Collaborating for our climate
How carbon emissions acidify our ocean Vladimir Tarakanov
Ocean acidification is a consequence of increasing carbon dioxide (CO2) emissions, a greenhouse gas driving climate change. The ocean absorbs around one third of all human induced CO2, causing a change in seawater chemistry called ocean acidification. It presents a serious threat to marine life, ecosystem health and people whose livelihoods depend on the ocean.
CO
CO2
50%
2
CO2
CO2 CO2
increase in CO2 emissions in 200 years due to human action.
26%
of all human induced CO2 is absorbed by the ocean.
CO2 O
When CO2 dissolves in seawater, it forms carbonic acid (H2CO3), releasing hydrogen ions (H+) and increasing ocean acidity. Acidity plays a key role in many biological mechanisms, including calcification.
C
O
O
H H2O H
Calcium carbonate (CaCO3) is crucial for organisms which need calcium to develop, build and maintain their shells and skeletons, such as certain types of plankton, oysters, crabs, sea urchins, shrimps and lobsters. Ocean acidification makes it harder for them to maintain these calcified structures. This can cause disruptions within food chains.
Lobsters Plankton
Crabs
Coral reefs
Shrimps
22 | IAEA Bulletin, December 2022
Ocean acidification can also impact the ability of coral reefs to recover from warming and other stressors, by making it harder for corals to build their calcium-based skeletons.
Sea urchins
Oysters