SEAREG – Sea Level Change Affecting the Spatial Development in the Baltic Sea Region | Umweltbundesamt

In the project, the regional climate model RCAO comes into use (Rossby Centre Atmosphere Ocean Model - with data from HadAM3H) for the projections of future changes in the sea-level. The three-dimensional high-resolution model takes into account atmosphere, land surface, sea and ice. Four climate scenarios, based on the emission scenarios A2 and B2 of the Intergovernmental Panel on Climate Change (IPCC), are used for assessing the uncertainties in the projections of the future changes in the sea-level.

Sea-level changes between 0 and 80cms, with three different scenarios being applied per case study area: for example, the values for the case study area of Itä-Uusimaa in Finland were +70 to +75cms in the "high" scenario, +20 to +25cms in the "medium" scenario and -22 to -27cms in the "low" scenario (with the decrease due to projected land uplifts). For the case study area of Pärnu, Estonia, the values ??are +5cms (low), +52cms (medium) and +104cms (high), relative to the annual mean water level for the period 1961-1990. As far as the river run-off patterns are concerned, a general trend was assumed that envisaged a reduced run-off in the south and an increased run-off in the north. The changes to the mean annual run-off levels over all rivers lay between -1.7% and +15%. The changes to the extreme annual run-off levels lay between -30% and +40%.

The climate effect examined was flooding in low-lying areas of the Baltic Sea region through the increase in sea-level or river run-off.

The vulnerability analyses of the project not only include an assessment of the climate effects, but also an evaluation of the socio-economic and ecological adaptive capacity. The level of vulnerability is thus a result of the strength of the climate change impact in each case, plus the adaptive capacity or ability to deal with the climate effects. The results show that the vulnerability of the case study areas varies with the exposure and adaptive capacity, in each case.

The focus of the project lay in assessing the climate effects, and not in the development of adaptation measures. However, the project results will be summarized in a decision support system for the assessment of climate effects. The decision support system addresses local and regional planning authorities in the case study areas and the cooperation agencies for the spatial development of the entire Baltic Sea region. From this, adaptation strategies can be derived in a next step, e.g., for spatial planning.