Ocean acidification is a threat to marine organisms, ecosystems, services, and resources. It has potentially considerable ecological and socio-economic consequences, adding to multiple stressors on ocean ecosystems, including other climate-driven changes (e.g. ocean warming, sea level rise, and deoxygenation) and local pressures from pollution, overexploitation, and habitat destruction.
One fourth of the carbon dioxide released into the atmosphere from anthropogenic activities is absorbed by the ocean.1 However, this vital service is not without consequence: when carbon dioxide enters the ocean it changes seawater chemistry, resulting in increased seawater acidity. That change severely affects biological processes, with potentially profound socio-economic impacts.
The long-term control of ocean acidification depends on the reduction of emissions of carbon dioxide into the atmosphere. In this regard, ratification and effective implementation of the Paris Agreement will be instrumental. Even if carbon dioxide emissions are reduced immediately, there will be a lag time before the acidity levels of oceans normalize, particularly since more acidic surface ocean waters mix with deep water over a cycle that lasts hundreds of years. Therefore, it is critical to build the resilience of ocean ecosystems and of the people that depend on them for their livelihoods to the effects of ocean acidification and climate change.