François Matthes introduced The Little Ice Age into the mainstream narrative in 1939 and within a decade the storyline of The Little Ice Age was firmly established as a period of glacier advances between 1600 and 1850 AD.
The Little Ice Age (LIA) was a period of cooling that occurred after the Medieval Warm Period (Medieval Climate Optimum).
While it was not a true ice age, the term was introduced into the scientific literature by François E. Matthes in 1939.
There was a re-advance of the glaciers in the western Alps about A.D. 1300 followed by a retreat to a minimum extent in the fifteenth century.
Near the end of the sixteenth century the glaciers advanced rapidly and about 1605 they overran settlements which had been occupied since the beginning of history.
About the same time the glaciers advanced in the Eastern Alps, Iceland, where they almost reached the moraines of the Late Glacial stages, and probably in other parts of the world; and the period from 1600 to 1850 has been termed the “Little Ice-Age.”
There were minor maxima of glaciation about 1820 and 1850; since then the glaciers and ice-sheets have been in rapid retreat in all parts of the world.
Climate Through The Ages – C E P Brooks
Ernest Benn Limited – 1950
The narrative of The Little Ice Age [and natural climate change] is well illustrated [and documented] by the freezing over of the River Thames in London.
From 1400 to the removal of the now-replaced medieval London Bridge in 1835, there were 24 winters in which the Thames was recorded to have frozen over at London; if “more or less frozen over” years (in parentheses) are included, the number is 26: 1408, 1435, 1506, 1514, 1537, 1565, 1595, 1608, 1621, 1635, 1649, 1655, 1663, 1666, 1677, 1684, 1695, 1709, 1716, 1740, (1768), 1776, (1785), 1788, 1795, and 1814.
So, of the 24, the by-century totals are: 15th 2, 16th 5, 17th 10, 18th 6.
The narrative includes three extreme cases [923, 1410 and 1683/4] where the River Thames was frozen over for extended periods of 2 or 3 months.
During the Great Frost of 1683–84, the worst frost recorded in England, the Thames was completely frozen for two months, with the ice reaching a thickness of 11 inches (28 cm) in London.
Solid ice was reported extending for miles off the coasts of the southern North Sea (England, France and the Low Countries), causing severe problems for shipping and preventing the use of many harbours.
Near Manchester, the ground was frozen to 27 inches; in Somerset, to more than four feet.
One of the earliest accounts of the Thames freezing comes from AD 250, when it was frozen solid for nine weeks.
As long ago as 923 the river was open to wheeled traffic for trade and the transport of goods for 13 weeks; in 1410, it lasted for 14 weeks.
However, this mainstream narrative sits very uncomfortably with the modern generation of Climate Alarmists because it documents the cyclical nature of Earth’s climate.
This mainstream storyline also sits very uncomfortably with the modern generation of Glaciologists because [according to their GISP 2 chronology] during The Little Ice Age temperatures oscillated within a very confined range of only 0.54° degrees Centigrade.
This confined range of 0.54° degrees Centigrade makes it difficult to understand the River Thames extreme freezing events of 1410 and 1683/4 whilst the 923 freezing event appears totally inexplicable.
The Younger Dryas Cold Interval as Viewed from Central Greenland
Richard B Alley
Quaternary Science Reviews – Volume 19 Issues 1-5 – 1 January 2000 – Pages 213-226
However, when the GISP 2 Ice Core chronology is re-calibrated using the Old Japanese Cedar chronology [established by Leona Libby in 1976] then The Little Ice Age suddenly becomes comprehensible with a temperature range of 2.66° degrees Centigrade.
Furthermore, the extreme River Thames freezing events [of 923, 1410 and 1683/4] also become comprehensible because they occurred very close to the cyclical minima.
See: The Medieval Warm Period and The Heinsohn Horizon
Clearly, mainstream Glaciologists are walking on very thin ice.
UPDATE: 3 December 2015
Moving further back in time, towards the transition into the Little Ice Age, the nitrate record develops two very curious habits.
Firstly, the annual nitrate signal occasionally sprouts a shoulder in the spring and/or autumn e.g. 1842, 1852, 1861, 1863.
Secondly, the annual nitrate traces with shoulders have a tendency to become fat fingers that spreads the annual signal over two years in the chronology e.g. 1841-42, 1854-55, 1856-57, 1864-65, 1866-67.
See: The Frozen Fat Finger Fudge
UPDATE 11 Dec 2015
The historical records of meteor observations from Korea might explain the Little Ice Age because of their variable density banding [over the centuries] and their seasonal variations which markedly peak during the last quarter of the year.
We have compiled and analyzed historical Korean meteor and meteor shower records in three Korean official history books, Samguksagi which covers the three Kingdoms period (57 B.C — A.D. 935), Goryeosa of Goryeo dynasty (A.D. 918 — 1392), and Joseonwangjosillok of Joseon dynasty (A.D. 1392 — 1910).
Analysis of historical meteor and meteor shower records: Korea, China, and Japan
Hong-Jin Yang, Changbom Park, Myeong-Gu Park
Icarus 175 (2005) 215-225
UPDATE 8 MAY 2016
The Old Japanese Cedar D/H Ratio trace includes a signature pattern [roughly between 1650 and 1750] that has been associated with the catastrophic division of a comet.