The geoengineering technique of ocean iron fertilization (OIF) has been proposed as a Plan B to complement current mitigation efforts to stabilize global average temperature increase at a non-dangerous level. However the technique has been criticized for its low effectiveness and the possibility that it may create adverse environmental impacts when applied at a larger scale. Due to the scientific uncertainty pervading both climate change impacts and the potential environmental risks of OIF, regulators are thus faced with an improbable balancing exercise. The international community has responded to this challenge through the adoption of a de facto moratorium on such activities; a response which may be overly restrictive, yet ineffective. While some in the scientific community advocate further, legitimate research into the technology, a recent unsanctioned OIF experiment has shown that unilateral deployment of the technology remains largely unregulated. This thesis provides an analysis of the processes, effectiveness and environmental impacts of OIF and identifies a set of key governance challenges unique to the technology. Based on these governance challenges, the thesis examines the suitability of existing international regulatory mechanisms that apply to OIF and exposes the gaps remaining in the regulation of such activities. On the basis of this comprehensive scientific and legal analysis a set of recommendations is formulated which aim to strengthen the existing regulatory framework and contribute to future governance of the technology.