pCO₂ measures how much CO₂ is dissolved in seawater. Coastal systems can either emit or absorb CO₂ in order to maintain equilibrium between the pCO₂ of the ocean and the atmosphere.
Visualization of ocean-atmosphere CO₂ exchange from 1861 to 2100 shows where the ocean absorbs CO₂ and where the ocean emits CO₂ (NOAA Science on a Sphere).
