Climate politics forms a subsystem of world politics. In this subsystem, states are differentiated by their ambitions to decarbonize their economies. These ambitions proceed from national policies and the nationally determined contributions (NDC) submitted by states in accordance with the Paris Agreement. Based on states’ climate ambitions, non-governmental organizations (NGOs) produce multiple reports ranking states and evaluating their contributions.The main parameter of state differentiation by climate ambition is the expected year of achieving carbon neutrality. In 2019–20, the UK and the European Union (EU) promoted this parameter with the Green Deal, and eventually other metrics were overshadowed. The previously used climate parameters and rankings based on them were contradictory and depended heavily on the chosen methodology. Apart from being untrustworthy, they put some western countries in unfavourable positions.N. Luhmann’s new systems theory identifying “carbon neutrality” is taken as the main code of the climate communication subsystem that differentiates the climate subsystem of world politics from other functional subsystems. In this review article, how the emerging code of carbon neutrality is used by states and international organizations to form a new hierarchy in international relations is examined. Various constructivist and normative theories, from Foucault’s poststructuralism to the historicism and normativity of the English School, are applied in order to capture the possible implications of the political use of carbon neutrality for international relations. The article concludes with a discussion of the potential prospects of climate politics hierarchization for power redistribution in international relations.