Environmental Engineering Reference
In-Depth Information
the course today. In the worst case scenario, the entire mass of Arctic ice will melt
away. The melting of the ice mass in Greenland alone could cause the sea level to
rise 7 m over the next several centuries. Figure 2.10 shows what the effect would
be on Germany.
North Sea
Baltic Sea
100
km
Figure 2.10
Threatened areas in Northern Germany if the sea level were to rise by 7 m in
the long term.
Graphics: Geuder, DLR.
2.3.1 Will It be Bitterly Cold in Europe?
The American climate researcher Wallace Broecker wrote an article in 1987 titled
'Unpleasant Surprises in the Greenhouse'. The article, which caused quite a sensa-
tion at the time, warned about potential surprises from the greenhouse effect that
could affect us very seriously: global warming could, paradoxically, turn Europe
bitterly cold.
While studying the history of the climate from ice drill cores in the Greenland ice
mass, climate researchers determined that the world's present climate is quite stable
- but it has only been this way for about 10 000 years. The average yearly tempera-
ture on earth has never deviated more than one degree from the long-time average
during this time. However, if one were to look back another 2000 years, one would
fi nd that major jumps occurred in temperatures even during short periods of only a
few years. Until now it was always thought that temperature changes as well as the
transition from ice ages to warming periods only happened very slowly. However,
this opinion had to be corrected as a result of the drill core studies.
Today it is assumed that the climate tends to behave erratically on its own, thus
making it a powerfully non-linear system (Rahmstorf, 1999). Linear systems are
easy to understand. The stronger that the attraction is, the clearer the reaction is.
For example, a water tap approximates a linear system. With two turns the amount
of water that fl ows is double the amount of one turn. Climate is a complex non-linear
system. It has the tendency of self-regulation and suddenly jumps into a different
