Results from simulations with the coarse-resolution version of MPI-ESM performed by the RETRO team at DKRZ. The left side shows a normal (prograde) rotating earth. The right side shows a backwards (retrograde) rotating earth. The simulations are forced with pre-industrial boundary conditions. For the full description see the Earth System Dynamics manuscript "The climate of a retrograde rotating earth". In the retrograde simulation (right), the Mediterranean Sea freshens strongly and develops an estuarine circulation. Similar effects can be seen in the Arabian Sea. This is due to increased precipitation over northern Africa and Arabia. The North Atlantic current can also be seen in the Sea Surface Salinity. It reverses its direction and flows much more southward. Strong increases in salinity can be observed in Eastern Asia.