and be washed away by the waves?
The coastal marshes and meadows, low fields and swampy forests to be flooded by sea water and salted, periodically or permanently? Hardly!

Climate change and its consequences
But all serious forecasts for ongoing climatic changes predict a sea level in the open oceans of between 30 and 100 cm higher than now by the end of the 21st century. If we imagine a 50 cm higher water level in the oceans, and so also in the Baltic Sea, by 2050, the Baltic Sea will contain 200 billion m3 of water more than today.
What happens to the easterly coasts after a long-lasting severe westerly storm with so much extra water in the basin? The wind will push up the water to the East, causing unprecedented high tides, maybe 3 or 4 m above usual sea level along the Baltic Coasts and the Finnish Gulf. And on the return of the backed-up water to the west, the low coasts of Poland, Germany and Denmark will be flooded worse than in the year 1872, so far the worst case in historical times.

The Baltic - a historical perspective
The Baltic Sea is young, in geological terms. 14.000 years ago when the last ice age came to an end, the sea bed was still filled with ice, namely the enormous glaciers of Upper Scandinavia. More recently, 13.000 years ago, the sea bed turned into a fresh water lake, the Baltic Icelake. This lake had contact to the salty ocean about 11.000 years ago through the central lowland of Sweden. This salty sea has been named the Yoldia Sea.
About 9.000 years ago the sea bed again became a fresh water lake, The Ancylus Lake, due to the isostatic rising of the land masses of Scandinavia. About 8.500 years ago the still melting ice cap had again raised the water level of the oceans and opened for salt water intrusion through the Danish straits. At that stage the sea was named the Litorina Sea.

Challenges of the future
What do these data tell us? That there is no single natural sea level or simple natural environment for the Baltic Sea. The coastal areas are constantly changing. We may either try to keep our habitats dry and secure through artificial methods (dams, dikes, canal systems equipped with pump stations etc.) or we may move to new settlements and urbanizations. A new Learner's Guide!?
Before this happens there will be a need to know how to deal with the changing nature and living conditions to be able to make informed environmental and geographical decisions. Based on the discussions between the editors of the BSP Learner's Guide no.8, our suggestion is to create a new Learner's Guide no.9 or 10 on this subject. The suggestion will be passed on to the new international coordinator of the Baltic Sea Project for 2009-2012, Latvia's national coordinator Velga Kakse, and is expected to be negotiated by the national coordinators as an option for the LG9 or perhaps LG10.

Note: Due to isostatic movements since the ice age all Nordic land north of a line from Blekinge- Riga - St Petersburg rises from 1-8 mm pr. year (while land to the south sinks), but the level of the sea is predicted to rise between 4 and 11 mm per year until 2100.