Reply #4: It doesn't work

[jpak]

Six mesoscale (open ocean) iron fertilization experiments have been conduct over the last decade.

None have produced a significant enhanced flux of particulate carbon from the surface ocean to the deep ocean (i.e., they did not enhance the "biological pump" and did not sequester atmospheric CO2).

The growth of heterotrophic bacteria is also stimulated by iron additions (and by the increased availability of organic carbon in the Fe-stimulated phytoplankton bloom). They (along with protists and zooplankton) rapidly respire any newly formed organic carbon back to CO2.

Finally, there are real concerns about the Fe eutrophication of large areas of the ocean. The American Society of Limnology and Oceanography has lobbied against these schemes...