly highlighted why not rubost… the proxies tell other story
          http://suyts.wordpress.com/2013/03/14/more-fishing-for-hockey-sticks-in-marcott-et-al-2013/


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          • #

            It is a continuing theme that the consensus hockey sticks are coming more and more into line with the view of the skeptics. Ian Pilmer and Bob Carter have been saying for years that there has been warm periods in the Bronze Age, Roman period and Medieval period.
            In fact, if you take Marcott’s PhD graph, it would look more at home in one of Bob Carter’s presentations than on the SkS website. Similarly the Gergis reconstruction, despite all the biases and errors, showed the 1990s was just 0.09 degrees warmer than the warmest decade in the thirteenth century.
            If you look at Mann’s 2008 reconstruction, it similarly shows a distinct MWP, whereas the 1999 construction did not.


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    • #
      Tim

      The motivation couldn’t be GRANT$, surely.


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      • #
        Peter Miller

        Tim

        Over 90% of the time the problem which corrupts ‘climate science’ is definitely grants, or grant addiction.

        Can you imagine a small room somewhere in the academic world, probably early last year, where Dr Marcott is sitting in front of a small panel of ‘eminent climate scientists’.

        The conversation eventually comes around to the subject of economic reality in the world of ‘climate science’.

        “Well, Dr Marcott your PhD thesis is excellent work, but if you want to have a career in ‘climate science’, you must realise you have to come to the right conclusions, something which was clearly not achieved in your thesis.”

        “Oh,” replies Dr Marcott, contemplating the bleak prospect of having to find a real job in the real world, “I understand, but what do I have to do?”

        “Well, we suggest you publish a new research paper along the lines of your thesis, but this time coming to the right conclusions. We can suggest some co-authors – people who are known to be sound on the subject of ‘climate science – they will provide you with the statistical methodology and whatever other ‘proof’ you need to reach the right conclusions. These people are masters in the interpretation of raw data and can be relied on to provide you with what you need to become one of us. In addition, in order to demonstrate our sincerity in this, we shall arrange publication of this paper in a prestigious science journal – and don’t worry about having any difficulties in the peer review process, they will be all our people.”

        “But how can I justify coming to a totally different conclusion?”

        “Trust us, nobody will ever know. And in the unlikely event anyone does, the re-interpretations of the data sets used in your new paper will be so complicated no one will ever be able to figure them out. In an absolute worst case scenario, you can talk about always being concerned about the robustness of data, so if there is something wrong it’s not your fault, it’s the fault of the data.”

        It is not certain at this point, whether or not Dr Marcott fell to his bended knee, realising his future was suddenly now secure as he clasped his hands together and gratefully bleated: “Thank you, oh thank you so very, very much.”


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      • #
        Grant (NZ)

        I do not provide the motivation for this paper :-)


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    • #
      Skiphil

      As I posted at CA….

      fyi, the thesis advisor, mentor, and also co-author for both Marcott (Marcott et al. 2013, Science) and Shakun (Shakun et al., 2012, Nature) is Peter Clark at Oregon State…. who just happens to be a big dude with the IPCC! Coordinating Lead Author (one of only 8 CLAs from the USA) for the IPCC’s AR5. So even if Marcott and Shakun are relatively new to public science and media, their mentor/co-author is a major IPCC figure:

      Peter Clark is a CLA for the IPCC’s AR5

      So even if that sea level chapter is not in the target zone for these two papers the IPCC’s AR5 process was certainly a (likely?? ha ha) topic of discussion for co-authors who seemed to get the Marcott et al. (2013) paper in just under the wire for consideration.


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      • #
        Rod Staurt

        And Oregon State just happens to be the University from which a prof was fired because he wouldn’t toe the line on this CAGW story. Oregon State also took it out on his children who were working on doctorates as I recall. Oregon State is a nasty little U.


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    • #
      Philip Shehan

      There is no uptick in Marcott’s thesis figure 4(a) as he is showing his proxy data up to mid 20th century. Figures 4 b,e and f do show the uptick as he is comparing his data to previously published data which also cover the last half century, including instrumental readings as do the graphs in figure 4.2

      Figure 1c from the subsequently published Science paper also includes data up to the current period. That is why the down trend to mid last century goes upward in the Science figure 1c.

      There is no contradiction. One graph covers a longer period than the other and includes instrumental readings..

      In the absence of the paper itself or the legend for figure 1c, the reasons for different presentation in the Science paper figure is not known to me.

      However I can state from personal experience that material from a 200 and more page thesis will often be combined or presented in a slightly different form when representing the material as a specific aspect of the thesis study for publication in a journal article of a few pages.

      As for the spike not being “robust”, this simply reflects the fact that the resolution of the last 50 years or so in which the data appears compared to the last 2,000 or 11,500 spread along the horizontal axis is scarcely the width of the line. It is not there to be able to read the lumps and bumps reflecting the variations within that period. It is there to show how the temperature record over the last 11,500 years compares with today’s temperatures.


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      • #

        One graph covers a longer period than the other and includes instrumental readings..

        The Science paper does not include instrumental readings. Steve McIntyre in an email asked Marcott the following

        Your NH Extratropics (NHX) reconstruction has a huge increase from 1920 to 1940 (1.92 deg C). There are only 10 NHX proxies that end after 1920, of which six have lower proxy temperatures in 1940. Only the Agassiz-Renland proxy has a major increase. I am baffled as to how you calculate a NHX reconstruction increase of 1.92 deg C given this data. Surely Agassiz by itself cannot account for such a large increase? Do you have any explanation or ideas?

        Marcott’s response was

        Please note that we clearly state in paragraph 4 of the manuscript that the reconstruction over the past 60 yrs before present (the years 1890 − 1950 CE) is probably not robust because of the small number of datasets that go into the reconstruction over that time frame.

        There is no instrumental data in either data set. Further, I doubt in the period 1920-1950 you can find a major reconstruction approaching that warming just trend, just as none of the proxies give such a trend. The twentieth century uptick is a fabrication, with no support from instrumental or proxy data.


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  • #
    PeterB in Indianapolis

    They got what they wanted, science by Press Release. “The Hockey Stick is BACK and it is SCARIER THAN LAST TIME!”

    Now they can quietly retract the article while still hoping the public is convinced that it actually meant something and succeeded in upping the global warming hype again for a while.


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  • #
    john robertson

    This “reconstruction” is desperately needed for AR5.

    Classic Climatology.
    Set desired headline.
    Gather random pseudo data sets.
    Massage said numbers in creative ways.
    Finger paint some graphs
    Announce headlines via normal channels, same breathless drivel.
    Data and massaging methods delayed in print or paywalled.(Not quite available for indefinite period)
    Fight rearguard delaying action until well after IPCC AR5 produced.

    Why not it worked for AR1-4, what could go wrong?


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  • #
    Mark D.

    Isn’t Monte Carlo a casino? There must be some wry humor to be uncovered.


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    • #
      Andrew McRae

      Sorry it’s quite boring. The Monte Carlo method is a method of integration using probability. The way it was explained to me, you randomly pick points (x,y) within the domain/range of interest of a function, and check whether that point’s y value is above or below the function’s output f(x). When you do this with enough random points, the fraction of # points that are below the function line / # points above the line gets closer and closer to the true fraction of the integral / total area in that range.
      It is useful for finding an approximation of the definite integral for functions that don’t have an easy or well-defined symbolic integral. (Sounds like that may be the case for sparsely sampled data.)
      The story I heard is that it is named after the perilous roads on the hills behind the Monte Carlo casino, not the casino itself, but that is a foggy memory.


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      • #
        Rereke Whakaaro

        It is also based on chance. And the punter inevitably looses in the end, because by running multiple simulations, the “croupier” can choose whichever one give the house the biggest win.


