Human response to climate change - The Global Climate System: Patterns, Processes, and Teleconnections - page 255

8.2.2 Migration
Reasons suggested for the beginnings of the Viking migrations are varied, and
probably all have some relevance. McGovern ( 1991 ) and Vail ( 1998 ) suggest
internal political conflict, population pressure, improved technological devel-
opments, scarcity of land, food and resources, and an improving climate, which
encouraged decisions to venture further from home. The Vikings were hardy
seafarers, who built excellent ships for long-distance ocean voyaging. Their
navigation skills were the best available during this period of history. They
seemed to have a spirit of adventure and discovery which allowed exploration
of the unknown distant horizon. Figure 8.2 shows the geographical extent of
movement between 800 and 1100 in the North Atlantic region.
By 874 the Vikings had settled Iceland, and in 985, Erik ''The Red''
Thorvaldsson formed a settlement on the southern tip of Greenland, termed
the ''eastern'' settlement. Soon thereafter, a second, ''western'' settlement was
formed, further north along the west coast (see Figure 8.2 ). By 1100, the
population of both settlements had grown to between 4000 and 6000, and the
colonies had an active trade with the Norwegian homeland. After about 1450,
however, all contact with the Greenland colonies ceased. The major question is,
why?; and then how important was climate change? In order to answer this
question, an understanding of the Norwegian way of life and structure of society
is needed, and how this society interacted with the environment.
8.2.3 Settlement and lifestyle in Greenland
The warmer, drier conditions of the MWP were ideal for sea transport. Analysis
from the marine sediment cores indicates that this period was dominated by the
warmer waters of the Atlantic Ocean, creating open water, limited sea ice, and
few icebergs (Ogilvie et al. 2000 ; Jensen et al. 2004 ). The intensity of circulation
was relatively low and dominated by zonal flow, creating a more stable climate
regime. Polar-equatorial temperature gradients were weak, and the circumpolar
vortex remained close to the Arctic (Lamb 1977 ). While there were periods of
intermittent cyclonic activity and cooler conditions, overall there was little to
hinder long-range migration across the North Atlantic.
The Vikings settled in the more protected areas on the inland edges of the
fjords on the southwestern side of Greenland. Here, they found a landscape very
much like home. These areas encouraged their agriculture-based lifestyle. The
colonists imported and maintained cattle, sheep, goats, and pigs. The environ-
ment was marginal, even in good years, but initially there was enough vegetative
support for survival and growth from year to year. McGovern and Pendikaris
( 2000 ) emphasize that the Greenland environment is not linked to the North
Atlantic Current, as is that of Norway. As a result, even during the MWP period,
summers were shorter, winters colder, and the vegetation much more fragile.