Abstract: This thesis studies the intersection between contemporary international political theory and global environmental politics. It asks whether concern for global environmental degradation requires a rethinking of the assumptions that underlie international political theory as a field of study within the discipline of International Relations. Answering this question, the thesis introduces three ‗images‘ of international political theory: the liberal cosmopolitan, the critical-theoretical, and the anti-foundationalist. It investigates the contributions of these three images of international political theory to global environmental politics. Assessing, through the three images, the status of contemporary international political theory in light of environmental concerns, the thesis suggests that while international political theory offers many important insights into discussions of global environmental politics it also appears significantly limited when dealing with environmental concerns. Key among its limitations is the human-centred framework and mission of contemporary international political theory that an encounter with environmental concerns helps expose. The thesis argues that international political theory, both to be true to its purpose – that is, the extension of moral and political inclusion in world politics – and to maintain its relevance in the contemporary world, must seek a more thorough engagement with environmental concerns. The thesis contends that a fundamental rethinking of the assumptions that underlie contemporary international political theory forms an important – and necessary – part of this engagement.