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  • #
    Betapug

    It is hard to think Marcott aimed this fragile instrument at Science readers…or thinkers.
    The Atlantic article, “We’re Screwed: 11,000 Years’ Worth of Climate Data Prove It” (with the humorous subtitle: “New research takes the deepest dive ever….”)
    http://www.theatlantic.com/technology/archive/2013/03/were-screwed-11-000-years-worth-of-climate-data-prove-it/273870/

    ..has access to millions of readers, with the rest of the Climate Desk network and repeaters adding many millions more to the audience that really counts.
    http://theclimatedesk.org/

    Readers are already primed to see debunking as evidence of attacks by the dark forces:
    “Mann himself….(said) he was “certain that professional climate change deniers will attack the study and the authors, in an effort to discredit this important work…”

    The whole exercise looks like a repair attempt on the broken Mann made hockey stick. Marcott “..said he was grateful scientists like Mann had “gone through hell” before him to build a support network for harassed climate scientists.

    “We are heading for somewhere that is far off from anything we have seen in the past 10,000 years – it’s through the roof. In my mind, we are heading for a different planet to the one that we have been used to,” said Jeremy Shakun of Harvard University, a co-author of the study.
    http://www.independent.co.uk/environment/climate-change/the-world-is-hottest-it-has-been-since-the-end-of-the-ice-age–and-the-temperatures-still-rising-8525089.html

    Star Wars it is.


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    • #
      Mark D.

      Betapug, did you have time to read the comments on theAtlantic link? Everyone SHOULD read them to know what we’re up against. All I can say is wow I mean wow…..


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      • #
        Roy Hogue

        The Climate Desk is a journalistic collaboration between The Atlantic, Mother Jones, Slate, and others, dedicated to exploring the impact—human, environmental, economic, political—of a changing climate. Learn more at theclimatedesk.org.

        With that bunch backing them up what do you expect? Mother Jones and Slate are not exactly known for their great integrity, are they?

        Atlantic, for that matter, has no expertise in science so why would any of these so-called journalists do anything but buy off on the thing at face value. Marcott wants to preempt criticism so he tells the world he’ll get a bad reception from the evil skeptics and voila, it’s a fact by fiat that we’re screwed.

        And if we’re really screwed I think I’m going to sit back and live my life with complete disregard for all this BS and enjoy myself.

        Let Marcott worry about it.

        As for the comments, well those people were always out there, so what’s the difference. If you follow the mind set of Atlantic and Mother Jones et al then how are you going to think any differently?


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          Roy Hogue

          I went a long way down the comments and every last bit of it was worthy of no more than a 15 year old intellect. Our problem is that we’ve let these jerks vote. Big mistake! We should have raised the voting age to about 35, not lowered it to 18.


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          Betapug

          Roy, the problem is The Atlantic is a 150yr old magazine started by Ralph Waldo Emerson, Oliver Wendell Holmes, Henry Wadsworth Longfellow, James Russell Lowell, and Harriet Beecher Stowe and is still seen by the millions of subscribers and site visitors as highly respectable and mainstream by most university educated in the US and Canada.

          Google the key phrases in this article and you will see that it is spread everywhere on the virtually infinite network of the Green choir.


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            Roy Hogue

            …The Atlantic is a 150yr old magazine…

            I know only too well what that heritage can imply. But it ain’t so any more, larger than life readership notwithstanding. But even in the founders’ time the science of the day would confound those guys I think — poets, authors, anything but science savvy.

            So where are we but right where we are? I cannot get all that excited now. Atlantic is not just publishing its first article on climate change and has had the same following for a long time.

            The time to have been looking after the hen house was 100 plus years ago if we had been astute enough to see where the world was going. We weren’t, so now we have to weather it while doing whatever we can do.

            Sorry to be so cynical about it but I got there honestly from watching all this go by for a long time now. I’ll be 74 shortly and looking back I can see the warnings all too easily, clear back to long before I was born. Hindsight can be 20/20. Foresight could be better too if we really wanted it to be. But it’s been neglected throughout human history from the look of things.


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            John Brookes

            I read an article in The Atlantic recently, and was pleasantly surprised. It wasn’t on climate, but I definitely finished the article better informed than when I started. Not something I experience with the Murdoch press.


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              Rereke Whakaaro

              Murdoch press is like the Dementers in Harry Potter – if you can’t resist, it sucks the soul out of you.


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              Roy Hogue

              I read an article in The Atlantic recently, and was pleasantly surprised.

              Congratulations on your good taste, John. I’ve read a bit of The Atlantic myself from time to time, mostly because I found it in a doctor or dentist’s waiting room, though not so much lately. It’s rather like reading fiction a lot of the time. Oh, I forgot, it is fiction a lot of the time.

              On the other hand, Rupert Murdoch isn’t busy spinning everything to death. I don’t always agree with what I see on the Fox News Channel (not nearly always) but I have a lot more confidence that the news is accurate and the commentary honest and well researched. And the best part of it is that they keep news and opinion scrupulously separated. That’s more than I can say for anything else, broadcast, Internet or print media proclaiming to be journalism. The contrast between anything Murdoch and — just for example — that Bill Gates spawned monstrosity, MSNBC, is like the difference between a good steak dinner and an enema.

              Now if I’ve missed a source I could benefit from, please point it out to me. Thanks! :-)


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          Chris Mooney is currently working for Mother Jones pushing Lewpaper ideas.


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        These people are anarchists–unfortunately anarchists are stupid by definition and never realize that what they are advocating is violence and right by might. They have no understanding that the government has all the weapons, the tanks, etc needed to crush them and push them into servitude. They see this as “freedom” but it’s really more like the wild west, where guns ruled, those with all the money have all the rights. Everything they claim to hate is actually what they are advocating but they’re too stupid to see it. I have no idea how to stop it–you can’t fix stupid. Maybe the advent of lawlessness will be enough to snap them back to reality. If not, they will learn a deadly lesson on why society has rules and dumping the rules does not lead to utopia.


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          Roy Hogue

          Absolutely true! And some of the rest of us go down in the resulting chaos. :-(


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            Rereke Whakaaro

            In every battle that is won, there are soldiers who individually lose.

            Winning is therefore all about the ratio of losing, and making sure that the enemy lose more than you do.

            Sobering thoughts, but true.


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              Roy Hogue

              If you are implying, as I think you are, that the goal is for the right army to win regardless of cost then I heartily agree. But I wonder if the right army can win.

              I will take the wins we can get, large or small and for now we have some reason to smile. I hope CG3 puts a long list of people in career and political jeopardy.


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                Rereke Whakaaro

                Yes, that was what I was implying.

                And, taking this right into the realms of Military Science (another “science” that is not really a science, just like climate), the good news is that the Skeptic faction has more troops than the Alarmists can field, and the Skeptics, in the main, are better trained, and have more experience. The rest of the population consists of concerned, and rather confused Civilians.


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          Rod Staurt

          Sheri did a number on Jose. He chose to troll where no troll had trolled before. And Sheri wupped the little pup for his trouble. He said “Venció a mi buen culo real!”


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        cohenite

        I gave up after the first page; it degenerated into an argument over ID and secularism.


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    Athlete

    About the only thing missing from Marcott’s concoction is a predated email saying “We have to find some way of getting rid of the Holocene”.


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      Actually, they maybe can find a way to blame humans and then they can put it back. It shouldn’t be too much of a challenge. These people are experts at getting the answer they want.


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    Roy Hogue

    More junk science — it’s so exciting! I think I’m having heart palpitations…wait…it’s only a boredom attack. Yawn!


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    “Does the hockeystick come from the southern hemisphere, the Antarctic?”
    That hockey stick does look a bit like this one.
    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.recent.antarctic.png


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      Roy Hogue

      Yep! Two whole years shows a real trend upward. Or does it show just the foolishness of those who are desperate to prove their place in the annals of climate science?

