Expert says oceans are turning acidic

The world's oceans are becoming more acidic, which poses a threat to sea life and Earth's fragile food chain, a climate expert said Thursday.

Oceans have already absorbed a third of the world's emissions of carbon dioxide, one of the heat-trapping gases blamed for global warming, leading to acidification that prevents vital sea life from forming properly.

"The oceans are rapidly changing," said professor Stefan Rahmstorf on the sidelines of a U.N. conference on climate change that has drawn delegates from more than 100 countries to Kenya. "Ocean acidification is a major threat to marine organisms."