This just reported on mongabay.com:
"The Southern Ocean may be 30 years closer to a tipping point for ocean acidification than previously believed, putting sea life at risk, according to research published in this week’s Proceedings of the National Academy of Science.
Analyzing seasonal changes in pH and the concentration of carbonate in the Southern Ocean, scientists from the University of New South Wales (UNSW) and CSIRO found that seasonal swings will amplify the effects of carbon dioxide emissions on ocean acidity, speeding up ocean acidification by 30 years relative to previous estimates."