2.2.4 Impacts of carbon dioxide on ocean life

Another impact of increasing greenhouse gas emissions on our oceans is that excess carbon dioxide in our atmosphere dissolves in seawater, making it more acidic. Indeed, more than one third of the carbon dioxide in our atmosphere is absorbed by seawater. Increases in acidity affect marine life, from shellfish like clams and oysters to whole coral reef communities, by removing minerals that they require in order to grow their shells and skeletons. This has knock-on effects on the survival and abundance of a wide variety of species.

The oceans are now 30% more acidic relative to the beginning of the industrial era, making them more acidic than any time in the last 65 million years. Today, ocean acidification is occurring approximately ten times faster than anything experienced during the last 300 million years - jeopardising the ability of ocean systems to adapt.