One of the main reasons of glaciation as well as lifting of land massifs is the varying distance from the earth to the sun equaling on average about 149 675 000 km. The earth rotates on the trajectory very close to the ellipse. Earth orbit changes with the eccentricity reaching its maximum value of 21 million km. This way the amount of heat coming from the sun is varying although some other factors also affect the formation of glaciers. The inclination of the earth's rotation axis to the orbit is also important and it changes from 22 6' to 24 50' during 40400 years. At present this inclination is 23 27'. Precession movement and higher mentioned phenomena are the main factors affecting the changes in climate on the earth. The earth shell undergoes continuous deformations. This phenomenon was first observed by Pratt and Airy. They claimed that equilibrium state in the earth shell may be unsettled. Lifting of lands of Scandinavia, Hudson Bay, Greenland, Antarctic, Alaska, Alps, etc. results in depressions in other sites of the earth, like Netherlands, north-west coast of Germany, Bavaria, England, Normandy, Brittany, North Sea, etc. In order to prove that the salinity in the Baltic Sea is decreasing one should move back in the history of earth geology, concerning specifically the Scandinavia sheath. The vertical/upright tectonic movements of the Scandinavia sheath are the main reason of the decrease in salinity of the Baltic Sea. In the 18th century A. Celsius (1743) observed the lifting of the Baltic coast and he calculated that its magnitude was about 1 meter per 100 years. The highest lifting has been observed on the west coast of Bothnia Bay (about 1 centimeter per year). This phenomenon has lasted for thousands years now. Centuries ago the localities lying on the Scandinavia coast are now away from the sea side, situated also quite high over the sea level. The lifting of Scandinavia causes shallowing of the Baltic Sea in the region of the Danish Straits as well as lower inflow of oceanic waters, which results in lowering of salinity of the Baltic Sea. The Scandinavia sheath inclines, which causes elevation of sea level in the southern part of the Baltic Sea, abation of the sea level in the north (Bothnia Bay). As a result of this geological phenomenon Polish coast is ingulfed by the water of the Baltic Sea (ruins of Trzęsacz church). It is fact that salinity of the Baltic Sea water is systematically decreasing. Assuming, that mean standard composition of oceanic waters, taking into account salinity [NaCl] is 24,53 g/dm3 [7,8], conclusion is, that the Baltic Sea becomes freshwater sea in higher and higher degree. The authors' studies of the salinity of the Baltic Sea water sampled on the beach of Mielno on the edge of 2002/2003 and in March 2003 indicate that its value is much less than that reported during last two decades of the 20th century for the Pomerania Bay. Taking into account a greater distance from the Danish Straits to Mielno it is still a very low value proving of the continuous desalination of the Baltic Sea.