Sydney Morning Herald: RISING carbon dioxide emissions are turning the oceans acidic in an irreversible process that threatens coral reefs and food security, the world’s scientific academies have warned. Seventy academies, including the Australian Academy of Science, urged governments meeting in Bonn for climate talks to tackle the issue in the new United Nations treaty on climate change to be agreed in Copenhagen in December. In the past 200 years the world’s oceans have absorbed about a quarter of …