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Ocean-Atmosphere Exchange

How oceans absorb and release CO₂, and why this matters for climate change

The Ocean: Earth's Largest Carbon Sink

The ocean is the largest carbon sink on Earth, absorbing about 25% of human CO₂ emissions. This happens through both physical and biological processes. However, climate change is making oceans less effective at absorbing CO₂, creating a dangerous feedback loop.

Physical Absorption

Chemical dissolution of CO₂ in seawater

  • • Governed by Henry's Law
  • • Cold water absorbs more CO₂
  • • Creates carbonic acid
  • • Forms bicarbonate ions

Biological Pump

Marine organisms capture and store carbon

  • • Phytoplankton photosynthesis
  • • Carbon export to deep ocean
  • • Marine food webs
  • • Shell formation (calcium carbonate)

Interactive Ocean CO₂ Calculator

280ppm
15°C
8.2pH

Ocean CO₂ Absorption Rate

90
Gigatons of Carbon per Year
vs Pre-industrial capacity: 0 Gt C/year
Capacity utilization:100%
Ocean acidification impact:-0%
Absorption Capacity100%
Henry's Law

CO₂ dissolves better in cold water. Warmer oceans release CO₂ back to the atmosphere, creating a feedback loop.

Ocean Acidification

Excess CO₂ makes oceans more acidic, harming marine life and reducing the ocean's ability to absorb more CO₂.

The Feedback Loop

Warming oceans release stored CO₂, reducing their absorption capacity. This creates a feedback loop where climate change makes the problem worse by weakening the ocean's ability to help solve it.

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