Then, starting in about 1310
and continuing for five and a half centuries, the climate became more unpredictable, cooler, occasionally stormy, and subject to sporadic extremes-the Little Ice Age.
"Little Ice Age" is one of those scientific labels that came into use almost by default. A celebrated glacial geologist named Francois Matthes first used the phrase in 1939. In a survey on behalf of a Committee on
Glaciers of the American Geophysical Union, he wrote : "We are living in
an epoch of renewed but moderate glaciation-a `little ice age' that already
has lasted about 4,000 years."' Matthes used the term in a very informal
way, did not even capitalize the words and had no intention of separating
the colder centuries of recent times from a much longer cooler and wetter
period that began in about 2000 B.C., known to European climatologists
as the Sub-Atlantic. He was absolutely correct. 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 Little Ice Age winters lives on in artistic masterpieces. Peter Breughel the Elder's Hunters in the Snow, painted during
the first great winter of the Little Ice Age in 1565, shows three hunters
and their dogs setting out from a snowbound village, while the villagers
skate on nearby ponds. Memories of this bitter winter lingered in
Breughel's mind, as we see in his 1567 painting of the three kings visiting the infant Jesus. Snow is falling. The monarchs and their entourage
trudge through the blizzard amidst a frozen landscape. In December
1676, artist Abraham Hondius painted hunters chasing a fox on the
frozen Thames in London. Only eight years later, a large fair complete
with merchants' booths, sleds, even ice boats, flourished at the same icebound location for weeks. Such carnivals were a regular London phenomenon until the mid-nineteenth century. But there was much more
to the Little Ice Age than freezing cold, and it was framed by two distinctly warmer periods.
A modern European transported to the height of the Little Ice Age
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 seesaw that swung constantly backwards 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.
Scientists disagree profoundly on the dates when the Little Ice Age
first began, when it ended, and on what precise climatic phenomena are to be associated with it. Many authorities place the beginning around
1300, the end around 1850. This long chronology makes sense, for we
now know that the first glacial advances began around Greenland in the
early thirteenth century, while countries to the south were still basking
in warm summers and settled weather. The heavy rains and great
famines in 1315-16 marked the beginning of centuries of unpredictability throughout Europe. Britain and the Continent suffered
through greater storminess and more frequent shifts from extreme cold
to much warmer conditions. But we still do not know to what extent
these early fluctuations were purely local and connected with constantly
changing pressure gradients in the North Atlantic, rather than part of a
global climatic shift.
Northern Hemisphere temperature trends based on ice-core and tree-ring
records, also instrument readings after c. 1750. This is a generalized compilation
obtained from several statistically derived curves.
Other authorities restrict the term "Little Ice Age" to a period of