By Devin Powell
Iron deliberately dumped into a patch of ocean has triggered a chain of events that pulls carbon dioxide out of the atmosphere and keeps it out. An explosion of microscopic life fertilized by the metal sank to the depths of the ocean after soaking up the greenhouse gas.
Geoengineering advocates who think iron could be useful for combating climate change will probably be heartened by the new finding, reported in the July 19 Nature. Carbon stuck on the seafloor tends to stay there a long time.
“Every one atom of iron removed 13,000 atoms of carbon” from the air, says Victor Smetacek, a biological oceanographer at the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, Germany. That carbon probably settled on the seafloor, he says, “like dust collecting in the corner of the room.”