The long, slow thaw?

by Tony Brown

A warming trend can be observed from 1659, the start date of Central England Temperature  (CET)- the oldest instrumental record in the world- to today.  It would be a notable coincidence if the warming started at the exact point that this record began. The purpose of this paper is to reconstruct CET from its current start point, through the use of diverse historical records, to 1538, in order to see if the commencement of this centuries long warming trend can be identified from within this time frame.

Figure 1 CET from 1659-in the style of Hadley 1772

Retracing our climatic steps provides an opportunity to revisit the respective works of Hubert Lamb and Dr Michael Mann- both famous for their reconstruction of temperature records- in the light of the evolving science and additional information that has become available over the last few decades. This paper re-examines some of their best known work, notes how each has influenced the debate over our climate, and places their contributions into the overall context as background to our own reconstruction.  

Section 1  Dr Mann’s reconstruction of Climate History

Dr Mann’s view of our past climate-epitomised by the iconic 1998 ‘Hockey stick-’ contradicted in substantial part the work of Hubert Lamb, the founder and first director of CRU from 1972,) who had died one year previously. (1)

Dr Michael Mann, born in 1962, is currently Professor of Meteorology at Penn State University in the US.  (2)

Hubert Lamb (born 1913) produced a number of books and papers during his long career as arguably the leading climate scientist of his era, of which the most influential was probably ‘The Early Medieval Warm Epoch and its Sequel’  published in 1965. (3)

Within this work was a pre computer era graph based on CET and other English records. It was probably derived from earlier work that was only published years later, as Figure 30 Chapter 5 of his 1982 book, ‘Climate History and the Modern World.’ The 1965 version was substantially re-interpreted by the IPCC for their 1990 assessment and used on page 202 Figure7c as the basis for a global record. Figure 2 below shows the (unattributed) version of the graph used by the IPCC

Figure 2

 

Below is a variation showing winters only.

Figure 3 This shows winter severity in Europe, 1000 – 1900. Note two cold periods in the 15th and 17th centuries. Based on Lamb, 1969 / Schneider and Mass, 1975.

The convoluted transformation of the original graph from Lamb’s version (Figure 2) into the one used by the IPCC is documented here. (4)

Dr Mann, together with colleagues Bradley and Hughes, used instrumental data from 1902 to 1998, (the date of the study) together with a variety of proxies such as tree rings, in order to reconstruct a Northern Hemisphere record of temperature anomalies back to the year 1400. Their April 1998 paper published in ‘Nature’ entitled ‘Global Scale Temperature Patterns and Climate Forcing over the Past 6 Centuries’ became known as MBH98. Figure 5b in the link here (5) illustrates their reconstruction the most clearly.

The following year the same authors produced an article entitled ‘Northern Hemisphere Temperatures during the last Millennium: inferences, uncertainties and limitations’. Published in The American Geophysical Union magazine in 1999 it extended the work of the 1998 paper by 400 years to 1000AD. The paper became known as MBH1999. (6)

The third IPCC assessment in 2001 subsequently adapted their figure 3 from this later 1999 work and it is this iconic version, which later came to be known as the ‘hockey stick,’ that is still much used to illustrate the apparent effect of human activities on temperature in recent decades, specifically through the release of co2.

Figure 4 (Figure 2.20:_ Millennial Northern Hemisphere (NH) temperature reconstruction (blue) and instrumental data (red) from AD 1000 to 1999, adapted from Mann et al. (1999). Smoother version of NH series (black), linear trend from AD 1000 to 1850 (purple-dashed) and two standard error limits (grey shaded) are shown. (7)

 The accuracy of the ‘hockey stick’ type reconstruction shown above was essentially confirmed by The National Academies of America in 2006 with their paper ‘Surface temperature reconstructions for the past 2000 years.’ (8) (Also see additional information in Note 1 of Section 8)

The increasing power of computer reconstructions since MBH98 and 99 resulted in the more sophisticated ‘spaghetti graphs’ using multiple proxies, which somewhat modified the findings of the  earlier hockey stick, but reinforced the notion of a world rapidly warming over the last century, in a manner unprecedented for at least a thousand years. This spaghetti graph comes from the IPCC working group 1 and illustrates twelve multi proxy reconstructions together with their locations, including mbh1999, which has instrumental temperature data added from 1902.  (9)

Figure 5

So we have two competing climate history stories-one developed over a lifetime of academic research mostly before the computer era, and the other derived from a scientist using modern statistical techniques and the extensive use of novel proxies interpreted in a highly sophisticated manner using computers.

The ‘hockey stick’ and Lamb’s graph remain potent symbols to this day, and have created two vociferous climate camps, as the reconstructions seem to tell very different stories. The work of Dr Mann and his colleagues have been argued over numerous times during the last decade, but it is his findings that underpin current mainstream thinking on the nature of our climate during previous centuries. Basically his study found a generally stable climate for a thousand years that exhibited a slight decline in temperatures until around 1900 when the temperatures dramatically escalated. Mann’s research was thorough and interesting, and like Manley’s work with CET, and Hansen’s with global temperature, was a considerable feat of research and re-interpretation of existing knowledge, which until then had accepted considerable variability, with previous episodes of warming exceeding those in the modern era.

Of course we can’t know whether more information and the availability of powerful computer modelling would have changed Lamb’s findings, so it is primarily his view of historic climate we shall follow, to see if the material now available may have influenced his thinking and results for the period 1538 onwards, to a position somewhat closer to Dr Mann.

Section Two     A brief examination of two differing versions of Climate History.

Towards the end of his long career, Lamb remarked that such elements as church and estate records, ships log books and a whole host of other historical records, now available in such places as the Met office archives, were only starting to become available. It is certain he would have found the enormous pool of information -observational and scientifically derived-now also available through the internet, to be a great help to his research.

Dr Mann often cited Hubert Lamb’s work; most notably for our purposes in figure 1 of his 2002 paper entitled ‘Medieval Climatic Optimum’ whereby reconstructions by the two scientists are usefully juxtaposed-Mann depicting the Northern Hemisphere- and Lamb, who used Central England records. (Note should also be taken of Figure 2 of this paper used by the IPCC, which show some differences.)  (10)

In looking at the two versions-reproduced below in Figure 6 -we can readily see that the divergence between the two climate camps was caused by the two apparently radically different versions of climate history it gave.

Figure 6

In the Mann version of historic climate there is very limited variation either side of a mean anomaly, which gave rise to a limited MWP, generally substantially cooler than today, with gently declining temperatures throughout the period from 1400 to 1900, coupled with a lesser impact of the ‘Little Ice Age’ than had previously been accepted. Most controversial of all is the very dramatic uptick from the 1902 instrumental temperature records-the so called ‘hockey stick’. The information for this was derived from table 5 in MBH98 -later extended in MBH99- and adapted in the IPCC assessment. Figure 1a in MBH98 (linked to in reference 5 above) shows the geographic location of the proxies-mostly tree rings- but with some coral sediments, bore hole and ice core data, with land based instrumental records from 1902. There were a total of 24 proxy indicators back to 1450, with 22 multi proxy to 1400, there are also some 1100 temperature records from 1902 with the additional grid points in figure 1b providing SST’s back as far as 1854.  The precise nature of the multi proxy data used in mbh98 is referenced here (11)

There was considerable controversy over Dr Mann’s reinterpretation of the size and extent of the MWP and LIA which we shall return to later, but as can be readily seen in Figure 6 his concept of climate history was at substantial variance with much of Lamb’s version, based on his 1965 CET work. (The extension of CET from 1965 to the year 2000 in the graph in Figure 6 appears to have been carried out by Dr Mann, not Hubert Lamb)

Lamb’s work showed substantially greater climate variability, with a distinct and warm MWP and two eras of the LIA-the second much more severe than the first, and a steadily climbing temperature from around 1690 to the present date , albeit with numerous statistically meaningful reverses and advances. Coupled with the long lived CET instrumental records, this appears to show that if the Mann reconstruction is correct, the British climate has at times varied substantially from that of the remainder of the Northern Hemisphere for 400 years or so.

We shall revert to the question of synchronicity and climate severity later in this paper, but it can be seen that even Lamb’s graph demonstrated modern ‘hockey stick’ characteristics (albeit it appears this data was later added by Dr Mann using CET) More intriguingly, Lamb shows another and much more dramatic ‘hockey stick’ just before the start of the 18th century-a period which seems to have aroused limited curiosity- and is the intended subject of a future article.

Dr Mann’s view that the climate had been relatively stable until man interfered with it in recent times, through excessive co2 emissions, became quickly accepted, as noted here by the UK Met office, a prime contributor through the Hadley centre to the IPCC assessments, who assert:

 “Before the twentieth century, when man-made greenhouse gas emissions really took off, there was an underlying stability to global climate. The temperature varied from year to year, or decade to decade, but stayed within a certain range and averaged out to an approximately steady level.”  (12)

The IPCC themselves say;

1   IPCC FAQ 6.2 Page114 of TAR4.

‘All published reconstructions find that temperatures were warm during medieval times, cooled to low values in the 16th 17th 18th 19th centuries, then warmed rapidly after that.’

These comments clearly refer to Dr Mann’s-rather than Hubert Lamb’s-version of climate events.

What we can determine with some certainty about the Little Ice Age (LIA), by looking at the available instrumental data and other records with the broader brush and sceptical eye they warrant, is that there were many anomalously cold periods which capture the episodic nature of the misleadingly named Little Ice Age. It is misleadingly named as the popular impression of unremitting cold for 400 years, when the Thames froze over each winter, is inaccurate. Although there were undoubtedly several long periods of intensely cold winters, particularly for much of the 17th century, with generally shorter recurrences through to the mid-19th century, the cold winters were punctuated by warmer ones, and there were many warm summers and other seasons similar to today, as noted here by the author. (13)

The term LIA was introduced into scientific literature by François E. Matthes as late as 1939 who subsequently believed the term ‘neo-glaciation’ was more accurate(14)

We can trace much of the LIA through the medium of CET from 1659 (see figure 1) which captures some of the coldest episodes. This also usefully leads back to Hubert Lamb who used this and other English based records extensively.

Section Three    What is CET?

It would be useful to clarify what CET is and isn’t, as it is a fundamental measure being used in this current reconstruction.  The instrumental record itself dates from 1659. Our own reconstruction has been extended from this date back to 1538 by using a variety of historic records (not instrument readings) taken from the same geographic area. These are detailed in the separate paper ‘supplementary information,’ (linked to in Section 8 of this paper)

It is during this period that a notable divergence begins between the two versions of climate history (see Figure 6) as Lamb notes a descent into a second and severe episode of the LIA that Mann didn’t record as being especially significant. The period prior to 1538 is outside the scope of this present paper.

CET is not a single continuous set of instrumental temperature readings to 1659 but was the result of a project that sorted a mass of thermometer based temperature readings into a single coherent record covering a specific area of England, many years after the event.  This notable achievement was carried out by Gordon Manley on behalf of the Met office. His 1953 paper describes in great detail how CET was assembled and the geographic area it covers. (15)

It is a fascinating piece of detective work carried out over a period of thirty years and was followed in 1974 by a further paper from the same author, which noted uncertainties and corrections, whilst commenting on the difficulties of trying to reconcile records due to the change from the Julian to Gregorian calendar- which occurred in 1752 in Britain making 11 days difference- but in different years in other countries.  (16)

Manley’s work was expanded by Parker, so a number of variations of CET have been established over the years, as can be seen in this official description by Hadley/Met Office who maintain the figures.

The CET dataset is the longest instrumental record of temperature in the world. The mean, minimum and maximum datasets are updated monthly, with data for a month usually available by the 5th of the next month. A provisional CET value for the current month is calculated on a daily basis. The mean daily data begins in 1772 and the mean monthly data in 1659. Mean maximum and minimum daily and monthly data are also available, beginning in 1878. These daily and monthly temperatures are representative of a roughly triangular area of the United Kingdom enclosed by Lancashire, London and Bristol. The monthly series, which begins in 1659, is the longest available instrumental record of temperature in the world.  Manley (1953,1974) compiled most of the monthly series, covering 1659 to 1973. This data was updated to 1991 by Parker et al (1992), when they calculated the daily series. Both series are now kept up to date by the Climate Data Monitoring section of the Hadley Centre, Met Office. Since 1974 the data have been adjusted to allow for urban warming.”

The geographic triangular area described is a heavily populated area of the country. In a private email to the author the Met office described the amount of UHI as follows;

“The urbanisation corrections to the CET series have been applied since 1974.  Initially they were just 0.1 degree C, in certain months, then gradually for more months of the year; from about 1995 onwards some of the corrections increased to 0.2 deg C, and by about 2002 all the corrections were 0.2 deg C.

The above applies to Mean CET.  The urban heat island effect is much more noticeable for minimum temperatures than for maximum, so for the Minimum CET series the corrections are double those for Mean Temperature, whereas for Maximum Temperature it was deemed in fact that no correction was required.”

Due to its longevity CET is probably the most scrutinized instrumental data set in the world, which makes it especially valuable as a useful resource. As much of this paper is concerned with instrumental records deriving from thermometers it should be noted that in Chapter 5 of his book ’Climate History and the Modern World’, Lamb makes many good points about the relatively limited accuracy of instrumental records. As observed in my own article on the same subject, at best we can believe in the general direction of travel of the local instrumental record-especially when backed by such things as crop records/ observations-but not in their accuracy to tenths of a degree (17)

‘Global’ records are much less reliable than local ones due to the manner in which they are assembled, and the reality of a meaningful single global temperature is the subject of much debate, as observed by French climatologist Marcel Leroux.  Yet, they know very well that there is not one “global” climate, but a large variety of climates, depending on latitude, geographic conditions, and atmospheric dynamics.’ (18)

Brown and Jones commented on the many instances of local cooling trends, seemingly recording different- and cooling- climates to that observed in the global – and warming- record  (19)

The Berkeley earth surface temperature project ( BEST) also confirm that one third of the Globes weather stations show a cooling, not warming, signal  again demonstrating that no single global climate prevails. (20)

Consequently Leroux’s comments seem a reasonable premise, and the attempt to find a warming signal in every piece of data somewhat counter-productive.

As a result of the various studies into CET referred to above, two sets of official temperature data relating to it are generally available. Hadley/Met office themselves tend to use the data to 1772 whilst this study has used the longer official figures to present the data to 1659 in a similar format. It is reproduced again at this point (Figure 7) as a useful springboard for further comment. In this context schematic diagrams, such as those already used in Figures 2 and 3, can be seen to be useful in providing a simplified view of extended timescales. However they are unable to show the enormous variability from month to month and year to year that is a feature of the British weather. This annual variability can be readily seen below, although the eye might be first drawn to the red trend line.

Figure 7  Hadley 1659 in the style of Hadley 1772

In his graph (used within Figure 6) Lamb records considerable temperature variation with a decline from 1400, then a rise after 1500, with a further decline to the early 1600’s but with the coldest point in the late 1600’s. The abrupt dip towards the end of the 17th Century and the astonishing recovery immediately after, lasting towards the middle of the following century, can be clearly seen in CET as perhaps the most notable feature of the entire record.

Clearly this period of some 250 years, commencing 1500, is critical in understanding the influences on our climate, being centuries before the impact of man-made co2 become a serious issue. Referenced here is the official Cdiac data to 1750 showing the trivial emissions at the start date. (21)

Section Four-Reconstruction of the period 1538 to 1659

The accuracy of the proxies, such as tree rings and bore hole material, used by MBH in their reconstruction are dealt with later in this paper in relation to the findings of both this reconstruction and that of Hubert Lamb.

 Our reconstruction, in order to identify the start of the warming trend, centres on the period 1538 to 1659. It was this latter date when the CET instrumental records began, and we can usefully bookend this era with two pieces of observational climate information.

A brief breakdown in the cold winter trend in Britain was recorded in the diary entry of Samuel Pepys for January 1660/61-the year the Royal Society was established- when he wrote;

“It is strange what weather we have had all this winter; no cold at all; but the ways are dusty, and the flyes fly up and down, and the rose-bushes are full of leaves, such a time of the year as was never known in this world before here.”   (22)

So here we can see that Pepys (born February 1633) had been living through a long period when cold winters had become the norm. We can take with a pinch of salt ‘as was never known in this word before here’ as people often tend to base such beliefs on their personal experiences, and as shall be seen in the research material there are numerous similar claims from other observers.

Summers could still be hot. Pepys noted that 1661 and 1665 were particularly warm, and more especially during 1666 when the UK had an extremely hot dry summer-said to be the warmest in living memory- that was brought on by a blocking high pressure system over Scandinavia. The dry North easterlies helped spread the devastating Great Fire of London in 1666. The following winter, however was so cold that the great oak trees of the English Midlands split. (Humidity has a great part to play in temperatures)

We can usefully roughly date the initial down turn by turning to 1560 when the Rev Schaller, pastor of Strendal in the Prussian Alps wrote;

“There is no real constant sunshine neither a steady winter nor summer, the earth’s crops and produce do not ripen, are no longer as healthy as they were in bygone years. The fruitfulness of all creatures and of the world as a whole is receding, fields and grounds have tired from bearing fruits and even become impoverished, thereby giving rise to the increase of prices and famine, as is heard in towns and villages from the whining and lamenting among the farmers.”

That this appeared to be the start of a trend comes from this comment by John King, an Elizabethan preacher from Britain who wrote in 1595;

“Our years are turned upside down; our summers are no summers; our harvests are no harvests!”

It is useful to note here that it is inclement summers being complained of, and this juxtaposition of intensely cold and intensely warm spells-although by no means annual events- seems to be a notable feature of this period.

The decline in the climate is reinforced by this account from 1610 when John Taylor, talking of the hills around him in Deeside Scotland, remarked that “the oldest men alive never saw but snow on the top of divers of these hills both in summer as in winter.”

(The 1560 and 1610 quotes from the book ‘The Little Ice Age’ by Brian Fagan)

Our apparent modern amnesia regarding previous climatic conditions can be seen to be nothing new by reading the comments from the annals of Dunfermline Scotland from 1733/4, when it was recorded that wheat was first grown in the district in 1733. Lamb wryly observes that was not correct, as enough wheat had been grown further north in the early 1500′s to sustain an export trade.

This information also confirms a warm period in the early 1500’s to one that had changed to a cold period by the time of Pastor Schaller commenting in 1560.

We can find another comment usefully topping and tailing our period of interest here;

“During the long cold spell between 1559 and 1652, average heights in Europe declined by 0.8 inches. That disastrous period in European history is referred to by historians as the General Crisis of the 16th Century. It was a time of starvation and deadly conflict, including the brutal Thirty Years War.”  (23)

There are various other records available relating to the 1500’s and 1600’s from a study entitled ‘Evidence for the climate during the Late Maunder Minimum from proxy data and model simulations available within KIHZ’   (24)

The above link has some useful graphs of likely temperatures from 1500 onwards, although it is mainly concerned with the period from 1680 on.

The following study on solar activity uses research by Groveman and Landsberg, who in 1979 reconstructed Northern Hemisphere temperatures from 1570 to 1860- (the remainder of the graph period is a composite study by Jones et al made in 1986 and 1988)  (25)

Figure 8

The 1997 book ‘Climate of the British Isles’ edited by Mike Hulme and Elaine Barrow (page 188) has a graph showing a temperature peak around 1550 followed by a very sharp decline straddling the beginning of the 17th century. (26)

Further evidence of the changing climate can be gathered from this unlikely source;

‘From 1564 to the 1730s—the coldest period of the Little Ice Age—malaria was an important cause of illness and death in several parts of England. Transmission began to decline only in the 19th century, when the present warming trend was well under way.’

‘From; Shakespeare to Defoe: Malaria in England in the Little Ice Age’  (27)

1564 has a special significance as can be seen here;

Figure 9. Hunters in the Snow by the Flemish painter Pieter Bruegel the Elder (1525–1569).

Completed in February 1565, during the first of the many bitter winters of the Little Ice Age. Bruegel painted at least seven such snow scenes.  (28)

An even more unlikely source of information comes from this study of witchcraft trials, events possibly precipitated by superstition of changes in climate which subsequently impacted on the economy of the time. Written by Harvard economics PhD Emily Oster it is entitled ‘Witchcraft, Weather and Economic Growth in Renaissance Europe ‘ and published in Journal of Economic Perspectives in 2004.  This is included as it covers our period of interest-especially figure 1- and also provides some intriguing and little seen sources of references.  (29)

Dr Pfister reported to Hubert Lamb that for several decades prior to 1564 the Swiss climate was on average 0 .4c warmer than today (1990’s) In Switzerland, the first particularly cold winters appear  to have begun  in the 1560s, with cold springs beginning around 1568, and with 1573 the first unusually cold summer (Pfister, 1995).

Dr Pfister has an interesting graph of central Europe temperatures showing a progressive cooling of winters from the 1540’s,  a subsequent recovery around the 1620’s, with another deterioration in the 1690’s (Fig 76 Lamb- Climate History and the Modern World.)

The following extract is from ‘The Little Ice Age’ by Brian Fagan;

“It was not only the cold that was a problem during the Little Ice Age. Throughout Europe, the years 1560-1600 were cooler and stormier, with late wine harvests and considerably stronger winds than those of the 20th Century. Storm activity increased by 85% in the second half of the 16th Century and the incidence of severe storms rose by 400%. “

There are many other references dating from this period available from the Alps: records of advancing snow and ice burying silver and gold mines, alpine villages, farms and pastures being abandoned due to colder climate, even physical evidence recovered today under retreating glaciers.

There are also the German chronicles of devastation, cold and starvation from the period before and during the Thirty Years War. These are discussed in the book, “Power, violence and mass death in pre-modern and modern times” by Joseph Canning, Hartmut Lehmann and J.M. Winter (pp.94-95) (29a)

“For the constitutive paradigm of the “Little Ice Age”, matters of power, violence and death depended on a fundamental change of climate.  To be sure, in the 1570s the average temperature fell by only a few degrees, and equally certain, after the 1570s we can observe periods of remarkably stable, warm weather.  However, as Christian Pfister and others have shown, after 1570 and continuing for more than a century and a half, these stable conditions were the exception, not the rule.  What the people of Europe were forced to experience after the 1570s were long, cold winters, the late arrival of spring, cold, wet summers, and an early winter.  In sum, weather conditions in the growing seasons of agricultural products tended to become too short causing the produce – if any grew at all – often to be of poor quality.  Ensuing food shortages triggered an avalanche of reactions: while some people turned to God, confessing their sins and imploring God to grant the food necessary for survival, others hunted witches whom they considered to be agents of the devil and whom they held responsible for the failed harvests.  As a result of malnutrition, illnesses of all kinds spread rapidly, including the plague. Thus long before the outbreak of the Thirty Years War, population began to decline in many European countries.”

Brian Fagan noted that Glaciers in the Alps advanced significantly between 1600 and 1610 again from 1690 to 1700 and around 1820 and 1850 and that there had already been some movement from around 1546. There seemed to be some retreat around 1563 for a decade, but 1670 saw the Maximum advance in the Eastern Alps, which started retreating again around 1712.

A downturn in climate between 1560 and 1610 in Spain is noted here;  (30)

There is an especially good graph by Prof. G. Patzelt who  has reconstructed the declining summer temperatures in the Alps some 7000 years back in history   (30a)

(Note; Prof Patzelt of the University of Innsbruck has been a noted glaciologist for many years. This graph was part of a presentation to controversial climate group Eike, but the venue should not detract from the science and reputation of the Professor)

Another study by Patzelt below, on forests, glaciers and temperature anomalies, shows how the tree line rose and fell over time: (30b)

An additional study by him from 2008; (30c)

“An Gletscherrändern werden immer wieder Holzreste freigelegt bzw. ausgespült. Sie deuten darauf hin, dass es in den letzten 10.000 Jahren häufig wärmer als heute gewesen ist.”

Translation; “Pieces of wood are found repeatedly at the edges of receding glaciers.  These provide evidence that it was frequently warmer than today over much of the past 10,000 years.”

That Glacier advance is thought to have begun around 1560 and reached their maximum around 1740 is noted here;  (31)

In the Andes it was similar The LIA maximum advance occurred between cal. yr 1550 and 1720 AD, and a re-advance occurred around cal. yr 1830 AD.’ (32)

In Alaska; “The Little Ice Age reached its maximum extent here about 1750, when general melting began.”  (33)

The following gives a useful summary of notable glacier advances and retreats that began around 1560 and had generally reached its maximum by around 1750 or earlier;  (34)

Gordon Manley made the interesting observation that glacier advances took place in periods of cooler summer and springs, rather than cold winters. (Or presumably a combination of consecutive cool summer and cold winters)    (35)

This recent study also seems to illustrate an upwards trend in temperature from the early part of the 17th century- figure 5  (36)

This graph derived from ice break up times in Talinn shows an increasing temperature trend from 1500  (See page 195 and 197)   (36a)

This reconstruction by Craig Loehle also demonstrates a rising temperature trend to the present day starting from a trough in the early 1600’s  ( 36b)

Figure 103 in Hubert Lamb’s ‘Climate History and the Modern World’ shows an estimate of the growing season near the upper limit of cultivation in Scotland which mirrors much of the glacial record and demonstrates a steady-but not constant-improvement after a modest peak in the mid 1550’s- from the trough of the early 1600’s to the present day.

The previous examples demonstrated temperature generalities over decades, rather than year on year specifics for the CET area. It has identified a widespread change in the climate dating from a peak reached around 1550 with a subsequent decline to a low point around 1607, that was the precursor of a sporadic period of intense cold throughout much of the 17th century, with the coldest decade of all being the 1690’s which was the subsequent genesis of a long slow warming trend towards the present day.

The purpose of this study is to extend the CET record from 1659 to 1538 and identify any correlation between scientifically determined events and those observed from historical observations and records. It is clearly pointless documenting here thousands of examples of specific records and contemporary observations during this period that relate to the geographic area CET covers, as it would make this document extremely unwieldy. Consequently all the research from online sources, reference books and that gathered by the authors personal research at the archives of the Met office are detailed in chronological order in the paper found on the link here ‘Supplementary information’ together with the criteria, assumptions and references that were used to create the reconstruction;

Long slow thaw supplementary information

Section Five      The reconstruction to 1538 and its interpretation

The interpretation of the data detailed in ‘Supplementary information’ is shown here in the form of a graphic reconstruction of each year between 1538 to 1659 showing actual likely temperatures. The warm spell centred on the 1630’s is of most note.

