Antarctic sea ice `shrinking'

briefing: Environment

Whaling records suggest that the floating sea ice surrounding the Antarctic shrunk by a quarter between the mid 1950s and the early 1970s, says an Australian scientist writing in Nature.

During those two decades the edge of the ice retreated southwards by nearly 3 degrees of latitude - or hundreds of miles. William de la Mare bases his finding on an analysis of the whale catching records dating from 1931 to 1987 and kept by fleets from several nations. It is thought to be more likely to be a natural phenomenon rather than an early sign of man made climate change.