Ocean fertilization, the process of adding iron or other nutrients to the ocean to cause large algal blooms, has been proposed as a possible 'geoengineering' solution to global warming because the growing algae absorb carbon dioxide as they grow. But research performed at Stanford University, the Carnegie Institution of Washington and Oregon State University, published in the Journal of Geophysical Research, now concludes that ocean fertilization is not an effective method of reducing CO2 in the atmosphere because of the seasonal dynamics of the way in which algae sink to the bottom of the ocean.
This discovery is very surprising. If, during natural plankton blooms, less carbon actually sinks to deep water than during the rest of the year, then it suggests that the Biological Pump leaks. More material is recycled in shallow water and less sinks to depth, which makes sense if you consider how this ecosystem has evolved in a way to minimize loss. Ocean fertilization schemes, which resemble an artificial summer, may not remove as much carbon dioxide from the atmosphere as has been suggested because they ignore the natural processes revealed by this research. - Dr. Michael Lutz, lead author, University of Miami's Rosenstiel School of Marine and Atmospheric Science the sale of offsets or credits from ocean fertilization on the unregulated voluntary markets is basically nothing short of fraudulent.