New acid fears for Southern Ocean

Australian researchers have found that the “tipping point” for Southern Ocean acidification – the point at which the shells of some marine animals will start to dissolve -- is much closer than anticipated, Science Online reports. Their research, based on seasonal changes, indicates a speed-up in the acidification process by 30 years.


Scientists from the University of New South Wales (UNSW) and the Commonwealth Scientific and Industrial Research Organisation (CSIRO) studied seasonal changes in pH and the concentration of the chemical element carbonate. Their results, published in the Proceedings of the National Academy of Science, show that these changes will amplify the effects of human-induced carbon dioxide (CO2) emissions on ocean acidity, speeding up the acidification process by 30 years.


 "The ocean is a fantastic sponge for CO2,’’ said Ben McNeil, a senior research fellow at the UNSW’s Climate Change Research Centre. But, he added, as CO2 — a greenhouse gas linked to climate change — dissolves in the water, it reduces the pH of the ocean; it then becomes more acidic.


When the acidity reaches a certain level, the shells of pteropods (a type of plankton) and other creatures with shells made up largely of calcium carbonate will begin to dissolve. "After that point, we can’t go back unless we suck the CO2 out of the atmosphere," said McNeil.


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