Abstract

Imagine you were a detective following a carbon dioxide (CO₂) molecule, for instance, one of the millions you just exhaled. Where does it go? Up away into the atmosphere? Is it used by a plant to build a green leaf? Guess what: a lot of the carbon we (and our cars and factories) ‘exhale’ actually ends up in the ocean. So get ready to get wet! Once in the ocean, the CO₂ molecule might hang around in the surface for a short while before jumping back to the air above, or it might travel deep down to the bottom of the ocean where it stays trapped for hundreds of years.

We created a computer model (a type of ‘virtual ocean’) to act like such a detective, tracking CO₂ in the ocean to discover where it goes and how long it will stay. We found that carbon cycles very differently in different latitudes of the ocean. This was not known before and provides important clues about how the ocean will respond to, and contribute to, global climate change.