      At least 11,000 years would be credible if there was enough data…oh…wait a minute…we aren’t supposed to notice that little deficiency, are we?


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      • #

        “Two whole years shows a real trend upward.”
        It was supposed to be a joke Roy!
        What time period will suffice?
        http://nsidc.org/data/seaice_index/images/s_plot_hires.png
        or
        http://www.ancientdestructions.com/antarctica-tropical-climate-paradise/


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          Roy Hogue

          Have no fear, I took it as a joke. :-)

          What time period will suffice? I don’t know for sure. And I think there’s a lot more interesting question to answer first, the one Jo raises in The Skeptic’s Handbook: where is the empirical evidence that CO2 is doing anything? I can’t seem to get anyone to answer that. And that lack of answer seems to make answers to other questions immaterial. What if the sun is really what is driving the warming since [pick any time you want]? It’s a perfectly credible alternative explanation for warming and cooling.


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              Roy Hogue

              Thanks for making my point. There is reasonable doubt. CO2 cannot be convicted.

              None of what I pasted below is proof but neither is there any proof for CO2.

              Research and Applications

              Measurements of total solar irradiance (TSI) are known to be linked to Earth climate and temperature. Proxies of the TSI based on sunspot observations, tree ring records, ice cores, and cosmogenic isotopes have given estimates of the solar influence on the Earth that extend back thousands of years, and correlate with major climatic events on the Earth. These estimates extrapolate many recent detailed observations to long-term observations of fewer (or even one) measurement. For example, accurate TSI measurements from the last 25 years are correlated with solar measurements of sunspots and faculae; these correlations can then be used to extrapolate the TSI to time periods prior to accurate space-borne measurements, since the solar records extend back 100 years for faculae and 400 years for sunspots. Over this extended time range, the extrapolated TSI record can be compared with longer term records, such as tree rings or ice cores, and correlation with these allows extension of the estimated TSI to more distant times, albeit with decreasing certainty. This extrapolation is important for understanding the relationship between TSI and the Earth’s climate; yet the extrapolation begins with the comparison of solar surface features to accurate TSI measurements, a record which is currently only 25 years long.

              Emphasis added for the doubters who will undoubtedly poo poo this.


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      PeterB in Indianapolis

      I predicted about 2 weeks ago on a blog comment (don’t remember whether it was here or another blog) that Arctic Sea Ice would touch the 1979-2008 Average line soon, and Antarctic Sea Ice would hit 1 Million square kilometers above normal also.

      We have a way to go with the Arctic Sea Ice (-0.382 M km^2), but the Antarctic is almost there (+0.912 M Km^2). Overall, GLOBAL Sea Ice is more than half a million square kilometers ABOVE NORMAL, but you won’t hear that at any of the “real climate science” websites now, will you?


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      Rereke Whakaaro

      OMG an extra million km2 of ice!!! It is worse than we thought!!! …

      (Oops, sorry … wrong blog …)


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    PeterB in Indianapolis

    Tree rings don’t make great thermometers, but certain parts of certain trees do make for great hockey sticks :)


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      Eddie Sharpe

      And you cann’t stick a tree everywhere you might like to stick a thermometer.


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      michael hart

      “Does the hockeystick come from the southern hemisphere, the Antarctic?”

      I wouldn’t be surprised. We are now well accustomed to people pulling hockey sticks out of places where the sun don’t shine.

      I’m surprised there isn’t a new medical term to describe what must be a very painful condition.


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      Yonniestone

      Hey Peter, by using the words “rings, thermometers, trees & hockey stick’s” your just giving us Newton/Kennedy fans too much ammunition! HAHA, or maybe it’s some remote Vlad Dracula projection going on (I’m sure we’ve all wished it on stick mann before) but thanks for the funny post, I’ll have a FIELD day if I go on ;)


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      Senex Bibax

      No, they are mostly composites these days.


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    Roy Hogue

    Meanwhile, whatever you may think of Milloy’s process and procedure, there are some interesting revelations over at junkscience.com if you haven’t been there recently.


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    NikFromNYC

    Comic version:


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    This junk science paper is a classic example of how modern climate science is conducted these days.
    The purpose of this paper is NOT to advance mankinds knowledge. Its purpose is to get into the upcoming IPCC report the AR5 and convince policy makers to do the bidding of the activist environmentalist zealots whom the authors are.

    PREDICTION: This paper, along with its predecessor by SHAKUN et al “Global warming preceded by increasing carbon dioxide concentrations during the last deglaciation” will be cited in the IPCC AR5, specifically Chapter 5 “Information from Paleoclimate Archives”.

    The list of authors (who take turns being lead authors with each new paper) of the Shakun et al paper is as follows…
    Jeremy D. Shakun, Peter U. Clark, Feng He, Shaun A. Marcott, Alan C. Mix, Zhengyu Liu, Bette Otto-Bliesner, Andreas Schmittner & Edouard Bard.

    The list of authors of the Marcott et al paper is as follows…
    Shaun A. Marcott, Jeremy D. Shakun, Peter U. Clark, Alan C. Mix

    This little cabal first tried to ‘prove’ that CO2 LEADS temperatures with their Shakun et al paper, and are now trying to ‘prove’ that the recent so called warming is unprecedented.
    The Mannian Hockey Stick zombie is alive and well.

    Bette Otto-Bliesner from the Shakun paper IS A LEAD AUTHOR OF CHAPTER 5 of the upcoming IPCC AR5.

    Peter U Clark is a coordinating lead Author of chapter 13 of AR5.

    p.s Shakun is a graduate of Clarke

    So that’s how current climate science is conducted. First you decide what needs to go into the IPCC report. Then you provide grants to known activist environmentalists (our universities are infested with them) who torture the available data to produce the needed papers with the needed conclusions, voila’, you have modern climate science.


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    Linde

    Uhmm. The ocean data which would seem to be the cause of the spike. Must be the undersea UFO bases. Was that programmed into the computer model?


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      Rereke Whakaaro

      Dunno, all of the techniques used by this crowd look alien to me …


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      Mark D.

      Linde, it’s probably worse than that, it will probably have come from Levitus etal. who simply disregarded ARGO data deemed to be to cold to be correct.

      It’s all about the hidden heat that no one yet has explained the mechanism of how it gets there (and hides).


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    When the facts are against you, create FrankenGraphs. FrankenGraphs are popular fantasies concocted by splicing two graphs together, much like how Shelly’s monster had the hands of a concert violinist surgically attached to the forearms of a blacksmith.
    This aforementioned study is crapola.

    The work of R. B. Alley conclusively shows that the GISP2 Ice Core Reconstruction temperatures were up only about 0.4C since the Industrial Revolution, but were 1.6C higher during the Medievel WP, 2.4C higher during the Roman WP and 3.2C higher during the Minoan WP.

    We are not getting warmer. In fact we are heading into a Grand Solar Minimum. These are the facts. When the facts do not support your theory, create FrankenGraphs!


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    drapetomania

    Even the c grade $CAGW$ team members are not here defending this trash..
    Doesnt (Non) Sceptical Science have a cut and paste for you(instead of thinking).
    Too funny.. :)


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    Escovado

    If you torture the data long enough, it will confess to anything.


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    warcroft

    You want a hockey stick? Well heres a hockey stick for you.

    The latest issue on New Scientist (16th March 2013) has Michael Mann’s 11,000 year hockey stick.
    Ive cut out the article and hockey stick for you here:

    http://www.warcroft.com.au/HockeyStick.png


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      cohenite

      That article sums it up; the horse or lie has bolted, the msm and the punters accept more’evidence’ and on the whole great stinking scam rolls.


