We hear a lot about what carbon emissions do to the atmosphere; what's less well known is that carbon pollution affects the planet's water as well. The specific effect of carbon emissions on the seas is an increase in acidity; scientists say that acidity of the oceans has increased 30% over the lest 100 years, a spike that may not have a historical precedent.
Bärbel Hönisch, a paleoceanographer at Columbia University, led a study that looked at carbon dioxide levels and ocean acidification over the last 300 million years, and found just one other time when oceans acidified at the rate we're seeing now. “We know that life during past ocean acidification events was not wiped out—new species evolved to replace those that died off," Hönisch said in a press release. "But if industrial carbon emissions continue at the current pace, we may lose organisms we care about—coral reefs, oysters, salmon.”
Ocean acidification is such a concern that the National Resources Defense Council has set up a web page and produced a documentary to educate the public on "the hidden side of the world’s carbon crisis." The page at nrdc.org/oceans/acidification/ explains the situation and the consequences, including this unpleasant scenario: "The polar regions will be the first to experience changes. Projections show that the Southern Ocean around Antarctica will actually become corrosive by 2050."
Below is the NRDC's eye-opening documentary, "Acid Test:"