Ocean Acidification
CO₂ + H₂O → H₂CO₃ → H⁺ + HCO₃⁻ — the ocean is becoming more acidic
Carbonate Chemistry
CO₂ dissolution
CO₂(atm) ⇌ CO₂(aq)
Carbonic acid formation
CO₂(aq) + H₂O ⇌ H₂CO₃
First dissociation (fast)
H₂CO₃ ⇌ H⁺ + HCO₃⁻
Second dissociation
HCO₃⁻ ⇌ H⁺ + CO₃²⁻
Ocean pH
—
pH change since 1850
—
Aragonite saturation Ω
—
Calcite saturation Ω
—
pH scale
0 Acid
7 Neutral
14 Base
Controls & Organisms
Atmospheric CO₂ (ppm)
423
Ocean temperature (°C)
20
🦪
Oyster
🐚
Pteropod
🪸
Coral
🦀
Crab
🐟
Fish
Pre-industrial pH was 8.21. Current pH ~8.10 (0.11 units = 28% more acidic). At pH below aragonite saturation horizon, pteropod shells dissolve.