Background and Theoretical Foundations: Since the 1980s, ocean fertilization has attracted much attention among various methods of climate engineering. Some foreign researchers have examined ocean fertilization from environmental, legal, and commercial perspectives. since 2007, as the London Convention / Protocol regulates ocean fertilization, and then with the adoption of the 2013 Amendment to the London Protocol on this technology, Legal research in this area has been Increased. Although the ocean fertilization process has not yet been widely operated and remains at a limited experimental level, but legal research has been written specifically to examine the conventional position of this technology. The present article aims to explore ocean fertilization technology as one of the methods to deal with global warming, to examine its potential environmental benefits and challenges, and to examine the approach of the principles of international environmental law to this challenging technology.
Methodology: Data collection of this research is library method and the procedure is descriptive analytical; Accordingly, after describing the process of ocean fertilization, it is most important environmental consequences have been studied, and finally, how international environmental law has dealt with this emerging technology has been analysed and Finally, we analyze this emerging technology in the context of the principles of international environmental law.
Findings: By strengthening the biological pump of the ocean, ocean fertilization as one of the new ways to deal with climate change, seeks to increase the absorption of carbon dioxide by the ocean and ultimately deal with global warming. Countering global warming, increasing of the fish resources, promote marine scientific research and the carbon trade have been cited as potential benefits of ocean fertilization, but in addition to these benefits, the possibility of environmental problems such as ocean acidification, toxic algal blooms and anoxia is not out of the question. The transboundary environmental effects of ocean fertilization — whether in the internal waters It is a testament to the need to intervene of international environmental law to regulate this technology and its consequences. Therefore, in the present article, we intend to examine the role of the principles of international environmental law in responding to issues arising from the ocean fertilization and its regulation and elimination of its treaty gaps.
 Conclusion: The ocean fertilization can be described as a double edged sword that on the one hand is able to overcome one of the most important environmental challenges of the present age, namely global warming and consequently climate change, and on the other hand is the cause of marine environmental damage. First of all, the findings of the present paper show that, there is insufficient scientific certainty about the environmental consequences of ocean fertilization, and further studies and experiments are needed to achieve scientific certainty. Second, a review of international treaties that have addressed this technology directly or indirectly shows that the Biodiversity Conventions, the London Convention / Protocol, have severely restricted ocean fertilization, citing scientific uncertainty and the need for a precautionary approach. But they face criticism such as non-global participation and an absolutely negative attitude. And Third, in the circumstances mentioned, the application of the principles of international environmental law to fill existing gaps and complete treaty documents can be very helpful.