Environment News Service: Seventeen eminent marine scientists warn that world leaders face a race against time in preparing coral reefs, and the coastal communities dependent upon them for the "inevitable impact" of rising levels of carbon dioxide in the Earth’s atmosphere. Their new study shows that levels of carbon dioxide could become unsustainable for coral reefs within 50 years. The warning comes in a new study published in the journal "Science" on December 14. "It’s vital that the public …