1. Divisions of Geological and Planetary Sciences and Engineering and Applied Science; California Institute of Technology; Pasadena; California; USA
2. CSIRO Atmospheric Research; Aspendale; Victoria; Australia
3. Department of Botany; University of Florida; Gainesville; Florida; USA
4. Climate System Modeling Group, Lawrence Livermore National Laboratory; University of California; Livermore; California; USA
5. Center for Atmospheric Sciences; University of California Berkeley; Berkeley; California; USA