Algae blooms are just one way to produce biofuels that won't strain cash crop production with corn to make ethanol. Iron fertilization helps algae grow faster to make more of it for biofuels production. The iron-heavy water can be cleaned up with filtration and any leftover iron can be re-used again to feed more algae blooms as the process keeps going.
Yes, iron fertilization of algae blooms should be part of plans to combat global warming. Increasing the algae population is not only good for the food chain, but it is also very helpful for combating global warming, because it has a positive effect on the atmosphere while having a positive effect on the ecosystem.