Making Holocene Spaghetti Sauce by Proxy

Holocene, historic and recent global temperatures from temperature proxies.

Guest post by: Frank Lansner, civil engineer, biotechnology

NOTE: Link to PDF of this article is HERE

In the climate debate, the temperatures of the past are used to determine if the present temperatures are unique and alarming. Any viewpoint can be supported by choosing specific science papers as reference

This paper is one of many attempts to give a realistic overview of the actual messages we get from the temperature proxies.

(“Temperature proxy”: Past temperatures reconstructed from samples using a row of techniques.

The “Spaghetti graphs” in the following gives an impression of the huge variability among the datasets. The essence of each graphic is the major trends. To enable display of multiple data series it was often necessary to interpolate temperature values to the specific years used in graphics.

To avoid most calibration problems, I have set specific years to zero for the different graphs I chose a year where practically all graphs has data, and no further calibration needed. In few cases I have calibrated from 1980-1990-2000 using UAH trend of approx. +0,1K/decade.)

Recent temperature proxies – 120 years


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Fig 1: 10 multi proxies shown for the 20´th century. In addition 14 temperature proxy datasets. The black curve shows average of the 14 datasets as 1 multi proxy. This multi proxy + the 10 of the most used bigger multi-proxy series is the basis for the WHITE graph: “Average of 11 multi proxies”.

The temperature proxies does not show strong net warming since around 1940. In fact, proxy data does not show any warming since 1940. This is no news, it has been recognised for example here:

The authors call the missing global warming in proxies for “The Divergence problem”. And they try to give reasons for this problem using characteristics of trees. But since other proxies than using tree ring proxies also indicates no global warming after around 1940, the problem seems not related with tree rings measurements.

The divergence problem”:


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Fig 2: The “divergence problem”.

The “All China” multi proxy: A reliable work where 8 regions of China where studied and then yield the final China multi proxy temperature line. The “All USA”, NOAA raw, is the official measured USA temperatures minus the official correction, that is, the raw USA temperature dataset. I find it stunning how close All-China and All-USA matches each other, see fig 2! (- a dataset of measured temperature compared to a dataset of proxies). And unlike GISS 2009, the Northern Hemisphere temperature set of 1976 supports the raw trends of US and China. Several of the multi proxy series have been smoothed with a “50 year weighted Gaussian filter” etc. and therefore any bigger dive around 1970 could not be seen in the multi proxy graph.

We see a divergence after 1950 between:

  • GISS 2009 vs. Average of the multi proxies, that is, the temperature evidence in the ground and trees.
  • GISS 2009 vs. USA, CHINA and NH temperatures
  • GISS 2009 vs. Solar activity.

So, at least when comparing with mostly raw datasets, the GISS 2009 dataset could seem to be the source of “the divergence problem” – “the outlier”. Problems for the GISS data set might be incorrect adjustments, problems with UHI and poor measuring sites, see!!

The “divergence problem” also seems to vanish when using satellite data (UAH/RSS) in stead of GISS data:

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Fig 3: A: Briffa´s 2001 illustration of tree ring proxies combined with the GISS dataset as “Observations” (as the adjusted GISS temperatures are called). B: Same, however this time “Observations” are raw satellite data UAH from 1980 – 2000 with a slope of 0,1K/decade.

There is no divergence problem when using satellite temperature data as “Observations”. We now have total compliance between proxy data and modern temperature measurements stating: No net warming since around 1940-50.

Historic temperature proxies – 1200 years

For this analysis 33 data sets was used. The first that strikes you when working with historic temperature proxies is the apparent chaos of data. However, after keying in 6-8 data sets the well known features “Middle age warm period” and “The little Ice Age” becomes clear. Keying in the rest of datasets doesn’t change much.

First, take a good look at the period 1900 to 2000..

Notice how these 33 datasets confirms the trends from fig 1, the recent temperature proxies. We can conclude that we have a good ability to reproduce the result quite accurate with quite different datasets, and thus, neither of the graphs ( fig 1 and fig 4) are likely to reflect “random” results. All data evidence used in fig 1. + fig 4. actually suggests that today’s temperatures resemble the temperatures of 1940-50. Yes, a divergence problem for the temperature data from GISS and Hadcrut.

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Fig 4: Historic temperature proxy data. Practically all methods and regions of the globe are represented.

6 of the data sets originate from tree ring data.

We see the Medieval Warm Period apparently ongoing already in year 800 and goes on for 5-600 years. First around year 1400 the Little Ice Age really takes over. It was around year 1400 the Vikings left the freezing Greenland.

From year 800 to year 1300 temperatures appears around 0,3 K higher than today. And from around year 1400 to 1900 temperatures appears to be are around 0,4 K lower than today. A difference from MWP to LIA of 0,7 K in average globally. (Max difference approx 1,1 K),

We will return to these historic data later, but lets first take a look even further back in time.

Holocene temperature proxies – 12000 years

For this analysis 29 long datasets where used. All graphs are calibrated to zero for year 1000.

First focus on years 800 to 2000…

Once again we see a reproduced trend between 2 different data sets. And again, the accuracy is nice. The MWP here appears almost 0,8 K degrees celcius warmer than the LIA, very close to what we saw it on fig 4, the historic data 0,7K. This once again confirms the impressing usefulness of data despite the chaotic and random appearance. There is however a tiny difference between the 2 graphs, around 0,1K. But it should be noted, that for the Holocene temperatures, no tree ring data was used. According to Loehle 2007, tree ring data tends to suppress the MWP somewhat. This we will return to.


