Planetary Boundaries

Ocean acidification

Around a quarter of the carbon dioxide humanity emits is ultimately dissolved in the oceans. Here it forms carbonic acid, decreasing the pH of the surface water. This increased acidity reduces the amount of available carbonate ions, an essential ‘building block’ used by e.g. corals, shellfish and many plankton species to grow and survive. Compared to pre-industrial times, surface ocean acidity has increased by 30 percent.

Caption: Modeled aragonite saturation 1850-1860 and 2090-2100 in high CO2 emission scenario (RCP 8.5)
Credit: Model data provided by Tatiana Ilyina from Ocean Biogeochemistry Group, Max Planck Institute for Meteorology, visualizations from Michael Böttinger, German Climate Computing Center (DKRZ).
Map Credit: Félix Pharand-Deschênes, Globaïa.