Future of the Baltic Sea

The Baltic Sea is a small and shallow brackish water basin, or rather a series of basins connected to the main Atlantic Ocean via the Danish Straits. The variable coastal geomorphology and the wide archipelago areas give the Baltic Sea its characteristic appearance (Figure 10.1). Mean salinity is about 7‰—one-fifth of the salinity of normal ocean water—and haline stratification is strong. This elongated sea lies between maritime temperate and continental sub-Arctic climate zones. In winter it is partly ice-covered and during the most severe winters it is completely frozen over. The Baltic Sea is young, has undergone several brackish and freshwater phases since the Weichselian glaciation, and from about 2,000 years ago salinity has been close to the present level. Land uplift is slowly changing the Baltic Sea landscape. Here it is possible to observe how land rises from the sea and how life on land gradually takes over.