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Fig 5: Holocene temperature data.

The data point for year 2000 are based on too few datasets to be really trustworthy. Therefore I have inserted the red star where I use the value of todays temperature taken from fig 4, historic temperatures. By doing so, temperature for year 2000 got 0,2 K warmer than from Holocene data.

Fig 5 also shows that the whole debate about MWP is irrelevant. Imagine there was no MWP. Practically ALL of the Holocene period the eath appears to be between 0,5 and 1,5 K warmer than today. The little ice age does resemble a mini ice age or at least it appears to be the coldest period in over 10.000 years.

Finally, the overall picture from the graph is an almost perfect mathematical curve that tops around 5-6000 years ago. These Data tells the story quite clear: We are on a down trend in temperatures globally, we should not fear warmth by now. How much lower can the temperatures on earth go before we reach a tipping point to much colder temperatures at earth?

Medieval warm period

Arguments against the MWP often focus on the “fact” that the warmer temperatures from that period are a phenomenon exclusively to have appeared on the northern hemisphere.

Fortunately, the results from fig 4 and fig 5 shows an excellent match for the period year 800 to year 2000. It thus makes very good sense to combine the datasets and then obtain a better data foundation to analyse the MWP.

Datasets from fig 4 and fig 5 combined, a northern/southern hemisphere display of the Medieval Warm Period:

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Fig 6: Historic temperatures, North and south hemispheres separated. Let’s first see what the graph actually says, very roughly:

NH MWP, 42 datasets:

Ongoing in year 800, temperatures mostly 0,3-0,4 K higher than today.

The temperature creeps below today’s level and ends around year 1300.

SH MWP, 13 datasets:

Ongoing in year 800, temperatures mostly 0,2-0,3 K higher than today.

The temperature creeps below today’s level and ends around year 1350.

Northern hemisphere is still much better represented than the southern hemisphere, so what can we conclude on this ground? Can we conclude anything?

On this ground I find it safe to accept the NH MWP approximately as described above.

To accept that globally there where no MWP, we will have to accept the following:

The 2 hemispheres have the ability to maintain a quite different temperature development for at least 500 years and did so from year 800 to year 1300.

What can we demand to accept this idea? We can demand solid evidence.

Anyone claiming the above must present solid evidence for a MEDIEVAL COLD PERIOD on the southern hemisphere.

IF data showed that the southern hemisphere had a MCP where temperatures for 500 years was 0,3-0,4 degrees colder than today, would this “kill” the MWP? Certainly not. Because, then we would have had 500 years with global temperatures just like today globally… – In that case, certainly no reason to be alarmed about the temperatures today.

No, if today’s temperatures should be alarmingly warm, the S. hemisphere temperature should show a very strong MCP at least 0,4 degrees colder than today in the 500 year period.

Is there ANY indication of a 500-year strong MCP in the southern hemisphere indicated in the data above? No, certainly not. There are not that many SH data, but still, there is not the slightest indication of a strong MCP on the S. Hemisphere.

Until the strong 500 year long MCP on SH has been proven, there is nothing that shakes the acceptance of a global MWP with temperatures resembling or higher than today’s temperatures.

I believe a massive use of tree ring graphs exclusively might show a strong southern MCP. In this case, the idea that there is no MWP globally is dependent on only on one specific method of making temperature proxies, tree rings. Tree rings are 1 of at least 20 different methods to measure temperatures of the past. As such, they should never dominate the measurements.

The South pole and MWP:

While examining temperature proxies, I found some odd results:

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Fig 7: -A stunning mismatch between 2 Antarctic data series.

Not only are they both from Antarctica, but they are both from near the south pole. The well known “MWP-signature” has found its way not only to the Southern hemisphere, but to the south pole. But in the near by Vostok location, for many centuries, there has been absolutely no sign of the MWP? Obviously this is absurd, so at least one of the two results is not accurate.

The black graph (from “Remote Plateau”) has a resolution of 1 – 3 years per sample, excellent. The blue graph (vostok) has approx 23 years between data points. Both series should be considered fine quality then.

How likely is it, that the “MWP/LIA-signature” has come up in “Remote plateau” (black graph) data by a coincidence? When it has also been spotted many other places on the SH? See fig 6: The Vostok data has a dotted red line. How well does vostok data then fit the rest of the Southern hemisphere data?

The use of vostok data also moves the SH temperature profile away from the NH average.

Tree rings

If the MWP only disappears using one a specific measuring method, the idea as well as the method is invalid.

Proxy temperature data from tree rings are easy to get, but the quality?

Craig Loehle: “There are reasons to believe that tree ring data may not capture long-term climate changes”.

Indeed. A good warm year will obviously help a tree growing, but decades of increasing temperatures could affect the whole area so for example more trees might be able to survive, the root nets would only be able to grow to some extend for other trees etc.

Example: Imagine that a warming after decades is accompanied by 10% more trees surviving in an area and eventually demands their “place in the sun”. By measuring tree rings for an individual tree you are not measuring the overall tree growth of the area. And measuring 10.000 trees does not change anything as all trees would have the same problem. Measuring tree pollen or isotopes etc in sediment cores avoids these problems and it makes me wonder how come so much energy has been used for tree ring analyses.

