Atmospheric carbon dioxide (CO2) levels are rising as a result of human activities, such as fossil fuel burning, and are increasing the acidity of seawater. This process is known as ocean acidification. Historically, the ocean has absorbed approximately 30% of all CO2 released into the atmosphere by humans since the start of the industrial revolution, resulting in a 26% increase in the acidity of the ocean (average global decrease in ocean pH of about 0.1 unit).
Ocean acidification make it more difficult for the numerous organisms that fix calcium carbonate in their skeletons and shells to do so, and can also impact metabolic and reproductive processes in many marine species. By impacting marine ecosystems at multiple levels, it has significant potential to affect food security and livelihoods that depend upon healthy marine ecosystems. The economic impact of ocean acidification could be substantial.
Reducing CO2 emissions is the only way to minimize long-term, large-scale risks from ocean acidification (IGBP, IOC, SCOR, 2013, p. 1).