2.3.9—Ocean carbon exchange

CO₂ moves both ways between air and sea; the net direction depends on concentration difference, temperature and mixing.

A colder or CO₂-poor surface can absorb more, while warming or upwelling can favour outgassing. Oceans are a net sink overall, not a one-way pipe.

If atmospheric CO₂ rises while ocean uptake increases more slowly, ocean carbon still rises even though the ocean remains a net sink.

Yes. Sink means total uptake exceeds total release; it does not mean release is zero.

Do not infer net flux from one local measurement or one season; compare both directions over the stated boundary.