Figure 10

The context of the reconstructed temperatures from 1538 in relation to the instrumental CET record from 1659 can be seen in this graph below in the style of Hadley 1772-which is shown as temperature anomalies.

 

Figure 11

In Figure 11 we can detect the peak of the warm period around 1540 that Lamb observed in Figure 6. From this high point there was then a notable initial decline, as observed by Pastor Schiller in 1560, and its continuation, observed by John King in 1595,  so that during the first decade of the 17th century cold was the norm, as observed by John Taylor of Deeside in 1610 and confirmed by glacier records.  By Taylor’s decade the climate had already reached lower values than during the cold trough noted by Lamb a century earlier, and indeed was colder than the 500 years that preceded it  (if Lambs reconstruction of the period preceding 1538 in Fig 6 is accurate )

The start of the 17th century had a substantial number of bitter winters, especially notable was 1607/8 which was one of the coldest in the entire 475 year extended CET record, but that first decade was somewhat balanced by some notably warm summers.

The period from the start of the ‘Bruegel’ winters from around 1564 to around 1620 appears to be probably the second coldest extended period in the record-but somewhat behind the decades commencing 1670. The notable warm bump around 1630 to around 1670 confirm the upwards trend we could note at the very start of the instrumental record in 1659, as shown in Figure 1, as the cold winters of that period were again ameliorated by some notably warm summers. This warm bump seems to be of equal value to the one around 1730 that Lamb observed, and like that period warrants further investigation in a future paper.

It appears therefore that the instrumental record did capture the coldest period of the LIA.

In the graph below (figure 12) showing ‘real’ temperatures rather than anomalies, the reconstruction from historic records is shown in green, instrumental records in red.

Because of the notably warm period at the start of the reconstruction and around the 1630’s, the green trend line to the present day is virtually flat. The red trend line illustrates that it is probably more accurate to describe the warming trend as commencing around 1660 rather than earlier. (The red line extension to 1538 is purely an artifice of Excel)

Figure 12

In this graph below (figure 13 ) showing the 10 year moving average, the low point is clearly the 1690’s with the very earliest part of the graph potentially around as warm as the modern era. This study also highlights the profound effect of the 40 year cold period around the 1690’s to 1710 and in particular the decade of the 1690’s.

Figure 13

The modern era is potentially showing the effects of needing a uhi adjustment greater than the Met office currently apply.  However, as we had earlier observed that instrumental records should not be considered accurate to tenths of a degree we are perhaps splitting hairs. Consequently, more accurately we should observe that the ‘direction of travel’ of temperatures, when combined and constrained by historic records, shows that at several points from 1538 there are similarities to the modern era as regards warm periods.

This was a little unexpected as the authors assumption had been that only the MWP itself would rival modern temperatures, and that with a long rising trend the warmest years would tend to cluster at the end of the record, rather than along its way. However this illustrates the great variability in our climate and that there appears to be some sort of natural cycle whereby notable peaks and troughs can be identified at irregular intervals.  The context can be seen by noting that despite the great variability that can be observed throughout the record, the British climate operates within a relatively small mean average temperature as can be seen in Figure 14 and the ‘hockey stick’ type effect from around 1900 can not be observed at all.

Figure 14

Below is a chart using all available databases, Berkeley, Giss Hadley/Cru etc. to the start of the CET instrumental record in 1659;  

 

Figure 15

It appears to demonstrate that the new Berkeley dataset is a reasonable match to CET and continues the series of peaks and troughs that can be observed in older instrumental records such as CET.

The graph below takes all available global data sets plus the ‘Hockey stick’ data (in black) used in the third IPCC assessment of 2001 and combines it with the extended CET reconstruction to 1538

Figure 15a

It should be noted that the vertical lines at the start of the BEST data and Hadcrut3 are merely a feature of the graphing package which note that the record started at that point. The BEST data in the period 1800 to 1830 appears to be somewhat exaggerated and perhaps reflect the very small numbers of stations being sampled rather than a real global climate state. Other than this, the instrumental CET record matches the instrumental global record quite well.

The research phase for the reconstruction of CET to 1538 has, as far as possible, tried to concern itself with the CET geographic area in order to compare like for like with the instrumental record. From looking at the graphs above and the joint graph reproduced again below as figure 16 we can make some observations

Figure 16

We can repeat our earlier observation that CET instrumental to 1659-this time augmented by the reconstruction using historical records to 1538, demonstrates a temperature profile that looks quite different to significant periods of the remainder of the Northern Hemisphere if the official version of extended climate-as epitomised by the ‘Hockey stick’- is taken as the appropriate set of data which it should be measured against.

Similarly the other extended instrumental records of this time –from cities-which illustrates a general warming trend throughout much of their history, incorporated within this article referenced below, may also not be representative of the general NH extended cooling trend that Dr Mann identified as lasting for 900 years until the start of the 20th Century. (37)

An alternative explanation is that the reconstructions and instrumental global data sets in fig 15a together with those city ones mentioned in (37) do in fact accurately represent the prevailing climates of the time, and therefore it is ‘the hockey stick’ that is not a reliable  representation. In unravelling the accuracy of any of the reconstructions, it is reasonable to try to determine if it is CET, together with the other records, or the Hockey stick, which is anomalous, by posing two interlinked questions. The first is to ask what evidence there is for the notable divergence of the various data sets -Lamb and this 1538 reconstruction on the one hand- and MBH 98/MBH99 on the other. To explore this it is useful to also ask if CET merely represents a specific area of central England or if it has a wider geographical application, as this impinges on the reality or not of a widespread and severe LIA.

Section 6    Can CET represent a wider geographic area and establish the existence of a Hemispherically significant cooling period?

According to our reconstruction from 1538 the first major trough was reached around 1607 (Figure 11) It can be seen as descending from a peak attained by 1560, following a century long broadly warming period (according to Lamb) that punctuated the LIA into two parts, a relatively short period following the end of the MWP, and another following a return to periods of bitter cold weather at the start of the 17th century that is confirmed both in this reconstruction and that by Lamb.

The divergence in the Mann/Lamb graphs (Figure 16) at this point is due to the considerable differences in the interpretation of the extent and warmth and extent of the MWP (outside our period of study) and the cold and extent of the LIA.

Contrary to popular belief Dr Mann didn’t refute the existence of either a MWP or LIA but thought of them as having a limited geographic impact. His 2002 article ‘Medieval Climatic Optimum’ amplifying his research on the MWP-one of the most controversial aspects of his reconstruction- is linked below (38)

He saw the MWP (covering a warm period predating the subject of this paper) as primarily a North Atlantic and adjacent regions anomaly (including part of Europe) and not a synchronous world-wide event, and that overall the Medieval warm period was substantially less warm than the two most recent decades, which he believed to be more global in its extent. Dr Mann also believed that the LIA was primarily a European matter from the 16th to mid-19th centuries due to solar variations, co-authoring a paper entitled ‘Solar Forcing of Regional Climate Change during the Maunder Minimum’ published in ‘Science’ in December 2001, that took a detailed look at this cold period.

“These results provide evidence that relatively small solar forcing may play a significant role in century-scale NH winter climate change. This suggests that colder winter temperatures over the NH continents during portions of the 15th through the 17th centuries (sometimes called the Little Ice Age) and warmer temperatures during the 12th through 14th centuries (the putative Medieval Warm Period) may have been influenced by long term solar variations.” (39)

His paper from 2002 entitled ‘The Little Ice Age’ comments;  (40)

 “If defined as a large-scale event, the Little Ice Age must instead be considered a time of modest cooling of the Northern Hemisphere, with temperatures dropping by about 0.6 C during the 15th–19th centuries (Bradley and Jones, 1993; Jones et al., 1998; Mann et al.,1998, 1999).”

And;

“The Little Ice Age may have been more significant in terms of increased variability of the climate, rather than changes in the average climate itself. The most dramatic climate extremes were less associated with prolonged multiyear periods of cold than with year to year temperature changes, or even particularly prominent individual cold spells, and these events were often quite specific to particular seasons. While the 17th century appears to represent the timing of peak cooling in Europe, the 19th century was more clearly the period of peak cold in North America (panel b).”  

His 2009 co-authored paper;

‘Global Signatures and Dynamical Origins of the Little Ice Age and Medieval Climate Anomaly’ goes into considerable detail on both topics with numerous graphics. (41)

It was reviewed by Skeptical Science who made these comments;

“The Medieval period is found to display warmth that matches or exceeds that of the past decade in some regions, but which falls well below recent levels globally. This period is marked by a tendency for La Niña–like conditions in the tropical Pacific. The coldest temperatures of the Little Ice Age are observed over the interval 1400 to 1700 C.E., with greatest cooling over the extratropical Northern Hemisphere continents. The patterns of temperature change imply dynamical responses of climate to natural radiative forcing changes involving El Niño and the North Atlantic Oscillation–Arctic Oscillation.”

And;

“Some regional warming greater than today, some regional cooling, over all no global warming comparable to today”.  (42)

Dr Mann was possibly under the impression that Hubert Lamb himself did not believe that the records he accumulated had any especial relevance beyond a relatively narrow geographic area as regards the existence of the MWP

Indeed, when Lamb (1965) coined the term Medieval Warm Epoch, it was based on evidence largely from Europe and parts of North America.

AND

“Although Lamb (1965) did not argue for a globally synchronous warm period, his characterization has often been taken out of context, and used to argue for global scale warmth during the early centuries of the millennium comparable to or greater than that of the latter 20th century”

Both comments from this 2002 document  (43)

This interpretation is not strictly correct as Lamb believed CET (and other reliable records) had a much wider relevance beyond that of the central portion of England. He observed in Chapter 5 of ‘Climate History and the Modern World’;

’…that the last centuries (CET) records ‘have been highly significantly correlated with the best estimates of the averages for the whole Northern Hemisphere and for the whole earth ‘

In Table 4 page 281 of his book Lamb explores the correlations he had established.  (44)

He further commented;

‘…over the 100 years since 1870 the successive five year values of average temperatures in England have been highly significantly correlated with the best estimates of the averages for the whole Northern Hemisphere and for the whole earth’ (In this last comment he is no doubt referring to his work at CRU where global surface records back to 1860 or so were eventually gathered) he continued;  ‘they probably mean that over the last three centuries the CET temperatures provide a reasonable indication of the tendency of the global climatic regime.’

‘Tendency’ is a very good word and is preferable to ‘preciseness’ which has become an integral part of the climate science lexicon.

Writing about tree rings in the same chapter (this was of course many years before Mann’s 1998 reconstruction made extensive use of this proxy) Lamb commented on the University of Arizona ‘Laboratory of Tree Ring Research’ (who Mann collaborated with for his later study) concerning bristlecone pine trees in the White Mountains.  ‘…this long series at the upper tree line essentially registers summer temperatures. It is of interest that from AD800 to the present century (20th) its hundred year averages are correlated in a statistically significant degree, with the temperature derived for central England.’

Coming closer towards the modern era this paper ‘British Winters in relation to World Weather’ written by E W Bliss and published in 1926 by the Royal Meteorological Society provides a scholarly examination of the relationships discovered, which gives us an insight into what was happening elsewhere in the world.  This portion from the summary is intriguing;

“The results indicate that conditions in the Southern Hemisphere play a part comparable with that of the North Atlantic oscillation in controlling subsequent winter weather in the British Isles.” (45)

In the 1997 book ‘Climate of the British Isles’ edited by Mike Hulme and Elaine Barrow (previously referenced) the authors distill a great deal of information from such luminaries as Phil Jones (a successor to Hubert Lamb at CRU)  (46)

‘An examination is made of the correlation between the British isles and Northern Hemisphere. The CET series is related to average land temperatures over the Northern Hemisphere, but probably no more than would be expected from any other region of comparable size in the hemisphere. The relationship appears to strengthen when temperatures are averaged over decades or more but considerable caution should be exercised in extrapolating trends from the long CET record to the hemisphere as a whole.’

This comment below from Physics World quotes an academic study by Mike Lockwood of the University of Reading  (47)

‘Comparing the changes in English temperatures (which the researchers say are representative of European temperatures as a whole) with fluctuations in solar activity, the researchers found a strong correlation.’

A further reference from Mike Hulme in his paper “Sensitivity to Climatic and other factors”

‘The Central England Temperature is perhaps the single most important and representative measure of the surface climate of the UK. It is also quite well correlated with land temperatures over the entire Northern Hemisphere. At an annual level this correlation is about 0.4, but when average values over 10-year periods are compared this correlation rises to about 0.75.” (48)

Geert Jan van Oldenborgh of KNMI makes the following comment;

 ‘…like most temperature records in Northwest Europe the Cet time series over the 20th century shows a striking similarity with the world average.’ (49)

In this study by Phil Jones and Michael Mann Figure 2 demonstrates that CET is a good proxy for much of the time for the Northern Hemisphere  (49a)

In the study referenced below CET trends are overlaid on to some of the oldest instrumental records available, and graphically demonstrate that there is considerable correlation in data sets as diverse as New York City to Geneva (50)

We must be cautious in believing that any single instrumental record can act as a reliable proxy for the entire world as was observed here;  (51)

“One drawback of local records is that they tend to show much larger scatter than global/hemispheric averages.” Compared to global, hemispheric, or even regional averages, the noise level in individual station records is huge. You can’t expect to be able to “see” what the long-term behavior is just by looking at graphs of individual station data, especially with trend-squashing y-axis scales. Hopefully an examination of a location over several hundred years will enable us to cut out the noise and hear the message underneath it.”

However, the extensive material available tends to provide support for the notion that the English temperature history and records presented in Fig 30 of Chapter 5 of ‘Climate History and the Modern World’- which appears to be the basis on which the IPCC subsequently produced their global graph in 1990-does perhaps have some wider significance that usefully illustrates general trends, especially in Europe and the North Atlantic, and arguably much further afield.  The importance of CET as a broader temperature proxy is further enhanced by its longevity and the scrutiny it has subsequently received by academics because of this.

Figure 17 IPCC 1990 view of Climate derived From Lamb

The CET records, especially when coupled with other instrumental and observed records,  appear to show that there is considerable divergence at times from the Mann Northern Hemisphere reconstruction seen in Figure 4. Why should that be?

An indication of the reasons can be gained by referring to Figure 5 and reference (11) which together shows the nature and location of proxies used by MBH98 amongst others.

Previous critiques of MBH98 and 99 tended to focus on the quality of some of the proxies used, or their highly complex interpretation. Few seem to focus on their appropriateness as the means of creating a temperature anomaly accurate to fractions of a degree dating to 1400AD and 1000AD respectively.

The studies used a substantial number of Sea surface temperature records as one of its data set series. Obtaining a SST depended heavily, for much of its history, on buckets being thrown over a ship at varying depths to collect water samples. That this is not a  reliable way to determine precise global ocean temperatures back to the middle of the 19th Century was observed here; (52)

The largest number of proxies used to reconstruct temperatures were derived from tree rings. These have a number of problems.  Some of the complexities are paraphrased from Loehle, C. 2009.   A Mathematical Analysis of the Divergence Problem in Dendroclimatology.  Climatic Change 94:233-245

‘…..in some species the tree may be responding to last year’s temperatures because they set buds in the fall.  In masting species, growth following a mast year will be poor, and also that over long periods a single tree is affected by the death and growth of neighbours and growth is correlated with local rainfall.  Many studies typically use ring width when they should be using basal area increment, which tends to be linear over the life of the adult tree (past the pole stage.”

Trees can only ‘record’ information during the growing season and growth is greatly affected by moisture, night/day temperature differential, day length and light intensity which includes the degree of shading from other trees. Prof Steve Wofsy of Harvard University says even a passing cloud can affect photosynthesis and growth. There are thus many local variables and information is subsequently extracted by the use of highly complex and controversial statistical analysis. Under all these circumstances it is somewhat perplexing as to why such proxies have come to be viewed as a reliable means of recording the equivalent of an annual mean temperature  accurate to fractions of a degree, from which it is possible to reconstruct one thousand year old climate scenarios

This potential inaccuracy can be seen in the very large error bars of such studies as the hockey stick (figure 4) of well over a degree.

Tree rings have been used to record basic information such as moisture since the 1780’s but extracting precise and highly detailed information would appear to be outside the scope of our present levels of knowledge.  This from the Paleontological Research Institution gives a useful and even handed primer on using tree rings in climate research. (53)

It would be misleading to give the impression that those involved in climate science are unaware of the limitations of historical documentary evidence (so called  ‘anecdotal’ material) or the potential shortcomings of proxies such as tree rings. These very subjects are dealt with in section 2.2 and 2.3 respectively of the 2004 article “Climate over Past Millenia” by Jones and Mann (reviews of Geophysics, 42, RG2002/2004   (53a)

The very pertinent comment is made that; “Inferences from regional data in isolation will clearly provide a biased view of larger-scale changes.” (Which is of course why this paper has tried to establish if CET has any meaning outside of Central England.) Jones and Mann provide several examples of historic documentary evidence that they believe has too much emphasis placed on them, including vineyards in medieval England-pointing out there are far more today than there were then- and commenting on the frequency of Frost fairs. In the case of the latter example they refer to Lamb (1977) who noted such events only occurred 22 times between 1408 and 1814 and eventually ceased due to the rebuilding of London Bridge, not necessarily because the winters became too warm to facilitate them.

‘The Long Slow Thaw’ has dwelt much on the LIA as it covers such a key part of this reconstruction and also made reference to the MWP, although it is outside this papers time scale . Section 6 of ‘Climate over past Millennia’ is entitled  “ FUTURE DIRECTIONS: WHERE DO WE GO FROM HERE?’ And what is written there is therefore of especial interest;

“[97] Section 4 indicates that the broadest features of the ‘‘so-called’’ MWP and LIA can be seen in the reconstructions of large-scale mean temperature variations over the past millennium, but such reconstructions show considerably greater detail that defies the use of these simplistic terms.”

And

“As the detail of our knowledge improves, the ‘‘MWP’’ and ‘‘LIA’’ are increasingly likely to be regarded as overly restrictive terms…. In the instrumental period, warming in the 20th century is generally qualified as occurring during the early to middle and/or the later decades [Jones and Moberg, 2003]. This interpretation is only possible with hemispheric and global average series and would be impossible to determine from series at local or regional scales. In a similar vein the climate of the recent two millennia at the largest of scales can only be described using composite series of the type displayed in Figure 5. “

And

“[98] Likely expansion and improvements in the network of available proxy series will increasingly in coming years lead to viewing the restrictive terms such as the MWP and

LIA as obsolete. We anticipate the field of paleoclimatology moving toward data sets that can be used to develop spatial maps (with associated errors) for each season of the last one to two millennia, using techniques that can easily accommodate continual revision to our best available estimates as new series are developed. Particularly at regional scales, such revisions will arise from the addition of specific new high-quality proxy series.”

The paper recommends the phasing out of such ’restrictive’  terms as the MWP and LIA and   ‘instead refer to anomalous climate periods by calendar dates, as is the practice in the description of more modern climate changes.’

In my article I have suggested the LIA is ‘misnamed’ so have no real problem with the reasoning, other than it has become a familiar and well understood term to describe the various periods of cold that can be observed over several hundred years and the alternatives suggested seem to minimise the importance of the periods.

‘Climate over Past Millennia’ is an interesting and detailed paper dealing with many aspects of the building blocks of our changing climate. In it are expressed some of the uncertainties and unknowns that are seldom mentioned in IPCC documents. it is well worth a read but does brings us back to whether CET can be more generally applied to the Northern hemisphere rather than being perceived as  representing a small geographic area, and also if it has any broader lessons in, for example, identifying the dates, severity and synchronicity of LIA periods.

The evidence on both counts-from a wide variety of scientific and observational sources- seems to strongly suggest that it can.

Section 7 Conclusions and Postscript

Conclusions;

1)    CET seems to be a reasonable-but not infallible- proxy for the Northern Hemisphere. Britain has a maritime temperate climate, so whilst it can usefully indicate wider trends it will not generally follow the extreme peaks and troughs of more climatically volatile regions. The moderate nature of the British Climate marks out the deep troughs of the LIA, observed around 1690 and various other periods, as extraordinary.

2)    CET matches well for much of the time with ‘global’ data sets (although the value or accuracy of a global record remains open to question). If instrumental CET is corroborated by global sets from their inception around 1850s it is reasonable to suggest that CET will also correctly portray the predominant climate since its own inception in 1659.

3)    Any attempt to construct a single global or even Northern Hemisphere temperature covering many centuries will encounter substantial difficulties, as incomplete information from novel proxies will probably not adequately represent the extremes that are experienced at either end of the temperature spectrum, so what is considered the ‘average’ is possibly representative of no climate state that actually ever existed. Considerable uncertainties abound in virtually every area of historic temperature reconstruction-including this one- and the ‘error’ bars are very broad. In the case of ‘1538’ plus or minus half a degree Centigrade.The existence of the UHI effect in many instrumental records confuses data even further and the allowance for this factor in recent decades is probably insufficient.

4)    The nature of the proxies used in MBH98 and 99 have inherent problems and have proved very controversial. Tree rings have an inability to adequately represent the conditions of the entire year, amongst other difficulties, whilst SST’s have their own considerable shortcomings. Mixing proxies also causes their own problems. Taken in total, the data used in such studies is unlikely to accurately represent the climates prevailing at the time back to 1400AD and 1000AD. Carrying out complex statistical analysis on questionable data does not render the initial data any more meaningful as a scientific measure. Paleo reconstructions as a whole should be treated with caution when it relates to precise representations of temperature.

5)    Lamb gathered together a variety of forms of evidence in his reconstruction. The schematic of composite graphs seen in figure 16 and 17 -when compared to the reconstruction to 1538- seems to confirm with other research that Lamb’s view of climate history was broadly correct. The main caveats we would place is that our own 1538 reconstruction seems to indicate slightly warmer humps around 1550 and 1630 than Lamb notes. This needs to be checked as it was unexpected

6)    The hockey stick remains a potent icon to this day. However the gradual decline in temperatures over the centuries that it depicts cannot be detected, nor the lack of variability of the climate over the same time scales. The sharp uptick in temperatures from the start of the 20Th Century is a likely artifact of computer modeling through over complex statistical interpretation of inadequate proxies. Modern warming needs to be put into its historic context with the patterns of considerable natural climatic variability that can be observed from the past.

7)    The available information seems to demonstrate that there is a long established warming trend dating back some 350 years to 1660-with various notable trends within the trend.

8)    When viewed from a 1538 perspective the warming trend becomes imperceptible. That period seems to have been around as warm as today and there are others that also seem to exhibit notable warmth to levels not dissimilar to today’s. This finding was unexpected and warrants further research.

9)    The Met office assertions of a virtually unchanging climate until the last century does not seem to be supported by the wealth of information available in their own archives, some of which is detailed in the document ‘supplementary information’.

10) The 1538 reconstruction will be updated as further evidence becomes available. In particular we need to assess the subjectivity of written records whereby one chroniclers ‘excessive heat’ may be someone else’s ‘pleasantly warm’.

Postscript.

In his book ‘The Little Ice Age’ Professor Brian Fagan notes;

 “The little ice age of 1300 to about 1850 is part of a much longer sequence of short term changes from colder to warmer and back again which began millennia earlier. The harsh cold of the LIA winters live on in artistic masterpieces….(such as) Peter Breughel the elders ‘hunters in the snow’ (see Figure 9) painted during the first great winter of the LIA but there was much more to the LIA than freezing cold and it was framed by two distinctly warmer periods. A modern day European transported to the heights of the LIA would not find the climate very different even if winters were sometimes colder than today and summers very warm on occasion too. There was never a monolithic deep freeze rather a climatic see saw that swung constantly back and forwards in volatile and sometimes disastrous shifts. There were arctic winters, blazing summers, serious droughts, torrential rain years, often bountiful harvests and long periods of mild winters and warm summers. Cycles of excessive cold and unusual rainfall could last a decade a few years or just a single season. The pendulum of climate change rarely paused for more than a generation.”

Having examined tens of thousands of accounts of the weather from 1500-1750-for this article, through books, online and also during several days research in the Met office archives in Exeter, Fagan’s account resonated with me. Being so dependent on the land and the successful raising of crops made our ancestors acutely aware of the weather and of climatic trends, and their accounts are often highly detailed.

Reading their vivid testimony of the seasons – sometimes in books several hundred years old- was like viewing their lives in a speeded up film.

First, a disastrously cold winter threatened their existence- but brought the chance of riotous frost fairs- which might quickly thaw to a mixed and floody spring where crop planting was a struggle, to be rapidly supplanted by a hot bucolic summer bringing anxious periods of drought, saved by rain that enabled a bountiful harvest, after which violent winds would blow in a stormy autumn as first one weather system gained ascendancy, only to be supplanted by another as the wind direction changed. During the following year all may be reversed, with complaints that an excessively wet mild winter didn’t destroy diseases, whilst the previous year’s baking hot summer was supplanted by a series of dull cool months threatening the all-important harvest, touching our ancestors with the ever present specter of famine.

Clusters of wet or dry years were as notable as clusters of cold or warm years, and sometimes all conditions coincided within one year demonstrating the variability which the Met office discounted.

The overwhelming impression I formed from reading the accounts of the vagaries of the climate of yesteryear was that they sounded exactly like today, with perhaps greater variability, extreme events and colder bits thrown in, although after the last few bitter winters the striking similarities with the past have become even closer. It is difficult to determine any evidence of notable climate change in recent years leading to a dramatic change in our climate or a surge in temperatures. What we can observe is a transition from the anomalously intermittently cold periods of the LIA together with lots of examples of climate variability.

Most notably the modern observer might feel that our current era seems to have lost the extreme winters of yesteryear- which in turn have had a considerable impact on the overall mean average temperature in the last few decades. However, once again history can show us that this apparent dearth of cold winters has had numerous precedents in our past.

