From The Daily Mail UK: http://www.dailymail.co.uk/sciencetech/article-2090253/Oceans-acidified-200-years-did-previous-21-000-years-claims-new-climate-change-research.html
23rd January 2012
Man-made carbon emissions have acidified the world's oceans far beyond their natural levels, new research suggests.
In some regions, acidity levels rose faster in the last two centuries than it did in the previous 21,000 years, a study from the University of Hawaii has shown.
Ocean acidity makes it harder for organisms such as molluscs and coral to construct the protective layers they need to survive.
Scientists looked at changes in the saturation level of aragonite, a form of calcium carbonate used to measure ocean acidification.
As seawater acidity rises, the saturation level of aragonite falls.