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        wes george

        Cohenite,

        The faithful might gratefully accept this tosh as salvation for their gospel, but, bloody hell, if this is the best the Alarmists got then the debate really is over.

        Marcott is a kind of last Hooray. A rare opportunity for the faithful to give a standing ovation. Maybe the last opportunity. A farewell feast.

        Nevertheless, Marcott might well be the “jumping the shark” moment, at least for a larger section of the science literate out there who weren’t paying attention to the last dozen times the AGW saga has jumped the shark.

        This paper is excellent news on so many levels! A gift, really.

        1. It confirms there is no real evidence to suggest the climate is doing anything unusual. (I should qualify that by noting The Team has thus far been so incompetent that if the Earth’s climate is spinning out of control it is questionable that they would have noticed anyway.)

        2. The wilful abuse of statistics confirms that The Team is not interested in a rational inquiry into climate, but instead are guided by evangelicalism for a special agenda. This casts doubt on the usefulness of all their work.

        3. The paper will tend to push people in charge of policy decisions away from the warmist agenda, because let’s face it, most people aren’t corrupt, nor fanatically committed to what is fundamentally an evangelical fervour. We can expect most rational people in a position of power to act in their self-interest to be on the right side of best practice, if possible. This paper will make any intelligent technocrat or business leader very uncomfortable if they have thrown their chips in with the Warmist gravy train.

        4. The illusion that the Alarmists are scoring meaningful points with this paper reinforces the suicidal denial that the career alarmists are now suffering en masse as they stride shoulder-to-shoulder towards oblivion. It’s a classic example of a terminal sub-culture choosing to believe that simply wishing reality conformed to their worldview makes it so. Epic fail. Marcott is like the band playing on the deck of the Titanic. They’ll keep it up until the icy cold waters of reality drown them out.

        5. There really is no coming back from Marcott. This is the real climate catastrophe. The alarmists have made their pack with the devil. From here on out, it’s going to be kamikaze pseudo-science as the CAGW meme waltzes towards the lunatic fringes of society. That said, I don’t expect the Alarmist energy to be destroyed, that would violate thermodynamics. Instead it will be transmuted into other forms every bit as virulently anti-human as Warmist philosophy is today.


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          Eddie Sharpe

          Well if a few MSM articles were to pick up on the fraudulence of how this presentation sharpens recent trends vs. dulling those of more indistinct timeframes, then populations might see it for what it is. There are a few and increasing number of MSM journalists ready to do that.


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    AndyG55

    As for the smoothing, many of the proxies are maritime proxies.

    They are not going to show up the large swings that land proxies will.

    I suspect that that spike at the end comes from one aberrant land proxy which has be over-emphasised on purpose.


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    Manfred

    So, post-normal science reaches a new high in ‘Science’. Riddled with spin, and with the lead author (Marcott) self-effacingly and openly acknowledging the lack of ‘robust’ data, one is left wondering whether in fact the whole exercise is a Trojan Horse, that is, it is weak, known to be weak, and acknowledged to be weak by the lead author. It is readily picked up by the MSM and may even feature in AR5 and in so doing, it will confirm to all the intellectual, scientific and political bankruptcy of the toxic Green activism associated with atmospheric climate science and their hapless stooges in both the MSM and politics.

    The first line of the Marcott et al. (2013) abstract states:

    Surface temperature reconstructions of the past 1500 years suggest that recent warming is unprecedented in that time.

    and the last lines of the abstract end with:

    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:

    Intergovernmental Panel on Climate Change model projections for 2100 exceed the full distribution of Holocene temperature under all plausible greenhouse gas emission scenarios. (my bold)

    Now, this is the important contrast, the Editor’s quite temperate and bland summary states:

    Marcott et al. (p. 1198) constructed a record of global mean surface temperature for more than the last 11,000 years, using a variety of land- and marine-based proxy data from all around the world. The pattern of temperatures shows a rise as the world emerged from the last deglaciation, warm conditions until the middle of the Holocene, and a cooling trend over the next 5000 years that culminated around 200 years ago in the Little Ice Age.

    and:

    Temperatures have risen steadily since then, leaving us now with a global temperature higher than those during 90% of the entire Holocene.

    One could forgiven for surmising that the author and editor were writing about different papers. The differences and orientation of the respective summaries are both glaring and incongruous. For example, the Editor talks of the last 11,000 years, but the title of the paper is the last 11,300 years. This is an important distinction as the temperature resolution in the data sets are stated to be 120 / 300 / 500 years. Is the Editor perhaps sending us a message? And again, the Editor states that global temperatures are higher now than 90% of the Holocene, whereas the abstract states this value at 75%. Bizarrely mistaken or deliberate? I’d go with the latter.

    And as McIntyre http://climateaudit.org/2013/03/13/marcott-mystery-1/#comment-404356 quotes Marcott stating: “Please note that we clearly state in paragraph 4 of the manuscript that the reconstruction over the past 60 yrs before present (the years 1890 − 1950 CE) is probably not robust because of the small number of datasets that go into the reconstruction over that time frame.” Thereafter, the ‘not robust’ term repeats itself with alarming frequency.

    It is fair to opine that the peer review process has failed ‘Science’, or perhaps it has been the pal review process that has worked well, who knows. The editorial position is clearly different. There notable inconsistency between the editorial summary and the abstract that frankly stinks.

    The last sentence of the abstract that refers to IPCC models is the truly clanging non sequitur that was inserted by the political spin meisters. It is bone-jarring in its irrelevance to the subject at hand and it betrays any science that has taken place.

    Finally, given the alleged similarities between Marcott’s PhD thesis and the publication, it would seem that postdoc Shaun Marcott has unwittingly just had his scientific career irretrievably hijacked to oblivion, whether unwittingly or otherwise.

    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. Marcott SA, Shakun JD, Clark PU, Mix AC.


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      john robertson

      Climatology is not a scientific pursuit.
      More like stage magician, with same methods and motives.
      Suspect this is peak of alarmism and with the fall of AR5 they’re gonna change to the next smoke screen for their cause.
      The cause seems to be about killing all the poor brown people in the world.
      The eco-nutbags seem to believe they can save the planet by killing mankind off.
      But if thats their logic, what happened to strength of conviction oh greenies? You first.


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        Roy Hogue

        And now I’ve just got to put this question to those of you who are better able to evaluate proxy evidence than I am. How valid is this in the first place?

        Forgive me for making a few arguments for the way I see things. And feel free to disagree.

        To me it’s just a few steps up from reading tea leaves. It’s one thing to investigate by whatever means you have and to theorize based on what you find. But to make bold assertions that you’re conclusions are absolutely correct, that no one can challenge you about it and then to make sweeping public policy decisions on that basis is quite another — wait a minute here! Who’s fooling who? And this isn’t the first use of proxy or questionable data.

        Even the theory that all this is based on, that CO2 in the atmosphere can somehow warm the planet, is a long way from proven. In fact, I’ve looked for evidence to support it and I don’t find it. I keep asking as you know (and probably wish I wouldn’t ;-) ). It’s a theory hanging over the edge of a cliff and losing its grip. What am I missing?

        Jo accepts that CO2 can warm the Earth. But then she holds to this day that there’s insufficient evidence to show that it can make any difference. Even the amount of difference it can theoretically make seems to be no more than a matter of opinion. If she changes her mind on it she’d have to publish a retraction of The Skeptic’s Handbook (if I misread you Jo, please correct me).

        It looks like what someone mentioned earlier, the band playing stoically as the Titanic goes down. Only the ship has sunk already. Who is fooling who? Are we not debating whether the band is playing a march or a waltz?

        Instead, let’s debate how large the funeral pyre should be. I’ll bring the match and the gasoline if you’ll bring the wood. Someone volunteer to bring hotdogs and marshmallows and we’ll have party! :-P


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      Roy Hogue

      One could forgiven for surmising that the author and editor were writing about different papers.

