Australian Broadcasting Corporation: A six week survey of marine life on the Antarctic sea floor will help predict the rate of climate change. Global warming is pushing up carbon dioxide levels in the ocean, which causes a slight rise in the acidity level of sea water. Martin Riddle is the voyage leader of the polar ship the Aurora Australis. He says as sea water becomes more acidic, it becomes more difficult for marine organisms to make and maintain their sea shells. "Calcium carbonate is more …