Ocean acidification is caused by the equilibration of the atmosphere with the ocean, a process that occurs worldwide. Carbon dioxide in the atmosphere equilibrates and dissolves into the ocean. During this reaction, carbon dioxide reacts with water to form carbonic acid. The carbonic acid then dissociates into bicarbonate ions and hydrogen ions. This reaction causes the pH of the water to lower, effectively acidifying it. Ocean acidification is occurring in every ocean across the world. Since the beginning of the Industrial Revolution, the World's oceans have absorbed approximately 525 billion tons of carbon dioxide. During this time, world ocean pH has collectively decreased from 8.2 to 8.1, with climatic modeling predicting a further decrease of pH by 0.3 units by 2100. However, the Arctic Ocean has been affected more due to the cold water temperatures and increased solubility of gases as water temperature decreases. The cold Arctic water is able to absorb higher amounts of carbon dioxide compared to the warmer Pacific and Atlantic Oceans.
The chemical changes caused by the acidification of the Arctic Ocean are having negative ecological and socioeconomic repercussions. With the changes in the chemistry of their environment, arctic organisms are challenged with new stressors. These stressors can have damaging effects on these organisms, with some being affected more than others. Calcifying organisms specifically appear to be the most impacted by this changing water composition, as they rely on carbonate availability to survive. Dissolved carbonate concentrations decrease with increasing carbon dioxide and lowered pH in the water.
Ecological food webs are also altered by the acidification. Acidification lowers the ability of many fish to grow, which not only impacts food webs but humans that rely on these fisheries as well. Economic effects are resulting from shifting food webs that decrease popular fish populations. These fish populations provide jobs to people who work in the fisheries industry. As is apparent, ocean acidification lacks any positive benefits, and as a result has been placed high on a priority list within the United States and other organizations such as the Scientific Committee on Oceanic Research, UNESCO's Intergovernmental Oceanographic Commission, the Ocean Carbon and Biogeochemistry Program, the Integrated Marine Biogeochemistry and Ecosystem Research Project, and the Consortium for Ocean Leadership.