Selective adjustments?

Many kinds of adjustments are used in connection with climate results. But one adjustment I haven’t heard of is the down-adjustment of recent temperatures from temperature proxy data due to CO2-induced extra growth. If the CO2 level is indeed extraordinary high, then it is a fact that plants grow markedly more. And they grow at higher altitude etc.

Here is an impressing overview of plant response to extra CO2 in the atmosphere:

I have chosen the letter P for the link since several tree ring analysis are made for pine trees. Check the responses for pine trees when adding extra CO2.

Therefore any temperature proxy based on plant growth should be adjusted down in times of high CO2. Otherwise you will measure CO2 and not heat. But this obvious kind of adjustment seems not to happen? Or? Can it really be, that the crew of alarmists so happy for adjusting for all kinds of tiny issues, simply don’t adjust when there is a really good reason to do so?

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Fig 8: Historic temperature proxy data with focus on tree ring-method. In the analyses I have used, it turned out that 7 of 55 datasets where from tree rings. On this figure, these 7 datasets actually does seem to differ in trend from all the rest. The 7 tree ring datasets suggests no MWP, in fact, they suggest that the MWP was 0,3-0,4 K COLDER than today’s temperatures. Quite the opposite result than the majority of datasets concerning MWP.

On might say that these 7 datasets are too little a basis for any conclusion, and therefore I have included a bigger tree ring multi proxi, “Esper et al 2002” and the trend from the 7 tree ring datasets are confirmed:

Unlike all other methods, tree rings shows no warm MWP.

Example, the European Alps:


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Fig 9: Here from fig 4, we have 2 different temperatures in the same area, the European Alps.

Quite like Antarctica, we have 2 datasets, one showing the well known “MWP/LIA-signature” and one not showing this. Both cannot be correct, so we know that at least one of the datasets is faulty.

In addition, these measurements where taken in the middle of Europe where we have an overwhelming amount of non-tree temperature proxy datasets confirming a very warm MWP.

Therefore, if the tree ring method was useful, we definitely should see a warm MWP from tree ring data in Europe. But we don’t. And unless all the other temperature proxy methods just shows a very warm MWP in Europe by coincidence, the tree ring method does appear to be the faulty method.

The tree graph appears flat compared to the other methods (- a “yummy” to use if you want to produce a hockey stick), but we are not here to produce a hockey stick, we seek the temperatures of the past.

Now it becomes relevant to examine jus non-tree temperature proxies (As Loehle concluded) for better accuracy:

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Fig 10: The Historic temperature proxy trend based on 27 non tree ring proxies show a slightly warmer MWP than when including tree rings, fig 4. The average temperature for year 800-1400 is approx 0,4 K warmer than today, and the years 1400-1900 is around 0,4 K colder than today. So the non tree historic temperatures now gives a MWP/LIA difference of 0,8 K like the (non tree) Holocene temperatures, fig 5.

We even see “peaks” in the MWP up to 0,6K warmer than today, and now 1950 actually appears slightly warmer than today.


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Fig 11: Briffa’s 2001 all tree ring proxy data, compared with non tree ring data.

First of all, I have every respect for the huge work done using tree rings. There are indeed many sources to errors (like the idea about different SH/NH temperature development etc.) – but despite all, this graph speaks a very clear language.

Here we see the 27 datasets of non-tree rings, together with the well known tree ring graphs.

It becomes clear, that the non tree rings world wide – THICK BLUE CURVE – matches extremely well in the 20’th century and all the way back to year 1450. Then exactly as the MWP starts, the tree rings and the non

tree rings simply “looses contact”.

What ever the reason for the differences between tree ring or non tree ring temperature proxies,

it becomes evident, that choosing tree rings or not is the same as choosing a MWP or not.


One partly explanation for this huge mismatch could be CO2. If indeed the CO2 concentration today is a lot higher in the atmosphere than it was in the MWP, then trees simply grows faster than in the MWP, apparently even though temperatures are not higher.



– Its way too early to consider the MWP gone. There is a lot of scientific work to be done before any such conclusion has any weight. MWP disappears when using tree ring data.

– In this writing we see that 48 non tree ring temperature proxies combined shows a MWP around 0,4 K warmer than today, lasting at least 500 years.

– Besides the MWP discussion: 80-90% of the Holocene period (last 10-12.000 years) has been warmer than today. The last 6000 years, the general temperature trend has been steady cooling. The temperature levels in the Little Ice Age were the lowest in the Holocene period.

I find it relevant to study the consequences of further cooling.

– Except for strongly adjusted temperature data, there is compliance between recent temperatures measured from satellites, evidence from tree-proxies, evidence from non-tree-proxies and more showing that: It does not appear warmer today than around 1940-50.

This is in compliance with solar activity in the 20’th century.

This does not suggest a warming effect of CO2 in the atmosphere.

ome of the non-tree-ring measurement methods includes Be, O and C isotopes etc, that in some cases are more independent of changing tree growth or the like. These methods would be preferable if we wanted to clear CO2-induced errors on temperature measurements.