Reginald Jeffery observed in his book ‘Was it Wet or was it fine,’  “By 1708 the middle aged would say where are our old winters?”

This query was being echoed on the other side of the Atlantic around the same time as the records of the Hudson Bay Company demonstrate that climate change was not restricted to Europe.

Over the fifteen years between 1720 and 1735, the first snowfall of the year moved from the first week of September to the last…”

Thomas Jefferson -third President of the United States- kept extensive weather records and referring to the period around the 1770’s remarked;

““A change in our climate however is taking place very sensibly. Both heats and colds are become much more moderate within the memory even of the middle-aged. Snows are less frequent and less deep. They do not often lie, below the mountains, more than one, two, or three days, and very rarely a week. They are remembered to have been formerly frequent, deep, and of long continuance. The elderly inform me the earth used to be covered with snow about three months in every year. The rivers, which then seldom failed to freeze over in the course of the winter, scarcely ever do so now.  (54)

A few decades later Noah Webster, 1758-1843 (founder- Webster’s dictionary) commented;

The temperature of the winter season, in northern latitudes, has suffered a material change, and become warmer in modern, than it was in ancient times. … Indeed I know not whether any person, in this age, has ever questioned the fact.”

Towards the end of the 19th Century a correspondent in the Canadian Horticulturist monthly of 1880 (page 7) remarked;

“I do not know whether or not the climate of Ontario is really becoming permanently milder than formerly, but I do know that for the past 18 years or 20 years we have not experienced the same degree of cold as the seven years preceding.”

Writing in 1931 after several decades of compiling his book ‘Was it wet or was it Fine’ Reginald Jeffery remarked;

“I have been asked so often during the period that I have been doing this work this question, well after all this grubbing into the wealth of the past, do you think that our climate is changing or has changed? Where are the old snow storms? We never quite know where we are with regards to weather.”

Whilst around the same time a farmer from Buchan in Scotland wrote to his local newspaper;

1934 has opened true to the modern tradition of open, snowless winters. The long ago winters are no precedent for our modern samples. During the last decade, during several Januarys the lark has heralded spring up in the lift from the middle to the end of the month. Not full fledged songs but preliminary bars in an effort to adapt to our climatic change.”

It then goes on to say;

“It is unwise to assume that the modern winters have displaced the old indefinitely”  and also; “Our modern winters have induced an altered agricultural regime”

In order to be able to offer a more rounded picture of our ever changing and variable climate, it might be useful if scientists were less credulous of the infinite accuracy of unlikely proxies and took more notice of the great wealth of ‘anecdotal’ accounts. This might help to strike a better balance between observed records and scientific data often derived from uncertain and fragmented raw data of questionable provenance, that has then been subject to highly complex statistical analysis. The end result is the presentation of data that claims considerable-but unlikely- accuracy. To paraphrase Hubert Lamb we can know the ‘tendency’ but not the ‘precision’ when we delve back in time. Uncertainty shrouds much of the past and in consequence perhaps we believe we know much more than we currently do.

References

JC note:  For the last several months, Tony has been sending me snippets from his research.  I find the climate-history nexus to be fascinating.  I offered to post this on Climate Etc.    As with all guest posts, the views expressed here are those of Tony Brown, and my publishing this here does not imply any endorsement by myself.


338 responses to “The long, slow thaw?

  1. Wasn’t the 2nd warmest Summer 1822 for CET?

  2. Thanks Tony, excellent read and an essential reference.

  3. It’s really all about the rate of temperature change.

    I put together the chart in the link below yesterday, which graphs rates of temperature changes from a Greenland temperature reconstruction

    The data is taken from a 30,000 to 80,000 year range. The histogram of cooling and warming rates is tabulated across the extremes in (a), on the cool side below average temperatures in (b), and on the warm side above average temperatures in (c). During this period, when the temperature started to warm something triggered a fast rise, which you can see in the flat area of the histogram. I will see if I can reproduce this for the Antarctic data, unless someone has seen this kind of chart before.
    The question is: now that we are already in a warm regime, could something like this happen again, to push us even hotter? IMOO, that is what the climate scientists are trying to figure out.

    • Web,

      What other changes were in that period of time?
      A slightly faster planet. More ocean water from 4.5 mm to 12mm.
      Slightly closer to the sun.

      Accuracy…accuracy…accuracy…
      This is what is lacking in science.

      • Latimer Alder

        How much closer to the Sun? Please be accurate

        And what do you mean by ‘more ocean water from 4.5mm to 12mm’ What are these measurements of?

      • If I had the funding and time…
        But I work for a living and can only allocate a certain amount of time.
        As for water mm changes, they are residue deposits from salt that I calculated a timeline from.

      • If I had the funding and time…
        But I work for a living and can only allocate a certain amount of time.

        Come on skeptics, Joe is one of your own. It seems like you should be able to raise at least a little bit of cash so he can buy himself a fresh box of crayons.

      • Web,

        In the spirit of the season, BACK TO YOUR CUBICAL! :) We need to see the comparison of GRIP v Vostok rates of change in temperature and rates of change in CO2 with temperature before the Mayan calendar runs out.

      • We need to see the comparison of GRIP v Vostok rates of change in temperature and rates of change in CO2 with temperature before the Mayan calendar runs out.

        Natural atmospheric CO2 concentration obviously has to follow Arrhenius rate laws with temperature, with an activation energy of a few tenths of an eV.

        You can estimate the activation energy from that slope.

        Because of the GHG effect, one can’t separate the effects of water vapor concentration, which also has an Arrhenius law, aka Clausius-Clapeyron . It is obviously impossible to get proxy readings of water vapor levels out of ice core data.

        I do a lot of these kinds of graphs because I am not sure if they exist in the scientific literature.

      • Web,

        I am more concerned with finding a way to estimate the change in water vapor. You will notice in the TonyB plot above, 1896 was pretty chilly in Arrhenius’ neck of the woods. Since his CO2 concentration estimate ranged up to 1.5 times his present or approximately 280 to 420ppm and performed pretty well up north, but not so well in the tropics or Antarctic, it could be interesting :)

      • The Arrhenius rate law is about vapor pressure of materials as a function of temperature, and I think that is a well understood concept.
        I was using this formulation years before I was even aware that Arrhenius had anything to do with greenhouse gas theory. We used it to calibrate vapor phase furnaces and mapping out phase transitions to first order. It is actually a shorthand for describing Maxwell-Boltzmann statistics applied to material properties :
        exp(-E/kT)
        where E is an activation energy. You map out two temperature points for either vapor pressure or a phase transition, and you can derive the activation energy on a semi-log plot with 1/T plotted on an axis. Some people like to call this Clausius-Clapeyron but it doesn’t really matter in terms of the first-order relationship that one is trying to extract.

      • Web,
        How well does it work with snow and ice cover? Available water due to snow/ice plus biological CO2/methane sequestered under snow/ice are things likely to have changed with land clearing. More of that happened in the NH, which should have an impact on circulation and energy storage.

    • WHT,

      Thank you for this. Very interesting.

      I am surprised the maximum rates of change are so small (if I am interpreting the charts correctly). I had read somewhere previously that the Greenland ice cores showed rates of change of several degrees per decade in some years in the past few thousand years. I don’t remember the details exactly and may have it wrong. Can you tell me what are the most rapid rates of change that have occurred in the Greenland ice cores in the past 10,000 years, and a link for future reference?

      • Sure the rates can vary to large extent. I have a plot for the last 10,000 years in Greenland and it looks totally different than the plot for earlier periods.

      • WHT,

        Thank you for your response. Can you give me a link to that plot (for the past 10,000 years of temperatures from the Greenland ice core data)?

        Can you say what was the maximum rate of change for a range of durations such as a year, decade, selected few years and selected few decades?

      • This is an even better analysis (as in free, and w/o funding) in describing the Holocene, up to the last 10,000 years, in Greenland:

        This histogram chart I put together indicates a very interesting dynamic in the warming and cooling slopes of the temperature transitions. I split the temperature into two sets, those below average temperature and those above average temperature. These are the cool and warm regimes. In the cool regime, warming starts out on average slower, and then when it gets to the warm regime, the tempo picks up. Then when the direction reverses in the warm regime, the cooling starts out slowly and then speeds up when it enters the cooler regime. I think this is indicative of a positive feedback kind of random walk. This is very hard to pick out unless one does a histogram binning as shown, since it is a stochastic effect.

        This is much more obvious in the pre-Holocene data but it looks like this mechanism also exists in the Holocene.
        The stochastic simulated process would look like this:

        Now does anyone have any idea of what this positive feedback mechanism is? I think I know.

        I have been keeping track of these findings here:

        http://theoilconundrum.blogspot.com/2011/11/multiscale-variance-analysis-and.html

      • Jim in SC,

        Thank you for the interesting paper. http://www.clas.ufl.edu/users/rrusso/gly6932/Steffensen_etal_Science08.pdf
        It did answer my question, (and so has WHT’s comment, which I will reply to separately below).

        This is the bit I was after:

        “The δ18O warming transition at 14.7 ka b2k is the most rapid and occurs within a remarkable 3 years while the warming transition at 11.7 ka b2k lasts 60 years; both correspond to warming of more than 10K (6, 19).”

        The rate is about 3 K/year for the first warming (in cold times) and 0.17 K/year in the second warming (in warmer times).

        I interpret the trend to suggest that the change is more likely to be slower next time (since we are even warmer than when the second rapid warming occurred).

        They seem to be saying that warming can happen suddenly and imply the next one could be very bad for us.

        “The high resolution records from the NGRIP ice core reveals that polar atmospheric circulation can shift in 1-3 years resulting in decadal to centennial scale changes from cold stadials to warm interstadials/interglacials associated with astounding Greenland temperature changes of 10K”

        However, each time I read these articles and stare at the charts, I feel I am more scared of cooling than warming (see my response to WHT below). I interpret several statements in the paper to suggest that any sudden warming event will be slower next time because we are warmer.

        “The 14.7 ka b2k event followed Heinrich event H1 at a time when the ice sheets in the North were still extensive whereas the North was more deglaciated at 11.7 ka b2k (34), reducing the amount of ice discharge available to change the density of North Atlantic ocean waters and thereby the THC before the warming onset.”

        (appolgies to readers; I posted my reply to Jim in SC at the end of the thread. Please read it together with this reply to WHT)

      • WHT,

        Thank you for this additional information. Very interesting.

        I understand very little of the detail. But, if I look at your Figure 19 here:

        http://theoilconundrum.blogspot.com/2011/11/multiscale-variance-analysis-and.html

        I like the look of past 10,000 years much better than the preceding 100,000 years. But I don’t like the downward trend in the past 10,000 years. I am much more worried about cooling than warming. If we are helping to reduce the probability of cooling and perhaps get a bit more warming, then I can’t see the problem. After all, the planet is in a Coldhouse phase, and well below the average temperature of the past 600 million years (there has been no polar ice caps for 75% of that time). When the planet is warmer life thrives, when colder life struggles. So why are we so concerned about a little warming?

        BTW, I think I understand the point you make with the Figure 22c and 23c. My interpretation of Figure 23c (two points at bottom right of chart) is that a warming rate in warm times of 0.2 K/year and 0.225 K/year is equally likely; the probability is a bit above 0.001 (or about once in every 500 to 1000 years). Correct me if I am wrong,

        But why do these points have a higher probability in Figure 23c than in 23a? (I presume they are the same points? Or am I misunderstanding the chart?)

      • I like the look of past 10,000 years much better than the preceding 100,000 years. But I don’t like the downward trend in the past 10,000 years. I am much more worried about cooling than warming.

        Let’s parse your three sentences:
        “I like the look of …”
        “But I don’t like the …”
        ” I am much more worried …”

        You know what? Science doesn’t care about what you like or what you are worried about. On these charts, a longer tail or shallower slope indicates a greater absolute value in historical warming or cooling rates. The probabilities tell us how often the different rates are operational. If this helps our collective understanding in how temperature evolves, that’s what I was intending to convey.

        The fact that the warming rate is stronger in an already warm regime, and that the cooling rate is faster in a cooling regime indicates that acceleration is taking place. And acceleration is most easily explainable by a positive feedback mechanism. This could be CO2/H2O GHG reinforcement, changing albedo or snow/ice cover, or something else. Also the fact that these accelerating episodes show self-limiting characteristics indicate that some physical effect eventually throttles the acceleration, perhaps something akin to an energy barrier. The obvious barriers are the saturating CO2 sensitivity along with Stefan-Boltzmann law on the high end and a latent heat of fusion barrier on the low end.

        This is all metastable so it can go in either direction depending on the forcing stimulus.

        I certainly would like to further discuss the interpretation and even the validity of my analysis, but think it is way too early to turn this into a rationalization for a subjective AGW analysis, either pro or con.

      • WHT,

        “You know what? Science doesn’t care about what you like or what you are worried about.”

        Thank you for your comment and mild rebuke. I agree with your remark that I should separate my musing about the consequences of warming from discussion of your excellent analysis.

        Getting back to your charts, I am not sure I understand what they are showing. Could you please help me on this? I asked some specific questions in my previous comments but you didn’t answer them.

        1. My third paragraph of my last comment asked if I was interpreting the charts correctly?

        2. Are the three points at the bottom right of Figure 23c the same as the three points at the bottom right of Figure 23a? If so, why do they have a higher probability of occurrence in 23a (about 1.0015) than in Figure 23c (0.001)? If these are plotted correctly, as I assume they are, it means I am not understanding the chart.

        3. Figures 23a and 23c have 18 warming-rate points and Figure 23b has 12. Why doesn’t figure 23 a have 30 (18 + 12)? I am clearly misunderstanding something.

        You said:
        “The fact that the warming rate is stronger in an already warm regime, …”

        However, the paper Jim in SC linked to gave a maximum warming rate of 3 K per year when colder (admittedly before the start of your chart) and 0.17 K when warmer. (see my comment to Jim in SC). This one example shows a much higher warming rate when colder than when warmer. This does not support your statement.

        Would you be able to plot a trend of warming rate versus temperature?

        My reason for asking this is I am wondering if perhaps the rate of warming at the temperature we are at now may be less than when colder. The basis for this is that the temperature rise of each of the previous integlacials has stopped at around the temperature we are at now. Does that suggest an upper limit to the temperature we can reach in the conditions of the ColdHouse phase we are in? Could that mean that we cannot warm much more? Could it mean that a future warming shift will be of little consequence?

        I’ll ask about the consequences and policy implications of a warming shift in my next comment.

      • Now, keeping my musing about consequences and policy implications separate from the science, I’d like to ask anyone who wants to answer about the consequences and policy implications of a rapid warming shift.

        1. If a rapid warming shift does occur this century, what would be the consequences?

        2. What would be the benefits and the costs of a warming shift? (what would be the net benefit or cost?). I imagine there is a lot involved in this. For example, we’d need to also take into account, what is the probability of a cooling shift if we do not continue to add GHG?

        3. What would be the cost of trying to prevent a rapid climate shift?

        4. What would be the probability of avoiding a rapid climate shift with the currently proposed policies to try to prevent a warming shift?

      • WHT,

        I saw a comment somewhere on this thread, but now I can’t find where it is. It gave this link: http://www.csmonitor.com/Science/2011/1202/Algae-helps-explains-Antarctic-ice-sheet-formation

        More musings from me about what all this means:

        Algae sent us into a Cold House Phase 34 million years ago.

        So, if the planet gets too warm, future generations will fertilise the oceans with whatever it takes to grow algae. But they’ll do it at just the appropriate rate to keep the planet in a temperature range that suits them. (I’m only half joking; if we need to do so in decades ahead we will. We can adapt. We always have).

        I’m currently of the opinion adaption will be much lower cost and much less damaging to people across the planet than the policies currently being promoted to try to prevent climate change.

        Am I correct that during HotHouse times, life thrives? Is it true that the oil was deposited in HotHouse times and in oceans that were warm, relatively calm and with abundant life?

        Is it true that the amplitude of the climate swings is much less in HotHouse times than in ColdHouse times (such as we are in now)? (refer to your Figure 19 here: http://theoilconundrum.blogspot.com/2011/11/multiscale-variance-analysis-and.html

        What is to be feared about a bit of warming?

      • I went to the link to “Living warmer: How 2 degrees will change the Earth”: http://www.livescience.com/10325-living-warmer-2-degrees-change-earth.html and saw this: “The warmer you get, the more bad stuff can happen and the more outside the natural range of the Earth’s climate we get.”

        What nonsense. The Planet is in ColdHouse phase. How can he justify comments about “outside the natural range of the Earth’s climate”? This is the sort scaremongering that makes me doubt the credibility of CAGW Alarmists.

        I understand most of the warming would be:
        – at high latitudes (good)
        – in winter (good)
        – at night (good)

        There would be little change:
        – at low latitudes (good)
        – in summer (good)
        – in the day time (good)

        A bit more insulation for planet Earth looks mostly good to me.

        The whole argument about more sever storms is very unpersuasive. We’ll just build better infrastructure, and we can do that better for all people if we don’t slow our economies by implementing irrational policies.

      • Getting back to your charts, I am not sure I understand what they are showing. Could you please help me on this? I asked some specific questions in my previous comments but you didn’t answer them.

        They are probability density function histograms of the slopes of temperature changes between time series points. Each curve is normalized to add up to a probability of unity. Nothing unusual about this kind of plot in other disciplines, i.e. velocity adjustments from a cruise control feedback, tabulated daily stock market movements, etc.

        The only thing that is hard about them is the interpretation. They show probability only, so they give you the general trend for the movements, but not every movement has to follow the mean.

      • WHT,

        Thank you for trying to explain how to interpret the charts. I am afraid it is still not clear for me. Could I ask some specific questions about Figure 23 http://3.bp.blogspot.com/-rLzIpTIE_z8/Ttm52TqxsQI/AAAAAAAAApE/YEs0768cD5U/s1600/greenland_ice_core_rates_10k.gif , I’ll provide what I think are the answers and you say if I have understood correctly.

        1. The two points at the bottom right of Figure 23c represent: warming rates for cases when the temperature is above average; the rates are 0.2 and 0.225 K/year and the probability is about 1 in 800 years. These two points represent two specific rapid warming periods in the ice cores.

        2. These three points seem to be the same as in Figure 23a but they have a lower probability (1 in 1000 years) in Figure 23a than in Figure 23c. Why is that? My answer: I don’t know.

        3. Can we draw a conclusion from these charts that the warming rate increases as temperature increases? My answer: No (I don’t think so). However, perhaps by comparing Figure 23b and 23c, we can conclude there is a higher probability of higher warming rate at the warmer temperatures (Fig 23c) than at the lower temperatures (Fig. 23b).

        I’d like to see a chart that of warming rates and cooling versus temperature. Would that be meaningful?

      • I’d like to see a chart that of warming rates and cooling versus temperature. Would that be meaningful?

        It certainly would be easy to do. A fast rising temperature going through a region would have less time weight than a slowly decreasing temperature, so I think you would have to split it into cooling and warming rates. Otherwise, every point would average to zero over a long time span with the same starting and ending point.

      • WHT,

        Thank you for responding to the last sentence of my last comment. Should I interpret that you do not what to answer my other questions in that comment? If so, please say so and I won’t pester you any further.

        Regarding the plot of rate of warming/cooling versus temperature, does your response mean that you may produce the chart(s) and display them on your web site? Clearly, I can make the chart. You have both the data, the tools and the skills to make the chart and make it meaningful.

      • Correction in last comment: It meant to say “Clearly, I can’t make the chart.”

      • You can sum histograms as long as the probabilities are normalized in the end.

        delta T ~ 3 * delta Isotope on these charts as I recall

      • Thank you for responding to the last sentence of my last comment. Should I interpret that you do not what to answer my other questions in that comment? If so, please say so and I won’t pester you any further.

        I read into your other comments that you pretty much understand the fundamentals. The effect is fairly subtle because if you look closely at the Greenland data from recent times of less than 10,000 years, it appears very noisy, as the numbers often move warm to cold from one data point to the next, indicating white noise and perhaps aliasing.

        The higher resolution data coming out from recent papers might help with this, but I haven’t seen the raw data yet.

      • WHT,

        You said “I read into your other comments that you pretty much understand the fundamentals.”

        That is a misunderstanding. Your maths and physics are way over my head. Could you please answer my three specific question I asked in my comment at December 3, 2011 at 10:47 pm http://judithcurry.com/2011/12/01/the-long-slow-thaw/#comment-146269 .

        If you could answer those questions in simple language, then I will know if I am close to understanding your charts or I am way off the mark.

        Also, could you say if you expect to produce charts showing warming and cooling rates versus temperature.

        I’d like to make a comment that I hope you will take as constructive. Michael Mann used convoluted language in his Hockey Stick papers then refused for 5 years of more to provide straight answers to questions by Steve McIntyre (a forensic statistician who was skilled at ferreting out lies in mining propositions). When someone continuously avoids answering a straight question, after a while it raises concerns about what is going on. I understand you have misunderstood my capacity to interpret your comments and your figures and you have given me more credit than you should. But much of what you have said is gobbledegook to me. That is why I asked you the simple questions and was seeking a simple, straight answer to them. I asked many times in different ways, but never got an answer I could understand. I really appreciate you taking the time to answer my questions, but hope you will take this comment as the way I mean it. It is intended to be constructive, and it applies to many people who use jargon that is specific to their special area of expertise. We can all do better at explaining this stuff so more people can understand it.

      • I’d like to make a comment that I hope you will take as constructive. Michael Mann used convoluted language in his Hockey Stick papers then refused for 5 years of more to provide straight answers to questions by Steve McIntyre (a forensic statistician who was skilled at ferreting out lies in mining propositions). When someone continuously avoids answering a straight question, after a while it raises concerns about what is going on.

        This is getting ridiculous. I posted on my blog two time series analyses of Greenland data covering pre-Holocene and Holocene periods. The pre-Holocene data detected a relatively frequent fast temperature rise that was picked up via a histogram analysis. Then you wanted to see the data for Holocene. I already had stated on my blog earlier that the Holocene time series was noisy and showed little long-term correlations, but since you asked, I provided it. Now you are complaining that I don’t snap to attention at your demands.

        Listen, I don’t do anything very complicated. My pet approach is to use conventional physics and math, but look at a specific phenomenon as if disorder and randomness plays a significant role. This contributes to aleatory uncertainty and is one of the reasons for me contributing to this blog. I believe that we can use some straightforward techniques to try to dig some signal out of the noise.

        The Holocene-era data in Greenland is very noisy and often appears to jump between extremes in temperature in consecutive data points. (There might be a different higher resolution set that I am not aware ). I had also earlier worked out a multiscale variance which suggested white noise (and perhaps even aliasing) since no long-range order is observed.

        The claim in recent papers is that the climate in Greenland during the Holocene appears highly sensitive to variations in environmental factors, which I find not too surprising, because that is what you see in these back and forth noisy fluctuations. The histogram showed that when temperature started increasing from cold to warm it tended to accelerate, which agrees with that sensitivity. Same observation going warm to cold.

        This is the temperature data you were asking for, you will have to convert it from O isotope level to degrees. I don’t see much here, and tabulating rates at the top and bottom of the extremes doesn’t generate very good statistics. The average value is -34.8.
        -36.4 24.98
        -36.2 49.7
        -36.1 29.06
        -36 33.85
        -35.9 30.09
        -35.8 49.47
        -35.7 53.57
        -35.6 127.83
        -35.5 136.48
        -35.4 275.27
        -35.3 281.8
        -35.2 521.98
        -35.1 664.88
        -35 770.34
        -34.9 696.92
        -34.8 877.14
        -34.7 771.73
        -34.6 755.54
        -34.5 650.26
        -34.4 495.13
        -34.3 401.18
        -34.2 333.22
        -34.1 170.72
        -34 122.89
        -33.9 80.61
        -33.8 56.03
        -33.7 58.39
        -33.6 28.49
        -33.5 4.77
        -33.4 16.7

      • WHT,

        This is a big misunderstanding.

        You say “This is getting ridiculous”

        I am sorry you took my comment this way. I wasn’t meaning to offend. I was just trying to pint out that I’d asked you three simple questions and you had not, and still have not, answered them, despite me asking the same questions repeatedly. That is frustrating and can lead to wondering about hidden agendas. The questions, I asked are:

        “Thank you for trying to explain how to interpret the charts. I am afraid it is still not clear for me. Could I ask some specific questions about Figure 23 http://3.bp.blogspot.com/-rLzIpTIE_z8/Ttm52TqxsQI/AAAAAAAAApE/YEs0768cD5U/s1600/greenland_ice_core_rates_10k.gif , I’ll provide what I think are the answers and you say if I have understood correctly.

        1. The two points at the bottom right of Figure 23c represent: warming rates for cases when the temperature is above average; the rates are 0.2 and 0.225 K/year and the probability is about 1 in 800 years. These two points represent two specific rapid warming periods in the ice cores.

        2. These three points seem to be the same as in Figure 23a but they have a lower probability (1 in 1000 years) in Figure 23a than in Figure 23c. Why is that? My answer: I don’t know.

        3. Can we draw a conclusion from these charts that the warming rate increases as temperature increases? My answer: No (I don’t think so). However, perhaps by comparing Figure 23b and 23c, we can conclude there is a higher probability of higher warming rate at the warmer temperatures (Fig 23c) than at the lower temperatures (Fig. 23b).”

        “Then you wanted to see the data for Holocene.”

        Yes. My original question was about the most rapid warming rate during the Holocene detected in the Greenland ice cores

        “Now you are complaining that I don’t snap to attention at your demands.”

        No. That is not correct. I am not understanding why you write stuff that does not answer my question. Are you playing games and avoiding the questions or did I not make the questions clear? If you don’t want to answer me, then just say so. I didn’t mean to pester you. You are clearly on top of your subject and have an enormous amount of valuable, up to date information. But I have not understood the basics of what the charts tell me. So I asked specific questions about three points on your Figure 23c. I have not understood your explanations. They do not appear to address the questions.

        “Listen, I don’t do anything very complicated.”
        May be not. But I haven’t understood your explanation because I have asked simple questions and haven’t got an answer.

        WHT, Thank you for the additional explanation in the last two paragraphs and for the data. Unfortunately, I don’t know how to “convert it from O isotope level to degrees”. This is way out side my area of expertise.

