The project aimed at supporting local and regional planners by transforming existing data sets from natural scientific research projects into an applicable format for spatial planning. The main objective was to create a tool for regional planners and natural scientists how to cooperate in the light of climate change in long term spatial planning. The tool was going to be designed as a decision support system that addresses the water level rise of the Baltic Sea over next 200 years and its implications for the spatial development of the Baltic Sea Region. In addition the project wanted to form a discussion platform that bring together experts on both local and regional level and from different disciplines as well as to formulate concrete recommendations to contribute to long-term decision making processes for sustainable spatial planning in the BSR.Climate change and its subsequent effects are currently discussed among the scientific community and the public. In order to better understand the possible spatial effects and impacts of sea level rise, the BSR Interreg IIIB project "Sea Level Change Affecting the Spatial Development of the Baltic Region" (SEAREG) focuses on presenting the results of climate modelling and subsequent changing shoreline calculations to end-users, such as planners and stakeholders. This process involves natural and social scientists, planning authorities and decision makers. The Baltic Sea presents a special case because of several reasons: For example, at present times the speed of sea level rise is slow and has not yet lead to major (catastrophic) impacts. Also, the southern shore of the Baltic Sea suffers from a higher sea level rise than the northern shorelines because the Fennoscandian shield is experiencing land uplift due to isostatic movements caused by the melting of glaciers that covered Fennoscandia during the last ice age. Large parts of the southern shore on the other hand face land subsidence caused by both the uplift in the north and other epirogenic crustal movements. The SEAREG project calculated the Rossby Centre Atmosphere Ocean Model (RCAO) and modelled the sea level rise in the Baltic Sea, utilizing two emission scenarios (A2 and B2) of the Intergovernmental Panel on Climate Change IPCC and downscaling these models to the BSR, including changing river runoff patterns. The net sea level rise in relation to the present shoreline is calculated by taking into account the land uplift rates, i.e. the land subsidence over a period of 100 years from present. The effects of the risen sea level are then shown on maps that contain the present land use. Furthermore, the sea level rise impacts are assessed by the Decision Support Frame (DSF) developed by the Seareg project. The DSF has four main pillars of which the climate modeling and the GIS calculations are the first step. The other tools of the DSF are: 2) A Discussion platform that brings scientists, planners, decision makers and other stakeholders together to ensure common understanding of the overall problem and the risks involved. 3) A vulnerability assessment that takes natural and socio-economic impacts as well as institutional coping capacity into consideration. 4) A knowledge base that ensures the appropriate knowledge transfers, enabling an interdisciplinary and cross-border exchange of views and experiences and an online application tool of the DSF. Achievements: The main outcome of the project is the Decision Support Frame (DSF), a tool for decision makers for assessing sea level rise impact in the Baltic Sea Region. The four sections of the tool are Discussion Platform, Knowledge Base, Modelling & GIS Applications and Vulnerability Assessment. The DSF is applicable online under www.gtk.fi/slr. The goal of the webpage is to inform the user how the DSF was developed and applied in order to facilitate an own sea level rise study in other areas of the BSR. The webpage guides the user through the four sections of the DSF. All steps that are necessary for a sea level rise impact study are described in several articles. The practical application of the DSF is shown in case study areas. In addition to the DSF tool the project produced three general overview maps on net sea level change scenarios in the BSR in the 21st century as well as regional and local sea level rise effect maps and storm surges in all case study areas. In some case study areas the results of SEAREG are taken into account in future planning strategies. A final report of the project containing the methodology of the project and the case study reports is going to be published in the special paper series of the Geological Survey of Finland. The project has initiated a follow-up project for further investigations on climate change impacts. This ASTRA project was approved in the BSR INTERREG III B 7th application round.