What Is Ocean Acidification?
Ocean acidification refers to a reduction in the pH of the ocean over an extended period of time, caused primarily by uptake of carbon dioxide (CO2) from the atmosphere.
Increased carbon dioxide (CO2 ) in the atmosphere due to fossil fuel use, causes changes in ocean chemistry, leading to a decrease in the pH of seawater.Potential adverse impacts include disruption of calcium carbonate shell and skeleton formation. Molluscs, our cold water coral reefs and the diversity these habitats support, some phytoplankton and many other organisms are likely to be at risk.
At least one-quarter of the carbon dioxide (CO2) released by burning coal, oil and gas doesn't stay in the air, but instead dissolves into the ocean. Since the beginning of the industrial era, the ocean has absorbed some 525 billion tons of CO2 from the atmosphere, presently around 22 million tons per day.
If the amount of carbon dioxide in the atmosphere stabilises, eventually buffering (or neutralising) will occur and pH will return to normal. This is why there are periods in the past with much higher levels of carbon dioxide but no evidence of ocean acidification: the rate of carbon dioxide increase was slower, so the ocean had time to buffer and adapt. But this time, pH is dropping too quickly.Buffering will take thousands of years, which is way too long a period of time for the ocean organisms affected now and in the near future.