The Little Ice Age (LIA) received much attention by those who were affected by it. Much was written about it, and most of that was forgotten again.
- The birth of Michel E. Mann’s Hockey-Stick Graph
- Debunking the Climate Hockey-Stick Graph
- Some of the notable weather events during the LIA
- A Cold Spell (2017 12 24 – 2018 01 2) and how it fits into the Scientific Climate Record Trend
- The Islamic Invasion and Conquest of the Roman Empire — Crime of Opportunity
- Related blog posting: Roman Warm Period — Timeline and Decline
The IPCC (Intergovernmental Panel for Climate Change) discussed the Medieval Warm Period (from about 950 to about 1250) and the subsequent Little Ice Age (from about 1300 to about 1850) in section 7 of the IPCC 1  climate report, from which a Figure 7c became a somewhat-less-than-commonly-used image, at times presented as evidence of that both the Medieval Warm Period and the Little Ice Age had occurred. The image does not quite match current standards for graphic presentations of data, is often not attributed to a specific author but was frequently attributed to Hubert H. Lamb, Ph,D. (22 September 1913 – 28 June 1997), who had founded the Climatic Research Unit in 1972 in the School of Environmental Sciences at the University of East Anglia. Hubert H. Lamb is considered by many to have been the father (or at least one of the fathers) of modern climate science.
The Medieval Warm Period and Little Ice Age regained prominence once more, lately, when Michael E. Mann produced a graph which showed a global temperature trend that glared by the absence of all evidence of not only the Little Ice Age but also of the Medieval Warm Period (MWP).
Michael E. Mann’s “Hockey-Stick Graph,” as it became known, caused many people in global-warming circles to love it, and many others — skeptics of the theory of catastrophic anthropogenic global warming (CAGW) — to write much about it, thereby to enable Michael E. Mann to acquire much infamy. For instance, Michael E. Mann took Tim Ball, a venerable, retired Canadian Climate scientist, to court for making an off-hand, humorous remark about Michael E. Mann, for having stated that the latter should not be at Penn State (University) but in the state pen. Michael E. Mann, for similar reasons, also sued Mark Steyn, an internationally renowned conservative journalist. Mark Steyn was nevertheless not deterred by that. Between court hearings of Michael E, Mann’s lawsuit against him, he penned a well-selling book about the affair of Michael E. Mann’s Hockey Stick graph.
The Medieval Warm Period had made all of the then known civilization thrive. Amongst other things, it helped the emergence of a construction boom in Gothic cathedrals in Europe, motivated the Vikings to settle in Greenland, and it caused the emergence of a burgeoning sector of agriculture, involving vineyards, the growing and harvesting of grapes, and a wine production in England rivaling that of France. Olive trees were cultivated in Germany, as stated in this,
Grapes were grown in England several hundred kilometers north of their current limits of growth, and subtropical flora such as fig trees and olive trees grew in regions of Europe (northern Italy and parts of Germany) well north of their current range. Geological evidence indicates that mountain glaciers throughout Europe retreated substantially at this time, relative to the glacial advances of later centuries (Grove and Switsur, 1994)
Source: Medieval Climatic Optimum
Michael E Mann
University of Virginia, Charlottesville, VA, USA
Michael E. Mann deliberately obscured, in reports he produced later, that the Medieval Warm Period and Little Ice Age were of global significance, ignoring all evidence to the contrary and argued that they were merely local phenomena that had affected only Europe.
Steve McIntyre and Ross McKitrick, Ph,D, debunked the claims by Michael E, Mann that his arguments against the Medieval Warm Period and Little Ice Age had any scientific validity. They demonstrated, furthermore, that Michael E. Mann had used dubious means for constructing the blade for his Hockey Stick Graph. He had tacked late modern temperature readings to the shaft of his hockey stick that was based on calculations of temperature values constructed from estimates of temperature proxies such as the measurements of tree rings. It is a scientific “no-no” to mix different sources of data in that manner, but that was not all.
