Since ancient times, there have been philosophers who have argued that climates are responsible for the moral qualities of different people. By contrast, climate is now seen as global and shared, and states are being called upon to take responsibility for the average global temperature. This article presents the climate system as composite and shows that we are very far from understanding the interconnections of energy, water, and what we call carbon exchanges. Global warming is based on the measurement of the average temperature of all the local temperatures all around the world. This temperature does not correspond to any immediate, physical, local, and perceptible reality belonging to the realm of statistics. Even if we limit ourselves to the brutal impact of human activities on the climate system, we are already within a space where different possible systems of responsibilities are in play. The text addresses in turn the “Common But Differentiated Responsibilities” normative framework (attribution modes of greenhouse gas [GHG] production, the criteria to be used in assessing states as bearers of the burden, and the mechanisms of participation in the fight against climate change), the conceptual link to be made between different types of justice in the (distributive) mitigation of GHGs, and (corrective) adaptation thanks to luck egalitarianism, along with the issue of establishing an equilibrium in the allocation of responsibilities when they are collective and complex. This leads to a discussion on the ethical theories in the background, and of the conceptions and functions of responsibility.