"Oceans' Acidic Shift May Be Fastest In 300 Million Years"
"The world's oceans are turning acidic at what could be the fastest pace of any time in the past 300 million years, even more rapidly than during a monster emission of planet-warming carbon 56 million years ago, scientists said on Thursday.
Looking back at this bygone warm period in Earth's history could offer help in forecasting the impact of human-spurred climate change, researchers said.