Second Chance for OIF?

Following the LOHAFEX misadventure and a string of studies casting doubt on its efficacy (see IOC Releases Ocean Fertilization Policy Guide, 1/26/11), ocean iron fertilization (OIF) has recently lost favor as a potential CO2 removal technique.  A new study published in Nature, however, suggests that OIF may have a climate remediation role to play after all.  In 2004, the European Iron Fertilization Experiment (EIFEX), led by Victor Smetacek of the Alfred Wegener Institute for Polar and Marine Research (who also led the LOHAFEX expedition), conducted tests using iron sulphate in the Southern Ocean.  Results from those tests indicate that the remains of at least half of the ensuing diatom phytoplankton bloom sank to a depth of at least 1,000 meters, thereby confirming the sequestration hypothesis central to OIF.  (It is unclear why it took more than eight years to publish these results.)

But environmental concerns persist regarding the effects of ocean fertilization on marine food webs and ocean chemistry.  And doubts remain about the scale of carbon reductions OIF can deliver.  "It's too little to be the solution, but it's too much to ignore," says Smetacek.