We would like to thank Dr. Matthias Münnich for his valuable comments on an earlier version of this manuscript, Dr. Moritz Flügel for providing the Hybrid Coupled Model, Dr. Ralf Giering for providing the optimization software, and Prof. Dr. Klaus Hasselmann for many fruitful discussions. This work was supported by the European Union under Grant ENV4-CT95-0109. The computations were performed at the Deutsches Klimarechenzentrum (DKRZ).
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