The world’s oceans have become 30% more acidic since the Industrial Revolution began more than two centuries ago. In that time, the seas have absorbed 500 billion tons of carbon dioxide that has built up in the atmosphere, primarily from the burning of fossil fuels.

By taking in that amount — more than one-quarter of the greenhouse gas that has accumulated in the atmosphere — the oceans have buffered the full effects of climate change, scientists say: Temperatures have not risen as much as they would have otherwise, glaciers haven’t melted as fast. Yet the benefits are coming at a cost to marine life, especially oysters, clams and corals that rely on the minerals in alkaline seawater to build their protective shells and exoskeletons. The ill effects of the changing chemistry only add to the oceans’ problems, which include warming temperatures and expanding low-oxygen “dead zones.”  http://www.latimes.com/news/local/la-me-acidic-oceans-20121007,0,7494056.story