        WHT, if you do not want to discuss this any further, please just say so. I’ll understand and there will be not offence taken. Thank you very much for all the information and explanations you’ve given so far. It is fascinating and I’ve learnt a lot.

      • 1. The two points at the bottom right of Figure 23c represent: warming rates for cases when the temperature is above average; the rates are 0.2 and 0.225 K/year and the probability is about 1 in 800 years. These two points represent two specific rapid warming periods in the ice cores.

        OK

        2. These three points seem to be the same as in Figure 23a but they have a lower probability (1 in 1000 years) in Figure 23a than in Figure 23c. Why is that? My answer: I don’t know.

        twice the points in a than b => histogram statistics.

        3. Can we draw a conclusion from these charts that the warming rate increases as temperature increases? My answer: No (I don’t think so). However, perhaps by comparing Figure 23b and 23c, we can conclude there is a higher probability of higher warming rate at the warmer temperatures (Fig 23c) than at the lower temperatures (Fig. 23b).”

        I must not have answered these before because I recognize rhetorical questions and have learned that these don’t need to be answered. When the questioner answers their own questions, it’s a signal of rhetorical questions. Now you are using that as evidence against me for being evasive. Sorry, I have been at this too long to start playing these kinds of games.

        Isotope to degrees conversion is scaled by a factor of 3.

      • WHT,

        Thank you for answer to Q1. Answer to Q2 is not clear (it’s obscure. You could perhaps explain what you mean). 23b has 12 points, 23c has 18 points so 23a should have 30 points if it is the sum of warm and cold, but it has 18 points. WTF?

        Answer to Q3:

        “I must not have answered these before because I recognize rhetorical questions and have learned that these don’t need to be answered. When the questioner answers their own questions, it’s a signal of rhetorical questions. Now you are using that as evidence against me for being evasive. Sorry, I have been at this too long to start playing these kinds of games.”

        You’ve made an assumption about my motives. You assumption is wrong. “When you assume you make a fool out of you and me”.

        The reason I answered my own questions, after I’d asked it at least three times already in different ways and you had avoided answering them, was to try to make it easy for you to understand what my questions was about and why I was asking it. So, I tried this tack to try to explain why I wasn’t understanding your obfuscation, avoidance and the gobbledegook you were writing in your answers.

        “Isotope to degrees conversion is scaled by a factor of 3.” What on Earth does that mean?

        Could I urge you to re-read through my questions and your answers and see if you actually ever answered my questions with a straight answer. You will benefit from doing so because you might then understand how confusing your comments were, given I was looking for an answer to my questions.

        You made wrong assumptions about my motives and therefore did not answer my questions.

    • WHT,

      This only makes sense if the warming and cooling regimes you describe are the result of *forcings*. If the T changes is just a random wiggling around the median you need to explain why T rise escalation suddenly stopped and reversed. If that would be the case you basically found that recent T changes can even be considered natural behaviour.

      There is to few information available to make sufficient conclusions like this.

      • If they are due to forcings, it doesn’t preclude that a forcing of a large CO2 increase could cause the same or greater effect. If they are due to natural behavior, it shows that the climate is very sensitive to variations in environmental factors, which could translate to increased sensitivity to CO2 levels.

        I agree that there is not enough evidence to derive conclusions that CO2 will not have an impact.

      • At the surface, the maximum reliable (as in easily calculated) forcing is at saturation. Once the surface layer is saturated, spectral broadening is needed to increases forcing. Broadening is a function of temperature and the composition of the gas mixture (water vapor concentration is the main variable). That seems to be the missing component in dF=5.35ln(cf/ci) The 5.35 is based on only one temperature not a range and does not fully consider water vapor, which is still the question mark, because it is not considered.

        Additional CO2 after saturation increases the depth of the saturation layer, effectively raising the average altitude of the radiant layer. Since broadening is temperature dependent, a cooling trend in some areas near saturation can have greater impact. In area near saturation without significant water for feed back, radiant forcing is at or near its maximum. Forcing is non-linear just about any way you look at it.

      • BTW, that 5.35 is an approximation of the S-B at the surface temperature Arrhenius assumed. The same limited approximation I compensated for when I modified the Kimoto Equation. I get grief for correcting the approximation and the old dead guy gets away with it.

        http://redneckphysics.blogspot.com/2011/11/learning-equation-kimoto-modified.html

      • WHT

        Actually not. If this is natural, so if a “warming regime” (the word choice may indicate bias, by the way) is changed unforced into a cooling regime you may very have proven that a positive feedback mechanism due to water vapor is impossible.

        You see, it goes like this: Water vapor is a greenhouse gas and as such increase is trapping more heat in the atmosphere. That principle does is exactly the same for any greenhouse gas: water vapor should have no other forcing impact than CO2. The concept of positive feedback dicates that increases in water vapor will escalate and cause increase in water vapor. The consequence of a mechanism functions also as cause: That is the basic idea behind positive feedback.

        Well, what stopped it, then? Why didn’t the water vapor feedback escalate far more? This question is the essential question in this discussion.

  4. Tony Brown,
    Thank you very much. This is quite a bit to read and think on.

  5. In 1976 the tar in the tarmac melted under ones feet, the only time I have witnessed that in the UK.
    I have had a look at the Max and Min of all the long temperature series in the UK and note that the Tmin is the most variable and this the the main component of the rising trend of (Max+Min/2).

    What is also odd is that different months give quite different slopes, Dec-Jan nosiest of all, but spring and Fall/Autumn are surprisingly flat.
    The UK series are on the Met office website, along with Armagh. What I find most odd is that the peaks/troughs do not match in the various places. The tide is not raising and dropping all boats.
    The Armagh has a nice uptick, post 1980, in both Max and Min.

    • Doc – you’ve reminded me of the summer of ’76. I was on a family holiday on the west coast of France and we observed a long stream of Brits heading up from the South – it was just too hot.

      Of course, when we got back home, as you say, the tarmac was melting under ones feet. ’77 was similar.

      Nobody quite realised at the time, but the droughts associated in Britain at the time were (for the UK at least) responsible for the majority of the acid rain scare of the 80’s. Actually ’83 was particularly dry too, but the ‘acid’ meme had already taken off by then, and it merely ratched up the hysteria.

  6. Number of commentators and even some scientists tend to dismiss the CET as irrelevant, a little local ‘difficulty’ irrelevant to global temperature data-set.
    I tested the claim and it shows existance of high correlation between the CET, the northern Hemisphere and the Global temperatures!

    http://www.vukcevic.talktalk.net/CGNh.htm

    If that was the case for the last 130 years, than we can take the CET as the best proxy available going back to 1660.

    • Vuk, Could you make the comparison between CET, NH and Global a bit longer in size, so that the little interannual variations show more clearly?

      Using GISS, I found around Salehard, Yamal that local stations were in good lockstep, both over short periods and over long periods, see http://www.greenworldtrust.org.uk/Science/Scientific/Arctic-Yamal3.htm#compare

    • Hi Vuk
      Is it perchance useful to compare CET with Klementinum in Prague which dates from about 1770?

      Lubos has some data here..

      https://skydrive.live.com/?cid=9cd81cfa06ff7718&id=9CD81CFA06FF7718!864

    • Lucy Skywalker
      Of course, but since the global and the N. Hemisphere temperatures are averaged over many hundreds times the area, the variability is much smoother than the one of the CET (smoothing area or time wise removes most of the fine detail). I didn’t realise you are from SW, my wife comes from ‘Soton’.

      Baa Humbug
      CET often fails to match some of the places included in it (due to averaging, Bristol, London, Lanarkshire triangle) it is also somewhat different to similar record from Armagh (NI), and often different to local temperatures in the Low countries just across the channel.

  7. Cautious and correct, so say incautious I.
    =================

  8. Tony, leaving aside the (possibly controversial) conclusions for accuracy, certainty and “unprecedented” weather, I’d have to say that from a pure entertainment point of view, I also found the historical snippets absolutely fascinating. Thanks.

  9. If you are going to talk about the Little Ice Age, I would have thought that reference to Jean Grove’s book on the topic (http://www.amazon.com/Little-Ice-Age-Jean-Grove/dp/0415014492/ref=sr_1_2?ie=UTF8&qid=1322768295&sr=8-2)> would have more than repaid the time invested.

    Her conclusion was:

    Historical evidence of Little Ice Age events is much more plentiful in Europe than elsewhere but the documentation from other continents though scantier, is supported by a great volume of field evidence (e.g. Hope et al 1976, Hastenrath 1984) which is presented in Chapters 7, 8 and 9. It emerges that the Little Ice Age was a global phenomenon and it is shown in Chapter 10 that it was not unique to the Holocene.

    There are copious graphs and references in the book to back up those conclusions. Sadly she died in 2001.

    • Dave

      There are around a hundred books on the LIA,. It is quite impossible to quote them all although I would certainly endorse your choixce.

      Tonyb

      • Interestingly there was a paper in Nature last week which documented lower Arctic sea ice extent over the Little Ice Age, concurrent with warmer SSTs in some key Arctic regions.

        A warm Arctic and cold Northern Europe is a familiar pattern from the past couple of winters so it could be the LIA exhibited similar Solar UV conditions as were recently experienced, but on a longer timescale.

      • There are many books about the Little Ice Age. But Jean Grove’s isn’t really just another, is it? It’s /the/ seminal text, built on decades of data collection, and evidence sifted from a far wider range of contexts than most number-crunching climate historians are now used to handling (e.g. Norwegian tax records).

        The first edition of The Little Ice Age came out in 1988, just ahead of the game. Which is precisely why various scientists were so keen to engage with Grove’s work in the 1990s, either to build on it, temper it, dismantle it, or work round it. But it’s worth noting though that Grove herself accepted the theory of the greenhouse effect, and the mounting evidence confirming its impact on C20th climate.

        Jean Grove’s scepticism was not built on prejudicial interpretation of data, nor did it extend to cynicism or flat denial of positions opposed to her own published views: which meant she was perfectly happy to accept new findings that forced her to adapt her own account, and perfectly happy to associate herself with courteous colleagues of /all/ persuasions — Soon, Briffa, Jones, Esper included (all of which is reflected in the second posthumous edition of her book, ‘Little Ice Ages: Ancient and Modern’, published in 2004). Many would do well to follow her example. Contrarians who cite her 1988 work blindly would do well to consider the views expressed in her final publications, including the revised edition.

        For a recent account by Jean’s husban and long-term collaborator, A. T. Grove, which builds from the position adopted by him and Jean in the 1990s, back have a look at this:

        http://www.realinstitutoelcano.org/wps/portal/rielcano_eng/Content?WCM_GLOBAL_CONTEXT=/elcano/elcano_in/zonas_in/dt25-2010

  10. Interesting piece, Tony. I think this part is missing the point though:

    ‘Global’ records are much less reliable than local ones due to the manner in which they are assembled, and the reality of a meaningful single global temperature is the subject of much debate, as observed by French climatologist Marcel Leroux. ‘Yet, they know very well that there is not one “global” climate, but a large variety of climates, depending on latitude, geographic conditions, and atmospheric dynamics.’

    If you take 10 people and average their height, you don’t necessarily get the height of a real person but the result is still meaningful for comparison with other populations.

    A global average temperature anomaly is a population of sampled temperatures, which can be compared with other populations e.g. compare the 2010 global temperature population with the one from 1990.

    • If you take 10 people and average their height, you don’t necessarily get the height of a real person but the result is still meaningful for comparison with other populations.

      —-

      Yes, but Paul, you already accurately KNEW the heights of your sample of 10 so averaging was easy.

      We don’t have a representative sample either in time or space of the temperatures of the Earth so we are a very long way from being able to compute anything like an accurate average. Even when such a so-called average is computed it is only a number, certainly NOT a “temperature”.

      • PaulS is partly right, you measure the heights of the people in a room, then you multiply the heights of the Arabs by the population of the Middle East, the average height of the African Americans by the population of Africa, you pretend that your one native American is a proxy for the inuit. The one Chinese guy you have does all China and SE Asia. Your population of Caucasians is too high, so you order all the males to leave, average the girls and multiply this by the worlds Caucasian populations.
        You use the two Mexicans you have for Mexico, and the whole of Central and South America; and also for Spaniards who you double count.
        Finally, you do the TOA error adjustment and multiply the average by shoe size/collar size, normalized to the one New Zealander you have in the class.

      • Fabulous, Doc.

      • that’s good, Doc Martyn.

      • This is a different point to the one I was addressing, made by Leroux and quoted by Tony. Leroux’s viewpoint would declare a global average to be meaningless even assuming perfect sampling.

        On your post, there have been enough different methodologies applied to the data by now, getting the same result, that we can declare with some confidence we’re seeing a real global signal back to about 1900. The BEST decadal variations paper even took a random sample of 2,000 out of 30,000 stations to construct a global average time series that matched previous estimates back to 1950 (Land data only, obviously)

        Going back further there are increasing uncertainties due to lower spatial coverage, even more so as you head into proxy data.

      • In nature, population samples are “normally” distributed while times series like temperature are rarely “normal”.

        the “normal” distribution allows you to make predictions about the average. temperature on the other hand is a fractal which does not have a meaningful average.

        Look at this chart of temperature for the past 600 million years.

        What is the average temperature of the earth from this chart? How common was the average? How stable is our current temperature of 15C based on past history?

      • That doesn’t mean it is fractal. The scale of temperature does not range over orders of magnitude, but stays above 273 degrees K in a range of 10 K.

        To determine fractal properties you need something that can change in scale by orders of magnitude. And even then, it is hard to tell the difference between fractal and classical random walk. You really have to understand random walk mechanisms to get beyond the hand-waving phase on this subject.

      • So I take that the average temp in the LIA which doesnt exist is lower than the average temperature today that doesnt exist

      • steven mosher

        And even lower than the average temperature in the MWP that doesn’t exist.

        Max

    • Paul S

      I believe you are missing Tony’s point.

      A “globally averaged” data set is only as good as the individual points it measures. To think of it as having an accuracy of tenths of a degree is probably wishful thinking. It is a useful construct to show trends, but may not mean too much over shorter-term periods of less than a century.

      On the other hand, Tony’s comparison shows that the CET record is a pretty good long-term proxy for the northern hemisphere or even global record.

      Tony’s extension of the CET record back by ~100 years suggests that there was a warmer period in the early 1500s, which then reversed itself rapidly to an extended colder than normal period around the time that the CET record started.

      This is valuable information, which I had not seen summarized anywhere prior to Tony’s study.

      Max

  11. I really enjoyed the article, in particular the historical vignettes. Thank you very much.

  12. You’ve been busy, Tony.

    Haven’t really read the whole post yet, and I will in time, but tell me something in the meantime – how would you compare the reliability of how people ascertained patterns in climate in the 1600s as compared to the mid-late 20th/early 21rst century?

    • Joshua

      Patterns of climate really mattered to people back in the 1600’s-in fact it was often a matter of life and death due to the agrarian nature of their society. So I would say their awareness of patterns was very good.

      tonyb

      • tony –

        Should I take it as meaningful that you answered my question by not answering my question? Allow me to restate:

        how would you compare the reliability of how people ascertained patterns in climate in the 1600s as compared to the mid-late 20th/early 21rst century?

        I’m asking you for your opinion of the relative reliability of the presumably anecdotal and non-systematic observational records (perhaps when I read your article in more detail I’ll see that there more more than just anecdotal and non-systematic observational techniques?) of the 1600s and the more modern techniques of the late 20th/early 21rst centuries.

      • Joshua

        Sorry, I thought I had answered it. People were more in touch with nature and recognising patterns mattered deeply to them if for no other reason than they could learn from past mistakes.

        The ancient Egyptians for example relied on the Nile flooding and kept very good records of previous years water levels.

        http://www.waterhistory.org/histories/nile/t1.html

        There are excellent detailed and reliable records of drought/floods/heat waves etc etc kept by many societies. For examnple we have over one thousand years worth of the climate records of the Byzantine empire. They learnt they needed to control water or impound it or that famine was ever present and means needed to be found to store food.

        So the ‘nilometer’ of ancient egypt was the IPad of its day and served its purpose very well as a reliable gauge of flooding.

        http://www.waterhistory.org/histories/cairo/

        Our ancestors knew patterns extremely well but obviously had to record them in a different manner to today as the technologies were different.
        I think you need to read the article and look at the nature of the records.
        There are some extremely good and detailed ones and others that are more casual.

        I try to interpret them with the helping hand of science-for example glacier records.
        tonyb

      • tonyb

        Arguably, the reliability of cultures as instruments to measure patterns is reflected in the prosperity of their people.

        Before the age of modern measurement, the average wealth of individuals was measured in pennies.

        As has been observed by Gibson, the future is here, it’s just not very evenly distributed yet.

        Where primitive superstitions are supplanted with thermometers and the oral tradition replaced with literacy, where science overtakes superstition, there the wealth of nations and of households is measurably multiplied.

        So I have to dispose of your argument on the fidelity of ancient observations of patterns as a figment, much as romantically it sounds mysteriously persuasive.

    • Ibrahim

      Thank you . The book covers the decade from 1807 onwards so is rather later than my study but it will no doubt come in very useful for a future article.

      Tonyb

  13. Fascinating article, Tony.
    I won’t comment further until I have done some more digesting, but thank you.

  14. Giving a regression “trend line” without an R-square value amounts to hiding necessary information that can guard against hyperbole (over-certainty), and is a bad, amateurish habit that too many scientists today engage in. And those “running average” lines are obviously misleading–especially for, but not limited to, the temperatures over the last decade–as are those time series that are graphed using columns instead of points (they turn into solid areas that attract the eye and magnify the apparent importance of points away from the mean value). “Spaghetti” graphs that try to compare and contrast half a dozen series at once are too messy and confused. Climate science–maybe all of science today–needs to clean up its graphing skills.

    • Actually a low r2 can mask certainty, by including irrelevant high-frequency fluctuations as part of the unexplained variance. Yes those fluctuations are unexplained and strong, but no they’re not relevant to long-term climate, they’re mainly relevant to the uncertainty of weather and short-term climate.

      An r2 figure only becomes relevant after removing those parts of the signal that should not be counted towards “unexplained variance.”

      • Agreed, with both.

        r^2 can be irrelevant, in the sense of arrived at too mechanistically and incorrectly interpreted.

        However, it’s hardly endearing to see a trend line presented with no pretense of an effort to generate some r^2, and to propose explanations that may account for its value, or equivalent means to quantify the fit of the hypothesis to the data.

        Tony Brown has done voluminous work. He’s been industrious. Sincere. Apparently thorough-going. In places brilliant. Committed. Interesting. Entertaining.

        And with no acknowledgement from him that we may never know what he seeks to find, because the current proxies just are not yet there, and the challenge is very great.

        I believe proxies can be improved perhaps a hundredfold with known techniques, if cost were no object. Distributions of biota in soil at various altitudes and latitudes over time, isotope ratios, and so forth might with a global effort create an effective grid that could reconstruct a fraction of what has been lost.

        Tony Brown’s work as a foundation would be helpful in starting such a process.

        I think proxies would need to improve about twenty times more than that to match the last third of the BEST project.

        I’m convinced we could use about a hundred times better than BEST productively.

        Don’t get me wrong. I’m personally sure there was an LIA and an MWP. I have faith in art and literature to reflect some truth.

        I just believe Shakespeare was not a thermometer of the temperature of his air, but of his culture, and interpreting Shakespeare is always a fuzzy prospect. And the Flemish Masters painted what the silver in their clients’ purses told them to paint, not what the mercury in their thermometers said. I can do statistics on word counts in Shakespeare’s compendia, or of the brush marks in Van Dyke. And they don’t add up to a thermometer.

        So there’s a limit to how much we can do with the figures from very far in the past.

        But it makes for a great detective story.

      • The art and literature of Florida indicate Europeans flocked there to escape the LIA?

        Sort of like people from North Dakota do today?

      • Huh.

        This explains the art and literature of Quebec, how?

        That many of the people who ‘flocked’ to Florida did so in chains, and not from Europe?

        I’m sorry, but the simplistic interpretation for the colonization of the New World as a result of the LIA is far too likely to induce a stroke if seriously considered, and a spleen rupture if joked about.

      • Don’t get me wrong. I’m personally sure there was an LIA and an MWP. I have faith in art and literature to reflect some truth.

        I just believe Shakespeare was not a thermometer of the temperature of his air, but of his culture, and interpreting Shakespeare is always a fuzzy prospect. And the Flemish Masters painted what the silver in their clients’ purses told them to paint, not what the mercury in their thermometers said. I can do statistics on word counts in Shakespeare’s compendia, or of the brush marks in Van Dyke. And they don’t add up to a thermometer.

        The existence of a MWP and LIA just goes to show us how sensitive the climate is.

        In the Flemish painting you can see the mountains in the background. From the jaggedness it looks more like the Dolomites than the Jura, which is the closest range to the low countries..
        I hate anecdotal information. What exactly is this supposed to mean? The Jura range has plenty of snow. There is cross-country skiing in Belgium.http://en.wikipedia.org/wiki/Signal_de_Botrange

        TonyB can respond but it is pointless to argue at this level of heuristics.

      • Wrong again Web. Why do you spread so much disinformation? This is a famous painting. It is one of very few Renaissance paintings with snow. Those mountains are the Alps and are painted with close proximity to the villages around Antwerp to show that they were becoming Alpine in climate.

      • Web Hub Telescope

        I think you must be unaware of the very considerable symbolism behind Breugels paintings and what he was telling us about the very real period of climate change he was living through? This article from the notably non sceptical Guardian explans it very well;

        http://www.guardian.co.uk/artanddesign/2006/dec/18/art.climatechange

        tonyb

      • So I was absolutely right in my guess based on the shape of the mountains. It was an imaginative painting of the Dolomites, which is in northern Italy. Painters paint evocative images.
        So whoopee, explain why Belgium has a cross-country ski area within 70 miles of Antwerp. http://www.ski-botrange.be/index.asp
        So places that have snow have gotten snow and ice before. Lots of schoolkids learned the Dutch story of Hans Brinker and the Silver Skates.

      • “explain why Belgium has a cross-country ski area within 70 miles of Antwerp”

        What’s to explain? The painting was commentary on the abnormal winters not on good places for cross-country skiing.

      • randomengineer

        So the story is that during the Bush years the pope was meeting with dubya on the presidental yacht, whereupon his cap flew off. George calmly walks across the water to get it, prompting WHT to exclaim “I knew it! Bush can’t swim!”

        In other words, you can count on WHT to always arrive at the upside down (and negative) interpretation of anything.

      • Like I said, all this is anecdotal information and anyone can bring forward counter information, equally anecdotal, to either negate or make the findings totally ambiguous.

        “explain why Belgium has a cross-country ski area within 70 miles of Antwerp”

        What’s to explain? The painting was commentary on the abnormal winters not on good places for cross-country skiing.

        No, actually the painting was just a painting, and you all have hyperactive imaginations. Remember the saying: “Sometimes a cigar is just a cigar”.

        In climate systems, everything we observe is disordered with the details not the least bit relevant until you get to the boundaries of the system — the input of energy balanced by the output of energy. The earth is clearly 10 degrees warmer than what a perfect black-body should measure given the input solar radiation, and the variations in absorptivity along the spectrum are the only explanation due to the isolated nature of the earth in its environment. Push that albedo up to 0.3 and it only makes it worse, as the earth’s temperature is now off by 33 degrees what is should be.

        Yet it’s perfectly rational to allow for deviations in the atmospheric transmissivity as a function of wavelength to explain the necessary temperature increase. The spectral measurements clearly show the absorption regions for the greenhouse gases of CO2 and H2O and the other GHG molecules. And none of this is anecdotal information as it has to fit together perfectly like a jigsaw puzzle because energy is conserved.

        Jeez, we build lasers which will create the exact opposite of black-body radiation, yet we can’t believe that small variations in the spectral absorption lines can’t change the mean temperature of the emitting body?
        What has gone wrong with the random engineers that have turned into skeptics?

      • The existence of a MWP and LIA just goes to show us how sensitive the climate is.

        I would say the existence of a MWP and LIA goes to show how variable our climate is.
        As far as “sensitive” is concerned, I’d have thought climates feelings were hurt once every 100,000 years or so. That’s when she turns a really cold shoulder.

      • I would say the existence of a MWP and LIA goes to show how variable our climate is.

        No, I would say the existence of a MWP and LIA goes to show how sensitive to variations in factors our climate is. Last time I checked, our climate isn’t prone to fickleness.

        Face it, no one wins these grammar wars.

  15. “[Mann] saw the MWP (covering a warm period predating the subject of this paper) as primarily a North Atlantic and adjacent regions anomaly (including part of Europe) and not a synchronous world-wide event”

    The same could apparently be said for Lamb: http://sites.google.com/site/medievalwarmperiod/Home/p171–172-of-lamb-s-climate-history-the-modern-world

    “and that overall the Medieval warm period was substantially less warm than the two most recent decades”

    This is also the case when you update the H. Lamb/IPCC curve (Jones et al. 2009): http://i.imgur.com/DJOUW.png

  16. Diaz et al. have a new look on the mwp/mca in press for BAMS

    Henry F. Diaz, Ricardo Trigo, Malcolm K. Hughes, Michael E. Mann, Elena Xoplaki, David Barriopedro
    SPATIAL AND TEMPORAL CHARACTERISTICS OF CLIMATE IN MEDIEVAL TIMES REVISITED

    http://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-10-05003.1

    and Christiansen and Ljungqvist consider the last two millennia and the last 500 years in a paper in climate of the past discussions

    doi:10.5194/cpd-7-3991-2011
    B. Christiansen and F. C. Ljungqvist
    The extra-tropical NH temperature in the last two millennia: reconstructions of low-frequency variability

    Christiansen and Ljungqvists Figure 8 is of interest for the present thread.

  17. Very Interesting and well done Tony. I’m just finishing up Brian’s book right now. I’ve always been a fan of history, and combining both climate and history in the same book makes a great read.

