1. Met Office Hadley Centre, Exeter. EX1 3PB, UK
2. Canadian Centre for Climate Modelling and Analysis, University of Victoria, PO Box 1700, STN CSC, Victoria, BC, V8W 3V6, Canada
3. School of GeoSciences, University of Edinburgh, Edinbrugh EH9 3JW, UK
4. School of Earth Sciences, University of Melbourne, VIC 3010, Australia
5. Climate Systems Analysis Group, University of Cape Town, Private Bag X3, Rondebosch, 7701, South Africa
6. Climate Research Division, Environment Canada, 4905 Dufferin St., Toronto, Ont. M3H 5T4, Canada