1) Alley, R.B., 2000 The Younger Dryas cold interval as viewed from central Greenland GISP2
2) Andersen et al., 2004 A high unstable Holocene climate in the subpolar North Atlantic: evidence from diatoms
3) Barron et al., 2003 High-resolution climatic evolution of coastal northern California during the past 16,000 years.
4) Biondi et al., 1999 July temperatures during the second millenium reconstructed from Idaho tree rings.
5) Büntgen et al., 2005 PYR – MXD Pyrenees reconstruction
6) Büntgen et al., 2006 Summer Temperature Variations in the European Alps, A.D. 755-2004
7) Büntgen et al., 2007 Growth responses to climate in a multi-species tree-ring network in the Western Carpathian Tatra Mountains, Poland and Slovakia
8) Cook, E.R., et al. 1998 Tasmania Temperature Reconstruction
9) D. Dahl-Jensen et al., 1998 Past Temperatures Directly from the Greenland Ice Sheet
10) D’Arrigo et al., 2006 Alpine Spruce Composite tree-ring record – living and historical material
11) DeMenocal and Ortiz 2000 Coherent High- and Low-Latitude Climate Variability During the Holocene Warm Period
12) Fang Jin-qix 1990 Climate changes during the holocene and their impact on hydrological systems
13) Filippi, M.L. et al., 1999 Climatic and anthropogenic influence on the stable isotope record from bulk carbonates and ostracodes in Lake Neuchatel, Switzerland, during the last two millennia
14) Ge, Q., et al 2003 Winter half-year temperature reconstruction for the middle and lower reaches of the Yellow River and Yangtze River, China, during the past 2000 years
15) Glen MacDonald 1996 (PALE) Paleoenvironmental Time Series from Postglacial Lake Basins on Kola Peninsula, Russia
16) Goni., 2004 Generation, transport, and preservation of the alkenone-based U37K’ sea surface temperature index in the water column and sediments of the Cariaco Basin (Venezuela). Global Biogeochemical Cycles 18: 10.1029/2003GB002132.
17) Grudd, H. 2005 Tornestrask updated reconstruction. Tornetrask tree-ring width and density AD 500-2004: a test of climatic sensitivity and a new 1500-year reconstruction of north Fennoscandian summers.
18) Hammerlund et al., 2004 Diatom inferred SST (August) variations in core MD95-2011, Voering plateau
19) Hendy and Kennett, 2000 SST estimates from planktonic foraminiferalassembl ages
20) Holmgren., et al. 2001. A preliminary 3000-year regional temperature reconstruction for South Africa
21) Hui Jiang et al., 2005 Evidence for solar forcing of sea-surface temperature on the North Icelandic Shelf during the late Holocene
22) Isaksson., et al., 2006 Austfonna ice core – Svalbard
23) J. R. Petit et al., 2000 Historical Isotopic Temperature Record from the Vostok Ice Core
24) K. Antonsson,. et al. 2008 Anticyclonic atmospheric circulation as an analogue for the warm and dry mid-Holocene summer climate in central Scandinavia
25) Kaiser, J., et al 2005 A 70-kyr sea surface temperature record off southern Chile
26) KERR et al., 2008 Ghiacciai e cambiamenti climatici durante l’ultimo secolo nella regione Aoraki/Mt Cook, Nuova Zelanda
27) Kim et al., 2002 Alkenone-base sea surface temperature record (8C) for core from the Benguela Current
28) Koutavas et al., 2005 Tropical Pacific SST gradients since the LGM in relation to the ITCZ
29) Linderholm et al., 2005 Summer temperature variability in central Scandinavia during the last 3600 years.
30) Liu, Z., 2006 Alkenone-based reconstruction of late-Holocene surface temperature and salinity changes in Lake Qinghai, China
31) Lloyd D. Keigwin The Little Ice Age and Medieval Warm Period in the Sargasso Sea
32) M.R. Besonen., 2008 A record of climate over the last millennium based on varved lake sediments from the Canadian High Arctic
33) Mangini, al., 2005 Reconstruction of temperature in the Central Alps during the past 2000 yr from a δ18O stalagmite record.
34) Mc Greggor et al., 2007 Rapid 20th-century increase in coastal upwelling off northwest Africa revealed by high-resolution marine sediment cores
35) Meixun Zhao et al., 2006 A millennial-scale U37 K sea-surface temperature record from the South China Sea (8°N) over the last 150 kyr: Monsoon and sea-level influence
36) Moore, J.J., et al., 2003 Baffin Island 1250 Year Summer Temperature Reconstruction,
37) Mosley-Thomson 1996 Holocene climate changes recorded in an east Antarctica ice core
38) Nesjea et al., 2004 Holocene millennial-scale summer temperature variability inferred from sediment parameters in a non-glacial mountain lake: Danntjørn,Jotunheimen, central southern Norway
39) Newton et al., 2006 Climate and hydrographic variability in the Indo-Pacific Warm Pool during the last millennium. Geophysical Research Letters 33: 10.1029/2006GL027234
40) Nyberg, J., et al., 2002, Northeastern Caribbean Late Holocene Sea Surface Temperature Reconstruction
41) Powers, L.A., et al 2005 Lake Malawi TEX86 Surface Temperature Reconstruction
42) Sachs et al., 2007 Cooling of Northwest Atlantic slope waters during the Holocene
43) Sallinger et al., 1988 The nature of New Zealand’s atmosphere and climate
44) Salzer, M.W. and K.F. Kipfmueller. 2005 Southern Colorado Plateau Temperature and Precipitation Reconstructions
45) Selvaraj et al., 2007 Holocene East Asian monsoon variability: Links to solar and tropical Pacific forcing
46) Seppa et al., 2003 Holocene annual mean temperature changes in Estonia and their relationship to solar insolation and atmospheric circulation patterns
47) Seppa et al., 2005 Diatom inferred SST (August) variations in core MD95-2011, Voering plateau
48) Societa Geologica Italiana 2007 Variabilità naturale del clima nell’Olocene ed in tempi storici:un approccio geologico
49) Stott et al., 2004 Climate/Ocean History of the Western Tropical Pacific
49) Stott et al., 2004 MD2176 Decline of surface temperature and salinity in the western tropical Pacific Ocean in the Holocene epoch
49) Stott et al., 2004 MD2181 Decline of surface temperature and salinity in the western tropical Pacific Ocean in the Holocene epoch
49) Stott, et al., 2004 MD2170 Decline of surface temperature and salinity in the western tropical Pacific Ocean in the Holocene epoch
50) Tan, M., et al., 2003 2650-Year Beijing Stalagmite Layer Thickness and Temperature Reconstruction
51) Tarasov., et al 2009 Late Glacial and Holocene changes in vegetation cover and climate in southern Siberia derived from a 15 kyr long pollen record from Lake Kotokel
52) Tyson., et al 2000 The Little Ice Age and medieval warming in South Africa.
54) Wang et al., 2000 Twentieth-century warming in the context of the holocene
55) Wilson, A.T., et al. 1979 Short-term climate change and New Zealand temperatures during the last millennium
56) Zabenskie, S. and Gajewski, K Post-glacial climatic change on Boothia Peninsula, Nunavut, Canada. Quaternary Research 68: 261-270.
57) Zinke et al., 2001 Evidence for the climate during the Late Maunder minimum…
58) Devi, et al ., 2008 Expanding forests and changing growth forms of Siberian larch at the Polar Urals treeline during the 20th century
59) Kim et al., 2006 Age and alkenone-derived Holocene sea-surface temperature records of sediment core SSDP-102

