Times (UK): Pen Hadow, the explorer, is to embark on a 700-mile expedition to the North Pole to measure the thickness of the shrinking Arctic icecap. The information will be used to refine computer models of the impact of climate change, helping to show whether their figures are accurate. Some of the models have suggested the poles are warming much faster than the rest of the world and that the Arctic could be ice-free in summer within a decade. Hadow, 46, is leading a team of polar …