Sources of uncertainty in estuarine climate impact modeling

Early planning decisions which take into account the impact of climate change have to be made under uncertainty. Thus, the explicit investigation of the level of uncertainty in climate impact research is becoming increasingly important. This article focusses on uncertainties in a climate impact assessment for the Weser estuary, Germany. The basis is a mean sea level rise scenario which is studied with a 3D baroclinic impact model. Uncertainties due to model parameters, structural limitations of the model, boundary conditions, the scenario uncertainty and variability in the impact model are discussed. The uncertainties due to natural variability and roughness are investigated by means of changes in high and low water levels. The results show that the uncertainty related to the impact model and the chosen model parameters in this study is small compared to the uncertainty induced by the natural variability and the boundary conditions.