Human response to climate change - The Global Climate System: Patterns, Processes, and Teleconnections - page 267

between 1645 and 1715, when sunspots and the aurora borealis were almost
absent, indicated a very quiet solar period, correlating with much colder tem-
peratures. Volcanism occurred in several decades during the seventeenth century
(see Table 8.3 ), increasing particulate concentrations in the upper troposphere
and lower stratosphere, and reducing incoming shortwave radiation. Despite the
cold, the advance of European glaciers was somewhat limited by the lack of
winter precipitation. Diaz et al.( 2001 ) suggest that ENSO and its teleconnec-
tions (see Section 2.8 ) were active from about 1680 onward.
Impacts on European society
The seventeenth century was one of great agricultural stress. According to Fagan
( 2000 ), at the beginning of the century, over 80% of the population of Europe
was still operating at subsistence level. Despite a number of inventions and
improvements in agriculture since the 1300s, the only places where major
innovations were applied were Denmark, Holland, and Britain. The wide
range of reports, publications, and economic summaries, which were then
newly available in printed form, had only minimal use. As a result, similar
to the fourteenth century, the poor tenants were at the mercy of short-term
climate fluctuations. Most of Europe and the Mediterranean went into economic
decline.
Aside from the cold, agricultural stresses occurred for a number of reasons
(Diaz et al. 2001 ). Growing seasons were shorter by at least a month, growing
altitudes were reduced by at least 200 meters, snowlines were lower, and
summer wetness prevented crop harvests. In southeast Scotland, marginal
lands were rapidly abandoned, as average temperatures fell by 2 to 2.5 8Cin
the Highlands. In France, average September temperatures in bad years fell by
2to38C, delaying harvests by up to 26 days (Lamb 1977 ). Grapes did not ripen
well, and the wine quality was poor. Wheat prices soared to four times the level
during the worst period in the thirteenth century. In the first half of the 1600s,
purchasing power for builders in England fell to the lowest level in three
centuries (Burroughs 1997 ), then began rising slowly. Not all of these income
variations can be blamed on climate change. Inflation, economics, and political
decision making (or lack of it) were also major factors. In the severest years of
the 1690s, famine struck in France (10% of the population was lost in 1693) and
in Finland (one-third of the population died in 1697).
England, however, was much better adapted to the climate variations than
were most of the European countries, especially France. Here, major changes
were made that removed the dependences of subsistence agriculture. Fagan
( 2000 ) and Michaelowa ( 2001 ) describe several of these innovations, which
began in Denmark and Holland several decades earlier. There was a deliberate
attempt to grow grass and other forage for animal feed. Crops were rotated, to
include the planting of legumes to enrich the soil. New crops, turnips to enhance
the winter survival of cattle and sheep, and flax and hops for industrial use, were