Final answer:
Ocean acidification, caused by increased atmospheric CO2 levels, lowers ocean pH and reduces the availability of calcium carbonate, impacting phytoplankton and other marine life, with significant ecological and economic consequences.
Step-by-step explanation:
Ocean acidification is a significant process resulting from increased carbon dioxide (CO2) emissions dissolving in ocean waters, leading to a decrease in pH and making the oceans more acidic. This process has a detrimental effect on marine organisms, especially phytoplankton, which are crucial to marine ecosystems and human food sources.
Acidified oceans mean that calcium carbonate, the substance many marine organisms use to build their shells and skeletons, becomes less available. As a result, phytoplankton and other calcifying organisms struggle to maintain their protective coatings, threatening their survival.