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Robert Bateman

Omigod, I can’t see to type, my glasses are all fogged up.
This is hysterical.
Johnny submits his first ‘picture’ to his teacher on PTA day.
The teacher is trying like hell to keep from busting up.
The parents are likewise red-faced.
Little Susie blurts out “Johnny’s picture looks like the dog we ran over last week”.


Great post! But I do not expect Hansen or GISS to be bothered as the agenda is settled the facts are without relevance.

Robert Bateman

Ok, I had my laugh. Sorry about that.
Seriously, does a tree know the difference for the most part between warm & dry vs cool & dry?


Great… Another article that will consume me for several days… Unfortunately, (or fortunately for you all) by the time I have enough understanding of the article to comment intelligently, there will be 8000 comments and the thread will have wandered into barycentric theory! LOL
😉 Good reading!

Richard deSousa

Wow!! Quite a report and difficult to digest in one sitting.

Jack Green

I’m dizzy. I guess I’ll watch the Masters and color Easter Eggs. I’ll come back to this later and read it for detail. It looks useful and underlines the conclusion that all of this AGW is dependent on the quality of the dataset.

Claude Harvey

That was truly “mind numbing”. I can’t wait to hear the smart kid (the one sitting under the teacher’s nose) pretend to understand the “true meaning” of Johnny’s picture. In the meantime, Johnny be “high fivin'” his pals in the back of the room.


Wonderful job!
I’m going to re-read this a few times. There is much to contemplate.
FWIW, having been through the GIStemp code, I would not call the output from GIStemp a ‘temperature series’. GIStemp fabricates numbers by repeated application of ‘the reference station method’ where one site can change the history of another site from 1000km to 1500km away. They use precision that massively exceeds their accuracy and they perform repeated operations on the data without have considered the impact this has on the low order bits. Then they get excited about changes in those low order bits that no longer have validity.
I’ve only done a fine review of the early steps (then I had to take a break from it, the mind recoiling in horror 😉 but all the source code is up for folks to look at (and anyone can post comments or reviews of any part of it).
That you found agreement between the proxies and satellites but GIStemp was a big outlier does not surprise me in the least. It is exactly what I would expect from what I’ve seen in the code.
IMHO, GIStemp is useless and any work that is based on assuming GIStemp is valid is itself worthless.

Solomon Green

The one clear message that comes through is that using proxies, be they tree rings, ice cores or speleothems, for measuring past temperatures (or CO2 levels, for that matter) produces highly dubious data. Adjusting the raw data introduces bias. At best he raw data can give us a very broad picture (over possibly a rather small – in global terms – area) that can be confirmed by geology and, more recently, contemporaneous history. Anything more is guesswork.
Climatology is to meteorology as astrology is to astronomy.

Martin Mason

absolutely fantastic and thank you very much. How to get information through into the real world?

Arguably, all analysis is “dependent on the quality of the dataset”. Imagine that!

Fantastic work Frank,
It’s good to see the different proxy types compared together. Especially the difference between hideously unreliable tree rings and the rest.
I didn’t expect much from this post when I started reading bc there is so much rubbish in proxies. I was pleasantly surprised at the extent of what you put together. Thank you.


This work should be published. It presents a compelling hypothesis backed up by abundant data.
If the major journals refuse it (and they may indeed do so, given their track record for studies that don’t conform to the meme), then E&E get it into the public domain in a way that WUWT can’t.


