Contra Costa Times: If man-made carbon dioxide emissions continue at their present pace, they will alter ocean chemistry enough to threaten the survival of corals and other marine organisms, scientists reported Saturday at the annual meeting of the American Association for the Advancement of Science in Boston. By burning fossil fuels, humans are on track to add 5 trillion metric tons of carbon dioxide to the atmosphere over the next 400 years. The last time so much carbon dioxide flooded the atmosphere …