Climate-change effects on the Baltic Sea ecosystem: A model study

The expected climate change is of growing interest on the regional scale, including the Baltic Sea. However, simulations with global models do not sufficiently resolve the regional impact. Consequently, dynamic downscaling methods are being used to convert the results obtained in global models to the regional scale.In the present study, two regional data sets for greenhouse gas emission scenarios, A1B and B1, for the period 1960 to 2100, were used to force transient simulations with a 3D ecosystem model of the Baltic Sea. The results showed that the expected warming of the Baltic Sea is 1–4 K, with a decrease in salinity and a much reduced sea–ice cover in winter. In addition, the season favoring cyanobacterial blooms is prolonged, with the spring bloom in the Northern Baltic Sea beginning earlier in the season, while the oxygen conditions in deep water are expected to improve slightly.