"Today, researchers at the University of Bristol are publishing a study comparing what happened in the oceans 55 million years ago to what the oceans are experiencing today.

Their research supports what other researchers have long suspected: The acidification of the ocean today is bigger and faster than anything geologists can find in the fossil record over the past 65 million years. Indeed, its speed and strength — earth scientists Andy Ridgwell estimate that current ocean acidification is taking place at ten times the rate that preceded the mass extinction 55 million years ago — may spell doom for many marine species, particularly ones that live in the deep ocean.

"This is an almost unprecedented geological event," says Ridgwell."

Carl Zimmer reports for Yale Environment 360 February 15, 2010. [2]