What is ocean acidification?
Ocean acidification, or OA, has been called an "inevitable consequence" of rising atmospheric carbon dioxide (CO2) levels. Like a dry sponge absorbing a puddle of water, seawater absorbs CO2 from the atmosphere in an effort to balance the CO2 partial pressures of air and ocean. In the past, this rebalancing occurred over thousands of years, which was slow enough that other natural processes like rock weathering could make up for this extra CO2 in seawater. Today, atmospheric CO2 levels are rising so quickly that the ocean is absorbing CO2 faster than the Earth can respond, making the world's oceans more acidic and affecting marine life.
The effects of OA are less clear
Scientists around the world are currently researching OA's specific consequences, but at this point they agree that the ocean, and especially ocean life, will be affected in many ways. Humans could feel OA's effects through changes in food supplies, natural resources, coastal protection, and economic activities. OA's full range of consequences is not yet completely known.
Find OA-related information organized by theme, under "Learn About OA" above. Topics include:
Chemistry---how does CO2 make seawater acidic?
Ocean acidification's effects could be far-reaching
Even after we know how individual marine animals will handle ocean acidification, we still must understand what will happen to marine food webs, many of which are very complex. We also need to study how changes in marine resources like fish and reefs will affect the human communities that depend on them. Ocean acidification is expected to have many indirect, and sometimes surprising, effects.