Argument: Algae bloom solutions require fertilizing too much ocean area
"A scientific critique of oceanic iron fertilization as a climate change mitigation strategy". Greenpeace Research Laboratories. September 2007 - Modelling studies have predicted that iron fertilization is likely to be highly inefficient. Estimates showed that it would require an impossibly large area to be fertilized each year (equivalent to about twice the Earth’s surface!) to have any significant impact as a carbon sequestration technology. Verifying the quantity of carbon sequestered from iron fertilization is also likely to be difficult (if not impossible) because of the large spatial and temporal scales involved.