Ocean acidification: the “evil twin of global warming”. Anthony Watts copies-and-pastes a report by marine biologists from James Cook University’s ARC Centre of Excellence for Coral Reef Studies about ocean acidification due to CO2 emissions and its impact on marine life.
“Ocean conditions are already more extreme than those experienced by marine organisms and ecosystems for millions of years,” the researchers say in the latest issue of the journal Trends in Ecology and Evolution (TREE).
“This emphasises the urgent need to adopt policies that drastically reduce CO2 emissions.”
This is extrapolation to predict biological impact, not climate research. This needs proper supporting evidence before we consider it an issue or discard it (as Anthony’s commenters are enthusiastically doing).
Wott's Up With That? 
One of the fascinating things about the denialist culture, to me, is the way they elevate assertion to the level of proof, if the assertion is agreeable to what they want to believe. The comments are full of people asserting that the ocean’s pH has not changed, that the scientists are “lying” and so on. And then there are the “science” comments:
“How can a very weak acid like carbonic acid (H2CO3) react with calcium carbonate (CaCO3), the stuff which corals etc. are mostly made off? It is just not chemically possible.”
That’s it — just a flat assertion based on ignorance of basic chemistry. For a denialist, if you know the chemical formula of carbonic acid, that’s it — you’re an expert. Proof enough. You’re ready to start teaching working scientists about their profession.
OK, one more, then I gotta go to work:
“What these clowns ignore is that only an outside source of acidity, such as hydrochloric acid, can affect the extended equilibrium from CO2 to carbonic acid to carbonate to calcium carbonate.”
Yep, because it’s not like more of a reagent drives the reaction in the opposite direction. That Le Chatelier, what a stupid “politician.”