Covering about 70 percent of the Earth’s surface, the world’s oceans
have a two-way relationship with weather and climate. The oceans
influence the weather on local to global scales, while changes in
climate can fundamentally alter many properties of the oceans.
Although the oceans help reduce climate change by storing large
amounts of carbon dioxide, increasing levels of dissolved carbon are
changing the chemistry of seawater and making it more acidic. Increased
ocean acidity makes it more difficult for certain organisms, such as
corals and shellfish, to build their skeletons and shells. These
effects, in turn, could substantially alter the biodiversity and
productivity of ocean ecosystems.