are the oceans a net source or sink of CO2?
One interesting question about the marine carbon cycle concerned whether or not the oceans are a source of CO2, adding it to the atmosphere, or a sink, removing it from the atmosphere. Recent research indicates that the oceans are a net sink, though some regions (generally colder and more turbulent) absorb CO2, and other regions (warmer and less turbulent) release CO2. The North Atlantic Ocean accounts for about 60% of the CO2 absorption by the global ocean. (CO2 is less soluble in warm water than in cold water.) For a variety of reasons, global warming could convert the oceans from a sink to a source, which is an example of bad positive feedback.
