Salt is essential to human life. Most people don't know, however, that salt -- in a form nearly the same as the simple table variety -- is just as essential to Earth's ocean, serving as a critical driver of key ocean processes. While ancient Greek soothsayers believed they could foretell the future by reading the patterns in sprinkled salt, today's scientists have learned that they can indeed harness this invaluable mineral to foresee the future -- of Earth's climate....