The supply of dissolved iron to oceans around continental shelves has been found to be more variable by region than previously believed – with implications for future climate prediction.

Iron is key to the removal of carbon dioxide from the Earth’s atmosphere as it promotes the growth of microscopic marine plants (phytoplankton), which mop up the greenhouse gas and lock it away in the ocean.

A new study, led by researchers based at the National Oceanography Centre Southampton, has found that the amount of dissolved iron released into the ocean from continental margins displays variability not currently captured by ocean-climate prediction models. This could alter predictions of future climate change because iron, a key micronutrient, plays an important role in the global carbon cycle.