Steve McIntyre and Ross McKitrick analyzed all of it and published their findings in this:
CORRECTIONS TO THE MANN et. al. (1998)
PROXY DATA BASE AND NORTHERN HEMISPHERIC
AVERAGE TEMPERATURE SERIES
512-120 Adelaide St. West, Toronto, Ontario Canada M5H 1T1;
Department of Economics, University of Guelph, Guelph Ontario Canada N1G2W1.
The data set of proxies of past climate used in Mann, Bradley and Hughes (1998, “MBH98” hereafter) for the estimation of temperatures from 1400 to 1980 contains collation errors, unjustifiable truncation or extrapolation of source data, obsolete data, geographical location errors, incorrect calculation of principal components and other quality control defects. We detail these errors and defects. We then apply MBH98 methodology to the construction of a Northern Hemisphere average temperature index for the 1400-1980 period, using corrected and updated source data. The major finding is that the values in the early 15th century exceed any values in the 20th century. The particular “hockey stick” shape derived in the MBH98 proxy construction – a temperature index that decreases slightly between the early 15th century and early 20th century and then increases dramatically up to 1980 — is primarily an artefact of poor data handling, obsolete data and incorrect calculation of principal components.
Critics of Michael E. Mann and MBH98 were and are not so much upset by that proxies were used and that the interval was arbitrarily truncated, but that unreliable proxies were used wrongly and had tacked to them values calculated from actual temperature readings for the late 20th century, that it was not the result of a scientifically correct and trustworthy effort, and that it uses selected data and weighted it preferentially and unacceptably to strengthen the desired argument. Moreover, it was noted by critics that data that did not fit the argument made by the report had been discarded or given less weight than preferred data.
Temperature measurements via thermometers was not done, globally and reliably, until after reliable thermometers and methods to use them spread, globally. Proxies exist and are ever more often discovered and examined to yield data from which trustworthy [and of course at times not so trustworthy] estimates [are produced] of what temperature trends were in ever more locations all over Earth, for when no thermometers existed. A collection of indicators of such studies can be examined at the website of CO2 Science, for example, identifying proxies that show evidence of the Medieval Warm Period and the Little Ice Age being found all over the Earth, in this:
- Earth’s Climatic History: The Last 1,000 Years;
- Rapid Climate Change (History), and in this,
- Little Medieval Warm Period (h/t to: Gregorio Enrique Sandoval; 2018 01 12)
Aftermath (added 2018 01 05):
Penn State climate scientist, Michael ‘hockey stick’ Mann commits contempt of court in the ‘climate science trial of the century.’ Prominent alarmist shockingly defies judge and refuses to surrender data for open court examination. Only possible outcome: Mann’s humiliation, defeat and likely criminal investigation in the U.S.
The defendant in the libel trial, the 79-year-old Canadian climatologist, Dr Tim Ball (above, right) is expected to instruct his British Columbia attorneys to trigger mandatory punitive court sanctions, including a ruling that Mann did act with criminal intent when using public funds to commit climate data fraud. Mann’s imminent defeat is set to send shock waves worldwide within the climate science community as the outcome will be both a legal and scientific vindication of U.S. President Donald Trump’s claims that climate scare stories are a “hoax.”…. (More)
Just a few examples from a much larger Chronology (the body of the text of is very large and contains more detailed summaries of the items in the list):
- The “Great Storm” that had the intensity of a major Category 2 hurricane which struck England in November 1703.
- The severity of winter in the Upper Midwest of the United States during the last Little Ice Age. Refer to the winters of 1680/1681 and 1747/1748.
- The massive firestorm that raced through Wisconsin, Illinois and Michigan and into Ontario, Canada in 1871.
- The severe winter of 1683/1684 when the English Channel froze.
- The drought in Egypt due to a lack of the annual inundation of the Nile River that resulted in the Great Famine of 1199‐1202.
- The global droughts and famines of 1783‐1785, 1876‐1879, and 1895.
- The three forms of microscopic diamond dust ice crystal (hexagon plates, hexagon columns and the deadly long prisms). The latter type occurs in diamond dust icefalls called by the American Indian name “pogonip” which translates to “white death”.