    As to the notion that the past century’s warmth can be attributed to a simple recovery from the LIA, on a broader time-frame, this seems inconsistent with the longer-term slow cooling that had been seen since the Holocene Optimum. After the Holocene Optimum, temps were undergoing a slow downward trend globally, with significant spikes up and down during such events as the 8.2 KY event, the Roman Warm Period, the MWP, and the LIA, etc. But overall the trend has been down, (as had the general direction of CO2 concentration, which had peaked during the Holocene Climate Optimum, and was also trending down until industrialization. The 20th century warming is remarkable for breaking the Holocene trend downward (even more so than the MWP or Roman Warm Period). And of course, CO2 is at the highest levels during any interglacial of the past 800,000 years at least. Global Temps have not yet matched those of the Holocene Climate Optimum, but, if one would believe even the most conservative of models, will during this century. Recovery from LIA, or CO2 led global warming? One thing for certain, we will find out.

  18. tonyb
    Thanks for such an interesting and informative posting. As a non-scientist, I’ve read it through several times and found it understantable. Thanks for reminding me that science is and adventure of discovery, rather than an obfuscation of reality.
    Thanks also to Climate Etc. for posting it.

  19. Stephen Wilde

    Well done Tony. A very useful piece of work. Thanks.

  20. Hi Tony!

    Wow, this work is “a keeper”, a dictionary to check out now and then.
    Superbe work, thankyou!

    Personally I believe that most of the south central UK has become one big UHI area which is likely to have made 20´th century warmer.

    For compare, see central Benelux and Germany trends:

    http://hidethedecline.eu/pages/ruti/europe/nw-europe-and-de-bilt.php

    K.R. Frank

    • Frank

      Thank you for your comments. I agree with your belief about the big UHI area which is why I tried to pin the Met office down. To be fair at least they do make some sort of correction. As to whether that is enough is somethimg that it would be interesting to get the opinion of others on.

  21. “The third IPCC assessment in 2001 subsequently adapted their figure 3 from this later 1999 work and it is this iconic version, which later came to be known as the ‘hockey stick,’ that is still much used to illustrate the apparent effect of human activities on temperature in recent decades, specifically through the release of co2.”

    Wonderful work, sir. The now thoroughly discredited hockey stick graph remains the crumbling foundation of the AGW movement. And now, with the release of the second batch of emails, it’s clear that even members of the team understand how flawed Mann’s work is…

    The silence on the part of the MSM is deafening. And damning. Funny how the NYT’s is willing to devote front page space to proving Gingrich was a lobbyist, as if we can’t figure that out for ourselves. And yet nary a word about the fraud of the century , a fraud they’ve been aiding and abetting for years now.

  22. Tony:
    Given that I believe that Jean Grove was on the first IPCC, and that her book summarized global data (much on glacier movement) around the globe, using trees more for chronological than temperature markers, I continue to believe that her work was somewhat more comprehensive than most. There is of course also (should you move away from trees) the data from the varves of Finland. Before the controversy that arose over the inversion of her data, Mia Tiljander was writing in her thesis (http://ethesis.helsinki.fi/julkaisut/mat/geolo/vk/tiljander/) (which is in English)

    During the Roman period there was in AD 140-220 an 80-year-long period in the Lake Korttajärvi area when organic matter deposition and the sedimentation was similar to that during the Medieval Warm Period (MWP), interpreted as milder climate condition. After this period, a clear mineral matter – organic matter varve structure existed, until the beginning of the MWP.

    The MWP, AD 980-1250, was an exceptional period. The MWP is characterized by thinly laminated varves rich in organic matter, almost lacking the mineral pulses (i.e. spring floods), indicating mild climatic conditions. This period was interrupted by a colder period from AD 1115- 1145, dominated by mineral-matter-rich varves. The sediment deposited during the MWP was highly organic and dark brownish in colour. Based on pollen and diatom studies (Kauppila 2002), the MWP was a two-stage event. AD 980-1100 was warm and dry, a cold spell (AD 1115-1145) interrupted the warm trend and the following period AD 1145-1220 was again warm and even drier than the first stage.

    • Dave

      One of my great regrets is that Historical observation (suitably combined with science) seems to have been sidelined in recent decades. I think I would date it from about the time of the first IPCC assessment which of course is when the older generation of scientists such as Hubert Lamb started to wthdraw from the field.

      I much enjoy reading historic books as they often tell us what we seem to have forgotten. THe book you cite is an excellent read

    • Re: the data series from Lake Korttajarvi in Southern Finland discussed in Tiljander et al (2003): it isn’t clear to me that these are well-suited as proxies for temperature. However, (1) this group’s work on varved Finnish lake sediments continues, with analysis expanded to include additional characteristics, e.g. stable isotope composition. (2) Other approaches to reconstructing paleoclimate from Finnish lake sediments appear to be bearing fruit. I’ve compiled a few references on the subject here (near the bottom of that post).

  23. TonyB, thank you for a good post.

  24. A fascinating and illuminating article. Thanks for posting it.

  25. Brilliant. Polite and thorough. Very much hope that Tony can see fit to take the CET back to 1100 to match up that original lamb graph. There’s plenty of written material on which to rely.

    Fantastic stuff, Tony. Mann won’t like it but really how can he complain?

    And from the recent email dump isn’t the Jones/Mann you’ve referenced the one that all the other scientists were saying was crap and embarrassing? I think it is.

    • WB

      Thank you for your kind comments. You will appreciate the amount of time it takes to attempt a thorough investigation of an extended period and that observations become more patchy as you go back in time.

      However I am working on my article ‘Historic variations in Sea levels Part two’ which will cover the period that you mention, and I expect that will bring forth material that will form the basis of a cautious reconstruction back to 1100AD or so.
      This was part1

      http://judithcurry.com/2011/07/12/historic-variations-in-sea-levels-part-1-from-the-holocene-to-romans/

      • Great to hear, Tony. Look forward to reading that. As a happy Italian Australian lawyer living and working in superfabulous Sydney it has been a constant source of surprise to me how common is the habit of climate scientists to fail to put their proposed histories of temperature into historical context. It was obviously warm in the Medieval period and to suggest otherwise strikes me as just nutty – all those major cathedrals – concrete sets beautifully in the warm so it’s no surprise lots of building was going. And I’d go further back and note it was darn hot during the Roman period – everyone who’s read any history knows it. The Romans were busy writing it all down daily because, as you noted, agriculture (and I would add construction) was the biggest deal in their lives. The Romans used to get out of Rome and head up to the hills of Tivoli and Frascati cos it was so darn hot. And Australia’s Aboriginal population, without the written word but with songlines that stretch back at least a couple millenia, talk about major heat and floods, droughts, fires and such. The idea, promulgated by many climate scientists, that x event is ‘unprecedented’ is more often than not a nonsense, seems to me. So someone taking a good hard look at climate history with a historian’s eye as much as a scientist’s eye, is doing us all a favour. History rocks. Keep up the good work.

      • WB

        As you say the Roman warm period was well documented and I wrote about it at some length in my article here (you need to follow the second link)

        http://wattsupwiththat.com/2011/05/23/little-ice-age-thermometers-%E2%80%93-history-and-reliability-2/

        The Romans kept some very goo0d records-we are fortunate in having the climate records of the Byzantium empire covering approximately a thousand years.

        They also wrote frequently about their experiences and we have such snippets that Nero was asked to re-build Rome tall and narrow after the fire in order to avoid the effects of UHI which by his time was forcing the richer inhabitants to flee for the hills during the summer.

        Rome was a million strong and stretched for fifty miles so its probably the first example of the UHI effect.

        ‘Unprecedented’ is a very overused word. ‘Context’ is a better one.

        Tonyb

  26. Tony Brown

    Thanks for a fascinating study, extending our knowledge to the century prior to the start of the CET record.

    It looks to me like there is good CET correlation with the BEST global land results for the time period of overlap.

    I have always thought that climate science (as promulgated by IPCC at least) has given far too little weighting to historical records, essentially writing them off as “anecdotal”, while placing too much emphasis on paleo-climate studies.

    Your study seems to confirm my conclusion.

    Max

  27. Another Gareth

    Tony Brown wrote:

    “The convoluted transformation of the original graph from Lamb’s version (Figure 2) into the one used by the IPCC is documented here. (4)

    An interesting link. The date of Steve McIntyre’s blogpost about the origins of the IPCC 1990 graphic is May 2008. SM references a blogpost by William Connolley from May 2007 about the same subject.

    In January 2007 WC was cc’d into an email chain that goes into some detail about the possible origins of that particular graphic in which Phil Jones wrote:

    “The background is that the skeptics keep referring back to it and I’d like to prove that it is a schematic and it isn’t based on real data, but on presumed knowledge at some point around the late 1980s. If you think it is based on something real.

    What we’d like to do is show this either on ‘Real Climate’ or as background in a future paper, or both.

    I’m attaching a few diagrams as background (attaching in order of introducing them) and giving some earlier thoughts. I assume you all have a copy of the said diagram in the first IPCC report.”

    FOIA2011 4039.txt

  28. I was raised to believe only short proofs, and to carve out exceptions only after a great many people had tried and failed to shorten the proof.

    My experience has been that the longer the argument the more places you can hide the one fallacy that was needed to make the argument go through.

    Debugging a large proof is like looking for a needle in a haystack. I eagerly await the Reader’s Digest account of this proof that Lamb was right after all.

    Note that I’m not questioning Tony’s conclusion, only his argument. For the former, as can be seen from this article, by the 14th century in Western Europe demand for wood for fuel was outstripping supply, and by the 17th century tree-hugging had set in, not by environmentalists however but by navies, as a strategic reserve for continued construction of wooden ships.

    As the timber shortage grew to crisis proportions the energy industry of its day cut over to coal, which previously had been used only on a relatively small scale for the preceding half-millennium or more.

    It is not hard to reconcile this history of intensive use of biofuels first, and then fossil fuels when the biofuel supply dried up, with observations of climbing Western European temperatures. In those days low-altitude aerosols would be more likely than anthropogenic GHGs to raise the temperature (low aerosols warm and disperse slowly, high ones cool and disperse rapidly).

    A more comprehensive account of that development, along with a suitably informative executive summary, might go a long way towards clearing the air. Whether it would best be done in competition or cooperation with those taking Mann’s side against Lamb-Brown is an interesting question. (I could write the screenplay but I couldn’t cast it.)

    • My parents tell me of walking home in the smog, in the late 40’s and early 50’s. Both state that you could not see you hands, visibility was less than a couple of feet. This was reasonably common in the large British cites burning sulphur rich coal. If you see the black and white pictures of London from about 1850 you notice the limestone buildings are black and not white.

      This is the color of the stone of the Palace of Westminster in 1897.

      After it’s cleaning in the 1980’s (not the same doorway).

      • Latimer Alder

        London used to be known a ‘The Smoke’ colloquially and my Mum (now 87) still uses that term in conversation.

        But I am too young to have ever experienced a London smog since the Clean Air Act was passed in 1956 (??). There are still occasional fogs, but no more smog.

    • Vaughan

      You are right in saying that there was extensive use of bio fuels and fossil fuels (often of very low grade) as population expanded and technology demanded addiutional sources of energy to the water or wind mill.

      Surely in these circumstances we should have seen a greater increase in co2 than was recorded in the cdiac link I provided?

      I agree with your last paragraph-it is a shame that more research is not carried out with someone from the ‘other side’ giving informed comment. I would have loved to have sat at Dr Manns side whilsthe was carrying out his work and I am sure the same could be said of those proposing AGW with regards to the likes of Spencers work.
      tonyb

    • Vaughan Pratt

      You are correct in saying that the historical record gives us a wealth of real-life information. TonyB has demonstrated this very well.

      The switch from burning wood to coal came about as forests gradually dwindled, but also as the technology for mining coal safely was developed.

      And with it came the Industrial Revolution, low-cost energy for all and a greatly improved standard of living for all of mankind fortunate enough to participate in this industrialization.

      Some very large nations are going through this development today (China, India, etc.) and others are just beginning to do so.

      This will happen not as a result of billion dollar “handouts” by the industrial nations for “past sins”, but by building up the energy infrastructures of these nations.

      And it will almost certainly be based on low-cost fossil fuels, along with other technologies, where these make economic sense.

      Max

      • You’ve previously written that current fossil fuel reserves will only allow CO2 concentration to increase to around 560ppm. This means there will be nothing left in 50 years time if current rates of growth are maintained. How are fossil fuels going to remain low-cost energy given their increasing scarcity?

      • Leonard Weinstein

        Paul S,
        Fossil fuels may vary (coal and oil to gas and methane hydrate), but the sum of all fossil fuels could last several hundred years if used in conjunction with increasing nuclear fission, and even solar (wind is a loser). Eventually fusion may be developed, but it is not necessary, as breeders and safer fission systems are possible to give energy for many centuries. From the start of the industrial age to present is only a short time. Why do you seem to expect no change in technology in the coming centuries?

      • “Why do you seem to expect no change in technology in the coming centuries?”

        Political forces could prevent technology from advancing.
        I am quite optimistic in this regards- internet being a large factor.
        But the future could look grim politically.
        In some ways we live in Brave New World and “1984” type
        world- going further in that direction is possible.
        Europe could be bit frightening at the moment.
        China is quite unpredictable.
        And Iran has made or is making nuclear weapons.

    • randomengineer

      It is not hard to reconcile this history of intensive use of biofuels first, and then fossil fuels when the biofuel supply dried up, with observations of climbing Western European temperatures.

      In later posts you will see that glaciers advanced and receded and advanced again, all for natural reasons, and not in sync with your supposition. It seems that the glaciers prove the fallacy of your simplified position. Simple only applies when it’s correct, i.e. when a system can be reduced to a small set of easily understood variables. Glacial advance and retreat defies the simple answer.

    • Dr. Pratt,
      I would point out that the use of coal is linked with the industrialization of Europe and an explosive growth in the amount of energy used.
      The timber crisis grew out of the need for more energy to take care of increasing populations that were able to grow due to the productivity leaps coal enabled.
      The emergence from the LIA seems much more profound than the increase in coal- which in the period in quesiton was burned with little or no regard at all for pollution. If aerosols do as seems to be widely accepted and act to cool, wold not burning coal in the least controlled manner possible act to actually cool areas, and not warm them?
      If the low level aerosols act to actually warm, then it would be a highly regional warming, since the plumes would not have altitude sufficient to hold them aloft for long.
      I think the simplest explanation for the period you are discussing is still that the Earth’s climate was warming with little to no significant forcing from humans.

    • Hi Dr. Pratt
      You logic and your argument are good, but in view of the global temperatures which represent oceans, Arctic, Siberia, Antarctica and many other non- or sparsely populated areas doesn’t stand as correct.

      http://www.vukcevic.talktalk.net/CGNh.htm

      Considering that the global and the Northern hemisphere temperature movements closely follow the CET , it is unlikely that in the late 19th and early 20th century global temperatures are moved upwards by human activity.

    • steven mosher

      Well, I went to the SI.

      I will be damned if I can reproduce Tonys temperatures from the documentary evidence.

      And these guys complain about calibration of thermometers
      It’s amusing to see selective scepticism at work.

      Hey, let me know when you get into town for AGU, Zeke and I present
      on the 7th.

  29. As History was my undergrad degree, I may have a bit of a bias here, but I found this a very good read. Kept me here at work almost an extra hour.

    I have an open question after seeing a Youtube video of a HS kid taking US temp data and comparing rural verses urban sites. If we know there is at least some UHI impact on temperture readings, why not eliminate them entirely and just go with rural readings? Your data set is smaller but shouldn’t it be more accurate? Seems better than trying to come up with adjustment factors for UHI.

    • The relationship between station temperature and local population size is logarithmic. Thus small changes in population in rural areas can have more of an impact than larger absolute changes in population in a metropolitan area. It is why the tests that BEST did on the effect of UHI failed.

      • Thanks.

        Although the small change in rural population having an outsized impact does not sound logical to me.

      • I ran a correlation for each of the contiguous states and discounted three because they were too small. (Using recent average annual temperatures against recent population count) The coefficient of determination (r-squared) value across the 45 studies averaged 0.14 with an equation of the form
        station temperature = 0.24 ln(population) + b
        where 0.24 is the average slope of the line and b is a temperature controlled by station latitude and elevation.

        There was a recent paper that showed the effects of just changing from natural to farmed land, IIRC, and the impacts of activity, power generators and users and the like close to a station can (see the station work at WUWT) have more impact than the growth of a city, which may well be outward away from the station.

      • randomengineer

        Talk to Dr Roy Spencer. He did a study showing this; IIRC the idea is that land use change has a greater effect than population density.

      • Thanks again guys.

    • timg56

      Eliminating all urban stations from the temperature record seems like a very good suggestion.

      In this fashion, no subjective ex post facto corrections or adjustments would have to be made to get a clearer picture of the warming we are experiencing.

      But I doubt if the “keepers of the records” want to risk having a record that cannot be “tweaked” a bit to show what they have predicted it “should” show.

      IMO this is the biggest obstacle to implementing your very logical suggestion, but maybe someone directly involved can show us a different reason why this should not be done.

      Max.

  30. Tony Brown
    Thanks for your carefully documented temperature reconstruction and documentation.
    Price of Wheat
    Supporting your extension to 1538, note that the price of wheat in England climbed about 60% from about 1540 to about 1630 – corresponding to the major cooling you show. See Tom Drake’s England Wheat price graph 1259-1975.

    There is growing evidence that the price of wheat (and thus weather) correlates with solar changes. e.g. INFLUENCE OF SOLAR ACTIVITY ON STATE OF WHEAT MARKET IN MEDIEVAL ENGLAND Lev A. Pustilnik, Gregory Yom Din. See their Fig. 5 for the rise in wheat prices.

    The International Institute for Social History has compiled historic prices including: Monthly grain prices in England, 1270-1955 etc.

    Hide the Decline Plus
    Stephen McIntyre points out the harm caused by selectively showing favorable data while hiding unfavorable data in Hide-the-Decline Plus He quotes Soon et al (EE 2003):

    If the failure of inter-calibration of instrumental and tree growth records over last two to three decades suggests evidence for anthropogenic influences. . ., then no reliable quantitative inter-calibration can connect the past to the future (Idso 1989).

    McIntyre points out:

    Indeed, they did not simply “hide the decline”, their “hide the decline” was worse than we thought. Mann et al did not merely delete data after 1960, they deleted data from 1940 on, You can see the last point of the Briffa reconstruction (located at ~1940) peeking from behind the spaghetti in the graphic below: . . .
    Had Mann et al used the actual values, the decline would have been as shown in the accompanying graphic:

    (Showing how the “decline” in the data was almost as large as the 20th century rise).

  31. Correction: Wheat rose ~ 600% (6x).

  32. Wow! What a magisterial survey! Thanks Tony (and Dr Curry).

  33. Thanks Tony. On several blogs these past three years, I’ve been talking up the value of the early instrumental temperature records, the historical, and anecdotal records. You did the hard work of putting a lot of it together in a credible and very readable fashion. Please continue your research and analysis. It both complements and acts as a scientific foil, by contrasting with other modes of inquiry in order to highlight particular qualities As to whether the London temperature record or any other temperature record has bearing on the global temperature record, I have said this over and over- the longer the record, the more likely it is representative of the global temperature trend. A local temperature trend of a decade or two or three may not represent the global trend; two or three hundred years very likely does,. Just as those of us who were long familiar with Lamb’s temperature reconstruction smelt a rat when we saw the hockey stick, so climate knowledge from history and anecdote can help us all appreciate recent trends and climate events in the context of a much longer time frame than our short lives and shorter memories.

  34. So, when in the last 800,000 thousand years has it been warm enough for Neodenticula seminae to cross the arctic and repopulate itself in the Atlantic? Oh, just within the last decade. OK, thanks.

  35. Also note the ice breaking dates on the river Tornio (northern Finland) recorded for the last 300+ years: http://maps.grida.no/go/graphic/trends-in-the-ice-breaking-date-in-the-tornio-river-finland

    • Hannu,
      If anythign the river ice data shows nothing is changing, and in the recent period it is breaking up later; The trend is a very smooth change.
      Where in the river is this data taken? is it faced with urbaization?

      • the ice breaking date is the rather dramatic date that the first crack appears on the frozen river. After that it takes only a day or two until the whole river is ready for navigation with the lightest boat.

        When you look at the graph you see that it’s breaking later, but not later than what it should considering the recovery from the little ice age. There is no acceleration in the 20th century. There is some urbanization in Tornio, but not anything that should make a lot of difference. It’s still a minor town.

        But take this graph, invert it and the plot it on top of the sunspot graph (http://en.wikipedia.org/wiki/File:Sunspot_Numbers.png) and then tell me there is no correlation.

        For some reason the sunspot number has obvious effect on the ice breaking date on river Tornio, but (they claim) no effect on global temperature. How on earth can the sun can have a localized effect but not global?

      • I meant “breaking earlier”, not later.

      • No one thinks that the sun has no effect on global temperature.

  36. CHALLENGE TO ALL COMENTERS, TO FIND BETTER ANSWERS

    Q: do you know that: oxygen + nitrogen are 998999ppm in the troposphere, CO2 only 260-400ppm? Q: do you know that O+N expand /shrink INSTANTLY in change of temperature? Q: do you know that where they expand up on the edge of the troposphere is minus – 90⁰C? Q: why O+N expand more, when warmed by 5⁰C, than when warmed by 2⁰C? A: when warmed by 5⁰C, they need to go further up, to intercept more extra coldness to equalize. Q: if O+N are cooled after 10minutes to previous temperature, why they don’t stay expanded another 5 minutes extra? A: not to intercept too much extra coldness, to prevent too much cooling. A2: they stay expanded precisely as long as they are warmer – not one second more or less – that’s how they regulate to be same warmth units overall in the troposphere, every hour of every year and millennia!
    Q: do you know that: if troposphere warms up by 2⁰C extra – troposphere expands up into the stratosphere by 1km, how much extra coldness is there to intercept? A: intercepts extra appropriate coldness to counteract the extra heat in 3,5 seconds > that extra coldness falls to the ground in minutes Q: if O+N are warmed extra for 30minutes, why they don’t shrink after 15minutes, or after one day? A: if O+N after cooled to previous temperature; stayed expanded for a whole day extra > they would have redirected enough extra coldness to freeze all the tropical rivers / lakes. Q: can CO2 of 260-400ppm prevent oxygen + nitrogen (998999ppm) of expanding when they warm up? A: O+N when warmed extra – they expand through the walls of a hi-tensile hand-grenade.
    Q: do you believe in the laws of physics, or in IPCC and the Warmist cult? The laws of physics say: part of the troposphere can get colder than normal – only when other part gets warmer than normal. B] if the WHOLE troposphere gets colder > air shrink > intercepts less coldness on the edge of the troposphere > retains more heat and equalizes in a jiffy. C] both hemispheres cannot get warmer simultaneously for more than few minutes – if they doo > troposphere expands extra > intercepts extra coldness and equalizes in a jiffy. Q: do the O+N wait to warm up by 2-3⁰C, before start expanding, or expand instantly extra when they warm up by 0,000001⁰C? Mitich formula: EH>AE>ECI (Extra Heat >Atmosphere Expands >Extra Coldness Intercepts) Tons of extra CORECRT proofs: http://globalwarmingdenier.wordpress.com
    Can Hubert Lamb, Mann past the test of physics?

    • stefanthedenier | December 2, 2011 at 1:21 am |

      Q: What’s a carriage return? ;)

    • Above this point- answer to Q: yes, more or less.
      “Q: do you know that: if troposphere warms up by 2⁰C extra – troposphere expands up into the stratosphere by 1km, how much extra coldness is there to intercept?”
      When gases expands it cools, rather than reaching a “coolness”- which suggest that a location is colder.

      “A: if O+N after cooled to previous temperature; stayed expanded for a whole day extra > they would have redirected enough extra coldness to freeze all the tropical rivers / lakes. Q: can CO2 of 260-400ppm prevent oxygen + nitrogen (998999ppm) of expanding when they warm up? ”

      Not correct. This relativity small mass does not, and can not have this “power”.

      “Q: do you believe in the laws of physics, or in IPCC and the Warmist cult?”

      I avoid a much belief as I can:)

      • gbaikie, when O+N warm up > volume of the troposphere enlarges. It’s same as when block of your car engine warms up – accordingly if the radiator can enlarge (as a piano-accordion) THAT’S HOW THE SELF ADJUSTING MECHANISM FOR TEMP IN THE TROPOSPHERE WORKS.

        B] human is made to believe in things. One either believes in the ”laws of physics” or doesn’t. (to use somebodies words: ”you are with us, or against us) My proofs are not: maybe… it’s possible… can happen.. My proofs are solid, can be proven all, now. No need to wait 100years, trick.

  37. Another well researched and thoughtful article. Your historical approach certainly puts the prognostications based on short term data that have been posted here by both sides of the AGW debate in its correct context.

    Strangely, the historical trend (either upwards or downwards – depending where the series starts) doesn’t seem to be affected by the amount of CO2 in the atmosphere in the latter part of the 20th century.

    The question remains: Will the well-documented natural negative feedbacks of the Earth’s climate system cope with this added forcing or will the system spin out of control through positive feedbacks as postulated by mainstream climate science?

    My bet is that the negative feedbacks will win out. I guess that makes me an optimist to some of the pro AGW contributors and I will live with that. :)

  38. TonyB,

    I’m surprised you are using the CET record. Its another hockey stick:

    If you superimpose any of the temperature records on top of Mann’s hockey stick graph, including the CET, then you can see that, within the stated uncertainty limits, there is no disagreement at all.

    If you were able to draw your own graphs you’d be able to verify this for yourself.

    • tempterrain

      The interesting part, which you miss on your graphs, is the period prior to the CET record, which Tony has reconstructed.

      This shows a warmer early 16th C with rapidly dropping temperature starting in the late 16th C through the early 17th C, around the time when CET started.

      (You also make the mistake of using 10-year running averages, which results in an upward “blip” at the end, i.e. today, when there is really a very slight downward “blip”, as we all know.)

      As Tony’s charts show, the overall trend since around 1530 to today was essentially flat (no hockey stick at all), with temperatures at the beginning of the record essentially at the same level as today).

      IOW the conclusions to be drawn from Tony’s graphs are quite different from those from yours.