Robert Bateman (08:47:36) : Seriously, does a tree know the difference for the most part between warm & dry vs cool & dry?
It depends on the tree… Eucalyptus evolved for dry, but die back in significant cold for many varieties. Redwoods don’t care much about the cold, but only really like it when there is plenty of moisture (coastal redwoods being especially fond of fog.) The list goes on.
So any proxy based on trees must have a detailed understanding of the particular trees in question. (And for very long time periods, how they might have evolved during that time – for example the American Elm has low resistance to Dutch Elm disease. The present recovery program has repeated crosses to Chinese Elm followed by back crossing with American Elm to transfer the Chinese Elm resistance to a ‘mostly American’ survivor. In the wild something similar can happen in a population under, say, water stress. The individuals with good growth in a 1000 year drought will change the composition of the stand over that time…)
In general you can say that most trees most of the time will grow better when warmer (up to their heat stress limit) and they will grow better with optimal water (growing less when drought stressed and dying if waterlogged, modulo trees like Mangrove that love water logged…)

Bob Shapiro

It appears most likely that tree-ring proxies are not valid for historical temperature use, but they may be useful for historical CO2 use. How do we check the CO2 relationship to verify this?


The curious case of Michael Mann’s two thousand year tree ring proxy once again rises from the golf course graveyard. It never seemed to be as good a proxy for temperature as it is for rainfall. Perhaps if the inverse correlation between seasonal temperature and seasonal rainfall could be taken into account it might actually be useful as a reliable temperature proxy.

Oh, and on the trees thing:
It has been found that higher CO2 levels let plants grow better with with the same water (or alternatively, let them grow the same with less water – that is: more CO2 compensates for the effects of water stress…)
So unless you calibrate your tree-ring ruler for CO2 growth promotion (which requires year by year historic CO2 data that is accurate) you will get a confounded answer.
It don’t know of any work on the effect of CO2 enrichment vs temperature. It may well have some ability to mitigate heat stress as well. AFAIK, this is an unexplored area.

An Inquirer

Given the methodology and quality issues with GISS, I am not surprised that GISS would end up as an outlier on land temperatures. Yet, GISS uses satellite data for oceans, and therefore I am not surprised when I see studies that GISS and UAH & RSS have similar global trends. Therefore, I am puzzled in my first reading of this post — that GISS diverges but UAH does not.


Wow, I could make a whole powerpoint presentation from this, “An Inconvenient Cooling” (if I use the data sets with 1000 yrs or more). The Earth has a cold…… It wouldn’t get media play, so I’ll use my time reading more Wattsupwiththat instead. The truth is starting to leak out. My wife doesn’t let me talk about not believing in AGW in public (I live in California). Someone at work spoke about the snow in New York City last week and mentioned Global Warming, we all had a good laugh. No one said anything else, but we new what everyone was thinking.


Very good presentation. May I ask what software you used to prepare the graphs?

L. Gardy LaRoche

Is it possible to make a .pdf version of this post available for those of us who need to hold paper in hand for the study of serious documents ?

Ask and you shall receive. Link to PDF is HERE


Excellent Article!
Brilliant really, and I agree with the others here, I don’t trust GISS that much either.
Trees are clearly not as simple as some might think
Great work, I will forward this along.

Juraj V.

How is the UAH temperature trend (measured in lower troposphere) recalculated to absolute degrees, to replace GISTEMP dataset (ground stations, 2m above ground)?

Richard M

One might conclude that the world was headed into another ice age around 300 years ago. What could have stopped it? Humans? Assuming a strong warming signal from soot as indicated by the NASA paper, the burning of wood and anything else humans could find to keep warm MAY have stopped the ice age in it’s tracks.
The addition of CO2 in recent times may well have continued that warming. IOW, we’d better keep on warming the planet with CO2 and whatever or nature may take over and get us back on track for an ice age.
It would be ironic if it turned out AGW was true and was SAVING our current way of life.

Juraj V.

Btw, it is kind of shame that we have to use non-direct proxies in 20th century for determining the “true” temperature record, with all those thermometers around..

As shown in one of Frank Lansner’s links, the atmospheric CO2 concentration makes a big difference on the growth rate of plants. That’s probably why, against both evidence and common sense, alarmists insist that CO2 concentrations have remained static at right around 280 ppmv for millenia.
And as E.M. Smith notes, GISS fabricates data. That in turn results in GISS claiming the planet is warming, while its peers document cooling: click
And as Prof. Richard Lindzen points out in his article last week [update 3]:

“…it has become standard in climate science that data in contradiction to alarmism is inevitably ‘corrected’ to bring it closer to alarming models. None of us would argue that this data is perfect, and the corrections are often plausible. What is implausible is that the ‘corrections’ should always bring the data closer to models.”