      Manfred,

      An interesting observation. Now does he get the message?

      As you say,

      …it would seem that postdoc Shaun Marcott has unwittingly just had his scientific career irretrievably hijacked to oblivion, whether unwittingly or otherwise.

      I hope it was, “…otherwise.”


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      Roy Hogue

      And whatever happened to AD anyway?

      CE, BCE, what do those mean? BC and AD at least had well known, unambiguous meanings with a very well known boundary date marking the line between them. They stood for a very long time. Now for some reason we can no longer keep time relative to the birth of Christ (who isn’t politically correct)? So change the names but leave the date stand because, after all is said and done, there is no other date to use.

      Someone please explain this to me.

      Yes, I think this change is strictly secular progressive political nonsense and without the slightest scientific, historical or any other kind of merit whatsoever.


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        Mark D.

        Roy, the PC “Common Era” is sold as “more respectful” of other religions and cultures but it’s rather obvious that it is simply anti Christian. The Western world pretty much uses the same calendar and the year numbering starts with Christ.

        Look for a push for a new yearly numbering system coming soon to a PC secular theater in your town….

        In the meantime read up on what drives at least part of what is going on in the world:
        http://www.secularhumanism.org/index.php?section=main&page=manifesto

        Sorry if this is off topic.


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          Roy Hogue

          Sorry if this is off topic.

          It’s very on topic to me, Mark.

          BCE/CE, I do know what those mean. And they stick in my throat like trying to eat sand — dry, sterile, devoid of context both culturally and historically. They nauseate me like being offered a plate of garbage to eat. I choke on that like it was poison — and it is.

          What’s coming is an attempt to completely erase western civilization. It will result in despotism of the worst possible kind from which there will be no refuge on this earth if we cannot reverse it. It will set mankind back into darkness of the mind spirit and soul. The body, of course, will then be free to indulge in anything it wants to do, except actually think for itself. Yea! Free love at last! Have you looked at sex education in your local schools?

          I see this world only too clearly, Mark. It’s all over the Internet, all over our schools and our government. It is malignant beyond belief. The serpent has offered the apple and Eve has swallowed it, hook, line and sinker. We may take solace only in the fact that the sinker is lead, therefore poisonous to the fools who go for it. But I am not going down silently. How about you?


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          Roy Hogue

          Look for a push for a new yearly numbering system coming soon to a PC secular theater in your town…

          Mark,

          It didn’t strike me until I reread that statement. But at least that change is likely to die the same death as the attempt to convert the U.S. to metric units. Inertia is a powerful force — politically speaking of course, not in the physics world (unless maybe a falling brick hits you on the head ;-) ).


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        Eddie Sharpe

        Yes, indeed. CE & BCE not to be confused with around 1534 when Henry VIII established the Church of England with himself at its head, to satisfy his rapacious appetite for brides.

        Is it any wonder youth gets confused ?


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    john robertson

    Slightly off topic, when are the CG3 emails expected?
    And WUWT is approaching 1 million comments, less than 1000 to go by my calculation of 1/2hour ago.
    Too bad John Brookes got himself banned, he might have won the Big Oil Money Prize.
    Thats a coffee cup to the rest of us.


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      Speedy

      Hi John (Robertson)

      Too bad John Brookes got himself banned,

      There’s always a positive. Sure, the traffic went down, but the average IQ went up considerably. :)

      Cheers,

      Speedy


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    Geoffrey Cousens

    Awful propaganda,will it never end?


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    KinkyKeith

    This paper, with the new hockey stick and the original un-enhanced version does what so much of the Global Warming “science” does;

    it provides more publicity for the Warming cause; nothing else.

    The main point of what I am writing should become obvious even to people like JB and SV, KR. Mr T, GA and JXXX to name a few.

    I intend to repeat it in a number of ways.

    It is important.

    The burden of proof, on the proponents of CO2 induced AGW,

    is to show that CO2 is actually linked to global atmospheric temperature in a CONTROLLING mechanism.

    That has not even been POSTULATED or “defined so that it can be disproved” in science speak.

    If a hypothesis is not clearly defined it is not falsifiable and therefore NOT a hypothesis.

    There is NO TESTABLE hypothesis for the CO2 – Atmospheric Temperature claim.

    All the warmer intelligentsia have is Public Commentary.

    There is no testable hypothesis and therefore NO SCIENCE OF CO2 RELATED GLOBAL WARMING.

    Any attempt to create the necessary hypothesis is immediately faced with a number of much stronger contenders such as orbital mechanics so

    the relative role of A-CO2 is not clearly defined.

    All that can be said, is that it will be relatively small compared to Solar and Orbital considerations.

    From a strictly scientific point of view, there has been no connection made between temperature change and CO2 levels in the “Forcing” sense

    so beloved of CAGW proponents, nor has the mechanism by which man made CO2 is supposed to lead to temperature change been quantified.

    All we have is “commentary” and science by association; still, after all these years.

    There is NO testable hypothesis and there is therefore no way of disproving the unavailable hypothesis and so all we have is public

    discussion and THAT is not science.

    I don’t know how or why mainstream scientists have let them get away with this for so long.

    No testable hypothesis in relation to CO2 induced climate change = NO PROOF of CAGW.

    KK :)


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    A C of Adelaide

    What surprises me is that I would expect the older the data – the greater the uncertainty. But it is actually the most recent data that shows the greatest range (see the spaghetti diagrams in the Thesis and paper) How could the uncertainty in the proxies(for say 1920) be so large when all you have to do is look in the newspaper of the day and see what the temperature really was? If the proxy data cant even match/replicate the modern era then what use is any of it?


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      Eddie Sharpe

      Ah but , it’s quite simply because for long ago you cann’t be so sure about the uncertainty, but for the recent past, when we have real thermometers to compare to, the uncertainty cannot be so easily fudged and explained away as there is evidence so plainly staring us in the face.


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    John Brookes

    One thing I’m a bit confused about – why do we need proxies in the modern era when we have instrumental records?


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      Skiphil

      If a proxy does not validate against the instrumental record (assuming for this discussion that we have accurate temp. records in recent decades) then why would you assume/believe that said proxy was always accurate for centuries prior, in eras when we cannot check it against any independent scientific instruments??


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        Sonny

        That’s when it becomes important to do tricks to hide the decline, (translation: hide the divergence)


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        Nice One

        If the proxy doesn have enough data in the modern timeframe, then there’s not much you can do – well except post strawman arguments obviously.


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          Winston

          No, NO,
          If you are Marcott then the whole point of your thesis, and therefore the crux of your argument, hinges on data you actually acknowledge on questioning are not at all robust and hence the conclusion is invalidated. Marcott is the one using that particular straw man as his evidence, not Jo, since if there was robust data there would be no hockey stick in the modern era as it is dependent on cherry picking among a cluster of proxies, many diverging in the direction of their dubiously significant data.

          So, it is one pseudoscience (dendrochronology) used to confirm another (climatology). I notice you have not been able to address any of Jo’s points above, and yet I recall a few threads ago that you, Nice One, were the first to gleefully point to this paper with much fanfare as some sort of gotcha moment. It appears your gloating was premature, and you lacked the inquiring mind and analytic capacity to pick apart the glaring errors in this paper as Jo has done, yet you feel qualified to criticise her- you are kidding yourself if you think you are the one defending science.


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          Streetcred

          Sitting on your “proxy” again, NO ?


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      AndyG55

      I though you were meant to have a degree in science or something..

      And yet you ask that question???

      How the **** did you ever pass !????


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      Eddie Sharpe

      In a nutshell, the instrumental record serves to show just how poor an indicator proxies really are.