- The great storms that struck the Spanish fleet in the Caribbean and the Atlantic Ocean during the summer of 1591.
- The severe winters of 642, 763/764, and 775 when the Black Sea froze. [That happened after end of the Roman Climate Optimum.]
- The effects of the Tambora volcanic eruption of 10 April 1815 which caused “a year without summer” in 1816.
- The great Atlantic hurricane of 9‐16 October 1780.
- The Great September hurricanes of 1752, 1782 and 1804.
- The Great Storm that struck Wales during the winter of 1171/1172.
- The “day of darkness” in New England that occurred on 19 May 1780.
- The great flood of 48 A.D and the great storm of 67 A.D. that struck England.
- A typical winter in Boston Massachusetts towards the end of the last Little Ice Age. (Refer to the winter of 1771/1772.)
- The thunder storm that struck Greenland in 1755.
- The avalanche of snow in Italy in 1755.
- The Atlantic hurricanes of 1553, 1559, 1590, 1591, 1600, 1601, 1605, 1622, 1644, 1666, 1680, 1689, 1694, 1715, 1719, 1722, 1747, 1751, 1752, 1766, 1767, 1768, 1772, 1775, 1776, 1780, 1781, 1782, 1784, 1785, 1791, 1800, 1804, 1813, 1815, 1817, 1825, 1831, 1870, 1873, 1893, 1899, and 1900.
- Typhoons/Cyclones that struck
— China in 1166, 1474, 1748, 1822, 1862, 1874, and 1881.
— Vietnam 1881.
— Bangladesh in 1584, 1699, 1737, 1767, 1787, 1822, 1831, 1876, 1886, and 1897.
— India in 1737, 1749, 1782, 1789, 1833, 1839, 1854, 1864, 1867, 1875, 1876, 1882, and 1886.
— Australia in 1795, and 1899.
— Japan in 1828.
- The great lightning storm that struck southern France in 753.
- Powerful storms that struck the coasts of France, Spain and England in 1751.
- The Powerful storm that struck the western coast of England in 1757.
- The great winters in Germany in 760/761, 1019/1020.
- The Canadian winter of 1741/1742.
- The severe European winters of 566/567, 821/822, 859/860, 874/875, 993/994, 1076/1077, 1114/1115, 1132/1133, 1149/1150, 1216, 1233/1234, 1305/1306, 1323/1324, 1363/1364, 1407/1408, 1433/1434, 1459/1460, 1490/1491, 1564/1565, 1594/1595, 1607/1608, 1620/1621, 1621/1622, 1657/1658, 1669/1670, 1680/1681, 1683/1684, 1691/1692, 1708/1709, 1739/1740, 1748/1749, 1753/1754, 1762/1763, 1766/1767, 1775/1776, 1781/1782, 1783/1784, 1784/1785, 1788/1789, 1794/1795, 1798/1799, 1812/1813, 1819/1820, 1829/1830, and 1844/1845.
- The Chinese winters of 1445/1446, 1510, 1574, 1627/1628, 1655, 1691, 1749, 1751/1752, and 1863/1864.
- The severe North American winters of 1696, 1697, 1716/1717, 1740/1741, 1742/1743, 1747/1748, 1761/1762, 1764/1765, 1765/1766, 1771/1772, 1779/1780, 1783/1784, 1786/1787, 1798/1799, 1799/1800, 1804/1805, 1806/1807, 1814/1815, 1816/1817, 1820/1821, 1830/1831, 1834/1835, 1835/1836, 1856/1857, 1863/1864, 1883/1884, 1884/1885, and 1898/1899.
- The winters when the Nile River froze: 829/830, 1011, and 1691/1692.
- The great winters of 1783/1784 and 1784/1785 in the Northern Hemisphere, followed by great spring floods as the snow melted.
- Mild Russian winters of 1303/1304, 1753/1754, 1758/1759, 1818/1819, and 1821/1822.
- This chronology is overflowing with times of Great Famines. Famines caused by excessive rainfall, droughts, hailstorms, severe winters, and summers robbed of the sun’s heat. Here are but a few examples:
— China in 463-464, 1033, 1328, 1333-1337, 1354, 1458, 1476, 1522, 1787, 1810-1811, 1846, 1849, and 1875-1878.
