The major focus of this dissertation is the global climate change issue which threatens the international ecosystem as the most complex and unique environmental problem today. The study attempts to contribute to the understanding of the climate change cooperation, which has been evolving within a global scope, by displaying the major political and legal processes in the international arena. It aims to answer the question of which elements and factors have played significant roles with respect to climate cooperation. For this end, the research concentrates on the impacts of international institutions and non-state actors and a neoliberal institutionalist theoretical framework is employed while analyzing the regime formation process over the issue. The study has found out that being the actors of the international system, international institutions, along with epistemic communities and nongovernmental organizations, have emanated as the adherents and promoters of climate cooperation, and they have had significant impacts on the emergence of a regime over the climate issue. Thus, the ultimate purpose of this work is to analyze climate cooperation - which requires a more effective and substantial contribution of world states - in connection with the important roles played by international institutions, and to emphasize the implications of this cooperation for the International Relations theory and discipline.