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        Nice One

        I agree. But the proxy data in this report can’t be used as evidence to show that it has warmed as rapidly as it is today.

        Funny how “so called skeptics” try use proxy data to claim the MWP was warmer than today (although Jo failed on that one – Still waiting Jo!).


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          Eddie Sharpe

          But the proxy data in this report can’t be used as evidence to show that it has warmed as rapidly as it is today.

          You are beginning to get it. The proxy data has been too smoothed to be capable of indicating any warming that actually occurred previously with a rate comparable to last century’s.
          So any conclusion from this report about the rate of last century’s warming would be non-sequitur.


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            Nice One

            So blog science says.


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              Eddie Sharpe

              No, so, Robert Rohde, the chief data analyst behind the Berkeley Earth Surface Temperature projec.says:

              their reconstruction appears to tell us about past changes in climate with a resolution of about 400 years. That is more than adequate for gathering insights about millennial scale changes during the last 10,000 years, but it will completely obscure any rapid fluctuations having durations less than a few hundred years.

              (My highlighting).
              And what’s more he goes on to say :

              The only time such obscuring might not occur is during the very recent period when dating uncertainty is likely to be low and sample spacing may be very tight

              So there you have it, apresentation that could hardly have been better chosen to accentuate recent warming while dulling past changes..


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                KinkyKeith

                Nice one Eddie!


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                Rereke Whakaaro

                Oh, so that implies that taking more frequent readings increases global temperatures.

                The conclusion therefore is that Climate Science is the cause of Climate Change.

                But of course, we knew that already.


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                Mark D.

                Nice One -30
                Eddie +15

                That’s what I call feed back.

                I wonder if NOise will be back with some tail-between-legs comment.


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                Nice One

                You missed this part of the discussion.

                In all likelihood many of these factors are discussed in the supplemental material, but since I don’t have access to that I can only comment on the parts that I can immediately see.

                And the part where I give a hoot what some guy on the internet says. When it’s part of the peer-reviewed literature, let me know.

                And why do you now accept the comments of one member of the BEST team (when it suits you) but won’t accept their findings on UHIE? (and watts screwed up on that one too – still waiting for him to publish his “blockbuster” paper).


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          Andrew McRae

          Mrs Nice, when you admitted:

          the proxy data in this report can’t be used as evidence to show that it has warmed as rapidly as it is today.

          …You have also admitted that these proxies cannot be used as evidence to show the rate of warming is unprecedented. They are averages of more than 60 years so they do not have 30-year rates of warming in the data.

          Rates of warming are a totally different topic to average temperature, and so it was a non sequitur for you to chime in

          Funny how “so called skeptics” try use proxy data to claim the MWP was warmer than today

          You have already been told why the same temporal resolution problem prevents making comparisons of extremes between ancient and modern times, regardless of alarmist headlines.

          Your dispute over the MWP > CWP issue is relevant to CAGW because it shows that anthropogenic forcing is not the only plausible explanation for current events.

          I note you have raised a rather good point that Idso’s method (according to your description of it) of just counting a proxy’s reconstructed temperature doesn’t identify a global warming when the periods they estimate do not sufficiently overlap.
          Be that as it may, let’s not get bogged down in his counting technique. The question is, Do proxies from around the world tell us of a warm period similar to today lasting at least 60 years starting some time between 900AD and 1100 AD with at least 50 year overlap?

          Greenland Ice Core says Yes at 900AD.
          The Vostok Ice Core says Yes at 900AD.
          A New Zealand cave stalagmite says Not Quite (only at 1150AD or later).
          Ocean sediment from the Indo-Pacific says Yes but only at 1000AD.
          Ocean Sediment in Gulf of Mexico says Yes at 900AD.
          Southern South America says yes for 900AD but shows a warmer period at 1080AD too.
          Marcott’s multi-proxy study says Yes for 900AD in several of the graphs above but without the raw data it hard to tell if it is more than 50 years apart from 900AD.

          So warm periods with significant overlap did occur in the southern hemisphere, and some proxies do show coincident warm periods separated as far as Antarctica and Greenland. Therefore the MWP was definitely NOT merely “a NH phenomenon”.

          But there is a 200 year spread that keeps some other proxies from warming at the same time, and 200 years is a fair amount of error if this non-alignment is due to error. I think the most you can say is that the Earth warmed at the poles first, but measurement error prevents us from concluding either way about whether the MWP was global or not global.
          Personally, I think a co-incident warming starting at 900AD in Vostok, the Gulf of Mexico, and Greenland, qualifies objectively as a global medieval warm period.

          What you cannot deny is that ancient warm periods lasting hundreds of years have been found in various places, in various times, and individually have been shown to be about as warm as the CWP. Also considering the Earth today is not warming at the same rate in all places, why should we insist that past warmings be simultaneous everywhere? It is probably an unnecessary condition.
          So natural variability is still a plausible explanation for the majority of CWP.


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      Speedy

      JOHN

      Don’t you think that data sets should be validated against reality? Failure to do so in an open forum made all the cafuffle with the hockey stick – the alleged scientists were conveniently slipping in real-time data in place of recent proxy data to hide the fact that their proxies were wrong. Their object seems not to have been not to inform but to spin. How do you spell “fraud”, Mummy?

      As someone employed by a University, aren’t you interested in Truth?

      If not, then you are paid on false pretences. Please join the queue behind wannabe Dr. Marcott. The going rate is $260/week, see Centrelink for details.

      Cheers,

      Speedy


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      Roy Hogue

      …why do we need proxies in the modern era when we have instrumental records?

      I give up, John. Why do we need those proxies? Could it be that the instrumental record doesn’t show what they want it to show? Could it be that they’re dishonest?

      You tell me and we’ll both know.


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      Philip Shehan

      Correct John. See my longer comment at #1.4. Figure 4a must be viewed in the context of Figures 4 b,e and f and Figures 4.2a-d which do show the uptick and how data may be represented differently in a short paper compared to a long thesis.


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    James

    John. Don’t you insturmental models manufactured to a certain conclusion based on instrumental records but not identical to.


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    dp

    This much is obvious from this report, and I will try to be brief.


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    Jimmy Haigh

    John Brookes

    March 16, 2013 at 3:43 pm · Reply

    “One thing I’m a bit confused about – why do we need proxies in the modern era when we have instrumental records?”

    That’s easy. it’s because the recent instrumental record shows that the temperature has not risen for the last 15 to 20 years…


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      Otter

      Don’t confuse brooksie with the facts. He might lose his religion. Provided, of course, that he had any intelligence to understand what you just said.

      Oh, and brooksie? I see your smugly ignorance got you banned at WUWT. The IQ level jumped a fair bit over there- who knew you could skew the average so badly, all by yourself?


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    Nice One

    The spike of the last century is found by looking at modern thermometer records from around the planet.

    Yet another strawman argument from Nova.

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      KinkyKeith

      How’s this for a pile of straw?

      The errors in estimating temperatures from ice cores and other proxies are large but relatively constant.

      These are shown on many of the graphs.

      What is also shown on the graphs is a pattern of wild fluctuations in some of the proxies.

      OK so what?

      Nothing really but I just wanted to make the point that I am not convinced that proxy record data should appear on the same graph as mercury/alcohol thermometer records for the last two centuries.


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      Roy Hogue

      Please don’t confuse Nice One with actual logic. Next you’ll want a pint of blood?

      Hey! Come to think of it…


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      Philip Shehan

      Correct N.O. See my further explanation at #1.4.


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    Dennis

    The blind man Brookes is back


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    Sonny

    Brookes and Nice One are proud members of the religion of AGW.
    No amount of evidence, no number of years without warming will convince them otherwise.
    Pointless to try.