— Japan in 626, 1230, and 1782-1788.
— Korea in 1784.
— India in 942, 1022, 1052, 1327, 1345, 1396, 1556, 1596, 1630-1631, 1661, 1769-1770, 1780-1784, 1790-1792, 1802-1807, 1810, 1812-1813, 1823, 1832-1835, 1865-1866, 1868-1870, 1873-1874, 1876-1878, and 1896-1900.
— Bangladesh in 1780-1784, and 1873-1874.
— Pakistan in 1780-1784.
— North Africa in 484 and 1784-1785.
— Egypt in 966/967, 1064-1071, 1199-1202, and 1784-1785
— Iran in 1870-1872.
— Western Europe in 1033.
— England in 310, 680, 700, 1004-1016, 1234, 1239, 1257-1259, and 1314-1316.
— Ireland in 963-964, 1116, and 1845-1851.
— France in 869, and 1030-1032.
— Scotland in 936-939, 954, and 1695-1699.
— Italy in 410, 450, 538, 776, 1230, and 1347.
— Belgium in 1587.
— Germany in 1310-1319, 1347, and 1772.
— Poland and Bohemia in 1281, 1312, 1315, 1737, and 1770.
— Hungary in 1505, 1782, and 1808.
— Finland and Estonia in 1695-1697, and 1867-1868.
— Russia in 1024, 1128, 1212, 1215, 1230, 1445, 1600-1602, 1701, and 1891-1892.
— Turkey in 1873-1876.
— Mexico in 1454, and 1785-1786.
— Cape de Verde Island and the Island of Sumatra in 1775.
- The tornado that struck Charleston, South Carolina in 1761.
- The ice hill at Shanghai, China during the winter of 1769/1770.
- The dense fog in the Netherlands during the winter of 1790/1791.
- The great hailstorm of 13 July 1788. [page 870]….
- [and much, much more….]
Source: “A Chronological Listing of Early Weather Events,” 7th Edition, James A. Marusek
Anyone who reads through the Chronology will be left with the firm impression that it is not so much warmth and warmer weather that kill, but that cold and cold climates are absolutely deadly and far more dangerous to human health, life and civilization.
Our severe cold spell (it is not really all that bad, as far as cold spells go) began 2017 12 17 and received first attention by the media and others on about Christmas Eve, when temperatures had fallen so low that no one could avoid noticing that it had become bitter cold and would remain so for some days in all or most of North America. I summarized some of the comments I had posted on Facebook about that, elaborated on them and published that summary in the form of a blog posting (2017 12 29) at dads&things.
The Little Ice Age was merely one of the latest of such events (the current Modern Climate Optimum is neither all that remarkable nor optimal) in a very long string of similar ones that had contributed to a very gradual cooling of our globe during the last 9,000 years or so. No one in the world knows why the long-term global cooling trend should stop now, reverse and turn colder (or much warmer yet), any time soon or at all. We have not experienced statistically significant global warming for close to 30 years now. No one graduating from high school and entering college has ever seen or experienced any of it.
In the much longer term of the life of our globe, for the last 4.5 billion years, neither the Medieval Warm Period nor the Little Ice Age mean much, nor can they even be noticed in any graph of the long-term trends of either temperatures or atmospheric CO2 content, but it is unavoidable to notice that it not atmospheric CO2 content that drove the climate history of Earth.
A Happy and Prosperous New Year to all (and make sure to keep warm),
Walter H. Schneider,
Bruderheim, Alberta, Canada
P.S. A the time of writing this, 2017 12 31 13:40 hrs, the current temperature had warmed up considerably. It was a relatively balmy -22.3°C, the sky cloudless and a bright blue, and the wind was very slight. It was comfortable inside. Let’s hope that the price of natural gas will not rise too much (ostensibly to cure us from being addicted to keeping our homes warm and comfortable, so as to allegedly have us help to pay for mitigating measures that will keep the globe from burning us to cinders).