much
cooler conditions over much of the world between the late seventeenth
and mid-nineteenth centuries. For more than two hundred years, mountain glaciers advanced far beyond their modern limits in the Alps, Iceland
and Scandinavia, Alaska, China, the southern Andes and New Zealand. Mountain snow lines descended at least 100 meters below modern levels
(compared with about 350 meters during the height of the late Ice Age
18,000 years ago). Then the glaciers began retreating in the mid- to late
nineteenth century as the world warmed up significantly, the warming
accelerated in part by the carbon dioxides pumped into the atmosphere
by large-scale forest clearance and the burgeoning Industrial Revolution-the first anthropogenic global warming.
Climate change varied not only from year to year but from place to
place. The coldest decades in northern Europe did not necessarily coincide with those in, say, Russia or the American West. For example, eastern North America had its coldest weather of the Little Ice Age in the
nineteenth century, but the western United States was warmer than in
the twentieth. In Asia, serious economic disruption, far more threatening than any contemporary disorders in Europe, occurred throughout
much of the continent during the seventeenth century. From the 1630s,
China's Ming empire faced widespread drought. The government's draconian response caused widespread revolt, and Manchu attacks from the
north increased in intensity. By the 1640s, even the fertile Yangtze River
Valley of the south suffered from serious drought, then catastrophic
floods, epidemics, and famine. Millions of people died from hunger and
the internecine wars that resulted in the fall of the Ming dynasty to the
Manchus in 1644. Hunger and malnutrition brought catastrophic epidemics that killed thousands of people throughout Japan in the early
1640s. The same severe weather conditions affected the fertile rice lands
of southern Korea. Again, epidemics killed hundreds of thousands.
Only a few short cool cycles, like the two unusually cold decades between 1590 and 1610, appear to have been synchronous on the hemispheric and global scale.
Unfortunately, scientifically recorded temperature and rainfall observations do not extend back far into history-a mere two hundred years or
less in Europe and parts of eastern North America. While these incomplete readings take us back through recent warming into the coldest part of the Little Ice Age, they tell us nothing of the unpredictable climatic
change that descended on northern Europe after 1300.
Some methods used to study the Little Ice Age
Reconstructing earlier climatic records requires meticulous detective
work, considerable ingenuity, and, increasingly, the use of statistical
methods. At best, they provide but general impressions, for, in the absence of instrument readings, statements like "the worst winter ever
recorded" mean little except in the context of the writer's lifetime and local memory. Climatic historians and meteorologists have spent many
years trying to extrapolate annual temperature and rainfall figures from
the observations of country clergymen and scientifically inclined
landowners from many parts of Europe. Extreme storms offer unusual
opportunities for climatic reconstruction. On February 27, 1791, Parson
Woodforde at Weston Longville, near Norwich in eastern England,
recorded : "A very cold, wet windy day almost as bad as any day this winter." Synoptic weather charts reconstructed from observations like Woodforde's reveal a depression that brought fierce northeasterly winds of between 70 and 75 knots along the eastern England coast for three days.
The gale brought the tides on the Thames "to such an amazing height
that in the neighborhood of Whitehall most of the cellars were underwater. The parade in St. James's Park was overflowed." Thames-side corn
fields suffered at least .£20,000 worth of damage.2
Fluctuating grain prices