Site chosen to drill 'oldest ice'

European scientists are going to a high spot in East Antarctica to retrieve a 1.5-million-year-long climate record. They will drill a continuous ice core at a place dubbed Little Dome C. The core should help researchers better understand the shift in the frequency of ice ages that occurred just over 800,000 years ago. Dr Rob Mulvaney, from the British Antarctic Survey, spoke with our science correspondent Jonathan Amos.