Ocean Acidification Simulator

What Is Ocean Acidification?

The ocean absorbs about 30% of human CO2 emissions, making it Earth's largest carbon sink. When CO2 dissolves in seawater it forms carbonic acid (H2CO3), which releases hydrogen ions (H+) that lower the pH. Since the Industrial Revolution, ocean pH has dropped from 8.2 to 8.1 — a 26% increase in acidity. This threatens coral reefs, shellfish, and entire marine food chains that depend on calcium carbonate.

Why does this matter? Coral reefs support 25% of all marine species. When pH drops and aragonite saturation falls below 1.0, shell-building organisms can no longer form protective structures — their shells literally dissolve. At current emission rates, ocean pH could reach 7.8 by 2100, a level not seen in 14 million years. This simulator lets you explore the chemistry driving these changes.

📖 Deep Dive

Analogy 1

Imagine dropping fizzy tablets into a fish tank. The water starts bubbling (CO2 dissolving) and slowly turns slightly acidic. The fish and snails don't notice at first, but eventually the snail's shell starts getting thin and crumbly — that's exactly what's happening to ocean creatures as we pump CO2 into the atmosphere.

Analogy 2

Think of the ocean as a giant antacid tablet. It's been absorbing the 'stomach acid' (CO2) we've been dumping into the air. But just like antacid tablets run out, the ocean's buffering capacity is being overwhelmed. Once the tablet dissolves completely, the acid builds up fast — and the 'patient' (marine life) is in serious trouble.

🎯 Simulator Tips

Beginner

Start with the default 10 GtC/yr emission rate and watch CO2 molecules fall from atmosphere into the ocean

Intermediate

Increase Wind Speed to see faster gas exchange — more CO2 gets pushed into the water at higher winds

Expert

Lower Total Alkalinity to simulate waters with less natural buffering (like coastal areas near river mouths)

📚 Glossary

Ocean Acidification

Decrease in ocean pH caused by absorption of atmospheric CO2, threatening marine ecosystems.

pH Scale

Measure of acidity from 0-14. Ocean pH has dropped from ~8.2 to ~8.1 since pre-industrial times (30% more acidic).

Carbonate Chemistry

CO2 + H2O → H2CO3 → HCO3⁻ + H⁺ → CO3²⁻ + 2H⁺. Increasing CO2 shifts equilibrium, reducing carbonate ions.

Calcification

Process by which marine organisms (corals, shellfish) build shells/skeletons from calcium carbonate.

Aragonite Saturation

Measure of calcium carbonate availability for shell-building organisms. Below Ω=1, shells dissolve.

Coral Bleaching

Stress response where corals expel symbiotic algae, turning white. Acidification compounds thermal bleaching.

Pteropod

Small swimming sea snail whose thin aragonite shell dissolves in acidified water — a key indicator species.

Carbon Sink

The ocean absorbs ~25% of human CO2 emissions, making it the largest carbon sink but driving acidification.

Buffer Capacity

Ocean's ability to resist pH changes, which is being overwhelmed by the rate of CO2 absorption.

Blue Carbon

Carbon captured by coastal ecosystems (mangroves, seagrasses, salt marshes) that also buffer local acidification.

🏆 Key Figures

Ken Caldeira (2003)

Stanford/Carnegie researcher who coined the term 'ocean acidification' and modeled its global impacts

Joanie Kleypas (1999)

NCAR scientist who first warned that ocean chemistry changes would impact coral reef calcification

Richard Feely (2004)

NOAA oceanographer who documented acidification spreading along the US Pacific coast

Jean-Pierre Gattuso (2010)

French researcher who led major European ocean acidification research programs (EPOCA, MedSeA)

Ove Hoegh-Guldberg (1999)

University of Queensland marine scientist connecting acidification and warming to coral reef futures

🎓 Learning Resources

Anthropogenic ocean acidification over the twenty-first century [paper]
Multi-model projection of global ocean acidification impacts (Nature, 2005)
Ocean Acidification: Present Conditions and Future Changes [paper]
Comprehensive review of ocean chemistry changes and biological impacts (Annual Review of Marine Science, 2009)
NOAA Ocean Acidification Program [article]
US federal program monitoring and researching ocean acidification
Ocean Acidification International Coordination Centre [article]
IAEA coordination center for global ocean acidification research

💬 Message to Learners

Explore the fascinating world of ocean acidification. Every discovery starts with curiosity!