Introduction: The global environmental governance system (GEG) has not proved very successful in achieving its main goals, namely protection of the environment and achieving sustainable development. The reasons for this failure, among other things, are the lack of cooperation and coordination among international actors, proliferation of multilateral environmental agreements (MEAs) as well as other international environmental instruments, inappropriate institutions and structures, non-compliance with international MEAs, failure to implement the obligations stipulated in agreements and other international instruments, inefficient use of resources, undemocratic decision-making methods, a global environmental governance system operating outside the environmental arena and the absence of non-state actors in this state-centric system(Najam et. al., 2006). This paper has sought to find reasons of failure of the global environmental governance system and identify the type of measures required to overcome such failures. Materials and Methods: Employing the library research method and using research papers and monographs by researchers who work on the subject of global environmental governance system as well as primary sources, the present paper has studied the current condition of global environmental governance system. Taking into account the serious global deterioration of the environment, this paper has surveyed some of reasons in respect of inefficiency of the current global environmental governance system and presents a number of proposed solutions in respect of global environmental governance reform. Results and discussion: In the global environmental governance system (GEG), through a process of producing documents and institutions, a structure consisting of necessary soft law and hard law documents has been developed for implementation of such documents and their obligations and requirements (Saunier and Meganck, 2007). However, even if states possess the political will for the protection of the environment, it is very unlikely that such states can actually protect the environment through the uncoordinated responses of such states, and one cannot expect to bring such trans-boundary phenomena, namely environmental deterioration, under control, without achieving an acceptable level of cooperation and coordination. Besides, current institutions like the United Nations Environment Programmeme (UNEP) suffers from inefficiency in protecting the environment (Charnovitz, 2002), and despite the numerous Declarations, Conventions, and other international instruments, there still remain a number of environmental challenges like climate change, air pollution, soil erosion, ocean contamination, hazards caused by nuclear activities or genetically modified organisms, depletion of natural resources, extinction of species, and landscape destruction. Therefore, it is essential for states to comply with the current multilateral environmental agreements as well as other international instruments, and implement and enforce such instruments through strengthening coordinating institutions, UNEP, and instituting closer and a more efficient cooperation of international actors including states, civil society institutions like non-governmental organizations, and the private sector. Conclusion: Reform in the global environmental governance system (GEG), among other things, requires cooperation and coordination between states, civil society institutions, and the private sector. It also need compliance with MEAs strengthening United Nations Environment Programmeme (UNEP), expanding the role of the Global Ministerial Environment Forum (GMEF), reforming existing United Nation’s bodies, strengthening financing sources and mechanisms, building up the environmental competence of the World Trade Organization (WTO), different possible models for a World Environment Organization, reforming the United Nations Trusteeship Council, expanding the mandate of the United Nations Security Council and establishing a World Environment Court.