Oh, again on the tree ring thing…
For many forests, you also need to know the history bear and salmon populations to properly interpret growth:
Bears can deposit about the same amount of “nitrogen fertilizer” (and since it’s from fish, it has a lot of P and other nutrients as well..) as professional forest management would use.
A tree (or any plant, really) will “growth limit” on some lacking nutrient and that will determine your growth ring. It may also limit on temperature extremes or on missing sunshine (think volcano dust or asteroid strike). If you don’t know for certain that the tree was not growth limited on a nutrient, then you are guessing that it growth limited on warmth, and at some times and in some locations that is demonstrably false.
So to make tree rings accurate, you need a soil nutrient profile (via bear population proxy? 😉 a solar output / atmosphere transparency profile, a soil moisture profile, and a CO2 concentration adjustment which depends on a CO2 profile. And all of these must be characterized for the particular species of tree in question and accurate for the particular site in question.
To the best of my knowledge this is not done. It’s just look at the rings and say “Oooh, look at the big ones!”…
(In some cases things would need to be known for the particular tree in question. A large tree shaded by a giant tree is not going to grow well; but will suddenly grow better when that giant tree blows over in a storm. One assumes that this is taken care of by averaging a large number of trees, but that is an assumption; and we all know where assumptions lead…)
In the end, all tree rings tell you is how happy or unhappy that particular tree was at that particular time. They do not tell you why.

Solomon Green (09:10:43) said: “Climatology is to meteorology as astrology is to astronomy.”
…One [Japanese] scientist likened computer climate modeling to ancient astrology…
…But with 50-year Gaussian filters applied to the empirical modules.


Excellent summary of the situation!
More and more, it seems AGW is not happening to any significant extent. The burden of proof is with the AGW camp. But, their empirical results, so far, leave a lot of questions to be answered — Urban Heat Island data pollution, CO2 increasing tree growth, proxies indicating that today is no warmer than years ago, and on and on.
The IPCC should write a comprehensive report proving their apparent data problems are not really problems — the burden of PROOF is with the AGW camp. We need only ask the questions.

Mike Bryant

“It would be ironic if it turned out AGW was true and was SAVING our current way of life.”
Don’t you get it? According to the powers that be, our current way of life is the problem. There’s just too many people around who are alive and free. Population numbers must be reduced by at least 90% while freedom is curtailed completely. So far so good.

I’d like to know why MSU2-UAH page is not working:

Allan M R MacRae

Please see
I posted this note mid-2008, almost a year ago.
The evidence to date suggests that increased atmospheric CO2 plays NO significant role in causing global warming.
The best data shows no significant warming since ~1940. The lack of significant warming is evident in UAH Lower Troposphere temperature data from ~1980 to end April 2008, and Hadcrut3 Surface Temperature data from ~1940 to ~1980.
The graph title says it all:
I have been accused of the usual cherry-picking, etc. by the warmists.
However, the warmists are the cherry-pickers – they choose the warming HALF-cycle of the PDO, extrapolate that modest warming to infinity, and then claim dangerous global warming.
I chose the FULL ~60-70 year PDO cycle and see NO net global warming.
Love that Divergence Problem – it lay quietly hidden until about 2006 – I first read about it on ClimateAudit.
The Divergence Problem is why Mann grafted recent Surface Temperature data onto older tree ring data – if he had used all tree-ring data, the blade of the hockey stick would have pointed downward!
Maybe the Hockey Team can explain to me how this was an innocent error.

Adam from Kansas

Seems to be evidence of the MWP, of course I didn’t read the whole thing, so many graphs and so many explanations O.o
On the suggestion the 1950’s may be warmer, Wichita set quite a few high temperature records in the 50’s, other notable record years were in the 30’s and 1980, we have not had a recent year where we broke as many or more high temperature records as a number of those years.

Henrik Oelund

Thank you very much Mr. Lansner. A great effort!
Frank Lansner is one of the few intelligent Danes in the Climate Debate in my country, and it makes me feel good and proud, that they still make them like this! Happy Easter.

Allan M R MacRae

More on the Divergence Problem, from Climate Audit
Juckes and the Divergence Problem
by Steve McIntyre on November 8th, 2006
not excerpted
More on the Divergence Problem
by Steve McIntyre on May 4th, 2007
Two new things on the Divergence Problem. The IPCC First and Second Drafts did not contain a whisper of a mention of the divergence between ring widths and density in the second half of the 20th century, although this is rather an important issue. It came up at the NAS Panel and was completely unresolved in the hearings discussed here, where D’Arrigo was only able to refer to Briffa’s cargo cult explanation of the phenomenon.
“In the absence of a substantiated explanation for the decline, we make the assumption that it is likely to be a response to some kind of recent anthropogenic forcing. On the basis of this assumption, the pre-twentieth century part of the reconstructions can be considered to be free from similar events and thus accurately represent past temperature variability.”
My comment:
One can understand why the Hockey Team did not want this Divergence Problem to be publicly discussed. The evidence points to fraud.
BTW, isn’t Briffa’s cargo cult explanation contrary to the Uniformitarian Principle, and also Occam’s Razor?

Antonio San

Nice post but I think the question is more scientifically treated on ongoing posts at climateaudit.

L. Gardy LaRoche

ERROR 404 returned for PDF link.

Leon Brozyna

Wow. Information overload. Everything from goofy GISS to questions of the effect of CO2 levels on current proxies.
Talk about data that’s subject to interpretation!
The paragraph just above Fig 4, reminds me of how the popular media overlooks inconvenient facts: “All data evidence … suggests that today’s temperatures resemble the temperatures of 1940-50.”
Remember how Newsweek, back in ’75, warned that the growing season was two weeks shorter than around 1950. And then I think it was on BBC in the past year or so where the politically and environmentally correct line was that the growing season was about two to three weeks longer than 30 years ago or so. Do the math — according to the popular media then, our climate now is more like it was during the period 1940-50. What a coincidence.

