TG Daily: Seeding the oceans with iron to combat global warming might be ineffective as well as risky, it seems. It’s long been suggested that adding iron particles to sea water would increase the amount of phytoplankton – free-floating, single-celled plants that form the base of the marine food chain. As phytoplankton take up carbon dioxide to grow, geoengineers have suggested that seeding key regions of the ocean with iron could be one way of offsetting increasing atmospheric CO2 …