      Max.

  39. Thank you Mr Brown for your comprehensive research and very readable tale. Excellent!

  40. Richard S Courtney

    Tony;

    Thankyou for at last publishing your work in a collated form. I sincerely believe it will be a reference work for years to come.

    I would have preferred your article were published in a formal journal, but its length would probably have needed several papers instead of a comprehensive article. And Dr Curry has earned such great deserved respect that in future her blog will probably be considered a better reference than ‘Nature’ from around this time.

    Importantly, your article is so cogent that none of the above comments has managed to find significant fault in it. Congratulations.

    Richard

  41. Tony B

    Didn’t mention this before, but in addition to providing some very interesting insight into early 16th century temperatures based on the CET record, which corrects some of the misconceptions of the hockey stick, you have made it all interesting reading rather than just a “data dump”.

    Thanks again.

    Max

    PS Thanks to Judith, as well, for posting it.

  42. Judith,

    I deep I dig, the more filthy my hand get from the stench of bad science practices.

    I see a vast number of mistakes by the assumption of using an average on a planet. This is the same assumption of using a proxy for a vast area.
    This average then assumes the planet is a cylinder rather than an orb.
    It misses a vast number of areas that should have been considered but the averaging disallows this.
    From solar rays of the sun, distance differences, angle of solar penetration and time of solar heat dispersion are NOT considered.
    The differences of velocities is the cause. The angles are NOT uniform in changing from the equator to the poles.
    See reference:

    http://jonova.s3.amazonaws.com/guest/lalonde-joe/world-calculations.pdf

    http://jonova.s3.amazonaws.com/guest/lalonde-joe/world-calculations-2.pdf

    • Joe,

      What about our satellites?

      Good question Joe!
      Satellites hug our atmosphere and do not record the size difference nor the velocity differences.

    • Latimer Alder

      Joe

      Thank you for showing your calculations (at very long last) in the referenced links.

      Now please explain what it is about this entirely unexceptional stuff about the mechanics of rotating bodies – known at least since Newtons’ time – that means everybody else’s understanding is wrong.

      As I have long suspected, your ‘new revelations’ could in fact be found in just about any Physics/Applied Maths O level text.

      Please make yourself familiar with the concept of Angular Momentum, for example here:

      http://en.wikipedia.org/wiki/Introduction_to_angular_momentum

      • Latimer,

        Have you REALLY looked at this???
        Their is vastly many mistakes.
        Use your head and NOT someones conclusions(which you seem to follow religiously).

    • “I see a vast number of mistakes by the assumption of using an average on a planet”

      If you just treat it as a metric — a single number that allows you to roughly compare the Earth’s state in 1900 with 1814 with 2011 with whatever — I think it is unobjectionable. If you try to subtract one year’s value from another’s and plug the difference into some equation where it is supposed to be an actual temperature difference, I agree, that’s likely a bad idea unless you somehow know EXACTLY what you are doing.

  43. Tony B

    One of the references you cite is Austrian glaciologist, Prof. Patzelt

    His study, based on carbon-dated tree remains, which were recovered under receding alpine glaciers, gives a clear picture of smaller glacier extent than today in several periods over the past 10,000 years. In one of the studies you cited, he has related this to averaged temperatures for these periods.

    Interestingly, Patzelt finds that over most of the past 10,000 years, temperature was warmer than today, and the time around 1850 was very likely the period of maximum glacial extent over the 10,000 years.

    I have seen independent studies from the Swiss Alps by Prof. Schlüchter at the University of Bern, coming to similar conclusions.

    This is interesting, because this is also around the time that modern measurements of glacial retreat started.

    While most of the data derived by these glacier studies precedes the early 16th century decline, which you describe, I have seen another record of alpine silver and gold mines being covered up by the advancing snow and ice around this time. One report tells us

    http://www.wissen.de/wde/generator/wissen/ressorts/natur/naturgewalten-lexikon/g/index,page=1578088.html

    Ein Beispiel für mittelfristige Gletscherschwankungen ist die Kleine Eiszeit, das “little ice age“.

    Waren die Alpengletscher im Mittelalter kleiner als heute, so kam es im 17. Jahrhundert zu einem allgemeinen Kälterückfall und einem kräftigen Gletschervorstoß, der seinen Höhepunkt um 1850 erreichte. Während dieser Zeit waren die Jahresmitteltemperaturen um etwa ein Grad Celsius tiefer als heute.

    In den Ostalpen stießen die Gletscher um 1600, 1640 und 1680 tief in die Waldregionen vor. In den Hohen Tälern wurden dadurch Bergwerksstollen vom Gletschereis überfahren.

    Seit dem neuzeitlichen Höchststand der Alpengletscher um 1850 weichen sie mit den genannten kurzen Unterbrechungen zurück.

    Translation: “One example of medium-term fluctuations in the glacier extent was the Little Ice Age.

    Although the glaciers were smaller than today during the Middle Ages, there was a general cooling in the 17th century leading to a strong expansion of the glacial extent, which reached its high point around 1850. During this period the annual average temperatures were around one degree Celcius colder than today.

    Around 1600, 1640 and 1680, the glaciers advanced deep into the forests in the eastern Alps. In the higher altitudes old mines were covered up by advancing glacial ice.

    Since the modern high point of the glaciers around 1850 they have been receding, with a few noted interruptions.”

    This report from Gastein describes how a silver and gold mine was covered up by advancing ice around this time:

    http://sagen.at/texte/sagen/oesterreich/salzburg/pongau/gastein/schatzsagen.html

    So reichlich die Goldadern durch Jahrhunderte geflossen waren, hatte der Erzsegen doch allmählich nachgelassen. Die Stollen waren ausgebeutet und neue nicht mehr gefunden worden, der Bergbau ging zurück und die Gletscher drangen auf den Höhen, wo Menschenhand nicht mehr waltete, immer weiter vor.

    Translation: “As rich as the gold veins had been over centuries, the deposits gradually dwindled. The mines had been exhausted and new deposits had not been found, mining activity slowed down and the glaciers advanced into the high valleys, where humans could no longer live.

    The local population could not understand why this was happening, and saw in it a sign that they were being punished for their sins and misdeeds.”

    An die Gegend des Bockart knüpft sich nun eine solche Sage. In den Tiefen des Bockartsees liegen, so berichtet die Sage, ungeheuere Schätze an Gold und Silber begraben. Einst war aber an Stelle des Sees ein herrlich fruchtbares Hochtal, aus jeder Felsspalte fast traten die edlen Metalle in Hülle und Fülle ans Tageslicht. Aber dieser Segen ward den Leuten zum Verderben; sie konnten ihren Übermut nicht mehr bändigen; besonders die Knappen schlemmten und praßten. Sie warfen mit silbernen Platten nach dem Ziele und tranken den Wein aus goldenen Krügen, waren grausam gegen die Armen und lästerten Gott, daß es aus der Art war.

    Da ereilte sie die Strafe des Herrn. Von einem Tage zum anderen verschwand die grüne Landschaft unter Schnee und Eis, das bis zum Tale hinabflutete, und in der Talmulde entstand aus dem abfließenden Schneewasser ein See, der alles verschlang und auch die reichen Schätze an Gold in seiner Tiefe versinken ließ.

    Translation: “This legend covers the region near Bockart. The Bockart Lake covers immense buried riches in gold and silver. In place of the lake there was once a rich high valley; gold and silver could be seen in every boulder crack. But this blessing brought the self-destruction of the people; they could no longer control their wantonness; especially the miners reveled and feasted. They threw silver platters at targets and drank wine out of golden cups, mistreated the poor and blasphemed God incessantly.

    Then the punishment of the Lord came. From one day to another the green landscape disappeared under snow and ice, which flowed down into the valley. In the bottom of the valley a lake formed from the melting snow, which swallowed up everything causing the rich deposits of Gold to be lost in its depth.”

    As the record show, this was obviously a case of rapid anthropogenic climate change!

    In an interview, the late climate science pioneer, Dr. Reid Bryson even reported about the remains of a medieval silver mine, which became exposed as a glacier retreated.

    http://www.wecnmagazine.com/2007issues/may/may07.html

    “A silver mine! The guys had stacked up their tools because they were going to be back the next spring to mine more silver, only the snow never went,” he says. “There used to be less ice than now. It’s just getting back to normal.”

    This report describes the reaction to the disappearance of the mine:

    Im Mittelalter konnte das Volk nicht glauben, dass die Klima-Verschlechterung und der Vorstoss der Gletscher auf ganz natürliche Weise vor sich ging, und sah darin eine Strafe höherer Mächte für das manchmal gottlose Leben, dem sich Herren und Knappen ergeben hatten.

    Heutzutage können viele auch nicht glauben, dass der Gletscherrückzug und die dafür verantwortliche Klima-Erwärmung auf ganz natürliche Weise vor sich gehen. Wieder wird der Mensch dafür verantwortlich gemacht, diesmal zwar nicht durch sein “gottloses” aber dafür durch sein “verschwenderisches” leben.

    Translation: “In medieval times people could not believe that the worsening climate and the advancing glaciers were happening naturally, and saw in them the punishment by a higher being for the godless manner, in which both mine owners and miners had behaved.

    Today many people are also unable to believe that the retreat of the glaciers and the climate change causing this are occurring for natural reasons. Again humans are being blamed, this time not for their ‘godlessness’, but instead for their ‘wasteful behavior’.

    Déjà vu all over again?

    Max

  44. Hi Max

    Thanks for some very interesting information.

    I think that glaciers are an interesting proxy and don’t receive as much attention as they should-a greater focus seems to be given to Arctic ice. This is ironic as evidence from the Alpine regions is quite comprehensive.

    Having read several dozen glacier papers I would make a rough estimate that if you were to look at figure 1 I would say that you could put a ‘glacier’ line at around the 0degree C anomaly. Above that it was warm enough for glaciers to be in stasis or recede and below that it was cold enough for advance. Just a very rough rule of thumb of course which would be affected by exceptional conditions in various years.

    tonyb

  45. Fantastic article. Something that is long, long overdue.

    • Well, it certainly is something that is long, long. I’ll give you that part.

      • That’s something a lot of people were being diplomatically quiet about…
        Also, it would have revealed them to be of the sound-bite generation
        FWIW if found it to be long….then very much worth the effort of studying.

      • Anteros sez: FWIW if found it to be long….then very much worth the effort of studying.

        Ok, then let me know how you enjoy the SkyDragons book. It’s even longer, I understand, so must be even more worth studying for you. I’ll pass.

      • Richard S Courtney

        rustneversleeps:

        You could find no fault in the article that you are willing or able to state so you complain that it is too long for your attention span. Perhaps it escapes your notice, but any rational person sees your comments indicate the article is of high quality.

        Richard

      • Ok, Richard Courtney, thanks for that insight. Hopefully my dismissiveness lead you to waste your time reading. I do try.

  46. The long, slow thaw

    of 0.06 deg C per decade

    since record begun 160 years ago => http://bit.ly/pxXK4j

  47. Dr C –

    Completely (or mostly) OT, but I just noticed the “I don’t know what she thinks she’s doing, but it’s not helping the ’cause'” quote in this little bit of satire at Steve M’s blog.

    http://climateaudit.org/2011/12/02/climategate-2-0-the-cause/

    I’m not quite sure what to make of it – possibly some Monty Python humour might have worked better this side of the pond, but it’s mildly amusing nonetheless :)

  48. Thanks, Tony.

    I have been seriously skimming, so sorry if this has already been mentioned. A fascinating historical snapshot is when Sweden’s King Charles led 5000 men across the ice in February 1658 and captured Copenhagen without much of a fight. It was a total surprise, so previous winters may have been warmer, or no one had the nerve to try that tactic; as it was soldiers drowned while searching for a safe route between nearby islands. (Based on account in Frost’s “The Northern Wars,” which is not at hand.)

  49. Apparently in the UK we can use Viticulture as proxy for climate to show the RWP, MWP, LIA and the Modern Warm Period:

    http://www.winelandsofbritain.co.uk/lecture.htm

    • Paul Biggs

      Thanks for posting interesting “winelands of Britain” map.

      It appears that current wine production area is roughly equivalent to that of the Medieval Warm Period and slightly less than that of the Roman Optimum.

      This is probably a very good proxy for climate, with the caveat that modern frost resistant grape varieties, the general use of hardier American grape roots and modern planting techniques have probably pushed the line a bit to the north, even with slightly cooler climate.

      The suggested projections for 2050 and 2100 “if global warming continues” are interesting.

      Will my great-grandchildren be drinking a Scottish Cabernet Sauvignon?

      The mind boggles.

      Max

      • Tacitus, The Agricola, Book 1 [10], on Britain:

        “With the exception of the olive and vine, and plants which usually grow in warmer climates, the soil will yield, and even abundantly, all ordinary produce.”

        Hey, don’t look at me, he was the Roman who was actually there.

      • J Bowers, I was unaware that Tacitus ever visited Britain. He wrote about them, certainly, but did he go there? (Honest question, no snark.)

      • Tom Fuller

        As J Bowers remarked Tacitus visited Britain and commented that the climate was unsuitable for growing grapes. 80 years later they were growng grapes.
        tonyb

      • Umm, TonyB, IIRC Tacitus wrote something about his father (in-law’s?) time in Britain. I always thought Tacitus did his sinning in Gaul and Germania…

      • Tom Fuller

        The life of Tacitus is somewhat closed-surprising bearing in mind he was such a fanous chronicler.

        Some years ago there was a major excavation of Roman Silchester near where I used to live

        http://www.silchester.rdg.ac.uk/guide

        I briefly helped out there and attended a talk by an eminent Professor of Roman History who talked about Tacitus as being thought to have visited Briatin sometime around 88/90Ad.
        Tacitus is claimed to have said something salong the lines that ‘Britain was not too cold’ so presumably he must have visited here in order to make that claim.
        tonyb

      • Telling comparison :
        garments worn by Henry VIII and typical centurion stationed in the roman Britain, there are good illustrations of both, verbal and pictorial.

      • If Tacitus in person visited England; does that prove that the planet was warmer…?! For many does… unfortunately… England represents the globe…? good / popular contemporary science… What was the temperature in Oceania, south America at that time? At that time they were never sailing further than 50km west from the pillars of Hercules / Gibraltar. – not to fall of the planet. If Europe was warmer by 2degrees – Oceania needs to get cooler by 0,2 degrees to equalize. Last 3 Januaries was colder in Europe / USA, but was extra warmth in Australia at that same time; is that GLOBAL warming or GLOBAL cooling?! Shame, shame

      • stefanthedenier

        There is new evidence to suggest the Romans visited Iceland and of course the ancient Greeks had got that far and discovered the principles of tides.

        tonyb

      • Of course England does not represent the globe, but its temperature record is a good proxy, and that is indisputable:

        http://www.vukcevic.talktalk.net/CGNh.htm

  50. J Bowers

    If I were a Roman, I would not travel to Britannia to grow wine grapes (neither today nor 2000 years ago).

    Max

  51. Tony Brown

    Thank you very much for the article.

  52. “Will my great-grandchildren be drinking a Scottish Cabernet Sauvignon?”
    Very likely. It’s doubtful that they would be able to afford a Chinese vintage!

  53. What I think is interesting, is displayed in Figure 11 and is discussed in the section of the CET reconstruction. The interesting portion is in the Instrument portion, not the reconstruction, however. Without the floating average but looking at raw temperatures, it shows a very large temperature swing (~2C) in the four decades between the timeframes of about 1690 and about 1730. Make the .5C change of the 10 decades in the “hockey stick” rise look a bit paltry – it’s just the starting and ending points are at different places on the Y axis.

  54. To me it comes down to this

    http://www.woodfortrees.org/plot/best/from:1900/to:2010/mean:120

    Is this a natural variation or a trend? Skeptics assert with almost no doubt that this is natural variation and could just as easily go down again, while most people looking at this would see a trend. Considering that AGW explains this trend in terms of GHG increases, and the 21st century will see at least five times more CO2 added as the 20th century , it seems reasonable to say this trend will only increase. This is where the discussion should be, because it is the instrument record and avoids unreliable measures.

      • Yes, BEST (which I showed) is land and this rises faster than when you include oceans as in HADCRUT or GISS global. This fact is also consistent with AGW, and not with the ocean as a driver, but the trends are so easy to see when you remove the sub-decadal noise as with these plots of 10-year running means. Also note the so-called recent flatline which is somewhat insignificant and is similar to previous occurrences.

      • It isn’t similar at all. The oceans and land temperatures have tracked quite closely until recently where the differences between ocean and land have become very pronounced with increasing divergence as is easily seen by comparing land data with land and ocean data.

        http://www.woodfortrees.org/plot/best/from:1900/to:2010/mean:120/plot/gistemp/from:1900/to:2010/mean:120

      • This is the point I was making. The land is warming faster than the ocean now when it never used to. This is consistent a fast-changing forcing from the atmosphere such as GHGs because the ocean would lag in its response due to its higher thermal intertia.

      • JimD said,

        “This is the point I was making. The land is warming faster than the ocean now when it never used to. This is consistent a fast-changing forcing from the atmosphere such as GHGs because the ocean would lag in its response due to its higher thermal intertia.”

        Not necessarily, UHI is pretty good evidence that surface impacts amplify atmospheric return. There is a difference. About 50,000,000 square kilometers of land use changed to farming plus roads, homes and Walmart parking lots could have a little impact :)

      • Captain, the urban area is still only 0.3% of the land surface. The global average is more affected by the other 99.7%. I thought BEST effectively killed the UHI argument.

      • LOL, I am not arguing that UHI drives climate. It is a indication of how land use change can drive climate. Land use change is total is a touch greater than 0.3% :)

      • Captain, do you think all land-use changes lead to warming, or might they cancel? For example, irrigation leads to cooling.

      • Jim,
        I know some cancel and some don’t. Impact on the hydrological cycle has the biggest impact cooling irrigated areas, but adding to water vapor feedback in others. Land use change has impacted roughly 15% of the global surface, mainly in the northern hemisphere. What would the temperature data indicate?

      • Jim D,

        The thermometers are located where the people are. That is where it is warming.

      • Land use can only change the net heating by darkening the surface albedo. Is the land albedo darkening in any substantial way? No, given the area covered, and how much it has to darken to have any measurable impact. Also adding lawn irrigation actually may be cooling some cities in arid environments. Bottom line, small effects in the global scheme of things, and self-canceling anyway.

      • steven and anybody interested WHY land and sea temperature data don’t move in same direction; have to peer review what’s on my website. Land / troposphere; if one part gets warmer – other must simultaneously get colder > children’s see-saw plank affect. Laws of physics.

        Sea doesn’t have the convenience as air; when warms up, to expand into the stratosphere – intercept extra coldness and equalize. Since WW2 the sea surface is getting covered more and more with industrial oils, more and more chicken, beef, pork fat, canola, olive oils > those oils prevent evaporation – evaporation is cooling process – less evaporation = less rain – rain cools the sea. Even bigger evil is overlooked; because of sick propaganda about CO2. Those oils prevent water to get replenished with oxygen when splashing + rain replenishes the sea with oxygen. Big part of the sea, for big part of the year is oxygen depleted to sustain most variety of fish. When the truth is known – Warmist will have a lot to answer. Molesting the essential CO2 will not be fashionable for much longer: http://globalwarmingdenier.wordpress.com

      • The point I am making is that it is not similar for the oceans to stop warming when there is so much of a disparity between how much the land has warmed and how much the oceans have warmed. It is not similar because it has never happened before. Now the question is how can the oceans not warm when there is such a huge disparity and looking at the past and ssaying it has happened before isn’t a good answer because the disparity didn’t exist before. If the oceans were warming faster than they used to but not keeping up with the land increase you would have a good argument. They aren’t.

      • When you say the oceans have stopped warming, are you referring to the last ten years, because I think it is premature to say that this is a climate change rather than natural circulation change. I tend to disregard things that don’t affect at least a ten-year average when talking about climate because then we are just trying to explain each short blip, which is worthless. You can see several such blips in the plots above before warming resumed.

      • Perhaps it has to do with the ocean temps being “Raw” and the land being “Adjusted”, sorry Quality Controlled.

      • I don’t think you will see a resumption in ocean warming anytime soon since the AMO will be heading south and taking SSTs with them. But that is the future and my Tarot cards aren’t registered. Would you agree that if you see a difference in the rate of warming on the land that you should be able to see the same phenomenon in the oceans over a longer period of time?

      • I would certainly expect the ocean to continue following the land warming but lagging it as the difference is explained by thermal inertia. The difference might get wider if the land warming accelerates in this century. This would lead to lower relative humidity and less rainfall over land according to my sense of it, and this drying would accelerate land warming even more.

      • steven, common belief is: on the polar waters, ice is white, reflects the sunlight. Make lots of corridors with ice crusher ships – ruff water will demolish the rest of the brittle ice – floats away in warmer water / melts.. Minus white ice, hopefully small GLOBAL warming – to get you out of trouble…! The truth is completely the opposite: in winter, water without ice as insulator (white ice is full of air as polyisterine)> absorbs extra coldness and the currents are taking it away. because colder water is deep down, not noticeable yet. Equatorial waters are getting warmer than normal, because oils and fats – north Atlantic, Mediterranean, Antarctic Ocean waters colder. If some of that extra colder water comes to Barrier Reef, will destroy it.. the Kyoto Cult are lying that warmer water is bad for coral…?? It’s not much on my website, read every page, they are all related; you will be shocked when you find out what the truth is and compare it with what comes from the propaganda: http://globalwarmingdenier.wordpress.com Every commenter should review, with critical eye, all I have there. I challenge you all, because is of urgency and national importance. If one doesn’t take the challenge = admission of guilt.

      • I’m a little skeptical as to how much mixing thus how much lag there is from the ocean. But even assuming there is substantial lag the warming trend of the oceans from the first half of the 20th century doesn’t appear any different to me that that from the last half as shown in the now non-displayed graph from NASA. (ps I don’t condone or condemn this website, it is just where I found the graph I wanted.)

        http://home.earthlink.net/~ponderthemaunder/id38.html

        This indicates to me that the rate of energy being added to the oceans has not increased over a longer time period and that there is thus a discrepancy between land and ocean temperature data. What does it indicate to you?

      • Looks like something changed I wonder which? land or ocean ?

      • What I see in this is similar to the woodfortrees plot you showed before. Each time the land warms quickly, the ocean follows more slowly. The early 1900’s warming was likely solar, I think, but a similar thing happen then and in the later period, with a pause where the ocean caught up around the 70’s.

    • Jim
      Has the heat capacity of land remained static?

      • I don’t know why it wouldn’t. It might reduce a bit if it is getting drier.

      • The heat capacity of land that has been built on by humans has not remained static. We like to build things that retain heat. Just in our nature to be warm.

    • Here’s another plot (starting to be like Girma here).

      http://www.woodfortrees.org/plot/hadcrut3vgl/from:1800/to:2010/mean:120/plot/esrl-co2/normalise/mean:120/offset:0.4

      The site doesn’t have CO2 estimates back beyond the Keeling curve, but if you extend the green line back it flattens out at about -0.35 to -0.4 on the left axis. I suggest the later part of the line is above the current temperature because of aerosol effects, and the earlier rapid rise was solar.

  55. This is a very interesting post as I find these historical records much more reliable that tree rings for example. In fact, I would suppose that by now the hockey stick had been so seriously debunked that even Fred Moolton would agree that its totally wrong. It is a shame for science that the NAS panel essentially found in favor of Mann. It detracts from my respect for that body. It tells us that climate is always changing and that those changes have consequences. Previous large changes of course require explanation and that is where modern climate science draws a blank. Their only option it seems to to erroneously show that these changes were relatively minor and insignificant.

    • “It is a shame for science that the NAS panel essentially found in favor of Mann.”
      I don’t agree with this statement. Could provide evidence- more than this assertion by yourself or others?

      • gbaikie

        You have apparently disagreed with David Young’s statement:

        “It is a shame for science that the NAS panel essentially found in favor of Mann.”

        The NAS panel (Drs. North and Bloomfield) was asked to testify under oath regarding the findings of the Wegman committee, which had previously testified under oath that the Mann hockey stick was statistically invalid.

        Dr. Wegman, an expert on statistics, was asked by US Congress to testify under oath regarding the validity of the McIntyre + McKitrick refutation of the Mann hockey stick.

        http://republicans.energycommerce.house.gov/108/home/07142006_Wegman_Report.pdf

        The Wegman committee concluded that the M+M critique was valid for statistical reasons having nothing to do with climate science per se and that the “hockey stick” conclusions were not valid.

        http://www.uoguelph.ca/~rmckitri/research/StupakResponse.pdf

        ”Our committee believes that the assessments that the decade of the 1990s was the hottest decade in a millennium and that 1998 was the hottest year in a millennium cannot be supported by the MBH98/99 analysis”

        “The paucity of data in the more remote past makes the hottest-in-a-millennium claims essentially unverifiable.”

        The NAS then issued a rather “wishy-washy” report, which did not address the statistical flaws in the hockey stick, but referred to several “copy spaghetti hockey sticks” that had popped up like mushrooms after a spring rain. The report gave confidence to the results after 1400 AD (well after end of MWP) but not before.

        The congressional committee then asked NAS for specific clarification regarding the Wegman testimony. A panel from the NAS subsequently confirmed the conclusion of the Wegman committee under oath.

        http://www.energy.probeinternational.org/climate-change/lawrence-solomon-under-oath-north-faults-mann-too

        CHAIRMAN BARTON: Dr. North, do you dispute the conclusions or the methodology of Dr. Wegman’s report?

        DR. NORTH: No, we don’t. We don’t disagree with their criticism. In fact, pretty much the same thing is said in our report.

        Barton then asked North’s colleague on the NAS panel, Peter Bloomfield, a similar question.

        Bloomfield’s reply: “Our committee reviewed the methodology used by Dr. Mann and his co-workers and we felt that some of the choices they made were inappropriate. We had much the same misgivings about his work that was documented at much greater length by Dr. Wegman.”

        A bit of light on a subject always clears things up.

