John Turner is a research scientist at the British Antarctic Survey in Cambridge, UK where he leads a project investigating recent Antarctic climate change and how it may change over the next century. He has had a long involvement with the Scientific Committee on Antarctic Research (SCAR): he was the Chief Officer of the Physical Sciences Standing Scientific Group from 2002 to 2006 and chaired the steering committee of the SCAR programme on Antarctica and the Global Climate System from 2005 to 2008. He is the co-author of Antarctic Meteorology and Climatology (1997) and Polar Lows: Mesoscale Weather Systems in the Polar Regions (2003), both of which are published by Cambridge University Press. He was awarded the International Journal of Climatology Prize of the Royal Meteorological Society in 2005. Gareth Marshall is a climatologist at the British Antarctic Survey where he is the climate programme coordinator. He has worked at BAS since 1995 after completing his PhD at the University of Cambridge. His research has included field work in both polar regions and he has contributed to more than 50 scientific papers. Recently, he was a corresponding author on the Intergovernmental Panel on Climate Change Fourth Assessment Report. He is also a member of the World Climate Research Programme CLIVAR Southern Ocean panel, which addresses climate variability and predictability in this region.