A study conducted by scientists from Cardiff University, showed that while maintaining the level of carbon dioxide emissions, acidification of the ocean will reach unprecedented levels. Ocean acidification occurs when the CO2 from the atmosphere is absorbed by seawater, resulting in more acidic water with low pH. About one third of the CO2released by burning coal, oil and gas, is dissolved in the oceans. Since the beginning of the industrial age the ocean has absorbed about 525 billion tons of CO2, equivalent to about 22 million tons a day.
Quick release CO2 into the oceans seriously threatens marine life as shells of some animals dissolve in acidic sea water.
In a new study published in the journal Earth and Planetary Science Letters, the researchers decided to reconstruct the levels of ocean acidity and atmospheric CO2 over the last 22 million years. In this they were helped by tiny marine animals that once lived near the ocean surface. It turned out that if we continue to throw out CO2 in the same pace as now, the atmospheric composition of this gas will be about 930 ppm in 2100 (today’s 400 parts per million).
The pH of the oceans will be less than 7.8 in 2100 (now is 8.1). This is important because the pH scale is logarithmic, and a drop of even 0.1 pH means a 25 percent increase in acidity. This level of atmospheric CO2 and acidity not seen since the climatic optimum of the middle Miocene, 14 million years ago when global temperature was higher than today by 3 degrees.
Professor Carrie Lear, co-author of the study, said: “the Current pH is probably lower than at any time over the last 2 million years. Understanding what this means for marine ecosystems requires a long-term laboratory and field studies, as well as additional observations of the fossil record”.