Acknowledgements
We thank T. Bösch, B. Bracher, U. Gutmann, C. de Guttry, M. Escher, J.
Kast, A. Knutti, C. Küng, E. Longange, E. Pereira-Alvarez, L. Wilkins,
and the members of the Pachtverein Rotache for assistance and/or
discussion. The study was funded by the Swiss National Science
Foundation (31003A_159579 & 31003A_182265).