Top, Antarctic ocean fertilization might cut carbon dioxide level in atmosphere. Bottom, Scanning electron micrographs of Antarctic phytoplankton that may suffer from iron deficiency. These single-cell diatoms have opal shells and spines to keep them afloat. Note very large Corethron criophilum diatoms in right micrograph.
Adding Iron to Ocean Makes WavesAs Way To Cut Greenhouse CO2: Approach would increase biological activity and thus CO2 uptake, but some contend it could impede policies to reduce CO2 emissions