Ocean acidification results from decreases in the pH of the Earth’s oceans caused by the natural uptake of carbon dioxide. In a nutshell, here’s how it works: The pH scale is a measure of acidity that ranges from 1 to 14, where 7 is considered neutral. Any pH reading that is higher is basic, anything lower is acidic. When carbon dioxide dissolves in water, it creates carbonic acid. In essence, the more carbon dioxide humans pump into the atmosphere, the more it is absorbed by the oceans, resulting in an increase in the production of carbonic acid, which in turn increases ocean acidity. Since the industrial revolution, there has been a 30 percent increase in ocean acidity. NOAA PMEL Carbon Program, A Primer on pH.