This article presents the impact of ocean acidification on human health, food security, and local economies. Acidification is one of the larger problems associated with greenhouse gas emissions, as oceans serve as a giant sponge for carbon dioxide. When carbon dioxide is dissolved in seawater, water chemistry changes and acidity increases. More acidic seawater can hurt ocean creatures, especially corals and shellfish, because it prevents them from properly developing their skeletons and shells. Shrinking coral reefs could dent eco-tourism revenue in some coastal areas. It also could trigger a decline in fish populations dependent on those reefs.