A mathematical Remark on the Prediction of the Sea-Level-Rise using global Temperature Averages

Large populations live close to coastlines, foresting the rise or fall of the sea level is of greatest importance for the protection of coastal cities. After an analytic discussion of the semiempirical Rahmstorf method and the improved Dual method for the prediction of the sea-level from global temperature averages, an simple mathematical example is given, which shows that the use of global mean averages is unsuitable to predict the changes of the sea-level rise at shores. The mathematical example is based on a simple model equation, which bears fundamental properties of more realistic mathematical models.