Professor Peter Wadhams is head of Cambridge Polar Consultants Ltd., Cambridge, and Emeritus Professor of Ocean Physics at the Department of Applied Mathematics and Theoretical Physics, Cambridge University. He was formerly director of the Scott Polar Research Institute. He is a highly experienced sea-ice field researcher, with more than 55 missions to the Arctic and Antarctic, including six submarine voyages to the North Pole to map the changing ice thickness as well as work from icebreakers, aircraft and ice camps.