L. Gardy LaRoche

REPLY: Ask and you shall receive. Link to PDF is HERE
Got it.
Thank You.
It appears the link to the PDF at the top of the post is broken whereas the one inline to the REPLY works.


Nice to see a conclusion I reached on my own look at several different data sources confirmed independently by someone else … that conclusion being that we have been in a general cooling trend for the past few thousand years (Fig 5). But there is something else that concerns me in Fig 5.
If you look at things about 11,000 years ago, you see that temperatures were rising, then appeared to “ring” a little with temps dropping then rising, then temps drop again but not as far and recover to a higher level and then the “ringing” damps out and we have a nice smooth curve until about 4000 years ago and it begins to “ring” again. It appears that as time passes, the temperatures cool and don’t quite recover to where they were before and each cooling period seems a little cooler than the one before. Then you get this rather large cycle with the MWP and the LIA.
As someone with some experience in electronics, this looks a lot like the ringing that occurs when a state isn’t quite stable and occurs on both sides of a state change. What I am saying is that the LIA might be an indication that we are very close … well within 1000 years of a major climate state change and are nearing the “flip” to 100,000 years of cold. As you can see from the figure, the last time temperatures were that cold were some 11.5k years ago.
My suggestion is to drill that North Slope oil while we still have access to it.

Bart Nielsen

I can hear the warmists already: “We’ve debunked this stuff a thousand times already.” Sorry, I missed the first thousand times. I would like to see the 1001st time actually address what Mr. Lansner has done here.


1. i think it is an extremely simplistic method, to simply stick all proxies together in a single year (1950). all those proxies with a big amplitude will show completely different results, depending on the year chosen. not a good start for a paper.
2. the claims about GISS are extremely problematic. GISS is in good agreement with all other modern datasets. any person with massive doubt about the GISS measurement of glabal temperature data has some serious explanation to do, while pointing at proxy results. whatever problems there are with GISS data, it will always be more accurate than any proxy can ever be.
3. i have been waiting for an eternity for the expansion of the MWP , that this article finally argues for. the MWP is now considered to be an incredibly long time (over 500 years) at a higher temperature than today. with the effect that we see on flora and fauna today, i will start believing in such a period, when i see the first medieval report about zebras in middle europe.
4. talking about today, the article (as many others) uses the term “today” in a pretty “free” way. most of those proxies ended at least a decade ago.
apart from that, i found the article to be at least well structured and written.


It seems an isosbestic point.

Sod- What species would Zebra displace from Middle European fauna?
Their slot is surely occupied by the horse, something that’s quite at home over a fairly wide range of temperatures. A bit like us humans really.


Man, those graphs will twist your eyeballs around the back of your head. Advice to others trying to follow a line, enlarge the graph. That will save you from that dizzy feeling.
Excellent post, though.

GISS is in good agreement with all other modern datasets.
What?!? Have you not looked at the satellite data?
whatever problems there are with GISS data, it will always be more accurate than any proxy can ever be.
More accurate, yes, but no less prone to systemic error.

Adam G.,
To follow up a little more, and to keep “global warming” in perspective, it’s good to remember that most of the arm-waving was done as the alarmists pointed to only a 0.6° C rise in temps over the past century.
Since then most of that small rise has been retraced, and the planet is back around 1980 temperatures. If the alarmists want to get picky, maybe the range of zebra habitat might have moved 80 – 100 miles north, given enough time.
But what actually happens is that the planet’s temperature naturally varies, as it oscillates around a trend line. Bill Illis gets credit for this chart: click, which shows reality vs the IPCC’s scary models.
It’s also good to keep in mind that CO2 is beneficial; more CO2 is better; any small warming helped along by CO2 is more than offset by other factors, and the claim that CO2 is in any way bad is simply an unfounded presumption at this point, since the models’ predictions have all turned out to be wrong in their predictions. GCM models are all the alarmist can point to, as the planet laughs at their hubris.
And I’m willing to bet that zebras won’t be moving north into Europe any time soon.

Steve Keohane

As regards tree rings. bear in mind this gem from Nature, June 11th, 2008:
From Canada to the Caribbean: Tree leaves control their own temperature
“Tree photosynthesis, according to the study, most likely occurs when leaf temperatures are about 21°C, with latitude or average growing-season temperature playing little, if any, role. This homeostasis of leaf temperature means that in colder climates leaf temperatures are elevated and in warmer climates tree leaves cool to reach optimal conditions for photosynthesis. Therefore, methods that assume leaf temperature is fixed to ambient air require new consideration.”
Sorry for not having the link, just kept the text on file, I’ll speak to my office manager about poor filing habits…


I think that most scientific discoveries or realizations result from the frustrated attempt to answer one simple question: “What the hell is going on here!?”
I have been intensely studying the AGW debate for 6-9 months and have been baffled as to why Dr Tom says that it was warmer in the MWP, Dr Dick says no, today is warmer than it has ever been, and Dr Harry says no, it was actually warmer in 1934.
None of the three are lying, they are (naturally) using the data that best supports their hypothesis.
Holocene Spaghetti has brought me to a moment of enlightenment. and helped me understand just what an absolute mess the historical temperature “records” really are.
BTW, for those not familiar with U. S. colloquialisms, “Tom, Dick, and Harry” simply means person #1, person #2, and person #3 (in no particular order.)


Great Video
The Climate is Constantly Changing
Question the Hype!