Oceans Acidifying Ten Times Faster Today Than at any Time in the Last 65 Million Years

By February 16, 2010Oceans

Oceans are acidifying ten times faster today than during the mass ocean extinction that happened 55 million years ago. A study by two University of Bristol scientists has bad enough news for the present, but as we continue this hyper-acidification event, these scientists are concerned that the coming extinction event will be greater than the one at 55 million years ago. This discovery was made from the study of a sediment core with a bright red swath running through the middle of it.  What happened 55 million years ago was that there was a massive release of greenhouse gases, likely from frozen methane on the ocean floor.  The resulting acidification of the oceans created an oxidizing chemistry that precipitated a lot of iron out of the ocean waters. This iron precipitate, or rust, caused the sediment to turn red, and there was a great extinction event.

The distinction between 55 million years ago and 65 million years ago is that 65 million years ago the giant asteroid hit the Yucatan peninsula. the extinction event that occurred then was greater than the one at 55 million years ago and consequently ocean acidification was greater. It is unclear from this study whether or not we are changing faster than 65 million years ago, but it is not unclear that we are changing 10 times faster than 55 million years ago.

Ridgewell and Schmidt, Past constraints on the vulnerability of marine calcifiers to massive carbon dioxide release, Nature Geoscience, February 2010.