        Max

        PS David was probably referring to the “wishy-washy” NAS report that preceded the congressional testimony of the NAS panel (North and Bloomfield). This report only confirmed that the LIA was cooler than today – a fact that few people really doubted – but did not give any confidence to earlier time periods.

  56. Jim in SC,

    Thank you for the interesting paper. http://www.clas.ufl.edu/users/rrusso/gly6932/Steffensen_etal_Science08.pdf
    It did answer my question, (and so has WHT’s comment, which I will reply to separately below).

    This is the bit I was after:

    “The δ18O warming transition at 14.7 ka b2k is the most rapid and occurs within a remarkable 3 years while the warming transition at 11.7 ka b2k lasts 60 years; both correspond to warming of more than 10K (6, 19).”

    The rate is about 3 K/year for the first warming (in cold times) and 0.17 K/year in the second warming (in warmer times).

    I interpret the trend to suggest that the change is more likely to be slower next time (since we are even warmer than when the second rapid warming occurred).

    They seem to be saying that warming can happen suddenly and imply the next one could be very bad for us.

    “The high resolution records from the NGRIP ice core reveals that polar atmospheric circulation can shift in 1-3 years resulting in decadal to centennial scale changes from cold stadials to warm interstadials/interglacials associated with astounding Greenland temperature changes of 10K”

    However, each time I read these articles and stare at the charts, I feel I am more scared of cooling than warming (see my response to WHT below). I interpret several statements in the paper to suggest that any sudden warming event will be slower next time because we are warmer.

    “The 14.7 ka b2k event followed Heinrich event H1 at a time when the ice sheets in the North were still extensive whereas the North was more deglaciated at 11.7 ka b2k (34), reducing the amount of ice discharge available to change the density of North Atlantic ocean waters and thereby the THC before the warming onset.”

  57. Most of the comments in the article were on ‘the hockey stick’ by Mann, giving the impression it is still widely considerd (or used as) the best temperature reconstruction of the past milennia. Hasn’t it been officialy debunked by now, or does someone still use it?
    Loehle 2008 was breafly referred to, but not commented on.

    http://www.econ.ohio-state.edu/jhm/AGW/Loehle/Loehle_McC_E&E_2008.pdf

    How widely is that reconstruction now/still accepted, and how does it relate to BEST?
    What is the de facto reconstruction today?

    • Sheik – up above there were links made to two recent temperature reconstructions.

    • Sheik, As to the question you pose, “What is the de facto reconstruction today?” From what I have been able to read, ‘hokey smoke’ does the trick .

    • Sheik

      Dr Manns hockey stick was iconic and therefore lives on in the MSM and popular imagination whether or not it has or hasn’t been discredited.

      It will still be pointed to by politicians and govt agencies and remains the warming icon of choice of the BBC. For His TV programme ‘climate Wars’ Dr Ian Stewart mounted a big billboard of the hockey stick on a lorry and drove it around the city.

      http://climateaudit.org/2008/09/17/bbc-climate-wars-part-2/

      I went to the trouble of seeing him in person give a lecture at Southampton University (and very good he was to) and the Hockey stick featured very prominently.
      tonyb

    • Just read the Climategate 2 emails, even his own “team” debunked the Hockey Stick before it was accepted in to the IPCC.
      The best temperature reconstruction of the past milennia it IS NOT

    • Agronomist will tell that 100 reasons affect the thickness of tree rings. In same orchards, with same irrigation / fertilizer; some trees are better than others. In nature is no equality. One tree fights for nutrients, moisture, sunlight against the next tree. The tree 10m away has no tree to compete with = bigger rings. Which one to believe? Trees are lying, boys, don’t use their lies!!! Only prolongs the lifespan of agronomist; laughter prolongs life

      In the debate, the only proof the tree rings are proving is: the user is too ignorant, or hopes that others are too ignorant, to take him seriously…

  58. Sheik

    You raise interesting questions.

    As we know, the Mann “hockey stick” was comprehensively discredited by McIntyre + McKitrick, as confirmed by the Wegman committee and endorsed by a panel from NAS under oath before US Congress. This much is history.

    But even more importantly, it was invalidated by the 20th century divergence problem (which was covered up by “Mike’s Nature trick”).

    The tree-ring reconstruction method used for the “hockey stick” could be checked against actual physical temperature observations over the late 20th century.

    It failed this check miserably and was thus invalidated.

    But how about other invalidations?

    Loehle 2008 is one of several independent studies from all over the world using different paleoclimate methodologies as well as actual physical evidence, which have also shown that there was a MWP, that it was global and that it was slightly warmer than today.

    TonyB has given us new data based on historical records, which extend the CET record back by around 100 years to ~1530 (but not anywhere near the MWP). These new data suggest a surprising warmer period, which consequently cooled off sharply in the early 17th century, just before the start of the CET record.

    These fluctuations are not shown in Mann’s hockey stick. But since it has already been discredited and invalidated independently, this is all a moot discussion IMO.

    Max

    • As we know, the Mann “hockey stick” was comprehensively discredited by McIntyre + McKitrick, as confirmed by the Wegman committee and endorsed by a panel from NAS under oath before US Congress. This much is history.

      That much is fantasy.

      In the real world, M&M is an often-debunked historical footnote, Wegman is a liar and a plagiarist, and Mann’s work has been replicated by multiple groups of investigators and remains the state of the science.

      • I didn’t realize there is still an ongoing scientific discussion about the validity of the ‘hockey stick’ vs. the newer reconstructions (as this CET continuation, Loehle 2008 and some others posted above), facinating!
        Surely there are enough studies conducted after the Mann study, that science can resolve if the WMP existed?
        If on other hand the discussion is no longer in the scientific comunity, but ongoing on a more religious level, then we may have seen the second comming, the ‘son of Mann’ is amongst us?

      • I didn’t realize there is still an ongoing scientific discussion about the validity of the ‘hockey stick’ vs. the newer reconstructions

        There’s no “vs.” The newer reconstructions all confirm the hockey stick. Only the most deluded denier fanatics lie to themselves about that.

        You can chose to remain ignorant of the science if you want, but it doesn’t magically make it go away.

      • Robert, shame on you for outright lying “remains the state of the science.”.
        have you not read the emails showing the “team” debunking the hockey stick?
        Not Sceptics, THE TEAM.

      • That’s hilarious. You’re still clinging to the delusion that the email thief’s worthless work gossip undermine the science?

        Rational people know better. But feel free to supply the emails debunking the hockey stick. No one has been able to find one in two years, but maybe you’ll be the first.

      • On second thoughts, you are totally correct, it does represent the “state” of the Climate Science of the IPCC.
        Totally debunked even by the team.

      • Your delusions do not get any more persuasive with repetition.

      • Your desire for the hockey stick to have life does not negate the flat line on the monitor. Cracking its chest and massaging its heart will do no good. Abusing the rest of the code team will not bring the hockey stick back to life.

        An autopsy may explain a lot to you, but drawing more blood from the hockey stick won’t. It’s time for you to be led sobbing from the body.
        =========

      • Robert, I do not need to find any emails as others have already found them.
        The fact that you can’t accept the reality just shows your mindset, it is not I that is deluded.
        If you want I can point you in the direction of quite a few Forums with those non existent emails. But you would only mis-read them and say they don’t do what everyone else can see that they do, which is your
        loss.

      • Oh, to get back to reality… I really became intrigued by what Mann thinks is the state of he science?
        What is Mann himself saying about the ‘hockey stick’ graph these days?
        Is he still showing his students his 2004 version, or does he now use someone elses reconstructions?
        Robert, you sound so convinced about this, you must have heard him speak recently? Maybe you could ask him to make a guest post here and enlighten us, that is what we are all here for; to fight denial.

      • Robert, I do not need to find any emails as others have already found them.

        So you can’t find any of these mythical emails?

        Can’t copy them? Can’t produce one single piece of evidence to support your assertion?

        Then that’s kind of the end of the line for you, isn’t it?

      • Skeik – from the paper to which I linked above:

        Previous hemispheric-scale, temperature reconstructions over the past millennium, with one notable exception (Mann et al., 2009), have focused on reconstructing tem- peratures in the time domain only, an understandable consequence resulting from few 20 and sparsely distributed high-resolution proxies that can be calibrated directly against instrumental observations. The unique approach of Mann et al. (2009) attempts to overcome this problem by taking advantage of statistically determined spatial tele- connections between instrumental temperature fields and temperature, precipitation or drought sensitive proxy data as well. …

        Both of the papers mention Mann’s more current work.

      • Thanks JCH,
        Science November 2009 Mann et al:
        “Global temperatures are known to have varied over the past 1500 years, but the spatial patterns have remained poorly defined. The Medieval period is found to display warmth that matches or exceeds that of the past decade in some regions…
        Considerable progress has been made over the past decade in using climate “proxy” data…”

        Christiansen and Ljungqvist 2011:
        “The reconstruction of Mann et al. (2008) shows a longer peak warming, covering the whole period AD 950–1100, and the reconstruction of Moberg et al. (2005) shows a somewhat later as well as longer peak MWP warming than in the present paper. The level of warmth during the peak of the MWP in the second half of the 10th century, equalling or slightly exceeding the mid-20th century warming, is in agreement with the results from other more recent large-scale multi-proxy temperature reconstructions by Moberg et al. (2005), Mann et al. (2008, 2009), and Ljungqvist (2010)”.

        At a glans the 2009 graph by Mann et al. doesn’t look anything like the ‘hokey stick’ (or are the most recent decades still differing from the others?). So, it is strange that this post by Tony Brown only makes references to Mann 98-99.
        It looks like Mann, and those who heavily critisized the ‘hokey stick’ have moved in the same direction, hopefully now along the scientific path. If Robert commented on this progress by the comment “there is no vs.”, I can partly agree. If Robert is saying “the hockey stick is true”, I hope he can eventually move on, like it appears Mann has done.

      • Talking to robert is like talking to a Parrot.

      • Except Parrots can learn.

  59. steven mosher | December 2, 2011 at 4:31 am |
    So I take that the average temp in the LIA which doesnt exist is lower than the average temperature today that doesnt exist.

    No need to be sarcastic. There are data-sets which are not disputed by either side. Solar temperature link is clear:

    http://www.vukcevic.talktalk.net/SSN-T.htm

    You can see also effect of aerosols in 60s, 70s and 80s (probably takes decade or two for them to disappear) and an overshoot in 2000, but no worse than one in 1730; add a volcanic eruption or two, I am sure they are all somewhere in there.
    What does this tell us?
    – the sun-earth link is strong
    – sun and the earth oscillate at same rate, but the temperature has a phase mod due ocean currents
    – no hockey stick visible
    – etc. etc.

    • vukcevic: There are data-sets which are not disputed by either side -WRONG!!!. Solar temperature link is clear…?!?! how can you say that? All what you say, stays on record!

      Temperature on the sun doesn’t fluctuate as a yo-yo; the sun is too big – heat / radiation released today, was produced in the core many, many moons ago.
      Do you expect anybody to take you seriously; when you pretend to know fluctuation for 17-18 century? You are reducing science to lower than astrology. Milutin Milankovich must be turning in his grave. He has proven with his wobbling of the planet theory; why some places indicates warmer than is today; others colder than is today. A] to eliminate speculations that THE WHOLE PLANET WAS WARMER. B] to eliminate speculations that Sun-flares / sunspots affect the temperature…?

      Not even solar eclipse can affect the temp on the earth, not for one day – because the good Lord has installed a thermometer in every atom of O+N; they INSTANTLY expand when warmed and release extra heat up into the stratosphere. Instantly shrink when cooled, to retain more heat = same temperature in the troposphere overall, every day and night of every year!!! Making up the intensity of solar radiation for 16-17 century, doesn’t say anything about the sun; but about you!

      • I have no idea what you are on about, two sets of data shown are accepted by all sides of the current argument, and were not seriously disputed by anyone that I am aware of.
        p.s. My university lectures were held in the same room once Milankovic gave his and the labs’ windows overlook the statue of Nikola Tesla.
        .
        .

      • Vuk, That’s why I pointed to you; Milankovich is turning upside down in his grave; he was for the truth; you are misleading yourself and others. Don’t tell others what you wouldn’t believe if somebody else told you. With those ”solar charts” for 17-18-19 century – your credibility is far below zero. People and economies suffer, getting ripped-off; because of lies from IPCC that you promote. When the truth is known, the masses FLEECED will have records from the net, of your lies > you will not be very welcome on Zvezdara. Tesla was a genius; into discoveries – you promote shallow / destructive lies

  60. John Vetterling

    Completely off topic, but Judith, I wonder if you would like to comment on Christopher Lansea’s opinion piece at NOAA

    http://www.aoml.noaa.gov/hrd/Landsea/gw_hurricanes/

    As an engineer I like the way he goes about normalizing the hurricane, but I’m no hurricane expert.

  61. This post is something we have often been promised from Tony Brown, but never before seen: a genuinely interesting historical digression, whether or not you agree with any of the major conclusions.

    It is nice to see Brown giving a more reasonable account of Mann and his work, rather than the demonization one often sees from “skeptics.” I think — although this is perhaps over-hopeful on my part — that the process of studying something at length, and crafting a piece of writing intended for mixed audiences, deepens and moderates our views.

    Comparing CET to more broadly-based reconstructions is similar to the modern problem of estimating the temperature in areas of low station density, like the Arctic.

    An interesting and thoughtful post from Tony Brown.

    • Robert –

      If I ever see evidence that you have moderated your views, I will eat my hat, my shirt, my shoes and my sofa.

    • Robert

      I will take your appreciative comment at face value and thank you for it.
      tonyb

    • As a non-scientist who has been fascinated reading numerous posts and comments by those who are scientists and those who are wannabes, I dont recall a post which got more favorable reviews from both sides of these climate issues than this one. I wonder if someone would like to step out of their camp and give an impartial analysis of why that appears to be the case, if it is at all. I enjoyed the post and the generally thoughtful responses to it. The usual suspects seemed to be moderate in their comments, although I dont remember Martha showing up.

      • It’s actually not a scientific post per se, and is mostly review with additional anecdotal information. Not much you can do about anecdotes except to nod your head in agreement, or discuss the cultural significance.

        The other aspect, which I think is gaining some recognition, is that climate sensitivity observed in the past works both ways. The fact that climate will change sensitively based on some subtle disturbance suggests that a large disturbance such as an excess CO2 impulse can also cause the climate to change. There is some historical precedent for this so it might happen again. That supports the evidence for AGW.

        The other way it works is that since this natural variability has occurred in the past, a similar or larger man-made variability may not be as significant an event as we think. That mitigates the impact of AGW, but it doesn’t prove that it won’t occur, just that it is more hidden in the noise and thus adaptable.

        The difference is in how sustained these changes are, and whether AGW starts rising out of the noise. The post can not address that issue..

      • WRONG WebHab, the laws of physics are the most reliable science. Same laws of physics will be in 100y as today. Therefore, those laws eliminate all the Warmist’ guessing.

        The trick that: in 100y, the Urban Sheep will forget what was mislead today, doesn’t apply any more. Those laws don’t work on: maybe.. could happen.. it’s possible… 90% possibility… WRONG!!! Unless you convince Obama administration to abolish the ”laws of physics” your ”fig-leaf” is removed > shame exposed!!!.

      • WHT –

        The difference is in how sustained these changes are, and whether AGW starts rising out of the noise. The post can not address that issue..

        This somewhat obvious truism doesn’t, in my mind, make the post any less interesting. I appreciate that the article doesn’t have enough ‘numbers’ in it for you, but I’m not sure that means it isn’t ‘scientific’. The great bulk of interest in AGW is the possibility that future climates may be ‘bad’, ‘problematic’, ‘disastrous’ or ‘catastrophic’. Little sense can be made of those things with statistical significance or applications of the S-B law.

        The bigger picture – the scientific picture – surely incorporates evidence that could be dismissed as anecdotal. Does ‘On the Origin of Species’ count as a work of science? It is almost exclusively anecdotal, with general reasoning and some speculative inferences.

        Perhaps I’m not disagreeing with you, merely saying Tony’s post perhaps carries more ‘weight’ with me than it does with you.

  62. This is a very interesting thread. Thank you tonyb, and also thanks to many others who have put up interesting links to related work.

  63. OT, but something that pops up frequently around here, the brilliance of the Chinese experiment in fascism:

    “Now comes the hangover. The public works projects are winding down, unleashing a wave of unemployment and an uptick in social unrest. The banks’ nonperforming loans are rising, and local governments are insolvent. The country is littered with luxurious county government offices, ghost cities of empty apartment blocks, unsafe high-speed rail lines and crumbling highways to nowhere.

    There is no easy way to avoid the bust that is coming. The silver lining is that China’s increasingly state-led growth model will be discredited, and a debate will begin on restarting the reforms that stalled in the mid-2000s.”

    http://online.wsj.com/article/SB10001424052970203833104577071901186892744.html

    Where is Tom Friedman when the Chinese need him?

  64. Stephen Singer

    Tony the footnote/link 16 seems to be broken, sends one to a not found page.

  65. Stephen Singer

    Tony

    In the last sentence of the paragraph before Fig 7 you say ‘red trend line’. The trend line is blue, the anomaly is red. Please clarify this discrepancy.

  66. Stephen Singer

    Yes, you are right, I meant of course the blue trend line . As regards the broken link, it was fine when the article went up. It can still be founfd under tlink 16 referenced at the back of the paper here;;

    http://curryja.files.wordpress.com/2011/12/references.pdf

    Thanks very much

    Tonyb

  67. Tony and I went together to hear Iain Stewart at Southampton. Polished and charismatic and delightful to listen to – what could we two loners possibly question in that setting?

    I love to see here the return to the cultural, archaeological, anthropological elements, with a fresh look at extracting scientific records from cultural records, and appropriate methodology to turn records into climate information. I suspect we all do. I suspect it is this rich background that inspired many to become climate scientists originally, under Lamb – this prospect of gleaning from muddy evidence a crystal clear picture of climate – another frontier for Science. I am absolutely delighted to see Lamb given a place of honour again, and to see the best of Mann and Jones given a place here.

    I really appreciate Tony going back to see what is good within the early Climate Science work, and what we can all agree to treat as honourable foundations. WHT raises an important issues here, in claiming that this is “not really a scientific post”. But it is at a really crucial scientific frontier, as it begs the question of what is truly science and what is not – as well as what human and cultural characteristics can help Science advance.

    Thank you Tony for what I hope will be seen as a milestone in the reconciliation and recovery of true Climate Science.

  68. You are missing 2011 which will come in quite coolish like 2008…ie: its back to what is was hundreds of years ago. Ergo… there is no AGW etc…

    • Caceres

      Interestingly 2010- the last full year- was, at 8.83C, exactly the same temperature as 1659 the first year in the record
      tonyb

    • Caceres | December 4, 2011 at 3:05 pm |

      Does this resemble how there is a grain of sand in the concrete in my driveway, ergo… I live on a beach?

      • Bart R

        The answer to your silly question to TonyB is: “NO”.

        Max

      • manacker

        That imagination of yours. My question was to Caceres.

        Truthfully, I’m only speculating on grains of sand in concrete, as I haven’t directly observed them. I have only guesses about general principles about hearsay about guidelines about approximations handed down over generations since 1659 about grains of sand in concrete.

        I have no real instrumental record of grains of sand in my driveway, at least nothing I can confirm except that at some point halfway around the world someone with an instrument once measured a grain of sand, and then that record bounced around a lot being prodded and poked and adjusted to various standards, so for all I know, there may be no indication whatsoever a reasonably skeptical person might rely on that I live on a beach.

        Even if that person were 99.9% imagination, and less than 0.1% competent to apply logic.

      • Bart
        Does that apply to ‘Tree Rings’ ?

      • John | December 4, 2011 at 5:21 pm |

        You betcha.

        Paleo proxies, fun entertainment value though they be, add up to a puny fragment of the reliability and utility of the lamentably vague modern instrumental record, for the uses that Climatology would wish to put them, for all the efforts made to clean up the datasets.

        Would that someone made like efforts to improve the paleo by so much as BEST improved the instrumental record, or as TonyB improved the fictional account.

      • Bart R

        There is a “typo” in your last post:

        Would that someone made like efforts to improve the paleo by so much as … TonyB improved the fictional account.

        Replace “fictional” with “historical” and your sentence makes sense.

        Max

      • manacker | December 4, 2011 at 7:05 pm |

        Fictional. Historical. Po-tay-to. Po-tah-to.

      • It’s ultimately fictional in the sense that we can’t project historical paleo data into a scenario of a 100 PPM increase in CO2 over such a short time span. This has never happened before as far as we can tell, so all these historical accounts are fictional. All we can infer is that the climate is very sensitive to variations in environmental factors. If the climate showed great stability, perhaps we wouldn’t be as concerned about an increase in CO2.

    • So maybe 1659 was as warm as 2010. What does that tell us about our knowledge? Not much imo, it tells me more about our ignorance.

      Say climate science would have been about the relationship between air-pressure and the speed of the wind, instead for CO2 & temperature. After twenty-five years of research we have just discovered that our scientist have been sitting in a roller coaster car taking wind measurements. We do not have a clue as to why it goes up and down, and we can only guess which way it will turn next. Until we understand the natural cycle of the roller coaster, and what controls it, we cannot tell anything about the wind, let alone if air pressure affects it. The revelation of our scientist indeed being on a roller coaster does not prove or disprove there is a relationship between windspeed and air-pressure, nor does it give as any information about what we should do to control the air pressure. It simply tells us we are unequivocally ignorant on AGV.
      A lame and pessimistic simile, I admit, but has climate science come much farther than this?

  69. Bart R

    As always, your logic is impeccable.

    Max

  70. Tony Brown, compare the truth, with what you have: medieval ages was MILDER climate, in EUROPE; not warmer PLANET! 2] Mini Ice Age was in EUROPE / N/H, not GLOBAL. It happened because the ice on Arctic ocean disappeared; similar as is happening now. (cannot put all details of a very complicated issue; it’s on my website)

    When ice decreases – no shield / insulator for the Arctic’s waters > water absorbs extra coldness from the air – with double strength radiates coldness south > intercepts all the moisture south = double amount of blizzards / snow – no moisture left for renewal of the ice on Arctic’s waters = chain reaction. I have given it a name in my book: ‘’ice doughnut affect’’ (too much ice in Europe / USA – no ice on Arctic) River in London was freezing, will be freezing again now. Because the ice is getting demolished for the ‘’climatologist’’ All details why / how; if permitted, I will supply to this blog.
    In short: 1] 75% of Russian rivers are draining into arctic – freshwater spreads on the top of the heavy salty water and protects the ice – Aral sea dry, more dry heat produced > less water in those rivers – use in industry and irrigation. 2] Sahara expands > more dry heat > increases evaporation in Mediterranean that should be for replenishing the ice – siphons more water from Mexican gulf – from Arctic ocean – via Bering straights warm / salty water from north Pacific. River Nile /Danube cannot supply the deficit. b] more dry heat from Sahara >destroys humidity in north Atlantic, that suppose to replenish the ice on Arctic next winter and next…

    Mini ice age was terminated by building Suez Canal. Less water needed from the routes I just explained – the benefit water from Red sea was accumulative > more ice on Arctic’s waters. Now nuclear ice crusher ships are vandalizing the ice; to get shonky climatologist, bias media further north. Lots of corridors > ruff water brakes the rest – ice floats south… biggest crimes in progress. All for badmouthing CO2 and to con the ignorant! Stating temperature for individual years in 17-18 century is insult to human intelligence; but not for people that believe you. http://globalwarmingdenier.wordpress.com

  71. Tony Brown; this is NOT the moon, on the earth the temperature is 3 dimensional!!! Can you tell us what was the temperature for last year; 123km SW of Ester Island, 34m altitude at 9AM? How about 234km NE of Fiji same altitude /at 3,45PM? Those places represent 20 times larger area than Europe. Those places are not on ‘’your globe’’?… How about 567km west of capital Brasilia at 1,15AM AT 298m altitude? How about 654km SW of Colombo, for lunch time, for the same 3days?

    Tony, not just you; but nobody knows what was the temperature in the troposphere for last year, to save his life; you pretend to know for 15-17 century…? You are lucky to have lots of thin air in your crystal ball, for harvesting from… Lots of people are ripped-off for billions of dollars, based on pathetic charts like yours and similar, data harvested from thin air. People go to jail for $1000 bucks.

    Can you supply the temperature of above mentioned places for 5 march 1712? (on witness stand, under oath) I can: temperature OVERALL in the troposphere was exactly the same as last year, in 11-13-15-17 centuries; every day of every year. That’s what the laws of physics say. SAME LAWS OF PHYSICS WERE THEN AS NOW, same will be in 100Y from now. Extra heat in the troposphere is not cumulative!!! Because oxygen+nitrogen INSTANTLY expand when get warmer – do you know where they expand up? Solar eclipse doesn’t cool the planet; because those two gases shrink when get colder. Do you know how much sunlight the moon blocks when in-between? O+N fix that instantly. When you know the laws of physics, is as traveling in time: http://globalwarmingdenier.wordpress.com

  72. Here is some work combining recovery from the “Little Ice Age” plus “Multi-Decadal Oscillation”. Graph here (among many, more see Akasofu, 2009): http://wattsupwiththat.files.wordpress.com/2010/04/orssengo3.png

    Akasofu, Syun-Ichi. 2008a. Is Earth still recovering from the “Little Ice Age? University of Alaska Fairbanks Fairbanks, Alaska: International Arctic Research Center, August 14. http://people.iarc.uaf.edu/~sakasofu/pdf/Earth_recovering_from_LIA_R.pdf

    ———. 2008b. The Recovery from the Little Ice Age (A Possible Cause of Global Warming) and The Recent Halting of the Warming (The Multi-decadal Oscillation). Research. University of Alaska Fairbanks, September 25. http://people.iarc.uaf.edu/~sakasofu/pdf/recovery_little_ice_age.pdf

    ———. 2008c. The Recovery from the Little Ice Age and The Recent Halting of the Warming. September 25. http://people.iarc.uaf.edu/~sakasofu/pdf/recovery_little_ice_age.pdf

    ———. 2009. Two Natural Components of the Recent Climate Change: University of Alaska Fairbanks Fairbanks, Alaska: International Arctic Research Center, April 30. http://people.iarc.uaf.edu/~sakasofu/pdf/Earth_recovering_from_LIA_R.pdf
    Updated: http://people.iarc.uaf.edu/~sakasofu/pdf/two_natural_components_recent_climate_change.pdf

    Lots of graphs from many sources in this paper.

