Rising acidity is eating away the shells of tiny snails, known as "sea butterflies", that live in the seas around Antarctica, leaving them vulnerable to predators and disease. A recent study presents rare evidence of living creatures suffering the results of ocean acidification caused by rising carbon dioxide levels from fossil fuel burning, according to the British Antarctic Survey. The world's oceans absorb more than a quarter of man-made carbon dioxide emissions, which lower the sea water pH.VIDEOGRAPHIC