The ASTRA project uses the climate models CSIRO2, HadCM3, PCM, and CLIMBER together with the IPCC emission scenarios (SRES) A1B, A2 and B1. Data for creating maps is made available by the Data Distribution Centre (DDC) of the IPCC (2007). The scientific studies have shown a general trend towards rising average temperatures and changes in precipitation patterns for the Baltic Sea region.

In the Baltic Sea region there is a trend towards a rise in the mean temperature and a change in the precipitation patterns. The Baltic Sea region therefore faces different regional and seasonal challenges, such as the level of coastal protection that will be needed in the future, and how to deal with severe flooding events or water shortages.

The climate effects considered include, for example, droughts and forest fires as a result of extreme temperatures, storm surges and floods resulting from winter storms and changes in the precipitation patterns in river basins, changes in surface run-offs and nutrient loads. This is associated with effects on primary production in the inner and outer coastal waters. Depending on the river system and the characteristics of the transformer function of the estuary or the internal coastal waters, this can have different effects on the coastal zone, such as for example an increase in the occurrences of blue-green algae bloom along the the coast of the southern Baltic Sea during the summer months, due to changing nutrient loads. Overall, a cross-sectoral analysis of the climate effects will be carried out.

The analysis of current and future vulnerability is the basis for the development of adequate climate change adaptation strategies. It is important to get an overview of the most vulnerable sectors and regions. The concept of vulnerability used in the project does not only include the level of exposure to natural hazards, but also the sensitivity of society towards them, which is, for example, defined by insufficient precautions or an inadequate capacity to react. Also, some groups of society are more vulnerable than others (e.g. due to age disabilities or health problems).

The sensitivity of society and the natural systems is part of the vulnerability concept. The waterbodies examined have a relatively low resilience.

An adaptive capacity and an institutional readiness to deal with the climate change are part of the vulnerability concept.

The climate effects are in direct conflict with economic interests in the coastal zone, so that there is an urgent need for action and investigation here.

Background:
The approaches to climate protection and adaptation to climate effects should be regarded as complementary. The more successfully both paths are followed, the lower the risks of the climate change will be for society. Adapting to the effects of the climate change has only recently found its way onto the political agenda, and a survey has shown that there only few national initiatives or sectoral programmes exist. According to the latest expectations regarding the ongoing change in the climate, adaptation should become an integral part of procedures for ensuring sustainable future development.

The recommendations for decision-makers include:

1. ⁠Adaptation⁠ is a cross-cutting issue that must be addressed by society as a whole. The public sector plays a central role in the complex process of adaptation to the climate change.

2. Integration of adaptation: Adapting to the effects of the climate change should not be construed as a separate unit. Rather, various policy fields should be examined to determine that they are "climate change proof" (e.g. zoning plans or cost-benefit analyses for investments).

3. Adaptation strategies must be developed gradually. Analyses of current and future vulnerability, as well as existing approaches, are the basis for the development of adequate climate change adaptation strategies. For these strategies, different options need to be considered to find the best solution. Evaluation and monitoring should be provided to verify the effectiveness of the measures and to allow follow-up control.

4. Adaptation and climate protection go hand in hand: Decision-makers should aim to take both ways into account in different policy areas.

5. The public sector must be involved at all levels: EU, Baltic Sea region, national and district level, as well as at regional and local level.

Adaptation measures are considered in connection with the planning time horizons and economic activities in different sectors. From this, it is clear that the lifespan of infrastructures and business plans is several decades, so that planning processes for adaptation must therefore start as early as possible.

Climate change effects in coastal ecosystems (e.g. toxic blue-green algae blooms due to changes in nutrient loads) lead to conflicts with tourism, which is an important economic sector in the coastal regions. Sustainable development requires an early consideration of the potential climate change effects (e.g. sea-level rise) in the planning processes, to avoid high costs in the future.