Ocean Acidification Simulator
See how dissolved CO₂ lowers ocean pH and threatens shell-forming animals.
About the Ocean Acidification Simulator
Free ocean acidification simulation. Raise atmospheric CO₂, see the carbonic acid chemistry, the drop in ocean pH and carbonate ions, and the effect on shells and corals. Built for real-world chemistry, the ocean acidification simulator runs instantly in your browser: change a setting or drag an object and the result updates at once, so you learn by trying things out rather than only reading about them.
See how dissolved CO₂ lowers ocean pH and threatens shell-forming animals. Use it to explore real-world chemistry ideas at your own pace, then check what you found against the key ideas further down this page.
How to use the Ocean Acidification Simulator
- Use the controls to change Atmospheric CO₂. The simulation reacts instantly.
- Pick an option such as Pre-industrial, Today, 2×, End of century (high) to switch modes or load an example.
- Where you see a glowing handle, object, weight or atom, drag it with your mouse or finger. Everything responds in real time.
- Watch the readouts and graphs update as you experiment, and compare what you see with the key ideas below.
Things to try
- Compare 280 and 800 ppm.
- Watch the shells.
- Read Ω.
- Find where growth stops.
Key ideas you can learn
- CO₂ dissolves in seawater to form carbonic acid, releasing H⁺.
- More H⁺ means lower pH and fewer carbonate ions.
- Shell and coral builders need carbonate ions to make calcium carbonate.
Where this is used in the real world
Ocean acidification threatens coral reefs, shellfish farming and fisheries that feed millions of people.
Who is this simulation for?
Students, teachers and citizens interested in environmental science, climate and water, who want to see the chemistry behind the headlines.
For teachers: project it on the board, let students predict what will happen, then run it together. For students: change one thing at a time and write down what changes.
Frequently asked questions
Why does CO₂ make the ocean more acidic?
CO₂ + H₂O forms carbonic acid, which releases hydrogen ions and lowers the pH.
How does this harm shell-building animals?
The extra hydrogen ions react with carbonate ions, leaving fewer for animals to build shells, which can even dissolve.
Is the Ocean Acidification Simulator free to use?
Yes. It is completely free, with no signup, no download and no ads inside the simulation. It runs in your web browser.
Does the Ocean Acidification Simulator work on a phone or tablet?
Yes. It uses touch as well as the mouse, so you can drag objects with your finger. A larger screen makes the controls easier to see.