Argument: Iron-fertilized algae blooms may release some greenhouse gases
"A scientific critique of oceanic iron fertilization as a climate change mitigation strategy". Greenpeace Research Laboratories. September 2007 - Dimethylsulphoniopropionate (DMSP) is produced by certain classes of phytoplankton. It degrades to dimethylsulfide (DMS), a climate-active gas that contributes to reducing the radiative flux to the Earth’s surface. DMS increased in some but not all mesoscale iron enrichment studies. Its effect would be to reduce atmospheric temperature but the scale of any change following commercial iron fertilization is hard to predict.