Introduction International relations refer to the branch of political science concerned with foreign affairs of a country. It defines the ways in which countries relate with one another in the currently globalised world. The concept of globalization has increased a global approach to seeking solutions to problems arising that could be facing a particular nation, like a disease outbreak in a particular country or global issues like global warming. Collective international efforts are always employed in addressing different forms of emerging issues. International relations have become central in the current times where international interdependence is critical for economic and political stability. The international relations facilitate the coordination of political and economic activities among nations. International relations have also established a basis for an international intervention on national, regional and international issues that affect humanitarian conditions directly or indirectly. This paper seeks to answer the question, “what international relations theory is the most effective in addressing environmental issues”. The paper will look into a variety of international relations theories that have been employed to address environmental issues with the aim of identifying the most effective theory. Environmental international relations theories International relations as a field of study has been explored since the early periods of the twentieth century. It was initiated by the urge to create a foundation for security among the European nations. The environmental issues were identified, recognized and instituted in the international business at around 1972. It was noted that degradations were, and still are being, caused by human activities. The increased economic activities initiated after the World War II exerted increased pressure on the available resources. Effects of the economic activities that were on the rise during this post war period also had negative implications on the environment due to pollution. The environmental concern then evolved into International Corporation besides the global concern through the United Nations (Kutting, 12). The Green Theory The green theory was a development of the environmental concerns that were continually raised by experts in the social science and humanities professions that led to environmental movement in the closing decades of the twentieth century. It was the environmental movement together with some other social movements that led to the green theory. The theory is concerned with social matters as well as the always predominant aspects of politics. One of the elements of the green theory was to discuss the irrationality that was exercised by economic forces, markets and nations towards the environment. The theory in this instance expressed the establishment of localized autonomous bodies to ensure stable ecologies in different localities. The green theory has also taken a political dimension with administrations ensuring that environmental institutions are established to look into arising environmental crises. The political dimension of the green theory has led to the emergence of “environmental justice, environmental democracy, environmental activism and the green states” (Dunne, Milja