Comment Re:It's more than just global warming gas (Score 1) 572
There's a very good, highly readable article about ocean acidification from 2007 in Science. If you have access to a subscription, you can see the article here.
If you don't have access to a subscription, you can find lots of research about ocean acidification in the freely-accessible pubmed central database. this article looks like it gives a good overview of ocean acidification.
The short answer is that the pH of the ocean has changed measurably since the industrial revolution, and the current pH is far outside the values that have been historically observed. Even based on conservative estimates of future CO2 emissions, it looks like hydrogen ion concentrations in the ocean (remember pH is a log scale) will more than double by 2100. Ocean acidification has a number of impacts on the marine environment, but most notably it increases dissolution of the CaCO3 deposits that make up coral reefs and decreases the rate at which new shells and reefs can be formed.