    ———. 2010a. “‘On the recovery from the Little Ice Age’.” Natural Science 2 (11): 1211-1224. doi:10.4236/ns.2010.211149. http://www.scirp.org/journal/PaperInformation.aspx?PaperID=3217&JournalID=69

    ———. 2010b. Guest Post “The Continuing Recovery From The Little Ice Age”. Scientific Blog. Climate Science: Roger Pielke Sr. December 27. http://pielkeclimatesci.wordpress.com/2010/12/27/guest-post-the-continuing-recovery-from-the-little-ice-age-by-syun-ichi-akasofu/

  73. Stefanthedenier

    As I make clear I do not believe there is such a thing as an accurate average global temperature as every bit of the planet experiences different temperatures, some going up some going down, and we do not measure them all in a meaningful way.

    Clicking on your name leads to a broken link. Clicking on the address in the last line of your last post does go to your site.

    Why don’t you write an article where you succinctly and logically put your case. Leave out the polemic and cite research that backs your claims then submit it to Judith for her consideration?

    all the best

    Tonyb.

    • tonyb, thanks for pointing to me that even my connection is wrong. You must be a very good person to do that; nobody else did, thanks again. Now I have to think how to correct it…

  74. stefanthedenier | December 4, 2011 at 9:46 pm |
    Mini ice age was terminated by building Suez Canal

    Definitely wrong.
    It was the Panama Canal that started 20th century warming, the Pacific – Atlantic teleconnection was short-circuited. Short circuits overheat!

    • vuc, you are trying to be sarcastic; without doing your homework. 1) because Nile and Danube cannot compensate for the deficit of evaporated water ”the Gulf-stream” exist. For same reason Norwegian and Labrador currents exist – for same reason intake from north Pacific warm / salty water via N/W Passage exists. That constantly creates the passage, into the ice. Start thinking / considering the laws of physics; not only the IPCC pagan belief.

      2) Waters from Mexican Gulf don’t have physical contact with the Pacific waters via Panama canal. I believe that ships use the canal to go to some lakes west and are lowered; similar as they lower ships on Gerdap Gorge on Danube. P.s. they are talking about building another canal in central America; if that one gets direct contact – because Pacific’s water on the west-coast is lower than Mexican gulf water – will siphon much more water from Arctic – on Arctic ocean will not be enough ice left to put in your whisky. You people are obsessed to mislead about CO2 – the real problems / solutions are overlooked > those are the Kyoto cult’s biggest crimes, not squandering billions, to prevent the phony GLOBAL warming; or the new edition: .”to stop the climate of changing” climate never stopped changing for one day in the previous 4 billion years; but they can, for big loot!… Anyway, I will have a laugh on your joke; just to make you happy.

    • vukcevic | December 5, 2011 at 4:32 am |
      vuk, I am really shocked that you don’t even know the influence of the currents on climate… H2O controls the climate, not CO2! It is not ”short circuits” as you ridicule (yourself) but currents bringing cold-water from Arctic to equatorial regions – or the other way – how much in volume… If you start learning the reality; your dedication can produce positive results. I didn’t ridicule you about your ”misleading temperature charts” I just pointed that you are barking up the wrong tree and are destroying your own credibility… I cannot be wrong, because I am guided by the laws of physics, not like you, by the characters in IPCC, characters that should be in jail. You are putting your foot in your mouth for them…? why?

      • You are jumping too quickly into conclusion by starting with a wrong premise. Rather than go into many details I’ll just say Tamino and Daniel Bailey of ‘Sceptical Science’ two arch AGWs accused me of being fraud, falsifying the data. Why? Petrified of natural variations. They verified that my data was good, resorted to personal attacks, but I think I’ve seen both off on that one.
        To see what I am about go to:

        http://www.realclimate.org/index.php/archives/2011/12/unforced-variations-dec-2011/

        and search for ‘vuk’ on pages 1, and particularly 2 and 3.
        Have you ever put piece of cheese in a mouse trap?

      • vukcevic, I heard about Tamino, my knowledge of him is zero. b] You are not falsifying any data, you are picking data from thin air. Putting on paper / temperature charts that; 1710 was warmer, or colder than 1717 is: harvesting from thin air, all your charts are COMPLETELY wrong. TEMPERATURE IN THE TROPOSPHERE (EARTH) IS 3 DIMENSIONAL, not like on the moon..I’m giving you an olive branch: your English is good, I have limited English vocabulary; but I have all the proofs, to see the end of the Kyoto protocol lies in few months. (anybody reading this, should offer assistance, to get the real proofs public)

        Vuk, go to my website, I have only few pages, they are all related; if is known what is there; misleading would become illegal. Because I have all the legitimate proofs; you people cannot rely any more on: the Urban Sheep will not remember in 100y about the crappy staff dished now. Nobody knows what was the temperature last year in the troposphere, to save his life; you are talking about 17 century temp, with PRECISION…???!!!

        As you have given me a tread, to see Galileo with his telescope; as a proof of ”sunspots” cannot get away with similar, on whiteness stand / under oath. Because they will give you only 10y old telescope, you cannot project sunspots. What you did, is same as some Jehovah Witnesses were showing me pictures of Adam and Eva, to prove that God created them from mud – (bot of them had belly buttons, in the picture). For the first time sun-flares were in human vocabulary in the beginning of 20century, sunspots on the end of it. They can falsify, paper takes any lie, Galileo was exactly against that.

        Vuk, you are a dedicated person, but; you are barking up the wrong tree, and in the process, lots of lives are destroyed. You giving me treads to get ”seconded” your misleading; is same as the old Serbian saying: ” if you don’t believe me, ask my brother, the other liar” Those tricks will not be fashionable for much longer!!! I warned you about your credibility; from now, don’t forget about the laws of physics for one minute! You have never had a friendlier advice. Millions of people are fleeced for billions of dollars; because of crappy science as yours. Join me; we get the real proofs public. My mission is to expose every Warmist lie. I have the legitimate proofs, beyond any reasonable doubt! I sincerely don’t want you to become a collateral damage. http://globalwarmingdenier.wordpress.com

        P.s. did you understand that: ice on Arctic is melted from below, by the salty water currents; not by the phony GLOBAL warming. If the currents increase below > ice decreases. Tesla and Milankovich did know that; ice starts melting on one degree C above zero. Average temp on Arctic is -30C, much colder than in your deep freezer. Your English is good, help me; don’t argue against me – you will lose. I have the proofs; you use the IPCC’s crap. Human is powerful enough to improve the climate Suez Canal is the best proof; if they dug a canal to have physical contact between Mexican Gulf and east Pacific – will produce bigger ice age than LIA – bad. Panama canal has no physical contact with both waters. The ”laws of physics” sound sometimes weird, but they control in nature; same as you are controlled by the crap from IPCC. I cannot ever be wrong, because I believe in the laws of physics as guidance, not in East Anglia and IPCC’s crap, as you doo!!!!

      • vukcevic, I just read some on that tread that you are pointing ; discuses about methane. There is a page on methane on my website, please read it. It’s the biggest crime misleading about methane, by both camps. If is known what’s on that page and in my book, lots of ”methane Bashers” would end up in jail. Because Chemistry is reliable science, same as physics, not like climatologist’ con. Can be demonstrated now, not to wait 100years trick that the Warmist as you are using!!! If you read the page on methane on my website, will tell you the magnitude of the crimes are in progress by the Warmist and many ”pretend Skeptics”

  75. Tony, thanks for this ensemble. It was being exposed to human history, and our encounter with climate over the years that made it obvious that Gore and the contrivers of his props were not doing science, rather trying to rewrite history, fallaciously holding up natural variation as human induced calamity. Thanks for all your efforts over these past few years, that I know of, to keep our history as it was.

  76. More gloom and doom from Durban: :-)

    Chestney, Nina, and Barbara Lewis. 2011. “Debt and doubt loom large over Durban climate talks.” Reuters.com, December 5.

    http://www.reuters.com/article/2011/12/05/us-climate-idUSTRE7B41NH20111205?feedType=RSS&feedName=worldNews&utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+reuters%2FworldNews+%28News+%2F+US+%2F+International%29&utm_content=My+Yahoo

    “Underlying the need for urgent action to cap further temperature change, a report UK Met Office report released in Durban on Monday forecast global temperature would rise between three and five degrees Celsius this century if emissions are left unchecked.”

  77. Tony,

    I’m late in reading all this, but loved it! History was my first discipline. Also enjoyed the cool and respectful tone. Wish there were like you.

    Keep posting!

    And a Merry Christmas and Happy New Year.

    Don

  78. Oh dear. ‘Wish there were more like you’!

  79. @ Tony Brown and Judith Curry:

    Best post I have ever read here.
    For it contains unaltered reality, that cold is the killer.

    It is the temperature downslide I fear as a unconvinced scientist of this ‘Global Warming’ scare. More posts like this spread about is what will wake up the children and young from their co2 nightmares planted in their minds every single day. Everyone on this planet should be thankful to whomever or whatever gave us this glorious modern warm period we live in today.

    The one consolation mankind has is if we should approach another ice age we may have the whether all to circumvent it’s manifestation. Maybe there is now too much life to allow it to get a grip. A rare six foot snowfall blanketing all of North America, Europe, and Asia without man would delay spring for many weeks as it reflected and slowly melted increasing the chance of the next winter being even worse.

    But today we have snowplows uncovering black asphalt, farm equipment to over turn dark soil that speeds that melting, also by weeks. I sprinkle my drive and some of my lawn with fireplace ash to do just that. The one thing we can so easily control is the earth’s albedo. Who knows, it may be pure black carbon that may one day save man from another ice age in the far future, let’s hope. But don’t count on co2 to save the day, if Dr. Miskolczi papers are in fact correct, it will have zero effect.

  80. I’m also a lover of history, but we do have to live in the future as time goes on, perhaps you could address the more recent 21st Century material from Mann et al. and the spaghetti stick etc

  81. So, from Section 3 of the SOM;

    “The mean average temperature or each year has been calculated as follows. Where no information-or too little information- was available, an ‘average’ for that period has been calculated (which has been amended as trends emerged). Some notably cold winters were balanced by exceptionally hot summers so mean averages for some of the frost fair years, for example, are not as cold as may be expected. Subject to revision as new evidence is found.”

    So, no paleoclimatology proxy data for central England, circa 1538-1659, I see.

    So, no instrumental temperature data for central England, circa 1538-1659AD, I see.

    So, no significant overlapping period of the written record versus the instrumental temperature record, you know, something to use to calibrate the written record with actual temperature data, I see.

    So, here’s a snippet (or chose your own for all I care) of the written record;

    “1557 Drought wof
    1558 Spring summer and harvest hot and dry Short
    Cold winter with north wind
    1559 Stormy autumn
    1560 In Switzerland, for example, the first particularly cold winters appear to have been in the 1560s, with cold springs beginning around 1568, and with 1573 the first unusually cold summer (Pfister, 1995).
    1561 Winter in N France cold (bb)
    1562/63 Thames froze ( bb)
    1563
    1564 on 21st Dec ‘began a frost which continued so extreme that on new year eve people played ‘foote-ball’ on the Thames at Westminster as if it had been on dry land’ it thawed on 3rd jan 1565 Wof
    Winter of 64 and the following spring a great frost”

    From the above written records we “somehow” (see the strict 0.1C resolution mathematical decription at the top of this post (You do see it, don’t you?) end up with an annual record with a 0.1C (or 0.01C) resolution;

    “1549 9.50c 1550 9.50c 1551 9.40c 1552 9.51c 1553 9.50c 1554 9.00c 1555 9.40c 1556 9.60c”

    (I’ll assume that for 1552AD “9.51c” should be “9,50c” as it’s the only 0.01C resolution in this so called “reconstruction”)

    Meanwhile, the CET is a point estimate for one location on Earth’s surface, and should never be misconstrued as truly representative of the global annual mean temperature, or the Northern Hemesphere annual mean temperature..

    Humans as thermometers? Not a good idea as we acclimate to both cold and warm conditions, so the only certifiable guide to temperature would be if water froze or melted or if water rained or snowed, outside of that one known data point, a human thermometer would have an accuracy of +/-5C.

    Not very encouraging at all if you were to ask me, and certainly not testable or repeatable via the standard practice of the scientific method.

    Much better to use real (non human thermometers) proxy data for real temperature reconstructions prior to the instrumental temperature record.

    GIGO :-(

  82. EFS Junior

    You quote me as saying:

    ” Where no information-or too little information- was available, an ‘average’ for that period has been calculated ”

    There are many dozens of studies covering the period that were used, many of which are quoted in the numerous references and which in turn lead to studies they have also referenced.

    I have also quoted a large varietry of sources that illustrate that CET does have a wider use than Central England but is by no means perfect.

    I carried out a 50 year overlapping of observations and instrumental record in order to try to calibrate the two.

    I am gathering together additional information in order to update version 1 in due course, incliuding other reconstructions
    tonyb

    • Well in that case, one normally does a calibration AND verification, say 50 years for calibration and 50 years for verification.

      That is known as standard practice in any modeling effort.

      It would also give you an estimate, or error bars for all those different human thermometers.

      Without some estimates of measurement errors from all those many different human thermometers, no confidence whatsoever can be placed on this method of reconstruction..

      And you just can’t take out the human element due to the fact that different
      people (several people each assigining temperature values to the written records independently of one other, call it an n-blind test) will assign different values to all those all too brief written texts.

      The written texts are also not in some standardized format of descriptive terms, certainly not in the qualitative sense. Different people attach different meanings to what might in fact be the same temperature.

      It’s not like so much computer code where 30C spits ouy “very hot” or 25C spits out “hot” or 20C spits out “warm” or 15C spits out “mild” or 10C spits out “cool” or 5C spits out “cold” or 0C spits out “freezing”

      You are subjects dealing with subjective writings, thus the only possible outcome will be subjective by it’s very nature at both ends (written texts and data reduction are clearly both subjective efforts).

      We’ve even tested for measurement biases in our laboratory, using the same measuring stick, with several different technicians, and guess what? No two series of independent measurements matched one another. The results improved greatly once the technicians were shown how to take those measurements properly. And those measurements were considered to be quantitative and thus objective. Something that you don’t really have with all those written texts from all those many different human thermometers.

      In other words, you are introducing observation bias at two points, those original writings by many different observers, and your own observations in translating those qualitative written words into quantitative temperature values.

      Finally, many people state that the SST/SAT are not accurate enough to determine trend lines or even have readings to 0.01C or even 0.001C, and that’s with thermometers accurate to 1C, but not me of course. as you can show that level of resolution for monthly and/or annual averages.

      So here’s what I don’t get.

      Either you fully trust the instrumental temperature record, assume it’s been entirely correct for all time. Because if you don’t believe the instrumental temperature record, then why even bother to attempt a very much less accurate method of reconstruction, where the error bars are most likely larger than the reconstructed time series itself?

      • EFS_Junior

        Either you fully trust the instrumental temperature record, assume it’s been entirely correct for all time. Because if you don’t believe the instrumental temperature record, then why even bother to attempt a very much less accurate method of reconstruction, where the error bars are most likely larger than the reconstructed time series itself?

        The temperature record we have is what we have.

        We know that around 70% of the globe is covered by oceans.

        We know that there are great problems with SST until very recently (and even there we have serious questions as to the geographic coverage and accuracy).

        We know that there has been urbanization all over the world.

        We know that urbanization causes a spurious warming signal (sorry BEST, your analysis showing that urbanization has caused slight cooling is absurd – toss it out and do some urgently needed rework).

        We know that airports are not ideal places for temperature measurement, because they also introduce some of the same warming bias as urbanization.

        We know that the number of measurement stations has been slashed by more than two-thirds around the 1990s, about the same time when temperature showed a strong rise.

        We know that many of the stations that were shut down were located in sub-Arctic regions of the old USSR, and that there were internal political reasons during that time to understate local temperatures in order to get fuel subsidies.

        We know that station coverage for many regions of our globe is very sparse with “blanks” being filled in rather arbitrarily.

        We know that thermometers placed next to AC exhausts, asphalted parking lots, buildings, etc. will show a spurious warming bias, and we know that there are such thermometers in the surface measurements comprising the global record.

        We know that the data from the surface stations are homogenized, adjusted and corrected after the fact in a process that is not totally transparent.

        We know that the same individuals who are in charge of managing the collection, adjustment and evaluation of the raw global temperature data are also those who have actively given forecasts of unusual warming.

        We know that the temperature record becomes more nebulous and uncertain the further back in time we go.

        We know that the rate of warming as shown by the tropospheric satellite records indicate a slower warming rate than the surface record.

        We also know that the troposphere should theoretically warm more rapidly than the surface, if the warming is caused by the greenhouse effect.

        And finally, we know that the “globally and annually averaged land and sea surface temperature” is an artificial construct, which means far less to humanity in the long run than individual regional and local temperature developments.

        But, in spite of all these many caveats, we WANT to know how the temperature of our planet has developed over our history and every bit of new light we can shine on past trends brings us new knowledge.

        Tony Brown’s work in extending the longest record we have, the CET, by around one hundred years has brought us new light into our past temperature.

        It has confirmed some previous beliefs but, surprisingly, has also shown us that there was a warmer phase in the 16th century, which reversed sharply in the the 17th century (about the time of the Maunder Minimum), resulting in a cold period about the time that the official CET record started

        Brown’s work will undoubtedly be tested and either validated or refuted by additional studies, but there is no doubt that it is a seminal piece of work that has given us new knowledge we did not have before.

        That is the main point here as far as I am concerned, and I thank Dr. Curry for having posted this guest post here.

        Max

      • Ha, Manacker, multiply what you said by 1000 and apply that to the historical reconstruction that was attempted in this post. That is the point that EFS_Junior is making. However inaccurate the data is today, it was much, much worse back then.

        Junior points out the painfully obvious, and you try to misdirect.

      • WHT

        You are wrong – once again!

        I am not “trying to misdirect”.

        Nor am I denying that the further back you go, the dicier the temperature record gets (read my post).

        I am simply saying that TonyB’s extension of the CET record back by about 100 years based on historical data, etc. is an important step in helping us understand how our climate has varied in the historical past.

        I would certainly add that one should also consider the many independent studies from all over the world using different paleoclimate methodologies, which demonstrate a colder LIA and warmer MWP that appear to be global (contrary to Mann’s tree-ring reconstructions, which have since been discredited anyway).

        But I would generally prefer actual physical or historical data (such as physical evidence found under receding glaciers or historical accounts of unusual cold during the 30-year war) to dicier paleoclimate stuff.

        This applies for paleoclimate studies that cover periods in our historical past.

        However, I would be even more skeptical if we are talking about subjective interpretations of carefully selected time periods of our geological past that go back millions of years – this is only slightly better than reading tea leaves IMO.

        Hope this clears it up for you.

        Max

      • I have worked on qualitative reasoning projects recently and they are called qualitative just for that reason. There is really no easy way to get quantitative numbers out of qualitative arguments. The human temperature readings back then should be taken as warmer than average, average, and colder than average and leave it at that level of qualitative reasoning.

  83. EFS Junior

    Thanks for your interesting remarks.

    Please see my comment 3) in ‘conclusions’. .All forms of reconstructions have their problems.

    I have written several articles citing what is wrong with instrumental records as although they show the ‘tendency’ they are certainly not accurate to tenths of a degree. We are fortunate in being able to put constraints on likely temperatures in my reconstruction, so your plus or minus 5C is unlikely to reflect reality-see see figure 14 which constrains it to 2C at the margins, and a variety of other records such as crops enable us to refine it further.

    As you will have gathered my prime interest is to ascertain the likely variability of our climate, and in particular get some idea of notable peaks and troughs.

    In this context I found the apparent peak at the very start of the reconstruction, the fall that plateaued around 1600,and the rise around the 1640’s to be of particular interest and worth trying to put some time in to determine their accuracy or not.

    Paleo records have their own inherent faults and bearing in mind the great amount of work that has gone into unearthing our past by such as Lamb or Daly it is not unreasonable to want to build on their work .They are now somewhat unfashionable, but bearing in mind that more information is coming to light that can help to determine their accuracy -or not- Historico science is once again an interesting (to me) route to follow. Others are of course perfectly at liberty to produce their own reconstructions based on their preferred method.

    People have sent me stuff since my article that will be useful in Version 2 so I am ‘parking’ this next reference here for future use.

    M. V. SHABALOVA and A. F. V. VAN ENGELEN : Evaluation of a reconstruction of winter and summer temperatures in the Low Countries, ad 764–1998

    http://www.springerlink.com/content/gu62270140g7r854/

    In Version 2 the CET reconstruction has been set besides the above study. My main interest is in the generality of trends from which my peak in 1640 and the upwards trend from the 1540’s is mirrored.

    I’m not saying that either of these reconstructions is 100% correct but the picture of variability is being built up which conflicts with the Met office view which basically reflects Dr Mann’s line shown in figure 15a

    All the best

    Tonyb

  84. WHT said

    “Ha, Manacker, multiply what you said by 1000 and apply that to the historical reconstruction that was attempted in this post.”

    Now WHT, If I’ve told you once I’ve told you a million times not to exaggerate. :)

    Seriously, we can do very much better than what you suggest, as we have a huge wealth of information from a variety of sources. Please note figure 14. As you can see CET operates within quite tight bands. Anything around a mean average of around 9 to 9.5C is pretty average. We can readily identify prolonged events that would impact significantly on this approximate average by half a degree or more, as our ancestors recorded such events as it had a great effect on their lives.

    I have extended graphs of each months CET data and as well as other methods of interpretation already described we can gather further evidence by reading the descriptions of events and work out the likely impact on temperatures by cross relating them to similar events that happened within the instrumental record.

    Winter has a greater potential for temperature variability and this will produce notable events that would be well recorded. Other seasons also have an impact of course, and again we can cross relate similar events with the instrumental record. Tie this in with crop records, droughts, harvest times and a myriad of other information and we can identify the likely spread of temperatures around this 9 to 9.5C average- which will vary according to the climate cycle.

    I think we can get to within half a degree of reality for the majority of the record and indeed the various reconstructions from other sources seem to confirm this 1538 reconstruction sits comfortably within the parameters of our existing knowledge, but of course its not perfect and I intend to carry out a version two in due course and if possible try to find the extent of the peak noted at the start of the reconstruction.

    As I said to EFS Junior my prime interest is to identify these peaks and troughs and the general ‘direction of travel’ of the temperatures in order to determine if the climate is more variable than is claimed. Science should work with history-its not an either or situation.

    I ‘parked’ another reconstruction on this thread for future use a couple of days ago and am also ‘parking’ this compilation of data kindly provided by vukcevic according to information I supplied him, and which needs updating with the 1538 data.

    http://www.vukcevic.talktalk.net/CET-D.htm

    Plus a reminder to upload the data from my Word Doc of 2/11 showing separately all available CET months to 1659.

    tonyb

  85. tonyb,

    In case you are still checking in on your thread,

    http://redneckphysics.blogspot.com/2012/01/history-of-modern-agriculture-and.html

    I just started with the Taymar tree rings to see if there is a change in the duration of extreme climate events. Seems like there is, bugger to prove, but interesting in any case. I am not a history kinda guy, but wheat is probably the agricultural factor to look for. Winter wheat can demand early spring application of ash or compost to help melt the snow in order to prevent snow mold. The Russians have gotten pretty good at clearing snow and breaking ice, so a little Russian agricultural history might be fun.

    dallas

  86. When I come to look at the unexpected warmth I identified at the 1538 start date of this article it would be useful to look at this paper in greater detail;

    http://www.cgd.ucar.edu/staff/mholland/papers/Polyak_2010_historyofseaiceArctic.pdf

    page 1772

    ‘The subsequent decline of bowhead abundances in the CAA is consistent with the abandonment of the high Arctic of Canada and Greenland by bowhead hunters, while Thule living in more southern Arctic regions increasingly focused on alternate food resources.

    The warming event around 1500A.D.is identified by climatic simulations in the Atlantic sector of the Arctic and is explained by the internal variability of atmospheric circulation (Crespinetal.2009). The subsequent cooling culminated in the‘‘LittleIceAge’’,between ca1600 and 1850AD, when ice conditions in the high Arctic remained especially prohibitive for navigation(e.g., Altet al.,1985).’

    tonyb

  87. This quote is placed here for reference in connection with a future article on the 1730’s . It comes from the 2000 book ‘History and climate-memories of the futrure?’ This chapter from Phil Jones-page 61

    ‘ All five series show long term warming from either the late 18th or early 19th centuries. Recent years are only marginally the warmest of the entire series because of the warmth of the 1730’s (particularly in western europe) and the 1820’s (northern Europe) THe five series are CET DE Bilt Berlin Uppsala Stockholm.
    tonyb

  88. Tony, this post deserves to be declared as ‘the biggest septic tank” produced by human, Thanks Tony, you made my day. Not just about you, but tells a lot about the commenters on this blog. WOW! I can see what mentally deformed the Fakes, why they don’t like me, brilliant!

  89. Note to self for part two of long slow thaw.

    The relative warmth of the climate around 1640 to 1660 approximately that I had expressed some scepticism about appears to be vindicated by glacial records. This records a general retreat approx 1644 to around 1663 or so. They then advanced again for twenty five years or so. Temperatures are not the sole cause of advance and retreat but are obviously a big factor. Sun levels, moisture, cloudiness etc all have a big effect.

    See book ‘ times of feast, times of famine’ by Emmanuel le Roy Ladurie Chapter three and chapter four in particular. Gives lots of first hand accounts of glacial advances and retreats mostly but not solely in the alps

    Tonyb

  90. Now I am going away to do my breakfast, afterward having my breakfast coming over again to read more news.

  91. Hey there just wanted to give you a quick heads up and let
    you know a few of the pictures aren’t loading properly.
    I’m not sure why but I think its a linking issue. I’ve tried it in two different browsers and both show the same outcome.