The concept of ‘iron fertilisation’ is based on the assumption that a lack of iron limits the amount of phytoplankton and thus marine life in large parts of the ocean. Phytoplankton sequesters CO2 therefore, so the argument goes, more iron will mean more phytoplankton and thus more CO2 removed from the atmosphere. The recent study in Nature Communications provides just one reason why such an argument is far from accurate: Additional iron could cause diatom blooms that could end up starving affected ocean waters of iron, thus over time reducing the amount of CO2 that would be trapped by the oceans. In short, dumping iron filements could end up increasing, not reducing CO2 in the atmosphere.
Another study reveals dangers of geoengineering through ‘iron fertilisation’ | Hands Off Mother Earth