Iron limitation in vast water bodies has been linked to decreased algal productivity, despite different iron-acquiring mechanisms, and the presence of ferritin in many algal species that act as an iron internal reservoir. Therefore, iron fertilization has been proposed to increase algal biomass and photosynthesis. This, in turn, will reduce carbon dioxide in the atmosphere and increase oxygen, thereby decreasing global warming, and achieving ecological balance. In addition, algal proliferation will hopefully lead to enhancement in biodiversity, Biological pump, fish productivity and, subsequently marine food industry. Many climate geoengineering experiments in the form of ocean iron fertilization have been conducted globally in order to achieve such a purpose. However, reservations remain as the outcomes are not as promising as were previously expected. As the temporal and spatial scales of iron fertilization experiments are limited, the effects on fish productivity remain speculative. On the other hand, side effects were also recorded. The main purpose of iron fertilization, for carbon dioxide sequestration and global warming mitigation, still remains to be fully realized and verified. Several improvements and future modifications are suggested, and legal issues are discussed in this review.