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      Neville

      Agreed.
      John Brookes and “Nice One” exhibit a clear pattern of disagreeing with anything at all that appears (to them) to be related to the time-honoured scientific method. The “skepticism” they offer is clearly enough (at least, to me) to be nothing more than attempts to devalue any discussion and arguments based on facts. And, as far as I’m aware, facts are the ultimate arbiter.
      To paraphrase Sagan: “If one fact disproves the theory, then the theory is wrong”. Ref Kinkykeith above; there IS NO stated hypothesis linking CO2 with warming, much less a theory of same – therefore there is no argument, only guesswork, at present.


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    Senex Bibax

    Marcott and Mann both forgot the first rule young hockey players are taught.. “Keep your stick on the ice!”.


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    jorgekafkazar

    Statistical conglomerations based on noisy, multi-source data, especially proxy data, are drivel. Embellishing them with weasel-word disclaimers is like putting lipstick on a pig.


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    Manfred

    And so it came again to pass, as it is written in the stars, the dreaded curse of the (sch)tick exacted its toll.

    The thirteenth sign of the Zodiac, the fabled Schtick (Hockey, Up, tick etc), guarantees debunking and worse.

    Northern hemisphere (Mann et al. 1998), southern hemisphere (Gergis et al. 2012) or global (Marcott et al. 2013)…lasting posters for ‘progressive’ science.

    Do they ever learn? (rhetorical / sarc)


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    Ross

    John & Niceone should look at the latest from Steve McIntyre on this “paper” from Marcott et al.

    http://climateaudit.org/2013/03/16/the-marcott-shakun-dating-service/

    This is worse than the Gergis situation.

    There are now a lot of reputations going down, you know where. They include Science mag. , these so called scientists, probably the University who employs them , Mann who rushed out to endorse the paper ( probably without reading it) and all the puppet journalists in the MSM.


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      Mark D.

      Ross, I can only guess that since the likes of KR and the other more analytical types in the warmist troll camp have NOT stepped out to defend this piece of “work” it truly isn’t worth much.

      One can ask if the media that first heralded it so loudly will retract and do that just as loudly?


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        Dennis

        The unprofessional media majority would never admit they got it wrong but the truly professional amongst them surely will.


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        Philip Shehan

        So typical that anyone on a discussion site who does not join in the group hugs and mutual congratulation of each others insights by the “skeptics” and is actually skeptical of their claims is a “troll”. Fine to put my hand up for that one so kindly respond with proper analysis to my post at 1.4


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      Manfred

      Ross, I believe you’re quite correct – Marcott et al. is indeed ‘much worse’ than Gergis et al. The paper should be withdrawn. However, given my previous comments, I think that it may have been ‘designed’ to crash and burn. It is hard to credit this work as anything more than rubbish. The authorial collective would normally have striven to ensure that their work was watertight, knowing it would be scrutinized very carefully. Instead, it will serve only to bring disrepute on the authors, their institution and the journal. It did nevertheless achieve one objective – help fuel the dying embers of the CAGW meme – but, as we know, the moment of incandescence was truly brief.

      There is something odd here, not least the obvious discord between the editorial summary of the paper and the abstract. Most postdocs endeavour to get their work published, which has been achieved, but at a horrible price I think. The work has been spin-meistered to death, including the utterly ridiculous non sequitur last sentence of the abstract (#19). I would love to know what was promised to Shaun Marcott.


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        john robertson

        Noticed same thing, so what is being slid by while this steaming pile of Marcott distracts our attention?


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        Ross

        Manfred

        A number of people are suggesting that this paper was rushed through to ensure it got into the IPCC report. But I think they have misjudged things completely. This is so bad there is no way the IPCC can include it. If it did then the IPCC’s reputation would be completely gone. It is shakey now but this paper is not just another debatable issue , it just does not hold water at all.
        Also I have feeling Steve McIntyre isn’t finished yet.


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      junkpsychology

      If Steve McIntyre is right about the redating of the alkenone core tops, I can’t see any way that the Marcott et al. paper will hold up.

      Amazing.


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        It appears that the spike comes from proxy data from the 30′s and 40′s reflecting the dust bowl era that the team and Jim Hansen have been trying to adjust out of the data. The “Trick” they used was to use the “1950 before present” time line to chop off the decline from the 40′s into the 50′s, 60′s and 70′s
        “ice age scare”.
        The spike was created from the heat of the long gone dust bowl era, we are to be soooo fearful of what “is going to happen” 75 years AGO!


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  • #

    The December 3rd 2012 Synod conjunction of Jupiter and Earth started an atmospheric oscillation that resonated with the Mars and Jupiter when they had a synod conjunction on the 16th of January 2013 to give Australia “the short term heat wave”.

    Be ready as this same effect will occur for several years yet, next year it almost comes altogether Earth and Jupiter on the 5th January 2014, Mars and Jupiter on the 8th, and Earth with Mars on the 11th of January 2014.

    By the 6th of February 2015 it is just Jupiter and the earth so expect the resultant short drought and heat spell to come later. These are the causes of the pulses of extreme weather and has nothing to do with background levels of CO2, it is due to blocking patterns generated in the global circulation due to the electromagnetic effects of the enhanced solar wind flows during synod conjunctions.

    The timing of the production of blocking highs in both NH & SH is predictable by this method, with a good track record used by myself, and Piers Corbyn, but still not paid attention to by Ken Ring, accounting for some of his greatest forecast errors.


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    ExWarmist

    latest work on this topic from Steve McIntyre

    By blanking out the three most recent values of their proxy #23, the earliest dated value was 10.93 BP (1939.07 AD). As a result, the MD01-2421+KNR02-06 alkenone series was excluded from the 1940 population. I am unable to locate any documented methodology that would lead to the blanking out of the last three values of this dataset. Nor am I presently aware of any rational basis for excluding the three most recent values.

    Since this series was strongly negative in the 20th century, its removal (together with the related removal of OCE326-GGC30 and the importation of medieval data) led to the closing uptick.

    Science by Omission: (Technique #1) Omit off-message or refuting data.


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    jaymam

    Has anyone noticed that the Google Autocomplete drop-down menu refuses to complete [Marcott et al]?
    So when you tell warmists to look for the paper and all the discussions, they can’t find it.


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    crakar24

    Came across this Cg email not sure if it is from I, II or III and cant be arsed going through 170 odd comments to see if it has already been posted so here it is, appologies to all if i am repeating what has already been said however i think it puts the hockey stick myth no matter what version it is to rest.

    Cheers

    Original Message
    From: Michael E. Mann
    Sent: Wednesday, May 02, 2001 8:14 AM
    To: Edward Cook
    Cc: tom crowley ; Michael E. Mann ; esper@xxxxxx ; Jonathan
    Overpeck ; Keith Briffa ; mhughes@xxxxxxx ; rbradley@xxxxxx
    Subject: Re: hockey stick

    Hi Ed,

    Thanks for your message. I’m forwarding this to Ray and Malcolm to reply to some of your statements below,

    mike

    At 10:59 AM 5/2/01 -0400, Edward Cook wrote:

    Ed,

    heard some rumor that you are involved in a non-hockey stick reconstruction of northern hemisphere temperatures. I am very intrigued to learn about this – are these results suggesting the so called Medieval Warm Period may be warmer than the early/mid 20th century? any enlightenment on this would be most appreciated,

    Tom
    Thomas J. Crowley
    Dept. of Oceanography
    Texas A&M University
    College Station, TX 77843-3146

    Hi Tom,

    As rumors often are, the one you heard is not entirely accurate. So, I will take some time here to explain for you, Mike, and others exactly what was done and what the motivation was, in an effort to hopefully avoid any misunderstanding. I especially want to avoid any suggestion that this work was being done to specifically counter or refute the “hockey stick”. However, it does suggest (as do other results from your EBM, Peck’s work, the borehole data, and Briffa and Jones large-scale proxy estimates) that there are unresolved (I think) inconsistencies in the low-frequency aspects of the hockey stick series compared to other results. So, any comparisons with the hockey stick were made with that spirit in mind.

