What is ocean acidification? What is causing it?
The ocean absorbs approximately 1/3rd of the CO2 emitted to the atmosphere from the burning of fossil fuels (1). However, this valuable service comes at a steep ecological cost – the acidification of the ocean. As CO2 dissolves in seawater, the pH of the water decreases, which is called “acidification”. Since the beginning of the industrial revolution, ocean pH has dropped globally by approximately 0.1 pH units. Past and present variability of marine pH. Future predictions for years shown on the right-hand side of the figure are model-derived values based on IPCC mean scenarios. From Pearson and Palmer (2), adapted by Turley et al. (3) and from the Eur-Oceans Fact Sheet No. 7, “Ocean Acidification – the other half of the CO2 problem”, May 2007 (4). While these pH levels are not alarming in themselves, the rate of change is cause for concern. To the best of our knowledge, the ocean has never experienced such a rapid acidification. By the end of this century, if concentrations of CO2 con
