Another study reveals dangers of geoengineering through ‘iron fertilization’
Yet another study questions shows how dangerously simplistic the assumption that dumping iron filements into oceans will sequester carbon is. This latest study, by Ellery D. Ingall et al, published in Nature Communications, looks at a particular type of phytoplankton, a diatom which soaks up iron from oceans and stores it in its skeleton and thus, when the phytoplankton dies, on the ocean floor.
The concept of ‘iron fertilization’ 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.