    What Jan Esper and I are working on (mostly Jan with me as second author) is a paper that was in response to Broecker’s Science Perspectives piece on
    the Medieval Warm Period. Specifically, we took strong exception to his claim that tree rings are incapable of preserving century time scale temperature variability. Of course, if Broecker had read the literature, he would have known that what he claimed was inaccurate. Be that as it may, Jan had been working on a project, as part of his post-doc here, to look at large-scale, low-frequency patterns of tree growth and climate in long tree-ring records provided to him by Fritz Schweingruber. With the addition of a couple of sites from foxtail pine in California, Jan amassed a collection of 14 tree-ring sites scattered somewhat uniformly over the 30-70 degree NH latitude band, with most extending back 1000-1200 years. All of the sites are from temperature-sensitive locations (i.e. high elevation or high northern latitude. It is, as far as I know, the largest,longest, and most spatially representative set of such temperature-sensitive tree-ring data yet put together for the NH extra-tropics.

    In order to preserve maximum low-frequency variance, Jan used the Regional Curve Standardization (RCS) method, used previously by Briffa and myself with great success. Only here, Jan chose to do things in a somewhat radical fashion. Since the replication at each site was generally insufficient to produce a robust RCS chronology back to, say, AD 1000, Jan pooled all of the original measurement series into 2 classes of growth trends: non-linear (~700 ring-width series) and linear (~500 ring-width series). He than performed independent RCS on the each of the pooled sets and produced 2 RCS chronologies with remarkably similar multi-decadal and centennial low-frequency characteristics. These chronologies are not good at preserving high-frquency climate information because of the scattering of sites and the mix of different species, but the low-frequency patterns are probably reflecting the same long-term changes in temperature. Jan than averaged the 2 RCS chronologies together to produce a single chronology extending back to AD 800. It has a very well defined Medieval Warm Period Little Ice Age 20th Century Warming pattern, punctuated by strong decadal fluctuations of inferred cold that correspond well with known histories of neo-glacial advance in some parts of the NH. The punctuations also appear, in some cases, to be related to known major volcanic eruptions.

    Jan originally only wanted to show this NH extra-tropical RCS chronology in a form scaled to millimeters of growth to show how forest productivity and carbon sequestration may be modified by climate variability and change over relatively long time scales. However, I encouraged him to compare his series with NH instrumental temperature data and the proxy estimates produced by Jones, Briffa, and Mann in order bolster the claim that his unorthodox method of pooling the tree-ring data was producing a record that was indeed related to temperatures in some sense. This he did by linearly rescaling his RCS chronology from mm of growth to temperature anomalies. In so doing, Jan demonstrated that his series, on inter-decadal time scales only, was well correlated to the annual NH instrumental record. This result agreed extremely well with those of Jones and Briffa. Of course, some of the same data were used by them, but probably not more than 40 percent (Briffa in particular), so the comparison is based on mostly, but not fully, independent data. The similarity indicated that Jan�s approach was valid for producing a useful reconstruction of multi-decadal temperature variability (probably weighted towards the warm-season months, but it is impossible to know by how much) over a larger region of the NH extra-tropics than that produced before by Jones and Briffa. It also revealed somewhat more intense cooling in the Little Ice Age that is more consistent with what the borehole temperatures indicate back to AD 1600. This result also bolsters the argument for a reasonably large-scale Medieval Warm Period that may not be as warm as the late 20th century, but is of much(?) greater significance than that produced previously.

    Of course, Jan also had to compare his record with the hockey stick since that is the most prominent and oft-cited record of NH temperatures covering the past 1000 years. The results were consistent with the differences shown by others, mainly in the century-scale of variability. Again, the Esper series shows a very strong, even canonical, Medieval Warm Period Little Ice Age 20th Century Warming pattern, which is largely missing from the hockey stick. Yet the two series agree reasonably well on inter-decadal timescales, even though they may not be 1:1 expressions of the same temperature window (i.e. annual vs. warm season weighted). However, the tree-ring series used in the hockey stick are warm-season weighted as well, so the difference between “annual” and “warm season” weighted” is probably not as large as it might seem, especially before the period of instrumental data (e.g. pre 1700) in the hockey stick. So, they both share a significant degree of common interdecal temperature information (and some, but not much, data), but do not co-vary well on century timescales. Again, this has all been shown before by others using different temperature reconstructions, but Jan’s result is probably the most comprehensive expression (I believe) of extra-tropical NH temperatures back to AD 800 onmulti-decadal and century time scales.

    Now back to the Broecker perspectives piece. I felt compelled to refute Broecker’s erroneous claim that tree rings could not preserve long-termtemperature information. So, I organized a “Special Wally Seminar” in which I introduced the topic to him and the packed audience using SamuelJohnson’s famous “I refute it thus” statement in the form of “Jan Esper and I refute Broecker thus”. Jan than presented, in a very detailed and wellespressed fashion, his story and Broecker became an instant convert. In other words, Wally now believes that long tree-ring records, when properly selected and processed, can preserve low-frequency temperature variability on centennial time scales. Others in the audience came away with the same understanding, one that we dendrochronologists always knew to be the case.

    This was the entire purpose of Jan’s work and the presentation of it to Wally and others. Wally had expressed some doubts about the hockey stickpreviously to me and did so again in his perspectives article. So, Jan’s presentation strongly re-enforced Wally’s opinion about the hockey stick, which he has expressed to others including several who attended a subsequent NOAA meeting at Lamont. I have no control over what Wally says and only hope that we can work together to reconcile, in a professional, friendly manner, the differences between the hockey stick and other proxy temperature records covering the past 1000 years. This I would like to do.

    I do think that the Medieval Warm Period was a far more significant event than has been recognized previously, as much because the high-resolution data to evaluate it had not been available before. That is much less so the case now. It is even showing up strongly now in long SH tree-ring series. However, there is still the question of how strong this event was in the tropics. I maintain that we do not have the proxies to tell us that now. The tropical ice core data are very difficult to interpret as temperature proxies (far worse than tree rings for sure and maybe even unrelated to temperatures in any simple linear sense as is often assumed), so I do not believe that they can be used alone as records to test for the existence of a Medieval Warm Period in the tropics. That being the case, there are really no other high-resolution records from the tropics to use, and the teleconnections between long extra-tropical proxies and the tropics are, I believe, far too tenuous and probably unstable to use to sort out this issue.

    So, at this stage I would argue that the Medieval Warm Period was probably a global extra-tropical event, at the very least, with warmth that was persistent and probably comparable to much of what we have experienced in the 20th century. However, I would not claim (and nor would Jan) that it exceeded the warmth of the late 20th century. We simply do not have the precision or the proxy replication to say that yet. This being said, I do find the dismissal of the Medieval Warm Period as a meaningful global event to be grossly premature and probably wrong. Kind of like Mark Twain’s comment that accounts of his death were greatly exaggerated. If, as some people believe, a degree of symmetry in climate exists between the hemispheres, which would appear to arise from the tropics, then the existence of a Medieval Warm Period in the extra-tropics of the NH and SH argues for its existence in the tropics as well. Only time and an enlarged suite of proxies that extend into the tropics will tell if this is true.

    I hope that what I have written clarifies the rumor and expresses my views more completely and accurately.

    Cheers,

    Ed

    Dr. Edward R. Cook
    Doherty Senior Scholar
    Tree-Ring Laboratory
    Lamont-Doherty Earth Observatory
    Palisades, New York 10964 USA


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    [...] science communicator Joanne Nova explains this in more detail here, citing Marcott et al as saying there is “…essentially no variability preserved at periods [...]


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